JP2003340264A - Hydrothermal reactor and hydrothermal reaction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double cylinder type batch hydrothermal reactor having a non-mechanical agitating means. <P>SOLUTION: In the hydrothermal reactor 10, annular heaters 22A-I are arranged vertically and independently on the cylindrical wall of a reaction cartridge 14 in order to heat solids, and the like, in the inside. The heating temperatures of the heaters are controlled independently by a temperature controller 24. By controlling differences among the temperatures of the heaters to be 50-100°C, convection occurs in fluid in the vicinity of the cylindrical wall surface to agitate the inside. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrothermal reactor and a hydrothermal reaction apparatus for treating an object to be treated in a batch manner by a hydrothermal reaction, and more specifically, to generate convection in a reaction cartridge. And a hydrothermal reactor equipped with such a hydrothermal reactor.

[0002]

2. Description of the Related Art At present, attention is being paid to attempts to decompose and detoxify environmental pollutants by utilizing supercritical water reaction, which has a high ability to oxidize and decompose organic substances. That is, by a supercritical water reaction utilizing high reactivity of supercritical water, harmful and hardly decomposable organic substances, such as PCB (polychlorinated biphenyl) and dioxin, which have been difficult to decompose by conventional techniques.
Decomposes organic chlorine solvents, carbon dioxide, nitrogen, water,
It is an attempt to convert into harmless products such as inorganic salts. As one of the attempts, recently, supercritical water reaction has been performed even in the treatment of various liquid and solid wastes such as sewage sludge, municipal waste, industrial wastewater, etc., containing such harmful organic compounds. Is being used.

By the way, when treating a contaminated solid substance in a continuous type supercritical water reactor, it is necessary to pulverize the solid substance to form a slurry, but it is technically pulverized depending on the solid substance. There are some difficult ones. Further, even if the solid matter can be crushed into a slurry, there are various problems peculiar to the slurry such as precipitation. Therefore, it is necessary to put the solid matter to be treated into the reactor as it is without making it into a slurry, and to perform supercritical water treatment in a batch system. In addition, the batch reactor is easy to suppress the corrosion of the reactor due to the supercritical water reaction, and since the reaction vessel is opened for each batch, it is easy to discharge the inorganic salt precipitated due to neutralization. It also has the excellent advantage that

The construction of a conventional batch type supercritical water reactor will be described with reference to FIG. FIG. 3 is a flow sheet showing the structure of a conventional batch type supercritical water reactor. The conventional batch type supercritical water reaction apparatus 30 is an apparatus for processing an organic solid substance to be treated by a supercritical water reaction in a batch type, and as shown in FIG. The reactor 32 is provided with a water feeding means 34 for feeding supercritical water, and an air compressor 36 for feeding air into the reactor 32 as an oxidant.

The reactor 32 comprises a lid 32a and a reactor body 3
2b, which is an autoclave type reactor that is openable and closable and that receives a solid substance to be treated therein and performs supercritical water treatment, supports the solid substance to be treated in a container, Eye plate-shaped support plate 38 for passing supercritical water
Have. The lid 32a includes a lid 32a and a reactor body 32.
Reactor body 32b by bolting flanges of b together
Are linked to.

The water supply means 34 is a water tank 4 containing water.
0, a water feed pump 42 for feeding water stored in the water tank 40, water fed by the water feed pump 42, and combined water of circulating water fed by a booster pump 58 described later flowed out from the reactor 32. A heat exchanger 4 that heats the combined water by exchanging heat with the treatment fluid and cools the fluid.
4 and a heating furnace 46 for raising the combined water to a predetermined temperature necessary for the supercritical water reaction, that is, the supercritical water temperature, and supercritical water is sent to the reactor 32 via a water supply pipe 48. The air compressor 36 is a variable flow rate compressor capable of changing the discharge flow rate by adjusting the pressure and the flow rate, and the reactor 32 is provided via the air supply pipe 50 and the water supply pipe 48.
Introduce air as an oxidant into the.

The reaction product outflow system includes an outflow pipe 52 for outflowing the processing fluid from the reactor 32, a gas-liquid separator 54 provided downstream of the heat exchanger 44, and a pressure of the gas-liquid separator 54.
Therefore, a pressure control device 56 that indirectly controls the pressure of the reactor 32 and a booster pump 58 that circulates the water component obtained by gas-liquid separation are provided.

