Organic waste treatment device and organic waste treatment method

Abstract

Suppress the enlargement of equipment and energy consumption, etc., suppress corrosion of the treatment tank, etc., and facilitate equipment management. 【Solution means】The organic waste treatment device 100 includes a treatment tank 1, an input section 4 that communicates with the outside and inside of the treatment tank 1 and enables the acceptance of organic waste and liquid water from the outside, a supply section 7 that supplies gas toward the inside of the treatment tank 1, and a heating section 6 that is installed inside the treatment tank 1 and heats the received water. The treatment tank 1 is configured to accept organic waste, water, and gas and maintain a sealed state. The supply section 7 supplies nitrogen as the gas, and when the gas sealed inside the treatment tank 1 is nitrogen, the heating section 6 heats the water sealed together with nitrogen and organic waste to a subcritical state. Further, the supply section 7 supplies oxygen as the gas, and when the gas sealed inside the treatment tank 1 is oxygen, the heating section 6 heats the water sealed together with oxygen and organic waste to a supercritical state.

Description

Technical Field

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

Background Art

[0002] Generally, since the water content of organic waste is high, organic waste is likely to rot and often emits an odor. Also, the bulk of organic waste is often large. Therefore, when performing normal combustion treatment, a storage place before treating organic waste, a dehydration process, odor countermeasures, etc. are required.

[0003] On the other hand, according to the treatment using water in a supercritical state, since odor-causing substances and fungi can be oxidized and decomposed, a deodorizing effect and a sterilizing effect can also be expected. For this reason, the treatment using water in a supercritical state is also suitable for treating medical waste and nursing care waste that require attention in waste handling. Furthermore, the final products are mainly carbon dioxide, water, and nitrogen, and no combustion exhaust gas is emitted. From the above, it can be said that the treatment using water in a supercritical state is a promising technology.

[0004] Conventionally, as a technique for treating organic waste, a technique for treating organic waste with high-temperature and high-pressure water is known. For example, Patent Document 1 discloses a system in which subcritical water and supercritical water are used. In this system, hydrolysis reaction treatment of organic waste and the like are carried out.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] According to the technology of Patent Document 1 described above, hydrolysis reaction treatment, sterilization treatment, and dehydration treatment can be performed on organic waste, but there is still much room for improvement. For example, since the target of the oxidation reaction by supercritical water is mainly organic compounds, it is not suitable for treating inorganic compounds. Also, the oxidation reaction by supercritical water is not very effective for treating large amounts of waste. This is similar to burning thick logs.

[0007] Therefore, a pretreatment process is combined to constitute a system that complements the oxidation reaction by supercritical water as a whole. As the pretreatment process, for example, a process of physically pulverizing or chemically dissolving organic waste is used. Therefore, the system often becomes a plant with large-scale equipment. In large-scale equipment, in order to constantly shift the state of water to the supercritical region, a large amount of energy is required to stabilize the water temperature. Also, a pump for pressurizing a large-capacity treatment tank and equipment for generating high-temperature superheated steam are also required, and the equipment itself becomes larger.

[0008] Therefore, not only is it difficult to easily install large-scale equipment, but the energy consumption of large-scale equipment also increases. From the perspective of efficiency, it is not suitable for treating a small amount of organic waste, and it is necessary to store the organic waste until the amount of organic waste reaches a sufficient treatment volume for a single input. Securing a place for that, as well as measures against malodor and hygienic countermeasures during that period, also become issues.

[0009] Also, subcritical water and supercritical water are likely to corrode metals due to their oxidizing power. For example, corrosion progresses when treating in a metal treatment tank for a long time. Also, although it is possible to shift the state of water to the supercritical region by increasing the pressure instead of raising the temperature, in this case, equipment wear is promoted and the risk of damage increases. From the above, equipment management is difficult, and frequent parts replacement and maintenance are required.

[0010] In view of the above, an object of the present invention is to provide an organic waste treatment apparatus and an organic waste treatment method capable of appropriately treating organic waste by suppressing the enlargement of equipment, energy consumption, etc., suppressing corrosion of a treatment tank, etc., and facilitating equipment management.

Means for Solving the Problems

[0011] The technical means of the present invention for solving this technical problem is characterized by the following points. The organic waste treatment apparatus of the present invention includes at least a treatment tank configured to receive organic waste from the outside and enable treatment of the organic waste with high-temperature and high-pressure water inside. The organic waste treatment apparatus of the present invention includes an input unit that communicates the outside and the inside of the treatment tank and enables reception 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 received water. The treatment tank is configured to receive the organic waste, the water, and the gas inside and maintain a sealed state. The material constituting the treatment tank is metal, The supply unit supplies nitrogen as the gas, and when the gas sealed inside the treatment tank is nitrogen, the heating unit heats the water sealed together with the nitrogen and the organic waste to a subcritical state.

