Organic waste treatment apparatus and organic waste treatment method

Abstract

This reduces the size of the equipment and energy consumption, thereby suppressing corrosion of the treatment tank and simplifying equipment management. [Solution] The organic waste treatment device 100 comprises a treatment tank 1, an input unit 4 that connects the outside and inside of the treatment tank 1 and allows the acceptance of organic waste and liquid water from the outside, a supply unit 7 that supplies gas into the treatment tank 1, and a heating unit 6 installed inside the treatment tank 1 that heats the accepted water. The treatment tank 1 is configured to accept organic waste, water, and gas and maintain a sealed state. The supply unit 7 supplies nitrogen as gas, and the heating unit 6 heats the water sealed inside the treatment tank 1 with the nitrogen and organic waste to a subcritical state when the gas sealed inside the treatment tank 1 is nitrogen. Alternatively, the supply unit 7 supplies oxygen as gas, and the heating unit 6 heats the water sealed inside the treatment tank 1 with the oxygen and organic waste to a supercritical state when the gas sealed inside the treatment tank 1 is oxygen.

Description

[Technical Field]

[0001] The present invention relates to an organic waste treatment apparatus, which is a device for treating organic waste, and an organic waste treatment method, which is a method for treating organic waste. [Background technology]

[0002] Generally, organic waste has a high moisture content, making it prone to decay and often emitting foul odors. Furthermore, organic waste is often bulky. Therefore, when using conventional incineration methods, pre-processing storage, dewatering, and odor control measures are necessary.

[0003] In contrast, treatment using supercritical water can oxidize and decompose odor-causing substances and fungi, thus offering deodorizing and sterilizing effects. For this reason, treatment using supercritical water is also suitable for the treatment of medical waste and nursing care waste, which require careful handling. Furthermore, the final products are mainly carbon dioxide, water, and nitrogen, and no combustion exhaust gases are produced. Based on the above, treatment using supercritical water can be said to be a promising technology.

[0004] Conventionally, a known technique for treating organic waste is to treat it with high-temperature, high-pressure water. For example, Patent Document 1 discloses a system that uses subcritical and supercritical water. In this system, hydrolysis reactions and other treatments of organic waste are carried out. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-153280 [Overview of the Initiative]

[0006] While the technology described in Patent Document 1 allows for hydrolysis, sterilization, and dehydration of organic waste, there is considerable room for improvement. For example, the oxidation reaction using supercritical water primarily targets organic compounds and is therefore unsuitable for treating inorganic compounds. Furthermore, oxidation reactions using supercritical water are not very effective for treating large waste materials, similar to burning thick logs.

[0007] Therefore, pretreatment processes are combined to form a system that complements the oxidation reaction using supercritical water. Pretreatment processes include, for example, physically crushing or chemically dissolving organic waste. Consequently, the system often consists of a large-scale plant. In large-scale facilities, a large amount of energy is required to stabilize the water temperature in order to keep the water constantly in the supercritical region. In addition, pumps to pressurize the large-capacity treatment tank and equipment to generate high-temperature superheated steam are also required, resulting in the large size of the equipment itself.

[0008] Consequently, not only is it difficult to easily install large-scale equipment, but the energy consumption of such equipment is also high. From an efficiency standpoint, it is not suitable for processing small amounts of organic waste, and organic waste must be stored until the amount is sufficient for processing at one time. Securing space for this storage, as well as addressing odor and hygienic measures during that time, also present challenges.

[0009] Furthermore, subcritical and supercritical water readily corrodes metals due to its oxidizing power. For example, corrosion progresses when metals are processed for extended periods in a metal treatment tank. While it is possible to increase the pressure instead of the temperature to bring the water to the supercritical state, this accelerates equipment wear and increases the risk of damage. For these reasons, equipment management is difficult, requiring frequent parts replacement and maintenance.

[0010] In view of the above, the object of the present invention is to provide an organic waste treatment apparatus and an organic waste treatment method that can appropriately treat organic waste by suppressing the enlargement of the equipment and energy consumption, and by suppressing corrosion of the treatment tank and other issues, thereby facilitating equipment management. [Means for solving the problem]

[0011] The technical means of the present invention for solving this technical problem is characterized by the following: The organic waste treatment apparatus of the present invention comprises at least a treatment tank configured to receive organic waste from the outside and to treat the organic waste with high-temperature, high-pressure water inside. The organic waste treatment apparatus of the present invention comprises an input unit that connects the outside and inside of the treatment tank and enables the acceptance of the organic waste and liquid water from the outside; a supply unit that supplies gas toward the inside of the treatment tank; and a heating unit installed inside the treatment tank that heats the accepted water. The treatment tank is configured to accept the organic waste, water and gas inside and maintain a sealed state, the supply unit supplies nitrogen as the gas, and the heating unit heats the water sealed together with the nitrogen and organic waste to a subcritical state when the gas sealed inside the treatment tank is nitrogen.

[0012] In the organic waste treatment apparatus of the present invention, the supply unit supplies oxygen instead of nitrogen as the gas, and the heating unit heats the water sealed together with the oxygen and organic waste in the treatment tank so that it reaches a supercritical state when the gas sealed inside the treatment tank is oxygen.

[0013] In the organic waste treatment apparatus of the present invention, the supply unit is configured to switch the supplied gas from nitrogen to oxygen, and the heating unit switches from heating the water in a subcritical state to heating the water in a supercritical state, corresponding to the switch from nitrogen to oxygen in the supply unit.

[0014] In the organic waste treatment apparatus of the present invention, the treatment tank is configured to be able to swing with respect to the installation surface when the water is heated by at least the heating unit.