The gas-liquid separator 54 gas-liquid separates the processing fluid to separate it into a gas component and a water component. The gas component is discharged to the atmosphere through a gas discharge pipe 60 connected to the top of the gas-liquid separator 54, or the gas is contained in the gas in a subsequent treatment step, for example, CO gas at a concentration higher than an allowable amount. If
It is sent to the CO converter. The pressure control device 56 that controls the pressure of the gas-liquid separator 54 uses the pressure control valve 64 based on the pressure measurement value of the pressure gauge 62 provided on the gas discharge pipe 60.
The valve opening is adjusted to control the pressure of the gas-liquid separator 54, and thus the pressure in the reactor 32, to a predetermined pressure. Further, a CO concentration meter 66 is provided in the gas discharge pipe 60 in order to measure the CO gas concentration in the gas component. The water component in the gas-liquid separator 54 is boosted by the booster pump 58 and is supplied as circulating water via the water pipe 68 to the water pipe 48.
Sent to.

When operating the batch type supercritical water reactor 30, first, the reactor 32 is opened, the solid substance to be treated for one batch operation is placed on the support 38, and the reactor 32 is closed. . Next, the water supply pump 42 is started to send water from the water tank 40 to the heating furnace 46 via the water supply pipe 48 via the heat exchanger 44 to heat and supply it to the reactor 32. The treatment fluid (water at the beginning of operation) flowing out of the reactor 32 passes through the heat exchanger 44 and enters the gas-liquid separator 54,
The pressure is increased by the booster pump 58, enters the water supply pipe 48 via the water supply pipe 68, merges with the water from the water supply pump 42, is heated in the heat exchanger 44 and the heating furnace 46, and then enters the reactor 32, and gradually. The circulation is started. booster·
As the circulating water amount by the pump 58 increases, the water feeding amount by the water feeding pump 42 is decreased. Eventually, the water supply pump 42 replenishes only the amount of water that accompanies the gas from the gas discharge pipe 60 and diffuses out of the system.

When the temperature measured by the thermometer 70 provided in the outflow pipe 52 reaches about 370 ° C., the air compressor 36
Is started to feed air together with water into the reactor 32 via the air supply pipe 50 and the water supply pipe 48. Air compressor 36
The amount of air supplied from is decreased when the temperature rises quickly while watching the temperature of the thermometer 70, and increases when the temperature rises slowly.
When the conditions in the reactor 32 reach the predetermined conditions for the supercritical water reaction, the supercritical water reaction is started and gradually progresses. The processing fluid flowing out of the outflow pipe 52 with the progress of the supercritical water reaction comes to accompany gas components such as CO ₂ gas and CO gas, is separated by the gas-liquid separator 54, and is released from the gas discharge pipe 6.
Released through 0. At the same time, the pressure control device 56 is operated to control the pressure in the gas-liquid separator 54, and thus the pressure in the reactor 32, to a predetermined pressure.

When the CO gas concentration measured by the CO gas concentration meter 66 becomes zero and the oxygen concentration becomes a value not different from the concentration in the atmosphere, it can be determined that the supercritical water reaction in the reactor 32 has reached the end point. When the supercritical water reaction reaches the end point,
The pressure of the whole batch type supercritical water reactor 30 is reduced, and then the reactor 32 is opened.

[0012]

By the way, there are two problems in the conventional batch type reactor when treating the contaminated solid matter in a batch type by the above-mentioned supercritical water reactor.
The first problem is that the cost of the reactor increases because the reaction conditions are high pressure and high temperature and the reaction zone is a strong corrosive atmosphere. The second problem is that since the reaction target is a solid substance, the concentration of the treated product, the reaction rate, etc. are different between the region near the solid substance and the region separated from the solid substance. It is difficult to make uniform, and for this reason,
It is difficult to improve the reaction efficiency.

The first problem was ameliorated by constructing the following double cylinder type reactor. That is, the reactor body and the lid constituting the reactor are each formed as a pressure vessel for holding the pressure of the supercritical water reaction, and a reaction cartridge having the inside as a supercritical water reaction zone is provided in the reactor, The reactor is configured as a double cylinder type reactor, and pressure balancing air is sent between the reactor and the reaction cartridge to maintain the pressure inside the reactor and the pressure inside the reaction cartridge at a predetermined pressure difference. . This reduces the required thickness of the reaction cartridge made of corrosion-resistant and expensive metal material,
Increase the economics of the reactor. That is, a double cylinder type by function of a reactor body and a lid that are pressure resistant containers that are not exposed to a corrosive atmosphere, a corrosion resistant container that is provided in the pressure resistant container, and a reaction cartridge that is a non-pressure resistant container. By configuring the reactor as a container, the cost of the reactor is reduced.