[0012] In the organic waste treatment apparatus of the present invention, the supply unit the supplied gas is configured to be switchable from the nitrogen to oxygen, and when the switching is executed, supplies oxygen as the gas instead of nitrogen, and when the gas sealed inside the treatment tank is oxygen, the heating unit heats the water sealed together with the oxygen and the organic waste to a supercritical state. configured such that, corresponding to the switching from the nitrogen to the oxygen in the supply unit, the heating of the water in the subcritical state is switched to the heating of the water in the supercritical state 。

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

[0015] The organic waste treatment apparatus of the present invention further includes a take-out part that communicates the outside and the inside of the treatment tank and enables the discharged treated content to be discharged to the outside. The treatment tank is configured to be a cylindrical container with one end open, and the opening is configured to be the input part and the take-out part. When the water is received by the input part and / or when the treated content is discharged by the take-out part, the treatment tank is configured to be swingable with respect to the installation surface.

[0016] The organic waste treatment method of the present invention receives organic waste from the outside and treats the organic waste using a treatment tank configured to be able to treat the organic waste with high-temperature and high-pressure water inside. and the material constituting the treatment tank is metal. The organic waste treatment method of the present invention includes a step of receiving the organic waste and liquid water from the outside in the treatment tank, a step of supplying nitrogen toward the inside of the treatment tank, a step of sealing the organic waste, the water, and the nitrogen inside the treatment tank, and a step of heating the water sealed together with the nitrogen and the organic waste inside the treatment tank so as to be in a subcritical state.

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

Advantages of the Invention

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

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0022] As shown in FIG. 1, the organic waste treatment apparatus 100 according to the embodiment of the present invention is an apparatus for treating organic waste. In the organic waste treatment apparatus 100, organic waste is treated with high-temperature and high-pressure water. The organic waste may be, for example, waste containing organic substances such as plastic resins, paper, food waste, livestock waste, animal carcasses, and felled plants, and is not limited thereto.

[0023] The treatment with high-temperature and high-pressure water in the organic waste treatment apparatus 100 is a treatment for decomposing organic waste inside the sealed treatment tank 1. In the treatment tank 1, the water enclosed together with the organic waste is heated and pressurized, whereby a phase transition of the water occurs. Based on the increase in the ionic product of water according to the phase transition, the decomposition of organic substances is promoted.

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

[0025] Subcritical water is a liquid in a state where both the temperature and pressure are slightly lower than the critical point. The characteristic of subcritical water is that it is easy to dissolve and hydrolyze non-polar organic substances and organic compounds. This is because subcritical water has a higher ion product (Kw = [H + [OH - ) than water at normal temperature and pressure. The ion product of water indicates the degree to which pure water H 2 O dissociates into hydrogen ions H + and hydroxide ions OH - .

[0026] The ion product of water at normal temperature and pressure is 10 -14 (mol / L) 2 . When the temperature and pressure of water increase, the ion product of water increases. For example, assume that water at normal temperature and pressure 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 is about 350 times that of water at normal temperature and pressure. Therefore, subcritical water itself exhibits the same function 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 water at normal temperature and pressure (1000 kg / m 3 ).

[0027] Supercritical water is a fluid with properties intermediate between those of a liquid and a gas, at a state where both temperature and pressure are higher than the critical point. The characteristic of supercritical water is that it easily dissolves and oxidatively decomposes non-polar organic substances and organic compounds. This is based on the fact that supercritical water has a higher ion product compared to water at normal temperature and pressure or subcritical water.

[0028] For example, assume that water at normal temperature and pressure 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 is approximately 440 times that of water at normal temperature and pressure. Therefore, supercritical water itself exhibits the same effect as an acid or an 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 water at normal temperature and pressure (1000 kg / m 3 ). For this reason, supercritical water can be said to be a liquid with a low density and also a gas with a high density.

[0029] The process of decomposing organic waste in the organic waste treatment apparatus 100 includes a subcritical water process and a supercritical water process (see Fig. 6). The subcritical water process is a process of decomposing organic waste with subcritical water under a nitrogen atmosphere, and is executed before the supercritical water process. The supercritical water process is a process of decomposing the organic waste treated in the subcritical water process with supercritical water under an oxygen atmosphere.