[0015] The organic waste treatment apparatus of the present invention further comprises a discharge section that connects the outside and inside of the treatment tank and enables the discharge of treated contents to the outside, wherein the treatment tank is configured to be a cylindrical container with one end open, and the opening serves as the input section and the discharge section, and is configured to be swingable with respect to the installation surface when water is received by the input section and / or when the treated contents are discharged by the discharge section.

[0016] The present invention relates to an organic waste treatment method which involves treating organic waste using a treatment tank configured to receive organic waste from the outside and to treat the organic waste with high-temperature, high-pressure water inside. The present invention relates to an organic waste treatment method which involves the steps of: receiving the organic waste and liquid water from the outside into the treatment tank; supplying nitrogen into the treatment tank; sealing the organic waste, water and nitrogen inside the treatment tank; and heating the water sealed inside the treatment tank together with the nitrogen and organic waste so that it reaches a subcritical state.

[0017] The present invention provides an organic waste treatment method that further comprises the steps of: heating the water to a subcritical state; discharging the nitrogen to the outside of the treatment tank; supplying oxygen to the inside of the treatment tank; sealing the organic waste, the water, and the oxygen inside the treatment tank; and heating the water sealed inside the treatment tank together with the oxygen and organic waste to a supercritical state.

[0018] In the organic waste treatment method of the present invention, the treatment tank is configured to be able to swing with respect to the installation surface when the water is heated, and the heating step involves heating the water while swinging the treatment tank. [Effects of the Invention]

[0019] According to the present invention, it is possible to suppress enlargement of equipment, energy consumption, etc., suppress corrosion of the treatment tank, etc., and facilitate equipment management. Therefore, organic waste can be appropriately treated.

Brief Description of Drawings

[0020] [Figure 1] It is an overall schematic view of an organic waste treatment apparatus according to an embodiment of the present invention. [Figure 2] It is a diagram showing the state of water introduced into the treatment tank of the organic waste treatment apparatus shown in FIG. 1, and is a diagram for explaining the positions of the subcritical region and the supercritical region in a graph defining the relationship between the pressure and temperature of water. [Figure 3] It is a flowchart showing the treatment of the subcritical water process and the supercritical water process in the organic waste treatment apparatus shown in FIG. 1. [Figure 4] It is a diagram showing a state in which the treatment tank of the organic waste treatment apparatus shown in FIG. 1 is swung when water is received by the charging section, and the charging section is directed obliquely upward forward. [Figure 5] It is a diagram showing a state in which the treatment tank 1 is swung when water is heated by the heating section in each of the subcritical water process and the supercritical water process in the organic waste treatment apparatus shown in FIG. 1. [Figure 6] It is a diagram showing a state in which the treatment tank of the organic waste treatment apparatus shown in FIG. 1 is swung when the treated content is discharged by the discharging section, and the charging section is directed obliquely upward forward.

Modes for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0022] As shown in Figure 1, the organic waste treatment apparatus 100 according to an embodiment of the present invention is a device for treating organic waste. In the organic waste treatment apparatus 100, organic waste is treated with high-temperature, high-pressure water. Organic waste may be, but is not limited to, any waste containing organic matter, such as plastic resin, paper, food waste, livestock waste, animal carcasses, and felled plants.

[0023] The treatment using high-temperature, high-pressure water in the organic waste treatment device 100 is a process that decomposes organic waste inside a sealed treatment tank 1. In the treatment tank 1, the water sealed together with the organic waste is heated and pressurized, causing a phase transition in the water. Based on the increase in the ion product of water in accordance with the phase transition, the decomposition of organic matter is promoted.

[0024] As shown in Figure 2, a critical point exists in the state of water. The temperature and pressure at the critical point are 374°C and 22.1 MPa, respectively. When temperature and pressure are shown on the horizontal and vertical axes of a phase diagram, the critical point defines the subcritical and supercritical regions. In the subcritical region, water is in a subcritical state. In the supercritical region, water is in a supercritical state.

[0025] Subcritical water is a liquid whose temperature and pressure are slightly below the critical point. A characteristic of subcritical water is that it readily dissolves and hydrolyzes nonpolar organic substances and organic compounds. This is because subcritical water has a higher ion product (Kw = [H]) compared to water at room temperature and pressure. + ][OH - The ion product of water is based on the fact that pure water H2O has hydrogen ions H + and hydroxide ions OH - This indicates the degree of dissociation.

[0026] The ion product of water at room temperature and pressure is 10 -14 (mol / L) 2It is so. When the temperature and pressure of water increase, the ion product of water increases. For example, assume that normal temperature and pressure water is heated and pressurized to undergo a phase transition to subcritical water. In subcritical water, the upper limit of the ion product is 3.5×10 -12 (mol / L) 2 . At this time, the product of the H+ concentration and the OH- concentration becomes about 350 times that of normal temperature and pressure water. Therefore, subcritical water itself exhibits the same effect as an acid or alkali catalyst. Consequently, the hydrolysis of organic substances and organic compounds is promoted. Also, the density of subcritical water is 235 kg / m 3 , which is smaller than the density of normal temperature and pressure water (1000 kg / m 3 ).

[0027] Supercritical water is a fluid with properties intermediate between a liquid and a gas in a state where both the temperature and pressure are higher than the critical point. The characteristic of supercritical water is that it is easy to dissolve and oxidatively decompose nonpolar organic substances and organic compounds. This is based on the fact that supercritical water has a higher ion product compared to normal temperature and pressure water and subcritical water.