However, the second problem is difficult to solve for the following reasons. In order to make the reaction conditions in the reactor uniform and uniform in order to increase the reaction efficiency of the supercritical water reaction, it is necessary to improve the mixing state in the reactor. To improve the mixed state, stirring is generally performed using a stirrer. However, in order to install the stirrer in the reactor,
It is necessary to seal the rotating spindle through the pressure vessel wall. If, for example, a gland type is adopted as the seal, the heat resistance of the gland becomes a problem, and it is necessary to cool the seal part to a temperature (usually about 100 ° C.) at which the sealing property can be secured. This requires a large-scale sealing mechanism in order to provide the stirrer in the high-pressure reactor, which is not practical.

In the above description, the reactor used in the supercritical water reaction apparatus has been described as an example, but this is not a problem limited to the reactor used in the supercritical water reaction apparatus. This is a problem applicable to all reactors for hydrothermal reactions including. Hydrothermal reaction means high temperature and high pressure water, for example, a temperature of 180
It refers to a reaction using hot water at a temperature of ℃ or more and a pressure of 1 MPa or more.

Therefore, an object of the present invention is to provide a double cylinder type batch hydrothermal reactor equipped with means for stirring the inside of the reaction cartridge by means other than mechanical stirring means.

[0017]

The present inventor has paid attention to the relationship between the density and the temperature of high-temperature high-pressure water in the course of research in which the inside of the reaction cartridge is stirred by means other than mechanical stirring means.
As shown in FIG. 4, the densities of the high-temperature high-pressure water at a pressure of 23.5 MPa were 0.9 g / cc at 200 ° C. and 0.1 g / cc at 300 ° C.
It is 75 g / cc. According to the experiment, the density difference is 0.15
If it is at least g / cc, a sufficiently high speed convection will occur.
Therefore, the temperature difference of the fluid in the reaction cartridge is 100 ° C.
With the above, convection can be generated and mixed in the reaction cartridge. Therefore, the present inventor has provided a ring-shaped internal heater along the outer periphery of the reaction cartridge, and divided the internal heater into a plurality of stages in the vertical direction of the reaction cartridge so that the heating temperature of each internal heater varies in height. It was conceived that a convection is generated in the reaction cartridge by providing a temperature difference between the high temperature and high pressure water in the reaction cartridge. Then, the validity of this idea was confirmed by experiments, and the present invention was invented.

In order to achieve the above object, a hydrothermal reactor according to the present invention is provided in a vertical reactor main body formed as a pressure vessel for holding a hydrothermal reaction pressure, and provided in the reactor main body. And a vertical reaction cartridge having a hydrothermal reaction area inside, and a pressure balancing fluid is fed between the reactor main body and the reaction cartridge, so that the pressure inside the reactor main body and the pressure inside the reaction cartridge In a hydrothermal reactor configured as a double-cylinder pressure balance type reactor for maintaining a predetermined pressure difference, the batch type treatment of the object to be treated by hydrothermal reaction,
Equipped with a plurality of ring-shaped internal heaters which are independent from each other in the vertical direction of the reaction cartridge and are provided along the outer periphery of the reaction cartridge, and a temperature control device which respectively controls the heating temperatures of the internal heaters of the multiple stages. The temperature control device controls the heating temperatures of the plurality of stages of internal heaters to different predetermined heating temperatures in the vertical direction of the reaction cartridge to generate convection in the reaction cartridge.

