Method for producing treated product

Abstract

To provide a method for producing a treated product, in which organic waste is efficiently reduced to low-molecular-weight components by subcritical water treatment to obtain a treated product.SOLUTION: According to one aspect of the present invention, a method for producing a treated product is provided, in which organic waste is reduced to low-molecular-weight components using a subcritical water treatment apparatus to obtain a treated product. The subcritical water treatment apparatus in this production method includes a pressure vessel and a heating mechanism that heats the pressure vessel. The pressure vessel includes a vessel body, an inlet through which organic waste is introduced into the vessel body, an outlet through which the treated product is discharged from the vessel body, and a liquid storage section that stores a liquid used for subcritical water treatment of the organic waste. In subcritical water treatment, liquid in an amount of 5% or more of a volume of the pressure vessel is stored in the liquid storage section, and the pressure vessel is heated by the heating mechanism in a state in which the organic waste is stored in the vessel body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a treated object. [Background technology]

[0002] Subcritical water treatment devices are known as devices for treating organic waste (see Patent Document 1). Conventional subcritical water treatment devices are equipped with high-pressure boilers, which require a large installation space and an extremely large capital investment. In addition, to ensure safety, it is required to install a partition wall to cover the subcritical water treatment device and the high-pressure boiler.

[0003] Furthermore, since the Industrial Safety and Health Act applies, only qualified boiler engineers with second-class or higher qualifications can operate and operate the above-mentioned equipment. These are major obstacles to the easy subcritical water treatment of organic waste in urban areas. To solve this problem, the present inventors have proposed a small-sized subcritical water treatment apparatus (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-088272 [Patent Document 2] Japanese Patent Publication No. 2023-030316 Summary of the Invention [Problem to be solved by the invention]

[0005] In the subcritical water treatment apparatus described in Patent Document 2, there is still room for improvement in the treatment efficiency of organic waste by subcritical water treatment. In view of the above circumstances, the present invention provides a method for producing a treated product, in which organic waste is efficiently decomposed into low molecular weight compounds by subcritical water treatment to obtain a treated product. [Means for solving the problem]

[0006] One aspect of the present invention provides a method for producing a treated material using a subcritical water treatment apparatus to reduce the molecular weight of organic waste to obtain a treated material. The subcritical water treatment apparatus in this production method includes a pressure vessel and a heating mechanism for heating the pressure vessel. The pressure vessel includes a vessel body, an inlet for introducing organic waste into the vessel body, an outlet for discharging the treated material from the vessel body, and a liquid storage unit for storing a liquid to be used in the subcritical water treatment of the organic waste. During subcritical water treatment, a liquid that occupies 5% or more of the volume of the pressure vessel is stored in the liquid storage unit, and the pressure vessel is heated by the heating mechanism while the organic waste is stored in the vessel body.

[0007] According to one aspect of the present invention, organic waste can be efficiently decomposed into smaller molecules by subcritical water treatment to obtain a treated product. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a conceptual diagram showing a partial cross section of an embodiment of a subcritical water treatment apparatus. [Figure 2] FIG. 2 is a plan view showing the configuration of a separator. [Figure 3] 1 is a photograph showing the appearance of the pressure vessel used in Tests A to E. [Figure 4] 1 is a graph showing an operation curve of a subcritical water treatment apparatus. [Figure 5] 1 is a table showing the relationship between the temperature (° C.) inside the pressure vessel and the pressure (MPa) inside the pressure vessel. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the method for manufacturing a processed object will be described with reference to the drawings. Various features shown in the following embodiments can be combined with each other. <Subcritical water treatment equipment> First, the subcritical water treatment apparatus used in this embodiment will be described. Fig. 1 is a schematic diagram showing a partial cross section of an embodiment of a subcritical water treatment apparatus, and Fig. 2 is a plan view showing the configuration of a separator.