[0030] As shown in Fig. 1, the organic waste treatment apparatus 100 includes a treatment tank 1, a charging section 4, a discharging section 5, a heating section 6, a supply section 7, an exhaust section 8, and a control section 11 (a swing control section 11a, a heating control section 11b, and a supply control section 11c). The control section 11 includes a CPU, an electric circuit, a memory for storing programs, etc. It may be configured such that the corresponding hardware operates based on the program processing of the CPU. The organic waste treatment apparatus 100 is installed on a horizontal installation surface G.

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

[0032] The axis of the treatment tank 1 is normally along the front-rear direction and parallel to the horizontal installation surface G. One end on the front side of the treatment tank 1 is an opening 1a. The opening 1a is configured to be an input section 4 and a take-out section 5. The opening 1a may be, for example, circular. On the other hand, the other end on the rear side of the treatment tank 1 is a butt of the container.

[0033] Support shafts 1b are provided on the outer side of the side surface of the treatment tank 1. Two support shafts 1b project in the left-right direction respectively. The support shafts 1b are always along the left-right direction and parallel to the horizontal installation surface G. Also, the support shafts 1b are orthogonal to the axis defining the cylinder of the treatment tank 1.

[0034] The treatment tank 1 is located above the installation surface G. The support shafts 1b are supported by, for example, columns or angles extending upward from the installation surface G so that the treatment tank 1 can rotate. Thereby, the treatment tank 1 can swing with respect to the horizontal installation surface G with the support shafts 1b as the rotation center. That is, by tilting the treatment tank 1, one end on the front side of the treatment tank 1 (the opening 1a, the input section 4, and the take-out section 5) can be directed not only in the horizontal direction but also obliquely forward upward or obliquely forward downward. The installation position of the support shafts 1b can be arbitrary as long as it is on the outer side of the side surface of the treatment tank 1, but it is preferably, for example, a position corresponding to the center of gravity of the treatment tank 1.

[0035] The input section 4 communicates the inside and outside of the treatment tank 1 and enables the acceptance of organic waste and liquid water from the outside. The extraction section 5 communicates the inside and outside of the treatment tank 1 and enables the discharge of the treated contents to the outside. An openable / closable lid 1c may be provided near the input section 4 (extraction section 5). When the lid 1c is open, the input section 4 (extraction section 5) is released, and the inside and outside of the treatment tank 1 communicate. On the other hand, when the lid 1c is open, the input section 4 (extraction section 5) is shielded, and the inside of the treatment tank 1 is sealed. With the lid 1c, the treatment tank 1 is configured to be able to accept organic waste, water, and gas inside and maintain a sealed state.

[0036] The heating section 6 is installed inside the treatment tank 1 and heats the received water. When the gas sealed inside the treatment tank 1 is nitrogen, the heating section 6 heats the water sealed together with nitrogen and organic waste to a subcritical state. When the gas sealed inside the treatment tank 1 is oxygen, the heating section 6 heats the water sealed together with oxygen and organic waste to a supercritical state. Further, the heating section 6 switches from heating water to a subcritical state to heating water to a supercritical state so as to correspond to the switching from nitrogen to oxygen in the supply section 7. The switching of the heating section 6 is controlled by, for example, the heating control section 11b.

[0037] The heating section 6 may be composed of a magnetic body (metal), a coil, etc. so that, for example, electromagnetic induction heating is possible. Electromagnetic induction heating uses a magnetic field in a coil based on an alternating current, and Joule heat is generated from the magnetic body. Therefore, compared with the case of using a heating wire heater, there is an advantage in that the power consumption is small and the response speed is high. The magnetic body may be, for example, a metal constituting the treatment tank 1, and the metal and water may be in contact. The degree of heating of the water in the heating section 6 is controlled by, for example, the heating control section 11b.

[0038] The heating unit 6 heats the water inside the treatment tank 1 to a temperature corresponding to the subcritical region and the supercritical region in a short time. Depending on the application, electromagnetic induction heating can raise the temperature up to the melting temperature of the metal. Therefore, the temperature can be easily controlled by electromagnetic induction heating. By electromagnetic induction heating, it is possible to perform both continuous processes of the subcritical water process and the supercritical water process in the same treatment 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 treatment tank 1. The temperature inside the treatment tank 1 may be detected by, for example, a temperature sensor. For example, based on the detected value of 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 treatment tank 1 is maintained and the subcritical state or supercritical state of the water continues.

[0040] For example, when nitrogen is supplied by the supply unit 7, the heating control unit 11b may control the heating unit 6 so that the water becomes subcritical. 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. For example, when oxygen is supplied by the supply unit 7, the heating control unit 11b may control the heating unit 6 so that the water becomes supercritical. This series of controls of the heating unit 6 may be automatically executed by the heating control unit 11b. Alternatively, the control of the heating unit 6 may be executed by manual operation of the operator.

[0041] The supply unit 7 supplies gas toward the inside of the treatment tank 1. The supply unit 7 supplies nitrogen as the gas and also supplies oxygen instead of nitrogen. The supply unit 7 is configured to be able to switch the gas to be supplied from nitrogen to oxygen. The supply unit 7 may include a nozzle, a heater, an on-off valve 14a, a switching valve 14b, a nitrogen generator 15a, an oxygen generator 15b, etc. The nozzle of the supply unit 7 is disposed inside the treatment tank 1. In the supply of gas, nitrogen or oxygen is supplied from the same nozzle. The mode of gas supply of the supply unit 7 is controlled by, for example, the supply control unit 11c.

[0042] The nitrogen generator 15a and the oxygen generator 15b are respectively disposed outside the treatment tank 1. The nitrogen generator 15a and the oxygen generator 15b are connected to the nozzle of the supply unit 7 by a pipe 16. A gas containing nitrogen is supplied from the external nitrogen generator 15a into the treatment tank 1 through the nozzle. A gas containing oxygen is supplied from the external oxygen generator 15b into the treatment tank 1 through the nozzle.

[0043] An on-off valve 14a and a switching valve 14b are respectively disposed in the pipe 16. The on-off valve 14a is fixed outside the treatment tank 1. When the on-off valve 14a is in the open state, it enables the supply of gas into the treatment tank 1. When the on-off valve 14a is in the closed state, it shuts off the gas supply and seals the treatment tank 1. The switching valve 14b is disposed at the position where the pipe 16 branches. The nitrogen generator 15a and the oxygen generator 15b are respectively connected to the branched ends of the pipe 16. 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 / closing control of the on-off valve 14a and the switching control of the switching valve 14b are respectively controlled by, for example, 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 so as to supply nitrogen to the treatment tank 1 in the subcritical water process. The supply control unit 11c controls the on-off valve 14a and the switching valve 14b of the supply unit 7 so as to supply oxygen to the treatment tank 1 in the supercritical water process. This series of controls of the supply unit 7 may be automatically executed by the supply control unit 11c. Alternatively, instead of this, the control of the supply unit 7 may be executed by the manual operation of the operator.

[0045] The exhaust section 8 communicates between the outside and the inside of the treatment tank 1 and enables the discharge of the gas inside the treatment tank 1. The exhaust section 8 may be configured as an opening / closing valve, for example. The exhaust section 8 is fixed to the outside of the treatment tank 1. When in the open state, the exhaust section 8 enables the discharge of the gas inside the treatment tank 1. When in the closed state, the exhaust section 8 shuts off the discharge of the gas and seals the treatment tank 1. The opening / closing control of the exhaust section 8 is controlled by the supply control section 11c, for example.

[0046] When shifting from the subcritical water process to the supercritical water process, the supply control section 11c controls the exhaust section 8 so as to discharge the nitrogen sealed in the treatment tank 1 and supply oxygen in place of the nitrogen. This series of controls of the exhaust section 8 may be automatically executed by the supply control section 11c. Alternatively, instead of this, the control of the exhaust section 8 may be executed by the manual operation of the operator.

[0047] During each of the subcritical water process and the supercritical water process, when the water is heated by the heating section 6, the rocking control section 11a controls the treatment tank 1 to rock (see FIG. 5). More specifically, the rocking control section 11a may control, for example, an actuator for rocking the treatment tank 1 clockwise or counterclockwise around the support shaft 1b as the rotation center.

[0048] In the subcritical water process, while the treatment tank 1 is rocking, the heating section 6 heats the water to be in the subcritical state. In the supercritical water process, while the treatment tank 1 is rocking, the heating section 6 heats the water to be in the supercritical state. That is, while the rocking control section 11a rocks the treatment tank 1, the heating control section 11b heats the water. In these cases, the rocking control section 11a may control the rocking of the treatment tank 1 so that the rocking direction continuously switches clockwise and counterclockwise around the support shaft 1b as the rotation center.

[0049] When water is received by the input section 4, the processing tank 1 is rocked so that the input section 4 is directed obliquely upward to the front (see FIG. 4). Further, when the processed contents are discharged by the take-out section 5, the processing tank 1 is rocked so that the take-out section 5 is directed obliquely downward to the front (see FIG. 6). The water may be input into the processing tank 1 and the processed contents may be taken out from the processing tank 1 while maintaining the processing tank 1 in an inclined state. A series of operations of water input and taking out of the processed contents may be performed by manual operation of an operator. Alternatively, this operation may be automatically performed by the rocking control section 11a. In these cases, the rocking control section 11a may control the rocking of the processing tank 1 so as to rock in either the clockwise or counterclockwise direction with the support shaft 1b as the rotation center.

[0050] With reference to the flowchart shown in FIG. 3, the actual operation of the organic waste treatment apparatus 100 will be described. First, when the subcritical water process (S1 to S17) is started, at step S1, the power supply of the organic waste treatment apparatus 100 is turned on. Next, at step S2, the operation preparation switch is turned ON, enabling various controls and operations. Next, at step S3, the processing tank 1 that has been maintained horizontally is rocked so that the input section 4 is directed obliquely upward to the front. Next, at step S4, while maintaining the processing tank 1 in an inclined state and keeping the lid 1c open, water is input from the input section 4 into the processing tank 1. Next, at step S5, while maintaining the processing tank 1 in an inclined state and keeping the lid 1c open, organic waste is input from the input section 4 into the processing tank 1.

[0051] As shown in FIG. 4, water is poured 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 so that a specified amount of water can be poured in, it is not necessary to measure the amount of water in advance. In other words, a specified amount of water can be accurately and easily poured into the treatment tank 1. The specified amount of water may be determined based on the following findings. For example, when water at normal temperature and pressure undergoes a phase transition to supercritical water, its density becomes less than 23% and its volume becomes 4.37 times or more. Therefore, when water is poured into the treatment tank 1, the amount of water that does not become excessive can be calculated and used as the specified amount. Following the pouring of water, organic waste is poured in. At this time, although water overflows according to the volume of the poured organic waste, since the moisture contained in the organic waste can also be utilized, a shortage of water in the treatment is 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, allows the switching valve 14b to supply nitrogen from the nitrogen generator 15a, and opens the on-off valve of the exhaust unit 8. Thereby, the air inside the treatment tank 1 is replaced with nitrogen. After the replacement of nitrogen is completed, the supply control unit 11c closes the on-off valve 14a and closes the on-off valve of the exhaust unit 8. Thereby, 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 the operation of rocking the treatment tank 1 and heating by the heating unit 6 is prepared. Next, in step S9, the inclined treatment tank 1 is rocked and maintained in a horizontal position. Next, in step S10, the heating unit 6 heats the water so that it becomes in a subcritical state. Next, in step S11, based on the detection value of the sensor or the like, it is confirmed that the water is in a subcritical state. The heating by the heating unit 6 is maintained until the treatment with subcritical water is completed.

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

[0055] As shown in FIG. 5, the treatment tank 1 rocks with respect to the horizontal installation surface G around the support shaft 1b as the rotation center. More specifically, the rocking control unit 11a continuously switches the rocking direction of the treatment tank 1 clockwise and counterclockwise around the support shaft 1b as the rotation center. As a result, inside the treatment tank 1, the organic waste and the subcritical water are agitated with each other and come into contact evenly. Therefore, the hydrolysis and destruction of the organic waste are promoted.

[0056] Furthermore, by heating the treatment tank 1 while it is rocked, the temperature inside the treatment tank 1 can be balanced as a whole, and in subcritical water, a sloshing impact load can be generated. Therefore, the decomposition and destruction of the organic waste can be further promoted. From the above, the effect of hydrolyzing the organic waste and the efficiency of subdividing the organic waste can be improved.

[0057] Next, in step S13, the treatment of the organic waste with subcritical water is completed, and the temperature inside the treatment tank 1 is lowered. The treatment time of the organic waste varies depending on the type of organic waste. For this reason, the rocking and heating control of the treatment tank 1 are continued until the preset time according to the type of organic waste is reached.

[0058] Next, in step S14, the treatment tank 1 is cooled. The treatment tank 1 is maintained in the horizontal position, and the treatment tank 1 is cooled until it is confirmed based on the detected value of the sensor or the like that the temperature and pressure inside the treatment tank 1 become safe values. Next, in step S15, it is confirmed that the temperature and pressure have become safe values, and in step S16, with the treatment tank 1 continuously maintained in the horizontal position, in step S17, the subcritical water process is completed. 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] When the supercritical water process (S18 to S28) is started after the subcritical water process (S1 to S17), 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 switching valve 14b to supply oxygen from the oxygen generator 15b, 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 replacement of oxygen is completed, the supply control unit 11c closes the on-off valve 14a and closes the on-off valve of the exhaust unit 8. Thereby, the organic waste, water, and oxygen are sealed inside the treatment tank 1.

[0060] Next, in step S19, the start switch is turned ON, and the operation of rocking the treatment tank 1 and heating by the heating unit 6 is prepared. Next, in step S20, the tilted treatment tank 1 is rocked and maintained in a horizontal position. Next, in step S21, the heating unit 6 heats the water so that it becomes supercritical. Next, in step S22, based on the detected value of the sensor or the like, it is confirmed that the water has become supercritical. The heating by the heating unit 6 is maintained until the treatment with supercritical water is completed.

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

[0062] According to the heating control unit 11b, the degree of heating can be controlled so that the temperature and pressure inside the treatment tank 1 become 375 °C or higher and 22.1 MPa or higher, and the state of water can be shifted to the supercritical region. Further, when heat generation based on the oxidation reaction by supercritical water is observed, the heating by the heating unit 6 may be suppressed. Furthermore, when the pressure inside the treatment tank 1 becomes equal to or higher than a preset pressure, the opening / closing valve of the exhaust unit 8 may be opened to discharge gas from the treatment tank 1 to adjust the pressure.

[0063] As shown in FIG. 5, the treatment tank 1 swings with respect to the horizontal installation surface G around the support shaft 1b as the rotation center. More specifically, the swing control unit 11a continuously switches the swing direction of the treatment tank 1 clockwise and counterclockwise around the support shaft 1b. Thereby, inside the treatment tank 1, the intermediate product derived from the organic waste and the supercritical water are agitated with each other and come into uniform contact. Therefore, the oxidative decomposition and destruction of the intermediate product derived from the organic waste are promoted.

[0064] Furthermore, by heating the treatment tank 1 while it is being swung, the temperature inside the treatment tank 1 can be balanced as a whole, and in super-subcritical water, a sloshing flow can be generated. Therefore, the decomposition and destruction of the intermediate product derived from the organic waste can be further promoted. From the above, the effect of oxidative decomposition of the intermediate product and the efficiency of subdivision of the intermediate product can be improved.

[0065] In addition, since the subcritical water process is executed before the supercritical water process, the treatment time required for oxidative decomposition in the supercritical water process can be shortened. For this reason, 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 decreased. It is preferable that the oxidative decomposition of the organic waste continues until the oxidation reaction of the organic waste to be treated is completed. For this reason, while the intermediate product generated in the subcritical water step is being oxidized and decomposed until the oxidation reaction is completed, the rocking and heating control of the treatment tank 1 are continued. Also, the rocking and heating control of the treatment tank 1 may be continued until the oxygen inside the treatment tank 1 is completely consumed according to the oxidation reaction.

[0067] Next, in step S25, the treatment tank 1 is cooled. The treatment tank 1 is maintained in a horizontal position and cooled until it can be confirmed that the temperature and pressure inside the treatment tank 1 reach safe values based on the detected values of the sensors and the like. Next, in step S26, it is confirmed that the temperature and pressure have reached safe values, and in step S27, the treatment tank 1 that has been maintained horizontally is rocked so that the take-out part 5 is directed obliquely downward forward.

[0068] As shown in FIG. 6, while maintaining the treatment tank 1 in an inclined state, the lid 1c is opened, and the treated contents are discharged from the take-out part 5 to the outside of the treatment tank 1. The treated contents discharged from the take-out part 5 are guided by the slope 17 downward outside the organic waste treatment apparatus 100. The treated contents are the contents remaining in the treatment tank 1 after the oxidative decomposition is completed in the supercritical water step. Most of the treated contents are carbon dioxide, water, and nitrogen. Trace amounts of sulfates and phosphates may be contained in the treated contents. Since the treated contents have undergone oxidative decomposition, they are in a sterile and virus-free state, and the odor has also been decomposed. Therefore, it can be said that the treatment of this embodiment is also suitable for the treatment of medical waste and nursing care waste. Also, it is possible to prevent the generation of a bad odor.

[0069] Next, in step S28, the supercritical water step is completed. Then, a series of treatments of the subcritical water step and the supercritical water step are completed, and the operation of the organic waste treatment apparatus 100 is stopped.

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

[0071] According to this, by treating organic waste with subcritical water, hydrolysis and destruction of the organic waste can be achieved. 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 with the case where physical pulverization or the like is performed as a pretreatment before the supercritical water process, an increase in the size of the equipment and energy consumption can be suppressed. In addition, treatment with subcritical water is possible under a nitrogen atmosphere. Therefore, corrosion of the treatment tank 1 and the like can be suppressed. From the above, organic waste can be appropriately treated.

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

[0073] According to this, the oxidative decomposition of organic waste can be achieved by treating the organic waste with supercritical water. By performing the treatment of the organic waste with supercritical water, for example, after a subcritical water step, the organic waste can be easily oxidatively decomposed. Also, the treatment with supercritical water can be carried out under an oxygen atmosphere. By the treatment with subcritical water, the organic waste has become an intermediate product that is easily oxidatively decomposed. Furthermore, since the oxygen in the treatment tank 1 can be used, the oxidative decomposition in the supercritical water step can be made closer to being complete.

[0074] In the organic waste treatment apparatus 100, the supply unit 7 is configured to be able to switch the gas to be supplied from the nitrogen to the oxygen, and the heating unit 6 switches from heating the water to a subcritical state to heating the water to a supercritical state so as to correspond to the switching from the nitrogen to the oxygen in the supply unit 7.

[0075] According to this, it becomes possible to switch from the subcritical water step to the supercritical water step using one treatment tank 1. That is, it is not necessary to install a plurality of treatment tanks corresponding to each step. For this reason, the equipment can be simplified. Also, since the subcritical water step is performed before the supercritical water step, the treatment time required for the oxidative decomposition in the supercritical water step can be shortened. For this reason, the corrosion of the container of the treatment tank 1 in the supercritical water step can be suppressed.

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

[0077] According to this, in the subcritical water process, inside the treatment tank 1, the organic waste and the subcritical water are agitated with each other and come into uniform contact. Therefore, the hydrolysis and destruction of the organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being rocked, the temperature inside the treatment tank 1 can be balanced as a whole, and in subcritical water, a sloshing impact load can be generated. Therefore, the decomposition and destruction of the organic waste can be further promoted. From the above, the effect of the hydrolysis of the organic waste and the efficiency of the subdivision of the organic waste can be improved. Also, in the supercritical water process, inside the treatment tank 1, the intermediate product derived from the organic waste and the supercritical water are agitated with each other and come into uniform contact. Therefore, the oxidative decomposition and destruction of the intermediate product derived from the organic waste are promoted. Furthermore, by heating the treatment tank 1 while it is being rocked, the temperature inside the treatment tank 1 can be balanced as a whole, and in super-subcritical water, a slashing flow can be generated. Therefore, the decomposition and destruction of the intermediate product derived from the organic waste can be further promoted. From the above, the effect of the oxidative decomposition of the intermediate product and the efficiency of the subdivision of the intermediate product can be improved.

[0078] The organic waste treatment apparatus 100 further includes a take-out part 5 that communicates the inside and outside of the treatment tank 1 and enables the discharged treated content to be discharged to the outside. The treatment tank 1 is configured to be a cylindrical container with one end open, and the opening is configured to be the input part 4 and the take-out part 5. When the water is received by the input part 4 and / or when the treated content is discharged by the take-out part 5, it is configured to be swingable with respect to the installation surface G.

[0079] According to this, when water is introduced from the input part 4, the treatment tank 1 can be inclined so that a specified amount of water can be introduced. For this reason, it is not necessary to measure the amount of water in advance. In other words, a specified amount of water can be accurately and easily introduced into the treatment tank 1. Also, when taking out the treated content from the take-out part 5, the treatment tank 1 can be inclined so that the treated content easily slides down. For this reason, the treated content can be easily taken out.

[0080] The organic waste treatment receives organic waste from the outside and treats the organic waste using a treatment tank 1 configured to be able to treat the organic waste with high-temperature and high-pressure water inside. The organic waste treatment method includes a step of receiving the organic waste and liquid water from the outside in the treatment tank 1, a step of supplying nitrogen toward the inside of the treatment tank 1, a step of sealing the organic waste, the water, and the nitrogen inside the treatment tank 1, and a step of heating the water sealed together with the nitrogen and the organic waste inside the treatment tank 1 so as to be in a subcritical state.

[0081] According to this, the hydrolysis and destruction of organic waste can be achieved by treating the organic waste with subcritical water. 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 with the case where physical pulverization or the like is performed as a pretreatment before the supercritical water process, an increase in the size of the equipment and energy loss can be suppressed. In addition, the treatment with subcritical water is possible under a nitrogen atmosphere. Therefore, corrosion of the treatment tank 1 can be suppressed. From the above, organic waste can be appropriately treated.

[0082] The organic waste treatment method further includes a step of discharging the nitrogen toward the outside of the treatment tank 1 after the step of heating the water so as to be in a subcritical state, a step of supplying oxygen toward the inside of the treatment tank 1, a step of sealing the organic waste, the water, and the oxygen inside the treatment tank 1, and a step of heating the water sealed together with the oxygen and the organic waste inside the treatment tank 1 so as to be in a supercritical state.

[0083] According to this, the oxidative decomposition of organic waste can be achieved by treating the organic waste with supercritical water. By performing the treatment of the organic waste with supercritical water, for example, after the subcritical water step, the organic waste can be easily oxidatively decomposed. Also, the treatment with supercritical water is possible under an oxygen atmosphere. Due to the treatment with subcritical water, the organic waste has become an intermediate product that is easily oxidatively decomposed, and furthermore, since the oxygen in the treatment tank 1 can be used, the oxidative decomposition in the supercritical water step can be made closer to being complete. Also, it becomes possible to switch from the subcritical water step to the supercritical water step using a single treatment tank 1. That is, there is no need to install a plurality of treatment tanks corresponding to each step. For this reason, the equipment can be simplified. Also, since the subcritical water step is being performed before the supercritical water step, the treatment time required for the oxidative decomposition in the supercritical water step can be shortened. For this reason, corrosion of the container of the treatment tank 1 in the supercritical water step can be suppressed.

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

[0085] According to this, in the subcritical water process, inside the treatment tank 1, the organic waste and the subcritical water are agitated with each other and come into uniform 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 balanced as a whole, and in the subcritical state water, a sloshing impact load can be generated. Therefore, the decomposition and destruction of the organic waste can be further promoted. From the above, the effect of the hydrolysis of the organic waste and the efficiency of the subdivision of the organic waste can be improved. Also, in the supercritical water process, inside the treatment tank 1, the intermediate product derived from the organic waste and the supercritical water are agitated with each other and come into uniform contact. Therefore, the oxidative decomposition and destruction of the intermediate product derived from 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 balanced as a whole, and in the super-subcritical state water, a slashing flow can be generated. Therefore, the decomposition and destruction of the intermediate product derived from the organic waste can be further promoted. From the above, the effect of the oxidative decomposition of the intermediate product and the efficiency of the subdivision of the intermediate product can be improved.

Explanation of Signs

[0086] 1... treatment tank, 4... input section, 5... extraction section, 6... heating section, 7... supply section, 8... exhaust section, 11a... oscillation control section, 11b... heating control section, 11c... supply control section

Claims

1. An organic waste treatment apparatus comprising at least a treatment tank configured to receive organic waste from the outside and treat the organic waste with high-temperature, high-pressure water therein, an input section that communicates the outside and the inside of the treatment tank and is capable of receiving the organic waste and liquid water from the outside; A supply unit that supplies a gas toward the inside of the treatment tank; A heating unit installed inside the treatment tank for heating the received water; Equipped with The treatment tank comprises: The container is configured to receive the organic waste, the water, and the gas and maintain a sealed state therein; The material constituting the treatment tank is It is a metal, The supply unit includes: Nitrogen is supplied as the gas; The heating unit includes: 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. 2. The organic waste treatment device according to claim 1, The supply unit includes: The gas to be supplied is configured to be switchable from the nitrogen to oxygen, and when switching is performed, oxygen is supplied as the gas instead of the nitrogen; The heating unit includes: 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, and the heating of the water to the subcritical state is switched to the heating of the water to the supercritical state in response to the switching from the nitrogen to the oxygen in the supply unit. Organic waste treatment equipment.

3. In the organic waste treatment device according to claim 1 or claim 2, The treatment tank comprises: The water heater is configured to be swingable relative to a surface at least when the water is heated by the heating unit. Organic waste treatment equipment.

4. In the organic waste treatment device according to claim 3, A discharge section that communicates the outside and the inside of the treatment tank and enables the treated contents to be discharged to the outside. Further comprising: The treatment tank comprises: The container is configured to be a cylindrical container having an opening at one end, the opening being the input part and the removal part, and is configured to be swingable with respect to the installation surface when the water is received by the input part and / or when the treated content is discharged by the removal part. Organic waste treatment equipment.

5. A method for treating organic waste, comprising the steps of: receiving organic waste from an outside source; and treating the organic waste using a treatment tank configured to treat the organic waste with high-temperature, high-pressure water therein, the method comprising the steps of: The material constituting the treatment tank is Metal 1. A method for treating organic waste, comprising: receiving the organic waste and liquid water from the outside in the treatment tank; supplying nitrogen into the treatment tank; sealing the organic waste, the water, and the nitrogen inside the treatment tank; heating the water sealed in the treatment tank together with the nitrogen and the organic waste so that the water is in a subcritical state; Equipped with Organic waste treatment methods.

6. The organic waste treatment method according to claim 5, The treatment tank comprises: When the water is heated, the heater is configured to be able to swing relative to a mounting surface, The heating step includes: The water is heated while the treatment tank is agitated. Organic waste treatment methods.

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