[0028] For example, assume that normal temperature and pressure water is heated and pressurized to undergo a phase transition to supercritical water. In supercritical water, the lower limit of the ion product is 4.4×10 -12 (mol / L) 2 . At this time, the product of the H+ concentration and the OH- concentration becomes about 440 times that of normal temperature and pressure water. Therefore, supercritical water itself exhibits the same effect as an acid or alkali catalyst. Consequently, the oxidative decomposition of organic substances and organic compounds is promoted. Also, the density of supercritical water is 228 kg / m 3 , which is smaller than the density of normal temperature and pressure water (1000 kg / m 3 ). Therefore, supercritical water can be said to be a liquid with a low density and also a gas with a high density.

[0029] The organic waste decomposition process in the organic waste treatment device 100 includes a subcritical water process and a supercritical water process (see Figure 6). The subcritical water process is a process in which organic waste is decomposed with subcritical water under a nitrogen atmosphere and is performed before the supercritical water process. The supercritical water process is a process in which organic waste treated in the subcritical water process is decomposed with supercritical water under an oxygen atmosphere.

[0030] As shown in Figure 1, the organic waste treatment device 100 comprises a treatment tank 1, an input unit 4, an output unit 5, a heating unit 6, a supply unit 7, an exhaust unit 8, and a control unit 11 (oscillation control unit 11a, heating control unit 11b, and supply control unit 11c). The control unit 11 includes a CPU, electrical circuits, a memory for storing programs, etc. The corresponding hardware may operate based on the program processing of the CPU. The organic waste treatment device 100 is installed on a horizontal mounting surface G.

[0031] The treatment tank 1 is configured to allow the treatment of organic waste with high-temperature, high-pressure water inside. Here, the high-temperature, high-pressure water may be subcritical water or supercritical water. The treatment tank 1 is configured to be a cylindrical container with a defined axis. The shape of the cylindrical container may be, for example, a cylindrical container shape. The treatment tank 1 may also be a pressure vessel, and the material constituting the treatment tank 1 may be a metal such as ferritic steel or stainless steel that has both corrosion resistance and magnetic properties.

[0032] The axis of the processing tank 1 is normally aligned in the front-to-back direction and parallel to the horizontal installation surface G. One end of the processing tank 1 on the front side is an opening 1a. This opening 1a is configured to serve as the input section 4 and the output section 5. The opening 1a may be circular in shape, for example. On the other hand, the other end of the processing tank 1 on the rear side is the abutment of the container.

[0033] Support shafts 1b are provided on the outer side of the processing tank 1. Two support shafts 1b protrude to the left and right. The support shafts 1b are always aligned in the left-right direction and are parallel to the horizontal mounting surface G. In addition, the support shafts 1b are perpendicular to the axis that defines the cylinder of the processing tank 1.

[0034] The processing tank 1 is located above the installation surface G. The support shaft 1b is supported by, for example, a column or angle extending upward from the installation surface G, allowing the processing tank 1 to rotate. This allows the processing tank 1 to swing relative to the horizontal installation surface G with the support shaft 1b as the center of rotation. That is, by tilting the processing tank 1, one end of the processing tank 1 on the front side (opening 1a, input section 4, and output section 5) can be directed not only horizontally, but also diagonally upward and diagonally downward. The installation position of the support shaft 1b can be any position on the outer side of the processing tank 1, but it is preferable, for example, to be at a position corresponding to the center of gravity of the processing tank 1.

[0035] The input section 4 connects the outside and inside of the treatment tank 1, allowing for the acceptance of organic waste and liquid water from the outside. The output section 5 also connects the outside and inside of the treatment tank 1, allowing for the discharge of the treated contents to the outside. A retractable lid 1c may be provided near the input section 4 (output section 5). When the lid 1c is open, the input section 4 (output section 5) is opened, and the outside and inside of the treatment tank 1 are connected. On the other hand, when the lid 1c is open, the input section 4 (output section 5) is shielded, and the inside of the treatment tank 1 is sealed. The lid 1c allows the treatment tank 1 to accept organic waste, water, and gases internally and maintain a sealed state.

[0036] The heating unit 6 is installed inside the treatment tank 1 and heats the water it receives. When the gas sealed inside the treatment tank 1 is nitrogen, the heating unit 6 heats the water sealed together with the nitrogen and organic waste to a subcritical state. When the gas sealed inside the treatment tank 1 is oxygen, the heating unit 6 heats the water sealed together with the oxygen and organic waste to a supercritical state. Furthermore, the heating unit 6 switches from heating water to a subcritical state to heating water to a supercritical state in response to the switch from nitrogen to oxygen in the supply unit 7. The switching of the heating unit 6 is controlled, for example, by the heating control unit 11b.

[0037] The heating unit 6 may be composed of, for example, a magnetic material (metal), a coil, etc., to enable electromagnetic induction heating. Electromagnetic induction heating uses a magnetic field in a coil based on alternating current to generate Joule heat from the magnetic material. Therefore, it has the advantage of lower power consumption and faster response speed compared to using an electric heating wire heater. The magnetic material may be, for example, a metal that makes up the processing tank 1, and the metal may be in contact with the water. The degree of heating of the water in the heating unit 6 is controlled, for example, by the heating control unit 11b.

[0038] The heating unit 6 quickly heats the water inside the processing tank 1 to temperatures corresponding to the subcritical and supercritical regions. Depending on the application, electromagnetic induction heating can raise the temperature to the melting point of metals. Therefore, the temperature can be easily controlled by electromagnetic induction heating. Electromagnetic induction heating enables continuous processing of both the subcritical water process and the supercritical water process within the same processing tank 1.