[0010] A subcritical water treatment device is a device that breaks down organic waste into smaller molecules to obtain a treated product. In a method for producing a treated product, the subcritical water treatment device is used to break down organic waste into smaller molecules to obtain a treated product. Here, subcritical water treatment is a method in which organic waste is brought into contact with gaseous subcritical water at a high temperature below the critical temperature of water and a high pressure above the saturated water vapor pressure to reduce the molecules of the organic waste. This reduction in molecules decomposes the organic waste, resulting in a treated product.

[0011] Examples of organic waste include paper, fabric, clothing, plastics, leather, wood and bamboo, straw, kitchen waste, medical waste, discarded food still in its packaging, etc., and the waste may contain one or more of these. 1 includes a pressure vessel 2, a heating mechanism 4 that heats the pressure vessel 2, and an agitation mechanism 3 that agitates the organic waste contained in the pressure vessel 2 (vessel body 21). In the following description, the circumferential direction refers to the direction around the center line, and the radial direction refers to the radial direction from the center line.

[0012] The pressure vessel 2 comprises a vessel body 21, an inlet 22 for feeding organic waste into the vessel body 21, an outlet 23 for discharging the treated material from the vessel body 21, and a liquid storage section 24 for storing liquid L used in the subcritical water treatment of organic waste. The pressure vessel 2 of this embodiment is a vertical pressure vessel supported by a stand (not shown) so that the center line O21 of the vessel body 21 is aligned vertically. The vessel body 21 comprises an upper vessel body 211 having a hemispherical (dome-shaped) upper head plate 2111, and a lower vessel body 212 having a hemispherical (dome-shaped) lower head plate 2121.

[0013] The upper container body 211 has a flange portion 2112 at its lower end that protrudes radially outward, and the lower container body 212 has a flange portion 2122 at its upper end that protrudes radially outward. By overlapping the upper container body 211 on the lower container body 212 and fastening the flange portion 2112 and the flange portion 2122 with, for example, bolts, the gap between them can be sealed and fixed airtight. The upper container body 211 can also be configured as a clutch door that can be opened and closed relative to the lower container body 212.

[0014] The insertion port 22 has a cylindrical body 221 and is connected to the upper container body 211 so as to communicate with an upper through-hole 2113 formed in the upper head plate 2111. Therefore, the center line O22 of the insertion port 22 (body 221) is inclined with respect to the center line O21 of the container body 21, and the opening 222 on the opposite side to the upper head plate 2111 faces diagonally upward in the vertical direction. The insertion port 22 also has a lid (clutch door) 223 that hermetically seals the opening 222 of the body 221.

[0015] Discharge outlet 23 has a cylindrical body 231 and is connected to lower container body 212 so as to communicate with lower through-hole 2123 formed in lower end plate 2121. Therefore, center line O23 of discharge outlet 23 (body 231) is inclined toward the side opposite to input port 22 with respect to center line O21 of container body 21, and opening 232 on the side opposite to lower end plate 2121 faces diagonally downward in the vertical direction. Discharge outlet 23 also has a lid (clutch door) 233 that airtightly seals opening 232 of body 231.

[0016] In this pressure vessel 2, by opening the lid 223 while the lid 233 is closed, organic waste can be introduced into the vessel body 21 through the body 221 of the inlet 22. Thereafter, the lid 223 is closed and the organic waste is subjected to subcritical water treatment within the vessel body 21. The treated product produced by the subcritical water treatment of this organic waste can be removed from the vessel body 21 through the body 231 of the outlet 23 by opening the lid 233. In particular, since the center line O22 of the inlet 22 and the center line O23 of the outlet 23 are each inclined with respect to the center line O21 of the container body 21, it is easy to insert organic waste into the container body 21 and to eject (remove) the treated material from the container body 21.

[0017] As described above, the subcritical water treatment apparatus 1 of this embodiment has the heating mechanism 4 that heats the pressure vessel 2 and the liquid storage section 24 that stores the liquid L used in the subcritical water treatment of organic waste. In the pressure vessel 2, the liquid storage section 24 is sealed with the liquid L stored therein, and heating is initiated by the heating mechanism 4. As a result, gaseous subcritical water is produced from the liquid L stored in the liquid storage section 24, and by bringing this subcritical water into contact with the organic waste, the organic waste is broken down into smaller molecules. Here, the liquid L only needs to contain water as its main component, and may contain other components such as hydrogen peroxide and sodium hydroxide.