As the internal heater of the present invention, a sheath heater, a pipe heater, an induction heater, a nichrome wire heating heater, etc. can be used. Also, as an internal heater,
A tubular heater in which a pipe through which supercritical water, subcritical water, high-temperature steam, a heat medium and the like are circulated is wound around the outer periphery of the reaction cartridge may be used. In the present invention, since the reaction cartridge having a small heat capacity is heated by the internal heater, it is easy to control the temperature of water in the reaction cartridge, that is, the density of water. Suitably, the predetermined heating temperature is different by 50 ° C. or more, preferably 100 ° C. or more in the vertical direction of the reaction cartridge. The hydrothermal reactor according to the present invention can be applied regardless of whether the object to be treated in the hydrothermal reactor is solid or liquid, and there is no limitation on the property of the object to be treated.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described specifically and in detail with reference to the accompanying drawings by way of example embodiments. Embodiment Example of Hydrothermal Reactor This embodiment example is an example of an embodiment of the hydrothermal reactor according to the present invention, and FIG. 1 is a cross-sectional view showing the configuration of the hydrothermal reactor of the present embodiment example. . The hydrothermal reactor 10 of this embodiment example is
1. A batch type pressure balance type reactor, as shown in FIG. 1, provided as a vertical reactor main body 12 formed as a pressure vessel for holding the pressure of hydrothermal reaction, and provided as an inner cylinder in the reactor main body 12. And a vertical reaction cartridge 14 having a hydrothermal reaction zone inside.

The reactor body 12 is a lid 12a that can be opened and closed.
Thus, for example, the lid 12a and the flange of the reactor main body 12 are bolted to each other, or closed by a clamp method. The reaction cartridge 14 is a closed container having a height of 1,160 cm in which an inside of a reaction object for a hydrothermal reaction containing a substance to be treated, for example, a solid substance, is housed, and as shown in FIG. It is composed of a tubular body 16 that is upright from the bottom portion 12b and has an open upper portion, and a tubular lid 18 that seals the upper opening of the tubular body 16, and the tubular body 16 and the tubular lid 18 are joined by a flange 20 via a packing 20 or It is connected so that it can be opened and closed freely by clamping.

Although not shown, an inlet pipe for a mixed fluid of water and air and an outlet pipe for a processing fluid are provided at the bottom portion 1 of the reactor body 12.
2b to communicate with the inside of the reaction cartridge 14, and a pressure balance air supply pipe and discharge pipe are provided in the reactor body 1
The bottom 12b of the second reactor 12 penetrates the bottom 12b of the second reactor 12 and communicates with the annular portion between the reactor body 12 and the reaction cartridge 14.

The cylindrical wall of the cylindrical body 16 has nine stages of ring-shaped heating bodies 22A to 22A serving as internal heaters for heating solid matter, water, air and the like contained in the reaction cartridge 14.
I are provided in the vertical direction of the cylindrical body 16 independently of each other. The heating temperature of each of the nine-stage ring-shaped heating bodies 22 is
Each is independently controlled by a temperature control device provided outside the hydrothermal reactor 10. Here, the heating temperature is the temperature of the cylindrical wall of the cylindrical body 16 facing the heating bodies 22A to 22I, respectively.

In the present embodiment, the reaction cartridge 14 is controlled by the temperature controller to control the reaction cartridge 14 to the first predetermined position by the heating members 22A to D and 22G to I other than the heating members 22E and 22F provided under the reaction cartridge 14, for example. While heating at the heating temperature, the reaction cartridge 14 is heated by the heating elements 22E and F at the second predetermined heating temperature higher than the first predetermined heating temperature, for example, the second predetermined temperature 100 ° C. to 150 ° C. higher than the first predetermined temperature. Is heated and maintained at the second predetermined temperature for a predetermined time.

The fluid in the vicinity of the wall surface of the reaction cartridge 14 heated by the heating elements 22E and F is heated and its density is lowered. The fluid with reduced density is
Ascends along the wall surface and flows into the central portion of the reaction cartridge 14 at the upper portion. Since the temperature of the central portion of the reaction cartridge 14 is low, the low-density fluid that has flowed into the central portion is cooled, becomes high in density, and descends. In this way, by heating the reaction cartridge 14 with the heating elements 22E and F at a heating temperature higher than the heating temperature of the other heating elements 22A to 22D to 22G to I, convection occurs inside the reaction cartridge 14, and Stirring and mixing occur.

Further, instead of heating the reaction cartridge 14 at different heating temperatures depending on the heating elements 22A to I, heating for turning on or off one or more of the heating elements 22A to I depending on the elapse of the heating time. By forming a program and controlling the heating elements 22A to 22I according to the heating program, it is possible to cause a difference in the density of the fluid in the reaction cartridge 14 and to cause stirring and mixing by convection.