[0039] The heating control unit 11b controls the degree of heating of the water in the heating unit 6 based on the temperature inside the processing tank 1. The temperature inside the processing tank 1 may be detected, for example, by a temperature sensor. For example, based on the value detected by the temperature sensor, the heating control unit 11b may control the power applied to the coil of the heating unit 6 so that the temperature inside the processing tank 1 is maintained and the water remains in a subcritical or supercritical state.

[0040] The heating control unit 11b may, for example, control the heating unit 6 so that the water reaches a subcritical state when nitrogen is supplied by the supply unit 7. When it is determined that the gas supplied by the supply unit 7 has switched from nitrogen to oxygen, the heating control unit 11b switches the degree of heating of the water. The heating control unit 11b may, for example, control the heating unit 6 so that the water reaches a supercritical state when oxygen is supplied by the supply unit 7. This series of controls for the heating unit 6 may be performed automatically by the heating control unit 11b. Alternatively, the control of the heating unit 6 may be performed by manual operation by an operator.

[0041] The supply unit 7 supplies gas into the processing tank 1. The supply unit 7 supplies nitrogen as a gas, and can also supply oxygen instead of nitrogen. The supply unit 7 is configured to switch the supplied gas from nitrogen to oxygen. The supply unit 7 may have a nozzle, heater, on / off valve 14a, switching valve 14b, nitrogen generator 15a, oxygen generator 15b, etc. The nozzle of the supply unit 7 is located inside the processing tank 1. In gas supply, nitrogen or oxygen is supplied from the same nozzle. The manner in which the supply unit 7 supplies gas is controlled, for example, by the supply control unit 11c.

[0042] The nitrogen generator 15a and the oxygen generator 15b are located outside the treatment tank 1, respectively. The nitrogen generator 15a and the oxygen generator 15b are connected to the nozzle of the supply unit 7 by piping 16. A gas containing nitrogen is supplied from the external nitrogen generator 15a to the inside of the treatment tank 1 via the nozzle. A gas containing oxygen is supplied from the external oxygen generator 15b to the inside of the treatment tank 1 via the nozzle.

[0043] A switching valve 14a and a switching valve 14b are installed in the piping 16. The switching valve 14a is fixed to the outside of the treatment tank 1. When the switching valve 14a is open, it allows the supply of gas to the inside of the treatment tank 1. When the switching valve 14a is closed, it shuts off the supply of gas and seals the treatment tank 1. The switching valve 14b is installed at a point where the piping 16 branches off. A nitrogen generator 15a and an oxygen generator 15b are connected to the branch of the piping 16, respectively. When the switching valve 14b allows the flow of nitrogen from the nitrogen generator 15a, it restricts the flow of oxygen from the oxygen generator 15b. Also, when the switching valve 14b restricts the flow of nitrogen from the nitrogen generator 15a, it allows the flow of oxygen from the oxygen generator 15b. The opening and closing control of the on / off valve 14a and the switching control of the switching valve 14b are controlled, for example, by the supply control unit 11c.

[0044] The supply control unit 11c controls the on / off valve 14a and the switching valve 14b of the supply unit 7 to supply nitrogen to the treatment tank 1 during the subcritical water process. The supply control unit 11c also controls the on / off valve 14a and the switching valve 14b of the supply unit 7 to supply oxygen to the treatment tank 1 during the supercritical water process. This series of controls for the supply unit 7 may be performed automatically by the supply control unit 11c. Alternatively, the control of the supply unit 7 may be performed manually by an operator.

[0045] The exhaust section 8 connects the outside and inside of the processing tank 1, allowing gas to be discharged from inside the processing tank 1. The exhaust section 8 may be configured as, for example, an on / off valve. The exhaust section 8 is fixed to the outside of the processing tank 1. When the exhaust section 8 is open, it allows gas to be discharged from inside the processing tank 1. When the exhaust section 8 is closed, it blocks the discharge of gas and seals the processing tank 1. The opening and closing control of the exhaust section 8 is controlled, for example, by the supply control unit 11c.

[0046] The supply control unit 11c controls the exhaust unit 8 so that when transitioning from the subcritical water process to the supercritical water process, the nitrogen sealed in the treatment tank 1 is discharged and oxygen is supplied in its place. This series of controls for the exhaust unit 8 may be performed automatically by the supply control unit 11c. Alternatively, the control of the exhaust unit 8 may be performed manually by an operator.

[0047] The oscillation control unit 11a controls the oscillation of the processing tank 1 when the water is heated by the heating unit 6 in both the subcritical water process and the supercritical water process (see Figure 5). More specifically, the oscillation control unit 11a may control, for example, an actuator that oscillates the processing tank 1 clockwise or counterclockwise around the pivot shaft 1b as the center of rotation.

[0048] In the subcritical water process, the treatment tank 1 oscillates while the heating unit 6 heats the water to a subcritical state. In the supercritical water process, the treatment tank 1 oscillates while the heating unit 6 heats the water to a supercritical state. That is, the oscillating control unit 11a oscillates the treatment tank 1 while the heating control unit 11b heats the water. In these cases, the oscillating control unit 11a may control the oscillating of the treatment tank 1 so that the direction of oscillating continuously switches between clockwise and counterclockwise with the pivot shaft 1b as the center of rotation.

[0049] The processing tank 1 is oscillated when water is received by the input section 4, so that the input section 4 is directed diagonally upward and forward (see Figure 4). The processing tank 1 is also oscillated when the processed contents are discharged by the removal section 5, so that the removal section 5 is directed diagonally downward and forward (see Figure 6). The water is added to the processing tank 1 and the processed contents are removed from the processing tank 1 while the processing tank 1 is kept in an inclined state. The series of operations of adding water and removing the processed contents may be performed by manual operation by an operator. Alternatively, these operations may be performed automatically by the oscillation control unit 11a. In these cases, the oscillation control unit 11a may control the oscillation of the processing tank 1 so that it oscillates clockwise or counterclockwise around the pivot shaft 1b as the center of rotation.

[0050] The actual operation of the organic waste treatment device 100 will be explained with reference to the flowchart shown in Figure 3. First, when the subcritical water process (S1-S17) is started, in step S1, the power to the organic waste treatment device 100 is turned on, and then in step S2, the operation preparation switch is turned ON, enabling various controls and operations. Next, in step S3, the treatment tank 1, which had been kept horizontal, is swung so that the input section 4 is directed diagonally upward and forward. Next, in step S4, with the treatment tank 1 in an inclined state and the lid 1c in an open state, water is introduced into the treatment tank 1 from the input section 4. Next, in step S5, with the treatment tank 1 in an inclined state and the lid 1c in an open state, organic waste is introduced into the treatment tank 1 from the input section 4.

[0051] As shown in Figure 4, water is added until it overflows from the opening 1a, that is, until the water level reaches the front lower end of the opening 1a. Since the treatment tank 1 is inclined to allow a specified amount of water to be added, there is no need to measure the amount of water in advance. In other words, a specified amount of water can be added to the treatment tank 1 accurately and easily. The specified amount of water may be determined based on the following knowledge. For example, when water at room temperature and pressure undergoes a phase transition to supercritical water, its density becomes less than 23%, and its volume increases by more than 4.37 times. From this, the amount of water that will not be in excess when added to the treatment tank 1 may be calculated and set as the specified amount. Following the addition of water, organic waste is added. At this time, water will overflow depending on the volume of organic waste added, but since the moisture contained in the organic waste can also be utilized, water shortages during treatment are suppressed.

[0052] Next, in step S6, the lid 1c is closed to shield the opening 1a, and the treatment tank 1 is temporarily sealed. The lid 1c may be locked mechanically or electrically. Next, in step S7, nitrogen is supplied to the treatment tank 1 by the supply unit 7. The supply control unit 11c opens the on / off valve 14a, the switching valve 14b allows the supply of nitrogen from the nitrogen generator 15a, and the on / off valve of the exhaust unit 8 is opened. As a result, the air inside the treatment tank 1 is replaced with nitrogen. After the nitrogen replacement is complete, the supply control unit 11c closes the on / off valve 14a and closes the on / off valve of the exhaust unit 8. As a result, the organic waste, water, and nitrogen are sealed inside the treatment tank 1.

[0053] Next, in step S8, the start switch is turned ON, and preparations are made for the oscillating of the processing tank 1 and the heating operation by the heating unit 6. Next, in step S9, the tilted processing tank 1 is oscillated to maintain a horizontal position. Next, in step S10, the water is heated by the heating unit 6 until it reaches a subcritical state. Next, in step S11, it is confirmed that the water has reached a subcritical state based on sensor detection values, etc. Heating by the heating unit 6 is maintained until the treatment with subcritical water is completed.

[0054] Next, in step S12, the water is heated by the heating unit 6 while the processing tank 1 is oscillated. At this time, the temperature and pressure inside the processing tank 1 are continuously detected, and the heating control unit 11b controls the degree of heating and adjusts the temperature and pressure so that the state of the water does not deviate from the subcritical region.

[0055] As shown in Figure 5, the treatment tank 1 oscillates relative to the horizontal installation surface G, with the pivot shaft 1b as the center of rotation. More specifically, the oscillation control unit 11a continuously switches the direction of oscillation of the treatment tank 1 clockwise and counterclockwise, with the pivot shaft 1b as the center of rotation. As a result, the organic waste and subcritical water inside the treatment tank 1 are stirred together and come into even contact with each other. Consequently, the hydrolysis and destruction of the organic waste are promoted.

[0056] Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibrated as a whole, and a sloshing impact load can be generated in the subcritical water. Therefore, the decomposition and destruction of organic waste can be further promoted. As a result, the effectiveness of hydrolysis of organic waste and the efficiency of fragmentation of organic waste can be improved.

[0057] Next, in step S13, the treatment of organic waste with subcritical water is completed, and the temperature inside the treatment tank 1 is lowered. The treatment time for organic waste varies depending on the type of organic waste. Therefore, the oscillation and heating control of the treatment tank 1 are continued until a predetermined time is reached according to the type of organic waste.

[0058] Next, in step S14, the treatment tank 1 is cooled. The treatment tank 1 is kept in a horizontal position and cooled until it can be confirmed that the temperature and pressure inside the treatment tank 1 are at safe values ​​based on sensor detection values, etc. Next, in step S15, it is confirmed that the temperature and pressure have reached safe values, and in step S16, with the treatment tank 1 still in a horizontal position, the subcritical water process is completed in step S17. If the operation is stopped at this point, it is also possible to obtain intermediate products such as low molecular weight hydrocarbons, organic acids, aldehydes, and ketones derived from organic waste.

[0059] After the subcritical water process (S1-S17), when the supercritical water process (S18-S28) is started, in step S18, nitrogen is discharged from the treatment tank 1 by the supply unit 7 and oxygen is supplied to the treatment tank 1. The supply control unit 11c opens the on / off valve 14a, allows the supply of oxygen from the oxygen generator 15b by opening the switching valve 14b, and opens the on / off valve of the exhaust unit 8. As a result, the nitrogen inside the treatment tank 1 is replaced with oxygen. After the oxygen replacement is complete, the supply control unit 11c closes the on / off valve 14a and closes the on / off valve of the exhaust unit 8. As a result, the organic waste, water, and oxygen inside the treatment tank 1 are sealed.

[0060] Next, in step S19, the start switch is turned ON, preparing the oscillating of the processing tank 1 and the heating operation by the heating unit 6. Next, in step S20, the tilted processing tank 1 is oscillated to maintain a horizontal position. Next, in step S21, the water is heated by the heating unit 6 until it reaches a supercritical state. Next, in step S22, it is confirmed that the water has reached a supercritical state based on sensor detection values, etc. Heating by the heating unit 6 is maintained until the processing with supercritical water is completed.

[0061] Next, in step S23, the water is heated by the heating unit 6 while the processing tank 1 is oscillated. At this time, the temperature and pressure inside the processing tank 1 are continuously detected, and the heating control unit 11b controls the degree of heating and adjusts the temperature and pressure so that the state of the water does not deviate from the supercritical region.

[0062] The heating control unit 11b controls the degree of heating so that the temperature and pressure inside the processing tank 1 are 375°C or higher and 22.1 MPa or higher, thereby transitioning the water state to the supercritical region. Furthermore, if heat generation due to oxidation reactions by supercritical water is observed, heating by the heating unit 6 may be suppressed. In addition, if the pressure inside the processing tank 1 exceeds a preset pressure, the on / off valve of the exhaust unit 8 may be opened to discharge gas from the processing tank 1 and adjust the pressure.

[0063] As shown in Figure 5, the treatment tank 1 oscillates relative to the horizontal mounting surface G, with the pivot shaft 1b as the center of rotation. More specifically, the oscillation control unit 11a continuously switches the direction of oscillation of the treatment tank 1 clockwise and counterclockwise, with the pivot shaft 1b as the center of rotation. As a result, the intermediate products derived from organic waste and the supercritical water are stirred together and come into even contact with each other inside the treatment tank 1. Therefore, the oxidative decomposition and destruction of the intermediate products derived from organic waste are promoted.

[0064] Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibrated as a whole, and a thrashing flow can be generated in the super-subcritical water. Therefore, the decomposition and destruction of intermediate products derived from organic waste can be further promoted. As a result, the effect of oxidative decomposition of intermediate products and the efficiency of their fragmentation can be improved.

[0065] Furthermore, since the subcritical water process is performed before the supercritical water process, the processing time required for oxidative decomposition in the supercritical water process can be shortened. As a result, corrosion of the container of the treatment tank 1 in the supercritical water process can be suppressed.

[0066] Next, in step S24, the treatment of organic waste with supercritical water is completed, and the temperature inside the treatment tank 1 is lowered. It is preferable that the oxidative decomposition of the organic waste be continued until the oxidation reaction of the organic waste being treated is completed. For this reason, the oscillation and heating control of the treatment tank 1 are continued until the intermediate product generated in the subcritical water step is oxidatively decomposed in accordance with the oxidation reaction. Alternatively, the oscillation and heating control of the treatment tank 1 may be continued until the oxygen inside the treatment tank 1 is completely consumed in accordance with the oxidation reaction.

[0067] Next, in step S25, the processing tank 1 is cooled. The processing tank 1 is kept in a horizontal position and cooled until it can be confirmed that the temperature and pressure inside the processing tank 1 are at safe values ​​based on the sensor detection values, etc. Next, in step S26, it is confirmed that the temperature and pressure are at safe values, and in step S27, the processing tank 1, which had been kept horizontal, is swung so that the outlet section 5 is directed diagonally downward and forward.

[0068] As shown in Figure 6, the treatment tank 1 is kept in an inclined state, the lid 1c is opened, and the treated contents are discharged to the outside of the treatment tank 1 from the removal section 5. The treated contents discharged from the removal section 5 are guided by the slope 17 to the outside and below the organic waste treatment device 100. The treated contents are the contents remaining in the treatment tank 1 after oxidative decomposition is completed in the supercritical water process. The majority of the treated contents are carbon dioxide, water, and nitrogen. The treated contents may also contain trace amounts of sulfates and phosphates. Because the treated contents have undergone oxidative decomposition, they are sterile and virus-free, and odors are also decomposed. For this reason, the treatment method of this embodiment is suitable for the treatment of medical waste and nursing care waste. It is also possible to prevent the generation of foul odors.

[0069] Next, in step S28, the supercritical water process is completed. Then, the series of processes including the subcritical water process and the supercritical water process are completed, and the operation of the organic waste treatment device 100 is stopped.

[0070] [Effects of the Embodiment] As described above, the organic waste treatment apparatus 100 according to an embodiment of the present invention comprises at least a treatment tank 1 configured to receive organic waste from the outside and to treat the organic waste with high-temperature, high-pressure water inside. The organic waste treatment apparatus 100 comprises an input unit 4 that connects the outside and inside of the treatment tank 1 and enables the acceptance of the organic waste and liquid water from the outside, a supply unit 7 that supplies gas towards the inside of the treatment tank 1, and a heating unit 6 installed inside the treatment tank 1 that heats the accepted water. The treatment tank 1 is configured to accept the organic waste, water and gas inside and maintain a sealed state, the supply unit 7 supplies nitrogen as the gas, and the heating unit 6 heats the water sealed together with the nitrogen and organic waste to a subcritical state when the gas sealed inside the treatment tank 1 is nitrogen.

[0071] According to this method, the treatment of organic waste with subcritical water enables hydrolysis and destruction of the organic waste. By performing the treatment of organic waste with subcritical water, for example, before the supercritical water process, the organic waste can be hydrolyzed and destroyed in advance. Therefore, compared to cases where physical crushing or other methods are performed as a pretreatment for the supercritical water process, the size of the equipment and energy consumption can be suppressed. In addition, the treatment of subcritical water can be performed under a nitrogen atmosphere. Therefore, corrosion of the treatment tank 1 can be suppressed. As a result, organic waste can be treated appropriately.

[0072] In the organic waste treatment device 100, the supply unit 7 supplies oxygen instead of nitrogen as the gas, and the heating unit 6 heats the water sealed inside the treatment tank 1 together with the oxygen and organic waste to a supercritical state when the gas sealed inside the treatment tank 1 is oxygen.

[0073] According to this, the treatment of organic waste with supercritical water enables oxidative decomposition of organic waste. By performing the treatment of organic waste with supercritical water, for example, after the subcritical water process, the organic waste can be easily oxidatively decomposed. Furthermore, it becomes possible to treat the organic waste with supercritical water under an oxygen atmosphere. After treatment with subcritical water, the organic waste becomes an intermediate product that is easily oxidatively decomposed, and since oxygen in the treatment tank 1 can be used, the oxidative decomposition in the supercritical water process can be made closer to complete.

[0074] In the organic waste treatment device 100, the supply unit 7 is configured to switch the supplied gas from nitrogen to oxygen, and the heating unit 6 switches from heating the water in a subcritical state to heating the water in a supercritical state, corresponding to the switch from nitrogen to oxygen in the supply unit 7.

[0075] According to this, it becomes possible to switch from the subcritical water process to the supercritical water process using a single treatment tank 1. In other words, it becomes unnecessary to install multiple treatment tanks to correspond to each process. Therefore, the equipment can be simplified. In addition, since the subcritical water process is performed before the supercritical water process, the processing time required for oxidative decomposition in the supercritical water process can be shortened. Therefore, corrosion of the container of treatment tank 1 in the supercritical water process can be suppressed.

[0076] In the organic waste treatment device 100, the treatment tank 1 is configured to be able to swing with respect to the installation surface G when the water is heated by at least the heating unit 6.

[0077] According to this, in the subcritical water process, the organic waste and subcritical water are stirred together inside the treatment tank 1, bringing them into even contact. Therefore, the hydrolysis and destruction of the organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibriumized as a whole, and a sloshing impact load can be generated in the subcritical water. Therefore, the decomposition and destruction of the organic waste can be further promoted. As a result, the effect of hydrolysis of organic waste and the efficiency of organic waste fragmentation can be improved. Also, in the supercritical water process, the intermediate products derived from organic waste and supercritical water are stirred together inside the treatment tank 1, bringing them into even contact. Therefore, the oxidative decomposition and destruction of the intermediate products derived from organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibriumized as a whole, and a slashing flow can be generated in the supersubcritical water. Therefore, the decomposition and destruction of the intermediate products derived from organic waste can be further promoted. Based on the above, the effectiveness of the oxidative decomposition of intermediate products and the efficiency of their fragmentation can be improved.

[0078] The organic waste treatment device 100 further includes an outlet 5 that connects the outside and inside of the treatment tank 1 and enables the discharge of the treated contents to the outside. The treatment tank 1 is configured to be a cylindrical container with one end open, and the opening is the input section 4 and the outlet section 5. The device is configured to swing relative to the installation surface G when water is received by the input section 4 and / or when the treated contents are discharged by the outlet section 5.

[0079] According to this design, when water is introduced from the input section 4, the processing tank 1 can be tilted to allow a specified amount of water to be introduced. Therefore, there is no need to measure the amount of water in advance. In other words, a specified amount of water can be accurately and easily introduced into the processing tank 1. Furthermore, when the processed contents are removed from the output section 5, the processing tank 1 can be tilted to allow the processed contents to slide out easily. Therefore, the processed contents can be easily removed.

[0080] The organic waste treatment method involves treating the organic waste using a treatment tank 1 that is configured to receive organic waste from the outside and to treat the organic waste with high-temperature, high-pressure water inside. The organic waste treatment method comprises the steps of: receiving the organic waste and liquid water from the outside into the treatment tank 1; supplying nitrogen into the treatment tank 1; sealing the organic waste, water, and nitrogen inside the treatment tank 1; and heating the water sealed inside the treatment tank 1 together with the nitrogen and organic waste to a subcritical state.

[0081] According to this method, the treatment of organic waste with subcritical water enables hydrolysis and destruction of the organic waste. By performing the treatment of organic waste with subcritical water, for example, before the supercritical water process, the organic waste can be hydrolyzed and destroyed in advance. Therefore, compared to cases where physical crushing or other methods are performed as a pretreatment for the supercritical water process, the size of the equipment and energy loss can be suppressed. In addition, the treatment of subcritical water can be performed under a nitrogen atmosphere. Therefore, corrosion of the treatment tank 1 can be suppressed. As a result, organic waste can be treated appropriately.

[0082] The organic waste treatment method further comprises the steps of: heating the water to a subcritical state; discharging the nitrogen to the outside of the treatment tank 1; supplying oxygen to the inside of the treatment tank 1; sealing the organic waste, water, and oxygen inside the treatment tank 1; and heating the water sealed inside the treatment tank 1 together with the oxygen and organic waste to a supercritical state.

[0083] According to this, the treatment of organic waste with supercritical water enables oxidative decomposition of organic waste. By performing the treatment of organic waste with supercritical water, for example, after the subcritical water process, the organic waste can be easily oxidized and decomposed. Furthermore, it becomes possible to perform the treatment with supercritical water under an oxygen atmosphere. Due to the subcritical water treatment, the organic waste has become an intermediate product that is easily oxidized and decomposed, and furthermore, since oxygen in the treatment tank 1 can be used, the oxidative decomposition in the supercritical water process can be made closer to complete. In addition, it becomes possible to switch from the subcritical water process to the supercritical water process using a single treatment tank 1. That is, it becomes unnecessary to install multiple treatment tanks to correspond to each process. Therefore, the equipment can be simplified. Also, since the subcritical water process is performed before the supercritical water process, the treatment time required for oxidative decomposition in the supercritical water process can be shortened. Therefore, corrosion of the container of treatment tank 1 in the supercritical water process can be suppressed.

[0084] In the organic waste treatment method, the treatment tank 1 is configured to be able to swing with respect to the installation surface G when the water is heated, and the heating step involves heating the water while swinging the treatment tank 1.

[0085] According to this, in the subcritical water process, the organic waste and subcritical water are stirred together inside the treatment tank 1, bringing them into even contact. Therefore, the hydrolysis and destruction of the organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibriumized as a whole, and a sloshing impact load can be generated in the subcritical water. Therefore, the decomposition and destruction of the organic waste can be further promoted. As a result, the effect of hydrolysis of organic waste and the efficiency of organic waste fragmentation can be improved. Also, in the supercritical water process, the intermediate products derived from organic waste and supercritical water are stirred together inside the treatment tank 1, bringing them into even contact. Therefore, the oxidative decomposition and destruction of the intermediate products derived from organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being oscillated, the temperature inside the treatment tank 1 can be equilibriumized as a whole, and a slashing flow can be generated in the supersubcritical water. Therefore, the decomposition and destruction of the intermediate products derived from organic waste can be further promoted. Based on the above, the effectiveness of the oxidative decomposition of intermediate products and the efficiency of their fragmentation can be improved. [Explanation of Symbols]

[0086] 1…Processing tank, 4…Input section, 5…Extraction section, 6…Heating section, 7…Supply section, 8…Exhaust section, 11a…Oscillating control section, 11b…Heating control section, 11c…Supply control section

Claims

1. In an organic waste treatment apparatus comprising at least a treatment tank configured to accept organic waste from the outside and to treat the organic waste internally with high-temperature, high-pressure water, An input section that connects the outside and inside of the aforementioned treatment tank, and allows for the acceptance of the organic waste and liquid water from the outside, A supply unit that supplies gas towards the inside of the processing tank, A heating unit installed inside the processing tank for heating the received water, Equipped with, The aforementioned processing tank is Internally, it is configured to receive the organic waste, water, and gas, and to maintain a sealed state. The aforementioned supply unit is Nitrogen is supplied as the aforementioned gas. The aforementioned heating section is When the gas sealed inside the treatment tank is nitrogen, the water sealed together with the nitrogen and the organic waste is heated to a subcritical state. Organic waste treatment equipment.

2. In the organic waste treatment apparatus according to claim 1, The aforementioned supply unit is As the gas, oxygen is supplied instead of nitrogen. The aforementioned heating section is When the gas sealed inside the treatment tank is oxygen, the water sealed together with the oxygen and the organic waste is heated to a supercritical state. Organic waste treatment equipment.

3. In the organic waste treatment apparatus according to claim 2, The aforementioned supply unit is The supplied gas is configured to be switchable from nitrogen to oxygen. The heating section is In accordance with the switching from nitrogen to oxygen in the supply unit, the heating of the water is switched from a subcritical state to a supercritical state. Organic waste treatment equipment.

4. In the organic waste treatment apparatus according to any one of claims 1 to 3, The aforementioned processing tank is At least when the water is heated by the heating unit, it is configured to be able to swing relative to the installation surface. Organic waste treatment equipment.

5. In the organic waste treatment apparatus according to claim 4, A removal section that connects the outside and inside of the processing tank, enabling the discharge of the processed contents to the outside. Furthermore, The aforementioned processing tank is The device is configured to be a cylindrical container with one end open, and the opening serves as the input and output section, and is configured to swing relative to the mounting surface when water is received through the input section and / or when the treated contents are discharged through the output section. Organic waste treatment equipment.

6. An organic waste treatment method that involves receiving organic waste from an external source and treating the organic waste using a treatment tank configured to allow treatment of the organic waste with high-temperature, high-pressure water internally, The aforementioned treatment tank includes a step of receiving the organic waste and liquid water from the outside, A step of supplying nitrogen to the inside of the treatment tank, The process involves sealing the organic waste, water, and nitrogen inside the treatment tank, A step of heating the water, which is sealed inside the treatment tank together with the nitrogen and the organic waste, so that it reaches a subcritical state, Equipped with Methods for disposing of organic waste.

7. In the organic waste treatment method described in claim 6, After the step of heating the water to a subcritical state, the nitrogen is discharged to the outside of the treatment tank. A step of supplying oxygen to the inside of the treatment tank, The process involves sealing the organic waste, water, and oxygen inside the treatment tank, A step of heating the water, which is sealed inside the treatment tank together with the oxygen and the organic waste, so that it reaches a supercritical state, It also has Methods for disposing of organic waste.

8. In the organic waste treatment method according to claim 6 or claim 7, The aforementioned processing tank is When the water is heated, it is configured to be able to swing relative to the installation surface, The aforementioned heating step is The water is heated while the treatment tank is oscillated. Methods for disposing of organic waste.

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