[0018] The subcritical water treatment apparatus 1 does not require a high-pressure boiler, which allows for a smaller size of the subcritical water treatment apparatus 1. Therefore, the subcritical water treatment apparatus 1 can be installed in a relatively small space. Therefore, if the subcritical water treatment apparatus 1 is configured to be portable and placed adjacent to a convenience store in an urban area, it can easily treat expired daily deliveries (mainly boxed lunches) that are to be discarded. Furthermore, since no high-pressure boiler is attached, the subcritical water treatment apparatus 1 can be operated by a cashier at a convenience store, not just a qualified boiler engineer, making the subcritical water treatment apparatus 1 extremely easy to operate and convenient.

[0019] In this embodiment, a part of the inner space of the outlet 23 is configured to function as the liquid storage section 24. This configuration can prevent an increase in the number of parts of the pressure vessel 2 and a complicated configuration of the pressure vessel 2. This contributes to further miniaturization of the subcritical water treatment apparatus 1. In addition, by changing the installation position of the outlet 23 or adjusting the angle of the center line O23 of the outlet 23 relative to the center line O21 of the container body 21, the entire internal space of the outlet 23 can be made to function as the liquid storage section 24. Furthermore, the liquid storage section 24 may be configured independently of the outlet 23. Examples of such a configuration include a recess formed on the inner surface of the lower head plate 2121, a container fixed to the inner surface of the upper head plate 2111 or a container suspended from the inner surface.

[0020] Furthermore, in this embodiment, the heating mechanism 4 is provided so as to cover the vertically lower portion (lower container body 212) of the container body 21. With this configuration, not only the inner space of the container body 21 but also the inner space of the outlet 23 can be efficiently heated, thereby smoothly generating vapor of the liquid L (gaseous subcritical water). Hereinafter, "vapor of the liquid L" will also be referred to as "gaseous subcritical water." When the temperature of water stored in the pressure vessel 2 is increased, the liquid phase expands and its density decreases, while the gas phase increases in pressure and density due to the increased amount of water vapor produced. If the temperature is further increased in this state, the densities of the liquid and gas phases become equal, and the liquid and gas phases become indistinguishable. This state can be likened to a high-density gas state that does not liquefy.

[0021] This point is called the critical point (374°C, 22.1 MPa), and the subcritical state refers to the state of water under pressure greater than that of saturated steam at a temperature below the critical point. In this subcritical state, water (subcritical water) and steam (gaseous subcritical water) are considered to exist within the pressure vessel 2. The heating mechanism 4 may be, for example, an alumina heater type, an oil heater type, a light heating (infrared) type, an IH heater type, or the like. Furthermore, a temperature sensor and a pressure sensor (neither of which are shown) capable of measuring the temperature and pressure inside the vessel body 21 (gaseous subcritical water), respectively, are connected to predetermined locations of the vessel body 21.

[0022] The stirring mechanism 3 includes a rotating shaft 31 disposed along the center line O21 of the container body 21, at least one stirring blade 32 (four in this embodiment) provided at the vertically lower end of the rotating shaft 31 and extending radially outward, and a motor 33 that rotates the rotating shaft 31. The rotating shaft 31 is preferably a magnetically coupled rotating shaft. The four stirring blades 32 are disposed at approximately equal intervals around the circumference of the rotating shaft 31. The stirring mechanism 3 further includes four fixed blades 34 fixed to the inner surface of the lower end plate 2121. The four fixed blades 34 are arranged at approximately equal intervals in the circumferential direction around the center line O21 of the vessel body 21. The four fixed blades 34 are also arranged slightly spaced apart from the stirring blade 32.

[0023] The agitation mechanism 3 having such a configuration can reliably splash the organic waste vertically upward in the container body 21, thereby enabling necessary and sufficient subcritical water treatment of the organic waste. In this embodiment, the rotational peripheral speed of the radially outer end of the stirring blade 32 is preferably about 5 m / s or more, and more preferably about 6 m / s or more. The upper limit of the rotational peripheral speed is usually about 7 m / s. At such a rotational peripheral speed, the above effects can be further enhanced while avoiding the use of a high-output, expensive motor 33.

[0024] Furthermore, the required void ratio of the vessel body 21 under subcritical water treatment is preferably 30% or more, and more preferably 30% to 50%. In this case, the rotational speed of the radially outer end of the agitator blade 32 can be reliably maintained at a predetermined value while preventing the amount of organic waste that can be treated in one subcritical water treatment from becoming too small. As a result, the reduction of the organic waste into smaller molecules can be further promoted. Here, the "required void ratio of the container body 21 under subcritical water treatment" is a value expressed as a percentage of the volume of the container body 21 at the start of the subcritical water treatment, which is the difference between the volume of the container body 21 and the volume of the organic waste (i.e., the volume of the space in the container body 21 where no organic waste exists).

[0025] The number of stirring blades 32 and the number of fixed blades 34 may be different from each other. The number of stirring blades 32 and the number of fixed blades 34 may be independently one, two, three, five or more. The installation intervals of the multiple agitating blades 32 and fixed blades 34 may be uneven along the circumferential direction. Furthermore, the agitating blades 32 may be arranged at multiple locations (multiple stages) along the axial direction (vertical direction) of the rotating shaft 31.

[0026] Furthermore, subcritical water treatment apparatus 1 has separator 25 provided at the boundary between vessel body 21 and outlet 23 (liquid storage section 24). Separator 25 allows the vapor of liquid L to pass through but has the function of blocking the passage of organic waste. This configuration can prevent or suppress the organic waste from being mixed into liquid L stored in outlet 23 (liquid storage section 24). On the other hand, the generated vapor of liquid L (gaseous subcritical water) can be brought into sufficient contact with the organic waste, reliably accelerating its decomposition into smaller molecules. 2 has a circular shape as a whole, formed by fixing a plurality of fan-shaped partition plate materials 251 to each other at the center so that they can be expanded. A plurality of through-holes 2511 are formed in each partition plate material 251, penetrating it in the thickness direction. Liquid L is supplied to the inner space (liquid storage section 24) of outlet 23 via through-holes 2511, and vapor of liquid L can move into container body 21 via through-holes 2511.

[0027] The volume of the pressure vessel 2 is preferably about 20 L to 400 L, more preferably about 50 L to 350 L, even more preferably about 100 L to 300 L, and particularly preferably about 143 L to 286 L. Use of a pressure vessel 2 with such a volume makes it possible to sufficiently miniaturize the subcritical water treatment apparatus 1 while preventing an extreme decrease in the degree of subcritical water treatment (decomposition into lower molecular weight compounds) of the organic waste. Furthermore, it can be housed in a container and transported to the desired location in this state.

[0028] The temperature inside the pressure vessel 2 (gaseous subcritical water: vapor of liquid L) is preferably about 180° C. to 230° C., and more preferably about 190° C. to 220° C. The pressure is preferably about 1.3 MPa to 4.5 MPa, and more preferably about 1.5 MPa to 3.5 MPa. The specific temperature and pressure inside the pressure vessel 2 are preferably about 200° C. and about 1.5 MPa. The time for the subcritical water treatment is set appropriately depending on the type of organic waste, etc., and is not particularly limited, but is preferably about 0.1 to 10 hours, and more preferably about 0.5 to 5 hours.

[0029] This subcritical water has a dielectric constant of 15 to 45, which is equivalent to the dielectric constant of low-polarity solvents. This allows it to dissolve many organic substances. Furthermore, subcritical water has an ionic product of 1×10 -12 mol 2 / kg2 More than 1×10 -11 mol 2 / kg 2 or less, and the proportion of hydrogen ions and hydroxide ions that separate is high, and therefore, the hydrolysis action is strong. The dielectric constant of water at room temperature and atmospheric pressure is about 80, and the ionic product of water at a temperature of about 25°C and atmospheric pressure is 1 x 10 -14 mol 2 / kg 2 is.

[0030] The organic waste that has been reduced in molecular weight (ie, the treated material) preferably has a solubilization rate of 50% or more, more preferably 70% or more, and even more preferably 85% or more. Here, the solubilization rate is the ratio of soluble organic matter to all organic matter after subcritical water treatment, and the higher the value, the more the organic matter has been broken down into smaller molecules. Specific examples of organic wastes that are broken down into smaller molecules include carbohydrates, proteins, fats, etc., which are broken down into their corresponding sugars, amino acids, higher fatty acids, etc. Furthermore, the subcritical water treatment in the subcritical water treatment apparatus 1 is a batch treatment by nature, but in this embodiment, it can be carried out at a rate of several batches per day.

[0031] <Method of manufacturing the processed material> Next, a method for producing a treated substance (a method for using the subcritical water treatment apparatus 1) according to this embodiment will be described. First, in performing subcritical water treatment, liquid L that is 5% or more of the volume of the pressure vessel 2 is stored in the liquid storage section 24, and organic waste is stored in the vessel body 21. According to the inventors' studies, it has been found that by using this amount of liquid L to perform subcritical water treatment on organic waste, the organic waste can be efficiently broken down into smaller molecules to obtain a treated product. The amount of liquid L contained in the liquid container 24 is preferably about 10% or more of the volume of the pressure vessel 2, more preferably about 20% or more, and even more preferably about 25% or more. In this case, the organic waste can be more efficiently decomposed into smaller molecules to obtain a treated product.

[0032] The amount of liquid L contained in the liquid storage portion 24 is preferably about 40% or less of the volume of the pressure vessel 2, and more preferably about the volume of the liquid storage portion 24 or less. In this case, necessary and sufficient subcritical water can be produced in the vessel body 21. The amount of liquid L contained in the liquid storage portion 24 can be about 5% or more and 40% or less. During subcritical water treatment, if the amount of liquid L contained in the liquid storage section 24 exceeds the capacity of the liquid storage section 24, it is preferable to agitate the organic waste using the agitation mechanism 3. This can suitably prevent or suppress the organic waste submerged in the liquid L from simply being exposed to high temperatures and carbonizing, without undergoing the necessary subcritical water treatment. Furthermore, it is possible to ensure a sufficient amount of organic waste can be placed in the container body 21.

[0033] Next, in this state, the pressure vessel 2 is heated by the heating mechanism 4. As a result, the generated gaseous subcritical water comes into contact with the organic waste inside the pressure vessel 2, and the treatment (decomposition into low molecular weight compounds) of the organic waste with the subcritical water progresses, resulting in the production of a treated product. As described above, this embodiment uses a relatively small subcritical water treatment apparatus that does not require a high-pressure boiler. Furthermore, because it does not require a high-pressure boiler, the subcritical water treatment apparatus is highly safe and easy to operate. Therefore, the subcritical water treatment apparatus can be installed anywhere, for example, in an urban area.

[0034] The pressure vessel 2 may also be a horizontal pressure vessel supported by a stand so that the center line O21 of the vessel body 21 is aligned horizontally (in a direction substantially perpendicular to the vertical direction). The gas discharged from the subcritical water treatment apparatus 1 may be subjected to water treatment by a water treatment apparatus and then deodorized by a deodorization treatment apparatus, or vice versa. Furthermore, it may be provided in the following aspects.

[0035] (1) A method for producing a treated product using a subcritical water treatment apparatus to reduce the molecular weight of organic waste to obtain a treated product, the subcritical water treatment apparatus having a pressure vessel and a heating mechanism for heating the pressure vessel, the pressure vessel having a vessel body, an inlet for feeding the organic waste into the vessel body, an outlet for discharging the treated product from the vessel body, and a liquid storage section for storing a liquid to be used in the subcritical water treatment of the organic waste, the method comprising: storing the liquid in an amount equal to or greater than 5% of the volume of the pressure vessel in the liquid storage section during the subcritical water treatment; and heating the pressure vessel with the organic waste stored in the vessel body by the heating mechanism.

[0036] (2) The method for manufacturing a processed object according to (1) above, wherein at least a part of the inner space of the outlet functions as the liquid storage section.

[0037] (3) The method for manufacturing a processed material described in (1) or (2) above further includes a separator plate provided at the boundary between the container body and the liquid storage section, which allows vapor of the liquid to pass through but prevents the organic waste from passing through.

[0038] (4) The method for producing a treated object according to any one of (1) to (3) above, wherein the center line of the container body is aligned along the vertical direction.

[0039] (5) The method for manufacturing a processed object according to (4) above, wherein the heating mechanism is arranged to cover a vertically lower portion of the container body.

[0040] (6) In the method for producing a treated material described in any one of (1) to (5) above, the subcritical water treatment device further has a stirring mechanism for stirring the organic waste contained in the vessel body, and during the subcritical water treatment, the pressure vessel is heated by the heating mechanism and the organic waste is stirred by the stirring mechanism in a state in which the liquid contained in the liquid container section is in an amount exceeding the volume of the liquid container section.

[0041] (7) In the method for manufacturing a processed material described in (6) above, the stirring mechanism comprises a rotating shaft arranged along the center line of the container body and at least one stirring blade provided at the vertically lower end of the rotating shaft and extending radially outward.

[0042] (8) The method for producing a treated material according to any one of (1) to (7) above, wherein the volume of the pressure vessel is 20 L or more and 400 L or less. Of course, this is not the case.

[0043] Finally, while various embodiments of the present invention have been described, these are presented by way of example only and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the accompanying claims. [Example]

[0044] Hereinafter, the method for producing a treated product will be described in more detail using the following examples, but the method for producing a treated product is not limited to the following examples.

[0045] In the following tests A to E, a boiler-less small-scale subcritical water treatment device (hereinafter referred to as "pressure vessel") shown in Fig. 3 was used. Fig. 3 is a photograph showing the appearance of the pressure vessel used in tests A to E. This pressure vessel has a double structure consisting of an outer jacket portion and an inner body portion, and is configured to heat the body portion so that thermal oil heated by a plug heater is supplied from a thermal oil tank to the jacket portion.

[0046] The pressure vessel is also equipped with a thermometer and pressure gauge, and these measurements can be monitored at all times. All measurements are collected in a data logger (manufactured by HIOKI) located inside the monitoring panel, and operational information can be displayed in graphs. The volume of the pressure vessel is 23.9 L.

[0047] (Test A) After storing 360 mL of water (1.50%) in the pressure vessel, 100 g of copy paper was added as organic waste, and the pressure vessel was sealed and heated with heated thermal oil. (Test B) The same procedure as in Test A was carried out except that the amount of water was changed to 1 L (4.18%) and 1000 g of simulated garbage was added as organic waste.

[0048] (Test C) The same procedure as in Test A was carried out except that the amount of water was changed to 3 L (12.55%) and the addition of organic waste was omitted. (Test D) The same procedure as in Test A was carried out except that the amount of water was changed to 5 L (20.92%) and 1010 g of airbags were added as organic waste. (Test E) The same procedure as in Test A was carried out except that the amount of water was changed to 7 L (29.28%) and 1000 g of simulated garbage was added as organic waste.

[0049] The changes in temperature and pressure inside the pressure vessel until the temperature reached 200°C or higher and the pressure reached 1.5 MPa or higher were shown in graphs and tables. The results are shown in FIGS. Fig. 4 is a graph showing an operation curve of a subcritical water treatment apparatus, and Fig. 5 is a table showing the relationship between the temperature (°C) inside the pressure vessel and the pressure (MPa) inside the pressure vessel.

[0050] From the operating curve shown in Figure 4 and the table shown in Figure 5, in Test A, once the temperature inside the pressure vessel reached 170°C, the temperature and pressure increase began to slow down, and the temperature did not reach 200°C or higher. In Test B, the temperature inside the pressure vessel reached 200°C or higher after 220 minutes, but the temperature and pressure increased more slowly than in Tests C, D, and E. In Tests C, D, and E, the temperature inside the pressure vessel reached 200°C or higher after 180 minutes (indicated by a circle in Figure 3), and the operating curves were almost identical.

[0051] From the above, it became clear that the relationship between the elapsed time and the increase in temperature and pressure required to achieve gas-liquid equilibrium in the subcritical water treatment device 1 requires more than 1 L of water (5% or more of the volume of the pressure vessel). Here, since the volume of the pressure vessel is 23.9 L, the minimum amount of water required for subcritical water treatment calculated from the amount of saturated steam is the amount of saturated steam at 200°C (7.8641 kg / m 3 ) × pressure vessel volume (0.0239m 3 ) = approximately 188 g (≒ approximately 188 mL) (hereinafter referred to as the "theoretical value"). However, this theoretical value was not sufficient for subcritical water treatment, and the results of this test (comparison of Tests A and B with Tests C to E) allowed us to determine the amount of water necessary and sufficient for subcritical water treatment. [Explanation of symbols]

[0052] 1: Subcritical water treatment equipment 2: Pressure vessel 21: Container body 211: Upper container body 2111: Upper head plate 2112: Flange part 2113: Upper through hole 212: Lower container body 2121: Lower head plate 2122: Flange part 2123: Lower through hole 22: Inlet 221: Torso 222 :Aperture 223: Lid 23: Outlet 231: Torso 232 :Aperture 233: Lid 24: Liquid storage section 25: Separation plate 251: Partition board material 2511: Through hole 3: Stirring mechanism 31: Rotation axis 32: Mixing blade 33: Motor 34:Fixed wing 4:Heating mechanism L:Liquid O21: Center line O22: Center line O23: Center line

Claims

1. A method for producing a treated material by reducing organic waste to low molecular weight using a subcritical water treatment device, the subcritical water treatment apparatus includes a pressure vessel and a heating mechanism for heating the pressure vessel; The pressure vessel comprises a vessel body, an inlet through which the organic waste is introduced into the vessel body, an outlet through which the treated material is discharged from the vessel body, and a liquid storage section that stores a liquid to be used in the subcritical water treatment of the organic waste, In the method for manufacturing a treated material, during the subcritical water treatment, the liquid is stored in the liquid storage section to account for 5% or more of the volume of the pressure vessel, and the pressure vessel is heated by the heating mechanism while the organic waste is stored in the vessel body.

2. The method for producing a treated object according to claim 1, A method for manufacturing a processed object, wherein at least a part of the inner space of the discharge port functions as the liquid storage section.

3. The method for producing a treated object according to claim 1, The method for manufacturing a treated material further comprises a separator plate provided at the boundary between the container body and the liquid storage section, which allows vapor of the liquid to pass through but prevents the organic waste from passing through.

4. The method for producing a treated object according to claim 1, A method for manufacturing a processed object, wherein the center line of the container body is aligned vertically.

5. The method for producing a treated object according to claim 4, A method for manufacturing a processed object, wherein the heating mechanism is arranged to cover a vertically lower portion of the container body.

6. The method for producing a treated object according to claim 1, the subcritical water treatment device further includes a stirring mechanism that stirs the organic waste contained in the container body, During the subcritical water treatment, the pressure vessel is heated by the heating mechanism while the organic waste is stirred by the stirring mechanism, with the liquid contained in the liquid container in an amount exceeding the volume of the liquid container.

7. The method for producing a treated object according to claim 6, A method for manufacturing a processed material, wherein the stirring mechanism comprises a rotating shaft arranged along the center line of the container body and at least one stirring blade provided at the vertically lower end of the rotating shaft and extending radially outward.

8. The method for producing a treated object according to claim 1, The method for producing a treated material, wherein the volume of the pressure vessel is 20 L or more and 400 L or less.

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