Example of Embodiment of Hydrothermal Reactor A hydrothermal reactor 28 using the reactor 10 described above is shown in FIG.
As shown in FIG. 5, the confluence pipe of the water supply pipe 48 and the air supply pipe 50 of the conventional batch type supercritical water reactor 30 and the outflow pipe 5
2 is connected to the bottom of the reactor 10 respectively, and the pressure balancing air is basically supplied to the bottom of the reactor 10 and then discharged from the bottom, and a temperature control device 24 is basically provided. Is the same as the configuration of the conventional batch type supercritical water reactor 30 shown in FIG. However, when supplying the pressure balancing air to the reactor 10, the supply pressure of the pressure balancing air should be less than the pressure inside the reactor 10 in order to make the reactor 10 function as a double cylinder type reactor. 1 to 0.3
Maintain high only MPa. In FIG. 2, a dotted line 25
Is a temperature control line for the heating elements 22A to 22I.

The water is heated by the heating furnace 46 only when the operation of the hydrothermal reactor 28 is started, and when the water reaches the first predetermined temperature, the heating by the heating furnace 46 is stopped,
The reaction cartridge 14 may be heated by the heating elements 22A to 22I as described above. Alternatively, the heating furnace 46
It is also possible to omit the above and heat only the heating element 22 from the start of the operation.

[0029]

According to the present invention, the temperature control device controls the heating temperatures of the internal heaters of a plurality of stages to predetermined heating temperatures different from each other in the vertical direction of the reaction cartridge so that the temperature distribution in the vertical direction of the reaction cartridge, Therefore, a density distribution of water is created in the reaction cartridge, which causes convection in the reaction cartridge. As a result, a batch-type hydrothermal reactor with high reaction efficiency can be realized without providing a large-scale stirring mechanism.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a hydrothermal reactor according to an embodiment.

FIG. 2 is a flow sheet showing a configuration of a batch-type hydrothermal reaction device according to an embodiment.

FIG. 3 is a flow sheet showing the configuration of a conventional batch type supercritical water reactor.

FIG. 4 is a graph showing the relationship between water temperature and density.

[Explanation of symbols]

10 Hydrothermal reactor of example embodiment 12 Reactor body 14 Reaction cartridge 16 cylinder 18 tube lid 20 packing 22 heating body 24 Temperature control device 28 Batch Type Hydrothermal Reactor of Embodiment 30 Conventional batch type supercritical water reactor 32 batch reactor 34 Water supply means 36 air compressor 38th plate-shaped support plate 40 water tank 42 Water pump 44 heat exchanger 46 heating furnace 48 water pipe 50 Air supply pipe 52 Outflow pipe 54 gas-liquid separator 56 Pressure control device 58 Booster Pump 60 gas discharge pipe 62 pressure gauge 64 Pressure control valve 66 CO concentration meter 68 water pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinya Ikukata             Olga 1-2-8 Shinsuna, Koto-ku, Tokyo             Within the corporation (72) Inventor Toru Sonobe             2-4-43 Ozenji Higashi, Aso-ku, Kawasaki-shi

Claims (4)

[Claims] 1. A vertical reactor main body formed as a pressure vessel for holding a hydrothermal reaction pressure, and a vertical reaction cartridge provided in the reactor main body and having a hydrothermal reaction zone inside. Then, a pressure balancing fluid is sent between the reactor body and the reaction cartridge to maintain the pressure inside the reactor body and the pressure inside the reaction cartridge at a predetermined pressure difference. In a hydrothermal reactor that is configured as a vessel and treats objects to be treated in a batch manner by hydrothermal reaction, a plurality of ring-shaped stages that are independent of each other in the vertical direction of the reaction cartridge and are provided along the outer periphery of the reaction cartridge. Equipped with an internal heater and a temperature control device for controlling the heating temperature of each of the plural stages of internal heaters, and the heating temperature of the plural stages of internal heaters are different from each other in the vertical direction of the reaction cartridge by the temperature control device. Hydrothermal reactor, characterized in that cause convection to a constant heating temperature controlled to within the reaction cartridge. 2. The hydrothermal reactor according to claim 1, wherein the predetermined heating temperature differs by 50 ° C. or more in the vertical direction of the reaction cartridge. 3. By controlling the ON time / OFF time of one or more internal heaters in the lower stage of the internal heaters to be different from those of the other internal heaters, or by one or more of the lower heaters. The heating temperature of the internal heater of the stage is changed with time differently from the other internal heaters.
The hydrothermal reactor described in. 4. A batch type hydrothermal reaction device comprising the hydrothermal reactor according to claim 1. Description: