JP2001170664A - Supercritical water treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supercritical water treating device which stably executes the treatment of a liquid to be treated which contains high-concentration organic compounds, such as PCB, for a long period and can make treatment so as to satisfy an effluent standard below 3 ppm. SOLUTION: A reactor 12 of this supercritical water treating device successively has an internal cooler 14 for cooling reaction products and a neutralizing mixer 16 for neutralizing the reaction products by injecting and mixing an aqueous alkaline solution into the reaction products, within an outer cylindrical body 12b downstream of a reaction cartridge 12b. The internal cooler is provided with a cooling water supply system and the neutralizing mixer with an aqueous alkaline solution supply system. The internal cooler comprises a titanium coiled pipe 14a and a stainless steel hermetic vessel 14b for housing the coiled pipe 14a. The cooling water is controlled in the inlet temperature to the internal cooler at 380 deg.C and flows into the lower part of the vessel, thereby cooling the reaction products of 400 deg.C. The neutralizing mixer is a vessel which is formed as a tantalum vessel internally having a static mixer 24 and injects the aqueous alkaline solution into the reaction products cooled in the internal cooler and mixes and neutralizes the reaction product. An aqueous NaOH solution controlled to 250 deg.C is injected into the reaction products.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercritical water treatment apparatus for treating an organic chlorine compound such as PCB, and more particularly, to a PC for producing high-concentration hydrochloric acid during supercritical water treatment.
The present invention relates to a supercritical water treatment apparatus capable of stably treating an organic chlorine compound with supercritical water without causing corrosion of the apparatus even if the organic chlorine compound such as B is used.

[0002]

2. Description of the Related Art With increasing awareness of environmental issues,
As one of application fields of a supercritical water treatment apparatus, attention has been paid to decomposition and detoxification of environmental pollutants. A supercritical water treatment device is a harmful hard-to-decompose organic substance, such as PCB (polychlorinated biphenyl), which is difficult to decompose in the prior art by a supercritical water reaction utilizing the properties of a reaction medium of supercritical water. ), A device that decomposes dioxins, organic chlorinated solvents, and the like and converts them into harmless products such as carbon dioxide, water, and inorganic acids.

[0003] Supercritical water refers to water that is in a supercritical state, that is, water that is beyond the critical point of water, and more specifically, has a critical temperature, that is, a temperature of 374.1 ° C or higher, and Of water under a critical pressure of 22.04 MPa or more. Supercritical water has a high ability to dissolve organic substances and can completely dissolve non-polar substances, which are abundant in organic compounds, but has a very low ability to dissolve inorganic substances such as metals and salts. The supercritical water can be mixed with a gas such as oxygen or nitrogen at an arbitrary ratio to form a single phase.

Referring to FIG. 8, a basic configuration of a conventional supercritical water treatment apparatus for treating a liquid to be treated containing an organic chlorine compound by a supercritical water reaction will be described. FIG.
Is a flow sheet showing the configuration of a conventional supercritical water treatment apparatus. Conventionally, the supercritical water treatment apparatus 86 is said to be the most suitable apparatus for oxidative decomposition of organic chlorine compound-based hardly decomposable organic substances in which salts are precipitated during supercritical water treatment. This is a so-called moder process type apparatus that includes a type reactor 87 and sediments and separates salts that precipitate as solids in supercritical water at the lower part of the reaction vessel.

[0005] As shown in FIG. 8, in the upper part of the reactor 87, conditions above the critical point of water, that is, supercritical conditions are maintained, and a supercritical water area 88 for retaining supercritical water is formed.
Reactor 87 via virtual interface 89 with supercritical water area 88
A subcritical water area 90 that is maintained at a temperature lower than the critical temperature of water and retains the subcritical water is formed in a lower part of the water.
An inflow pipe 91 that allows the liquid to be treated and the oxidant to flow into the supercritical water area 88 is connected to an upper portion of the reactor 87. The inflow pipe 91 has a treated liquid line 92 for supplying a treated liquid having an organochlorine compound to be treated by the supercritical water reaction, an air line 93 for supplying air as an oxidizing agent for oxidizing organic substances, and , A supercritical water line 94 for feeding supercritical water or makeup water for generating supercritical water.

A neutralizer line 95 for supplying an alkali neutralizer for neutralizing hydrochloric acid generated by an organic chlorine compound in the liquid to be treated is connected to a liquid line 92 to be treated. The liquid to be treated and the neutralizing agent are supplied to the reactor 87 through an inflow pipe 91, atomized downward by air as an oxidizing agent, and sprayed into a supercritical water area 88 in the reactor 87. You. Organochlorine compounds and other organic substances in the sprayed liquid to be treated are instantaneously oxidized and decomposed in the supercritical water area 88. In the process of the supercritical water reaction, the chlorine of the organic chlorine compound contained in the liquid to be treated is neutralized with the alkali neutralizer to form a salt, and shifts from the supercritical water region to the subcritical water region. Above the reactor 87, a processing liquid line 96 is further provided.
Is connected, and the organic matter in the liquid to be treated is mainly converted into water and carbon dioxide by a supercritical water reaction and flows out of the supercritical water area 88 through the treatment liquid line 96 together with the treatment liquid. Although not shown, the processing liquid line 96 is provided with a cooler for cooling the processing liquid, a pressure control valve for controlling the pressure in the reactor 87, a gas-liquid separator, and the like. If necessary, an auxiliary fuel line for supplying auxiliary fuel to the supercritical water area may be connected to the inflow pipe 91.

On the other hand, a subcritical water line 97 and a subcritical drainage line 98 are connected to the lower part of the reactor 87, and the subcritical water line 97 supplies subcritical water to the subcritical water area 90, The line 98 discharges subcritical water in which salts generated by the supercritical water reaction and the neutralization reaction are dissolved from the subcritical water area 90 as wastewater. Although not shown, the subcritical drainage line 98 is provided with a cooler for lowering the temperature of the subcritical wastewater to a predetermined temperature, a decompression device for reducing the pressure to a predetermined pressure, and a gas-liquid separation / solid-liquid separation device.

[0008]

However, the following problems have been encountered when attempting to treat a liquid to be treated containing high-concentration PCB with supercritical water using the above-described conventional supercritical water treatment apparatus. First, as before, a reaction temperature close to the critical temperature of water (374.1 ° C.), ie, 450 ° C. to 5 ° C.
At a temperature in the range of 00 ° C., it was extremely difficult to reduce the PCB content of the processing solution to 3 ppb or less, which is allowed by the discharge standard. Conversely, it is expected that higher reaction temperatures will be required.

Second, there are two problems caused by the two-zone system in which a supercritical water area and a subcritical water area are formed in a reactor. One problem is that corrosion of the reactor wall, particularly near the boundary between the two regions, is remarkable. Normally, the neutralization reaction proceeds concurrently with the supercritical water reaction, so that no corrosion problem occurs. However, if the neutralization is incomplete, corrosion becomes a problem. In the conventional method, since a high-temperature supercritical water area and a low-temperature subcritical water area exist in the reactor, a severely corrosive area always exists, which is an obstacle to the practical use of PCB supercritical water treatment. Had become. Second, if the spraying of the liquid to be treated is not good in the conventional method, the PC
B and the like may enter the subcritical water area 90 without being completely decomposed. In this case, since the temperature of the subcritical water area is low, undecomposed substances mixed in the subcritical water area remain without being decomposed and are discharged as wastewater from the subcritical water area. There was a problem that the content exceeded the emission standard.

Third, when the concentration of organic chlorine in the liquid to be treated is high, as in the case of treating PCB, there are many unclear points in the mechanism of the neutralization reaction and salt formation / separation. In the water treatment, the hydrochloric acid generated from the organic chlorine in the PCB is completely neutralized in the reactor as in the conventional method.
In practice, it was difficult and lacked certainty.

Therefore, a neutralization and quenching section for injecting an alkali aqueous solution into the treatment liquid and quenching and neutralizing the treatment liquid is provided at the outlet or downstream of the reactor. Attempted. However, in this method, since the processing liquid flows out of the reactor and enters the neutralization quenching section, it is neutralized only after the process, and a large amount of hydrochloric acid generated by the supercritical water reaction is present in the reactor. for that reason,
Nickel alloys such as Inconel 625, which have been conventionally used as a corrosion-resistant material on the inner wall of a reactor, have a problem in that they are significantly corroded by hydrochloric acid and cannot be used. Further, even in the quenching neutralization section, there is a problem that the corrosion of the pipe is remarkable up to the point where the neutralization reaction between the alkaline aqueous solution and the processing solution is completed, and it is difficult to use the nickel alloy for the pipe for a long time. .

Further, attempts have been made to employ a pressure balanced reactor in combination with a neutralization and quenching section. As shown in FIG. 9, the pressure-balanced reactor 100 has an outer cylinder 101 formed as a pressure vessel and a reaction cartridge 102 provided as an inner cylinder communicating with each other inside the outer cylinder 101. It is formed as a heavy cylinder. From the inlet nozzle 103 connected to the inflow pipe 91 (see FIG. 8), the liquid to be treated and an oxygen-containing gas, such as air, as an oxidant are caused to flow into the reaction zone 104 in the reaction cartridge 102, and are used for pressure balancing. Annular part 1 between outer cylinder 101 and reaction cartridge 102 from air inlet 105
At 06, for example, air is supplied as a pressure balancing gas. The pressure balancing air is supplied to the annular portion 1 through the upper gap 107 between the pressure vessel 101 and the reaction cartridge 102.
06 flows into the reaction zone 104 and is consumed as a part of the oxidizing agent.

The reaction zone 104 in the reaction cartridge 102
Is oxidized and decomposed by oxygen in the air in the supercritical water and flows out of the reactor outlet pipe 108. The neutralization quenching unit is provided on the inside or outside of the pressure vessel 102 downstream of the reaction cartridge 102. In a conventional pressure-balanced reactor, there is almost no pressure difference between the inside and the outside, and there is an advantage that the reaction cartridge 102 can be formed as a non-pressure vessel. Therefore, the reaction cartridge 102 is made of an expensive corrosion-resistant metal, for example, a nickel alloy such as Inconel 625. Has formed. Further, since the annular portion 106 is not in a highly corrosive atmosphere, the outer cylinder 101 does not necessarily need to be formed of the same material as the reaction cartridge 102, and is usually formed of heat-resistant carbon steel or stainless steel. However, there is a problem that even a reaction cartridge formed of an expensive nickel alloy is significantly corroded by hydrochloric acid and must be replaced in a short time.

Accordingly, an object of the present invention is to provide a liquid to be treated containing a high concentration of PCB or the like at a discharge standard of 3 ppb.
An object of the present invention is to provide a supercritical water treatment apparatus having the following PCB concentration, which can be operated stably for a long period of time.

[0015]

In order to achieve the above object, the present inventor has set forth the following object. (1) The present inventors have determined that a liquid to be treated having a high organic chlorine concentration such as PCB is supercritical to a PCB concentration of 3 ppb, which is allowed on a discharge standard. It was considered necessary to establish a reaction temperature at which water treatment was possible, and (2) to establish a reactor material that could be used at that temperature.

[0016] First, the relationship between the decomposition rate of PCB and the reaction temperature of the supercritical water reaction was investigated in order to reduce the PCB content of the treatment liquid produced by the treatment of PCB with supercritical water to 3 ppb or less. As a result, a reaction pressure of 23 MPa, and 2
Under the conditions of a reaction time of not less than 1 minute and not more than 4 minutes, when the reaction temperature is 500 ° C., the PCB concentration is not less than 3 ppb and cannot satisfy the discharge standard of 3 ppb, and the reaction temperature is 550 ° C. and 650 ° C. It was found that by setting the temperature to ° C, the PCB concentration could be reduced to 3 ppb or less. When the reaction temperature is 500 ° C., even if the reaction time is 4 minutes or longer, the PCB concentration is 3 p.
It was also found that it could not be less than pb.

That is, the reaction temperature is 550 ° C. or higher and 650 ° C.
By setting the temperature within the range of not more than 3 ° C., the PCB or P is adjusted so that the PCB concentration in the processing solution becomes 3 ppb or less.
A liquid to be treated containing an organic chlorine compound comprising a CB-like compound can be oxidatively decomposed by a supercritical water reaction. PC
The B-like compound is a compound having a chemical structure substantially similar to that of PCB, such as dioxins, chlorobenzene compounds, chlorophenols, and the like.

Next, in order to select a material having corrosion resistance to high-concentration hydrochloric acid at a temperature of 550 ° C. or more, reactors are made of various materials, and the PCB is actually treated with supercritical water to obtain a material. A corrosion test was performed to evaluate the corrosion resistance. By the way, for example, when a PCB of 100% purity from trichloride to pentachloride is subjected to a supercritical water reaction treatment,
The concentration of the generated hydrochloric acid is about 10 to 15% by mass. Therefore, in the first corrosion test, as conditions for treating the PCB with supercritical water, the pressure was set to 22 MPa, the reaction temperature was set to 600 ° C., and the corrosion rates of various materials by the hydrochloric acid aqueous solution having a hydrochloric acid concentration of 20% by mass were as follows. Was measured.

First, autoclave-shaped reactors were prepared from the materials shown in Table 1, respectively. A hydrochloric acid aqueous solution having a hydrochloric acid concentration of 20% by mass was accommodated in each reactor, and the hydrochloric acid aqueous solution in the reactor was heated at a pressure of 22 MPa and a temperature of 600 MPa. C. and maintained at that temperature for 500 to 600 hours, and the corrosion rate of the vessel wall of each reactor was measured. When the corrosion rate of the vessel wall is less than 1 mm / year, the material is optimum, when the corrosion rate is 1 mm / year or more and 5 mm / year, the material is applicable, and when the corrosion rate exceeds 5 mm / year, the material is not applicable. According to the corrosion test criteria, based on the corrosion rate of the container wall,
The results shown in Table 1 below were obtained.

Table 1 Material Judgment Inconel 625 Not applicable Hastelloy 276 Not applicable Platinum Not applicable Titanium Optimum Tantalum Not applicable Alumina Not applicable (slow corrosion rate, but cracking)

Next, in the second corrosion test, the pressure was 22 MPa, and the temperature was lower than the condition of the first corrosion test.
The temperature was set to 00 ° C., and the corrosion rate by a hydrochloric acid aqueous solution having a hydrochloric acid concentration of 20% by mass was measured. Autoclave-shaped reactors were made from the same materials as in the first corrosion test, and the hydrochloric acid concentration was 2
A 0% by mass aqueous hydrochloric acid solution is accommodated in each reactor, and the aqueous hydrochloric acid solution in the reactor is heated to a temperature of 400 ° C. at a pressure of 22 MPa and maintained at that temperature for 500 to 600 hours. The corrosion rate of the wall was measured. According to the same corrosion test criteria as the first corrosion test, the results shown in the following Table 2 were obtained based on the corrosion rate of the container wall.

Table 2 Materials Judgment Inconel 625 Not applicable Hastelloy 276 Not applicable Platinum Not applicable Titanium Applicable Tantalum Optimum Alumina Not applicable (slow corrosion rate, but cracking)

Further, in the third corrosion test, the pressure and the temperature are lower than those of the second corrosion test by a pressure of 18MP.
a, and the corrosion rate with a hydrochloric acid aqueous solution having a hydrochloric acid concentration of 20% by mass at a temperature of 350 ° C. was measured. Autoclave-shaped reactors were each made of the same material as in the first corrosion test, and a hydrochloric acid aqueous solution having a hydrochloric acid concentration of 20% by mass was accommodated in each reactor.
The hydrochloric acid aqueous solution in the reactor is heated to 350 ° C. at a pressure of 18 MPa.
And the temperature was maintained for 500 to 600 hours, and the corrosion rate of the vessel wall of each reactor was measured. According to the same corrosion test criteria as the first corrosion test, the results shown in the following Table 3 were obtained based on the corrosion rate of the container wall.

Table 3 Material Judgment Inconel 625 Not applicable Hastelloy 276 Not applicable Platinum Not applicable Titanium Not applicable Tantalum Optimum Alumina Not applicable (Slow corrosion rate, but cracking)

For further detailed examination, a fourth corrosion test was conducted at 380 ° C., 450 ° C., and 500 ° C. in the same manner as the first to third corrosion tests. 4 was obtained. Table 4 Corrosion test of 380 ° C, 22MPa, 20% hydrochloric acid aqueous solution Titanium Applicable Tantalum optimum 450 ° C, 22MPa, 20% hydrochloric acid aqueous solution Titanium optimal Tantalum Applicable 500 ° C, 22MPa, 20% hydrochloric acid aqueous solution Titanium optimal Applicable tantalum In addition, a reactor made of a titanium alloy instead of titanium and a tantalum alloy instead of tantalum was manufactured, and the same first to fourth corrosion tests were performed. The same results were obtained for titanium and tantalum, respectively. Could be obtained.

The following conclusions can be obtained from the results of the first to fourth corrosion tests. (1) Titanium can be applied to a container wall that comes into contact with a concentrated hydrochloric acid aqueous solution having a temperature of 380 ° C. or higher, and there is no material which can be applied only to titanium at 500 ° C. or higher. However, at a temperature of 350 ° C. or less, the corrosion rate of titanium is so high that it cannot be applied. Titanium forms an oxide film, which serves as a protective film, and therefore has high corrosion resistance. In particular, at a temperature of 380 ° C. or more, the formation of an oxide film is good, and the corrosion resistance is further enhanced. Therefore, a reactor wall having a temperature of 380 ° C. or higher, for example, a reaction temperature of 55 ° C.
Titanium can be suitably applied to the reactor wall of the PCB treatment reactor at 0 ° C.

(2) Tantalum can be applied to a container wall which comes into contact with a concentrated hydrochloric acid solution having a temperature of 450 ° C. or less,
In the following, only tantalum is applicable. However, 500 ° C
Above, the corrosion rate is too large to be applied. So 45
Tantalum is most suitable as a material for a neutralization mixer for injecting and neutralizing an alkali aqueous solution into a reaction product at a temperature lower than 0 ° C. At high temperatures of 500 ° C. or higher, tantalum becomes tantalum pentoxide and becomes unstable, so that the corrosion rate is thought to increase. (3) In order to solve the corrosion problem that differs depending on the temperature range of the material, first, titanium is used in a titanium application region having a lower limit of 380 ° C., and tantalum is used in a tantalum application region lower than 450 ° C. For example, the reaction product is first cooled to 400 ° C. using a titanium cooler, and then neutralized and mixed using a neutral mixer made of tantalum.

Based on the knowledge obtained in the PCB decomposition experiment obtained as described above, if the reactor is a pressure balanced type reactor, the supercritical water treatment apparatus according to the present invention (hereinafter referred to as the first
A pressure-balanced reaction formed as a double cylinder comprising an outer cylinder formed as a pressure vessel and a reaction cartridge disposed in the outer cylinder and comprising an inner cylinder communicating with each other. A liquid to be treated containing an organochlorine compound is introduced into supercritical water in a reaction cartridge,
In a supercritical water treatment apparatus that oxidizes and decomposes with an oxidizing agent at a temperature of 50 ° C. or more and 650 ° C. or less, a reaction fluid flowing out of a reaction cartridge is cooled by a cold fluid having a temperature of a first predetermined temperature or more and a second predetermined temperature or less. A cooling means for cooling directly or indirectly to a temperature equal to or higher than the second predetermined temperature and equal to or lower than the third predetermined temperature; and a neutralizing agent aqueous solution is injected into the reaction product cooled by the cooling means. A means for cooling is provided inside the outer cylinder downstream of the reaction cartridge, and a temperature region equal to or higher than the first predetermined temperature is included in a temperature region where the corrosion rate of titanium or a titanium alloy material is low, The temperature range of 3 or less is a temperature range where the corrosion rate of the tantalum or tantalum alloy material is low, and at least the surface layer of the member wall that contacts the reaction product among the members constituting the cooling means is titanium, or At least the surface layer of a member wall which is formed of a tantalum alloy material and which comes into contact with a mixed fluid of a reaction product and a neutralizing agent aqueous solution among members constituting the neutralization and cooling means is formed of tantalum or a tantalum alloy material It is characterized by:

In the first invention, the reaction cartridge is formed of titanium or a titanium alloy, or has a two-layer structure of an inner layer made of a titanium layer or a titanium alloy layer and an outer layer made of a tantalum layer or a tantalum alloy layer. Is formed. In the first and second inventions, indirect cooling refers to a method of cooling a reaction product by exchanging heat with a cold fluid using a heat exchanger. Inject into the product,
A method of mixing and cooling the reaction product.

In the first invention, there are no restrictions on the structure of the cooling means and the neutralizing and cooling means. For example, a cooler is provided as the cooling means, and the cooler is provided with a pipe through which the reaction product flows, A container for housing the pipe line, and a container through which cooling water flows, wherein at least the inner surface layer of the pipe line is a heat exchanger formed of titanium or a titanium alloy material, and a neutralization mixer is provided as a neutralization and cooling means. The neutralization mixer is a container in which at least the inner surface layer is formed of tantalum or a tantalum alloy material. Alternatively, the cooling device may be a cooling water mixing type cooling device having a container in which at least the inner surface layer is formed of titanium or a titanium alloy material.

The supercritical water treatment apparatus (hereinafter referred to as "second invention") according to the present invention is a supercritical water treatment apparatus which can be applied regardless of whether the reactor is a pressure balanced type or a single cylinder type non-pressure balanced type. , A reactor containing supercritical water, a liquid to be treated containing an organic chlorine compound is introduced into supercritical water in the reactor, and oxidized and decomposed by an oxidizing agent at a temperature of 550 ° C to 650 ° C. In the water treatment apparatus, the reaction product flowing out of the reactor is directly cooled to a temperature equal to or higher than a second predetermined temperature and equal to or lower than a third predetermined temperature by a cold fluid having a temperature equal to or higher than a first predetermined temperature and equal to or lower than a second predetermined temperature. Cooling means for cooling, or indirectly, and a reaction product cooled by the cooling means, a neutralizing agent aqueous solution is injected, and a means for neutralizing and cooling is provided downstream of the reactor, The temperature region equal to or higher than the predetermined temperature of 1 is titanium, Titanium corrosion rate of the alloy material is included in the low temperature region, the temperature region below the third predetermined temperature is,
In a temperature region where the corrosion rate of the tantalum or tantalum alloy material is low, at least the surface layer of the member wall that contacts the reaction product among the members constituting the cooling means is formed of titanium or a titanium alloy material, and neutralized and cooled. It is characterized in that at least the surface layer of the member wall which comes into contact with the mixed fluid of the reaction product and the aqueous solution of the neutralizing agent is formed of tantalum or a tantalum alloy material.

In the second aspect of the present invention, at least a surface layer of a reactor wall of the reactor is provided with a corrosion-resistant layer made of a titanium layer or a titanium alloy layer. Alternatively, at least a surface layer of the reactor wall has a titanium wall made of a titanium layer or a titanium alloy layer,
It is also possible to provide a two-layer corrosion-resistant layer provided on the inside of the titanium wall and the tantalum wall made of a tantalum layer or a tantalum alloy layer. Further, a corrosion-resistant layer made of a tantalum layer or a tantalum alloy layer may be provided on at least the surface layer of the reactor wall in a region where the temperature calculated based on the temperature distribution in the reactor is less than 400 ° C.

In the second aspect of the present invention, there are no restrictions on the structure of the cooling means and the neutralization and cooling means. For example, a cooler is provided as the cooling means, and the cooler includes a pipe through which the reaction product flows, A pressure vessel that houses the pipeline and through which cooling water flows,
At least the inner surface layer of the pipe is a heat exchanger formed of titanium or a titanium alloy material, and a neutralization mixer is provided as neutralization cooling means, and the neutralization mixer has at least an inner surface layer of tantalum or a tantalum alloy. It is a pressure vessel formed of a material. Alternatively, the cooler may be a cooling water mixing type cooler having a pressure vessel at least whose inner surface layer is formed of titanium or a titanium alloy material.

In the first and second inventions, the flow rate of the liquid to be treated, the flow rate of the supercritical water, the flow rate of the make-up water to be fed into the reactor for generating the supercritical water, and the make-up A temperature control device for controlling the temperature in the reactor to a range of 550 ° C. or more and 650 ° C. or less by adjusting at least one of the temperatures of water is provided in the reactor.

The titanium and titanium alloy used in the first and second inventions are specified by JIS or ASTM standards. For example, according to JIS, pure titanium is J
Titanium metals and titanium alloys specified by IS 1 to 3 are JIS 11 to 13 titanium alloys specified as titanium palladium alloys, and T is used as other titanium alloys.
There are i-6Al-4V alloy and Ti-6Al-4VELI alloy. According to the ASTM standard, pure titanium is AST
The titanium metals and titanium alloys defined by M Grade 1 to Grade 4 are titanium alloys of ASTM Grade 7 and Grade 11 specified as titanium palladium alloys. Also, Grade 12 and the like can be applied according to the ASTM standard.

The tantalum and the tantalum alloy used in the present invention are specified by the JIS standard or the ASTM standard. In addition to pure tantalum, a tantalum-tungsten alloy or the like can be applied.

In the first and second inventions, the first, second, and third predetermined temperatures are temperatures set based on the corrosion test described above, and are the first, second, and third predetermined temperatures. The temperature is selected from a temperature range of 374 ° C to 420 ° C, a temperature range of 380 ° C to 430 ° C, and a temperature range of 390 ° C to 500 ° C, respectively. For example, if the first predetermined temperature is 38
0 ° C., the second predetermined temperature is 400 ° C., and the third predetermined temperature is 450 ° C. Then, a first temperature controller for controlling the inlet temperature of the cooling water supplied to the heat exchange type cooler to 380 ° C., and adjusting the inflow rate of the cooling water to reduce the cooler outlet temperature of the reaction product to 400 ° C. And a second temperature control device for controlling the temperature. Thereby, the cooler can be maintained at the predetermined temperature.

In the case of the cooling water mixing type cooler, the inlet temperature of the cooling water supplied to the cooling water mixing type cooler is set to 380.
A first temperature controller for controlling the temperature of the cooling water to 400 ° C. and a second temperature controller for controlling the cooling water inflow rate of the reaction product to 400 ° C.

According to the first and second aspects of the invention, the reaction product is cooled by the cooling means to a temperature range lower than the second predetermined temperature which is the application temperature range of tantalum, and then neutralized by the neutralization cooling means. And maintaining the cooling means at a temperature equal to or lower than the reaction temperature and equal to or higher than the second predetermined temperature, and using titanium or a titanium alloy, and maintaining the neutralizing cooling means at a temperature lower than the second predetermined temperature to obtain tantalum. Alternatively, by using a tantalum alloy, the problem of corrosion of a supercritical water treatment apparatus for treating a liquid to be treated containing a high concentration of an organic chlorine compound such as PCB can be solved. Also, the first and second inventions are based on PCB
Thus, a supercritical water treatment apparatus capable of stably treating a liquid to be treated containing a high-concentration organic chlorine compound such as that described above for a long time and satisfying a discharge standard of 3 ppb or less has been realized.

[0040]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment 1 This embodiment is an example of an embodiment of the supercritical water treatment apparatus according to the first invention, and FIG. 1 is a flow sheet showing the configuration of the supercritical water treatment apparatus of this embodiment. FIG. 2 is a flow sheet showing the main parts of the embodiment, that is, the configuration of the lower part of the reactor and the cooling / neutralizing part. The supercritical water treatment apparatus 1 of the present embodiment is an apparatus for treating a liquid to be treated mainly containing PCB by a supercritical water reaction in the presence of supercritical water,
As shown in FIG. 1, as a reactor for performing a supercritical water reaction,
A vertical pressure-resistant closed type reactor 12 is provided.
A secondary cooler 3 for sequentially cooling the processing liquid to a predetermined temperature, a pressure control valve 4 for controlling the pressure in the reactor 12, and a processing liquid for supplying the processing liquid to the processing liquid pipe 2. And a gas-liquid separator 5 for gas-liquid separation.

The supercritical water treatment apparatus 1 includes, as a supply system for supplying a reactant to be subjected to a supercritical water reaction to a reactor 12, a liquid to be treated pump 6 whose discharge amount can be adjusted by inverter control or stroke control; An air compressor 7 for feeding a liquid to be treated containing PCB to the reactor 12 via a liquid to be treated 8, and an air inlet pipe 9 and a liquid to be treated 8
Through the reactor 12 with air as an oxidant together with the liquid to be treated.
Send to Further, the air compressor 7 feeds pressure-balancing air to the reactor 12 through a pressure-balancing air-feeding pipe 10 branched from the air-feeding pipe 9. Further, the supercritical water treatment apparatus 1 includes a cooler 14 and a neutralization mixer 16 described below.
Each has a cooling water supply system and an aqueous alkali solution supply system for supplying a cooling water and an aqueous NaOH solution, respectively. In addition,
Although not shown, supercritical water or make-up water for generating supercritical water may be supplied to the reactor 12 as necessary,
Further, a heater for heating the makeup water to a desired temperature can be provided.

The supercritical water treatment apparatus 1 includes a main temperature controller 11 for controlling the reaction temperature in the reactor 12 to, for example, 550 ° C. by adjusting the flow rate of the liquid to be treated. The main temperature controller 11 has a thermometer 13 for measuring the temperature in the reactor 12, and adjusts the discharge amount of the liquid to be treated 6 based on the temperature of the thermometer 13 to adjust the flow rate of the liquid to be treated. To make the reaction temperature 550 ° C. or higher and 65
Control is performed at a set temperature within a range of 0 ° C. or less, for example, 550 ° C. The configuration of the main temperature control device 11 is not limited to this. For example, the supply of supercritical water is adjusted, or the supply flow of make-up water for generating supercritical water is adjusted. The reaction temperature in the reactor 12 can be controlled within the range of 550 ° C. or more and 650 ° C. or less by adjusting the temperature at which water is fed.

The reactor 12 has the same configuration as the conventional pressure-balanced reactor 100 shown in FIG. 9 except that the internal cooler 14 and the neutralization mixer 16 are incorporated. That is, as shown in FIG. 2, the reactor 12 is formed of a heat-resistant carbon steel or stainless steel vertical cylindrical pressure vessel having a pressure at the time of supercritical water treatment, for example, having a mechanical strength against 23 MPa. An outer cylindrical body 12a, and a reaction cartridge 12b made of titanium or a titanium alloy provided as an inner cylindrical body communicating with each other inside the outer cylindrical body 12a, and provided between the outer cylindrical body 12a and the reaction cartridge 12b. Air for pressure balancing is introduced into the annular portion 12c from the air inlet pipe 10 for pressure balancing.

Further, the reactor 12 of this embodiment is provided with an internal cooler 14 for sequentially cooling the reaction product to a predetermined temperature in the outer cylindrical body 12a downstream of the reaction cartridge 12b, and an alkaline aqueous solution. And a neutralization mixer 16 for injecting, mixing and neutralizing the reaction product. The internal cooler 14 is provided with a cooling water supply system for supplying cooling water, and the neutralization mixer 16 is provided with an alkaline aqueous solution supply system for supplying an alkaline aqueous solution. The liquid to be treated including the PCB and the air pass through the liquid to be treated tube 8 and flow through the reaction cartridge 12b.
The pressure balancing air is introduced into the reaction cartridge 12b via the annular portion 12c. The liquid to be treated is treated with supercritical water in the reaction cartridge 12b,
It is cooled by the internal cooler 14, neutralized and mixed by the neutralization mixer 16, and flows out of the liquid pipe 2 to be treated.

The internal cooler 14 is provided for the reaction cartridge 12
b is an indirect cooler that cools the reaction product flowing out from the bottom of the reactor through the reactor outlet pipe 15 to a reaction temperature, for example, from 600 ° C. to 400 ° C. by heat exchange with cooling water passing through a cooling pipe. The internal cooler 14 includes a titanium coil 14a.
And a closed container 14b made of, for example, stainless steel for accommodating the flexible tube 14a. The flexible tube 14a is connected to the reactor outlet pipe 15 at the upper end, and is connected to the neutralization mixer inlet pipe 2 at the lower end.
5 is connected to a neutralization mixer 16. The reaction product flows downward from the top in the flexible tube 14a and cools down, and the cooling water flows countercurrently from the bottom upward in the container 14b to cool the reaction product.

The cooling water flows into the lower part of the container 14b with the temperature of the inlet to the internal cooler 14 controlled to 380 ° C.
The cooling water supply system includes a cooling water supply pump 17 having a variable discharge flow rate, an electric furnace 18 for heating the cooling water, a thermometer 19 for measuring a cooling water outlet temperature of the heating furnace 18, and a heating furnace. And a first temperature controller 20 for controlling the cooling water outlet temperature of the heating furnace 18 to 380 ° C. by adjusting the heating by the heating furnace 18. Further, the supply system adjusts the temperature of the reaction product outlet of the internal cooler 14 and the discharge flow rate of the cooling water by the cooling water supply pump 17 to adjust the temperature of the internal cooler outlet of the reaction product. And a second temperature control device 22 for maintaining the temperature at 400 ° C.

With the above-described configuration of the internal cooler 14 and the cooling water supply system, the purified fresh water is pressurized by the cooling water supply pump 17, then heated to 380 ° C. in the heating furnace 18, and then cooled. The cooling water flows into the lower part of the container 14b of the internal cooler 14 through the supply pipe 23 as cooling water, and flows out from the upper part of the container 14a through the cooling water outflow pipe 37. On the other hand, the reaction product flows from the bottom of the reaction cartridge 12b into the flexible tube 14a of the internal cooler 14 at a reaction temperature of about 600 ° C., is cooled to 400 ° C. by cooling water, and
Out of the bottom of

The neutralizer 16 has a static mixer inside.
This is a container formed as a pipe-shaped tantalum container having a mixer 24 and injecting, mixing and neutralizing an alkaline aqueous solution into the reaction product cooled by the internal cooler 14.
Note that the static mixer 24 is not always necessary, and may be omitted as long as mixing can be performed uniformly. The neutralization mixer 16 has a neutralization mixer inflow pipe 25 at the upper end.
And the lower end is connected to the neutralization mixer outlet pipe 26. The neutralization mixer outlet pipe 26 is connected to the processing liquid pipe 2 that guides the reaction product to the downstream secondary cooler 3 (see FIG. 1) and the like. The neutralization mixer inflow pipe 25 is a tantalum pipe, and the neutralization mixer outflow pipe 26 is a stainless steel pipe or a nickel alloy pipe.

The alkaline aqueous solution includes, for example, a predetermined concentration of N
An aOH aqueous solution is used. The supply system of the alkaline aqueous solution pressurizes a predetermined flow rate of a predetermined concentration of NaOH aqueous solution,
A NaOH aqueous solution pump 30 for feeding the neutralizing mixer inflow pipe 25 through the OH aqueous solution pipe 28 and a variable discharge flow rate type fresh water supply pump 32 for injecting fresh water into the NaOH aqueous solution supply pipe 28 are provided. The supply system is a thermometer 3 for measuring the inlet temperature of the NaOH aqueous solution to the neutralization mixer 16.
4 and the discharge flow rate of fresh water by the fresh water supply pump 32 is adjusted so that the inlet temperature of the neutralization mixer 16 for the NaOH aqueous solution becomes 2
A third temperature control device 36 for maintaining the temperature at 50 ° C. is provided, and a cooling water outflow pipe 37 of the cooling water flowing out of the internal cooler 14 is joined to the NaOH aqueous solution pipe 28 upstream of the thermometer 34.

With the above-described configuration of the neutralization mixer 16 and the supply system of the alkaline aqueous solution, the NaOH aqueous solution having a predetermined concentration is pressurized at a predetermined flow rate by the NaOH aqueous solution supply pump 30, and then mixed with the fresh water supplied by the fresh water supply pump 32. It then merges with the cooling water flowing out of the internal cooler 14 through the cooling water outflow pipe 37 and flows into the neutralization mixer inflow pipe 25 through the NaOH aqueous solution pipe 28. N
The temperature at which the aOH aqueous solution is injected into the neutralization mixer inflow pipe 25 (the temperature of the thermometer 34) is controlled at 250 ° C. by adjusting the discharge flow rate of fresh water by the fresh water supply pump 32. The reaction product flowing out of the internal cooler 14 flows into the upper part of the neutralization mixer 16 through the neutralization mixer inflow pipe 25, and flows from the alkaline aqueous solution supply system to the neutralization mixer inflow pipe 2
The mixture is mixed with the aqueous solution of NaOH supplied to 5 by the static mixer 24, neutralized, and flows out from the neutralization mixer outlet pipe 26 at a temperature of 300 ° C.

In the present embodiment, by controlling the temperature in the reactor 12 to 550 ° C. by the main temperature controller 11, the liquid to be treated including PCB is completely decomposed by supercritical water treatment, and PCB residual amount can be suppressed to 3 ppb or less. Since the temperature inside the reaction cartridge 12b is controlled to 550 ° C. by the main temperature controller 11, the titanium reliably functions as a corrosion-resistant material for the reaction cartridge 12b. Since the temperature of the internal cooler 14 is controlled by the first temperature control device 20 and the second temperature control device 22 and does not drop below 400 ° C., titanium reliably functions as a corrosion-resistant material of the internal cooler 14. Further, the temperature of the neutralization mixer 16 is controlled by the third temperature control device 36 and does not rise to 400 ° C. or higher, so that tantalum reliably functions as a corrosion-resistant material of the neutralization mixer 16.

In this embodiment, the pressure of the reaction product in the neutralization mixer 16 is
b, and the pressure of the cooling water in the container 14b of the internal cooler 14 is reduced via the cooling water outflow pipe 37 to the pressure of the reaction product in the neutralization mixer 16, ie, the reaction pressure. It is almost the same as the pressure in the outer cylindrical body 12a of the vessel 12. Therefore, since the mechanical strength required for the container walls of the internal cooler 14 and the neutralizing mixer 16 is small, the container walls of the internal cooler 14 and the neutralizing mixer 16 can be made thin and economical.

Embodiment 2 This embodiment is an example of an embodiment of the supercritical water treatment apparatus according to the second invention, and FIG. 3 is a main part of the supercritical water treatment apparatus of this embodiment. That is, it is a flow sheet showing the configuration of the lower part of the reactor and the cooling / neutralizing part. The supercritical water treatment apparatus and the main part 40 of the present embodiment are provided with a cooler 42 and a neutralization mixer 44, which are sequentially provided downstream of the reactor 12, except that their configurations are different. It has the same configuration as the supercritical water treatment apparatus 1 of Embodiment 1 and the main part 10 thereof, and exhibits the same functions.

The cooler 42 of this embodiment is provided with a coiled tube 14a.
The container 42b, which contains the container, does not come into contact with the high-temperature corrosive fluid, and thus may be made of, for example, a heat-resistant carbon steel or a container made of, for example, stainless steel. It has the same configuration as the cooler 14 of Example 1. Further, the neutralization mixer 44 of the present embodiment has the same configuration as the neutralization mixer 16 of the first embodiment except that the neutralization mixer 44 is different from that of the first embodiment and needs to be configured as a pressure vessel. Have.

Embodiment 3 This embodiment is another example of the embodiment of the supercritical water treatment apparatus according to the first invention, and FIG. 4 is an essential view of the supercritical water treatment apparatus of this embodiment. 2 is a flow sheet showing the structure of the lower part of the reactor and the cooling / neutralizing part. The supercritical water treatment apparatus of the present embodiment and the main part 50 thereof are different from the heat exchange type internal cooler 14 in that a cooling water of a direct mixing type is used in which cooling water is injected into a reaction product to mix and cool. 52, and the same configuration as the supercritical water treatment apparatus 1 of Embodiment 1 and the main part 10 thereof, except that the temperature control method of the reaction product outlet temperature of the neutralization mixer 16 is different. It has.

The cooler 52 is formed as a mixer composed of a titanium container provided with a static mixer 54, connects the cooling water supply pipe 23 to the reactor outlet pipe 15, and reacts the reaction product flowing out of the reaction cartridge 12b. 380 ° C
And cooled to 400 ° C.
In the present embodiment, a thermometer 56 provided in the neutralization mixer outlet pipe 26 for allowing the reaction product to flow out of the neutralization mixer 16 in place of the thermometer 34 of the first embodiment is provided. The outlet temperature of the neutralization mixer 16 is controlled at 300 ° C. Thereby, the injection temperature of the NaOH aqueous solution was set to 250 ° C.
Can be maintained. In addition, the static mixer in the cooler 52 and the neutralization mixer 16 is not necessarily required, and may be omitted as long as mixing can be performed uniformly.

As in the first embodiment, the cooler 52 and the neutralization mixer 16 of this embodiment have advantages in terms of corrosion resistance and mechanical strength, and the structure of the cooler 52 is the same as that of the first embodiment. It is economical because it is simpler than the structure of the internal cooler 14 of Example 1.

Embodiment 4 This embodiment is another example of the embodiment of the supercritical water treatment apparatus according to the second invention, and FIG. 2 is a flow sheet showing the structure of the lower part of the reactor and the cooling / neutralizing part. The supercritical water treatment apparatus of the present embodiment and the main part 60 thereof are the same as those of the third embodiment except that a cooler 62 and a neutralization mixer 64 are sequentially provided downstream of the reactor 12. It has the same configuration as that of the supercritical water treatment apparatus and its main part 50, and exhibits the same functions.

The cooler 62 of the present embodiment has the same configuration as the cooler 52 of the third embodiment except that the container needs to be configured as a pressure vessel. Further, the neutralization mixer 64 according to the present embodiment has the same configuration as the neutralization mixer 16 according to the third embodiment except that the neutralization mixer 64 needs to be configured as a pressure vessel.

Embodiment 5 This embodiment is still another example of the embodiment of the supercritical water treatment apparatus according to the first invention, and FIG. 6 shows the supercritical water treatment apparatus of this embodiment. The main parts, namely the lower part of the reactor and the cooling
6 is a flow sheet illustrating a configuration of a neutralizing unit. The main part 70 of the supercritical water treatment apparatus of the present embodiment is different in that the configuration of the cooling water supply system is different, that is, that the cooling water flowing out from the internal cooler is discharged out of the system, Except that the configurations of the vessel 16 and the supply system of the alkaline aqueous solution are different from those of the first embodiment, and are the same as those of the third embodiment, the same configuration as the supercritical water treatment apparatus 1 of the first embodiment and the main part 10 thereof It has.

The cooling water supply system includes a cooling water supply pump 1
A heat exchanger 72 for exchanging heat between the cooling water flowing out of the internal cooler 14 and the fresh water between the heating furnace 7 and the heating furnace 18, and the high-temperature cooling water flowing out of the internal cooler 14 and the heat exchanger 72. It has the same configuration as the cooling water supply system of the first embodiment, except that the heat exchange is performed to heat the fresh water. Further, the cooling water outflow system of the present embodiment is provided with a NaOH aqueous solution supply pipe 28.
Unlike the cooling water outflow system according to the first embodiment,
In addition to the heat exchanger 72, a cooling water cooler 76 for sequentially cooling the cooling water exiting the heat exchanger 72 with another low-temperature cooling water, and a cooling water outflow pipe 74 A self-contained pressure control valve 78 is provided for controlling the pressure of the cooling water, and thus the pressure of the cooling water in the vessel 14b of the internal cooler 14, to the same pressure as the pressure in the outer cylinder 12a of the reactor 12. The self-standing pressure control valve 78 self-adjusts the valve opening based on the pressure in the outer cylinder 12a so that the pressure becomes the same as the pressure in the outer cylinder 12a. To control the pressure of the cooling water upstream.

With the above configuration, in this embodiment,
As in the first embodiment, the pressure of the reaction product in the neutralization mixer 16 is almost the same as the pressure in the outer cylindrical body 12 b via the reaction cartridge 12 a of the reactor 12, The pressure of the cooling water in the container 14b is substantially the same as the pressure in the outer cylindrical body 12a of the reactor 12. Accordingly, since the mechanical strength required for the container walls of the internal cooler 14 and the neutralization mixer 16 is small, the internal cooler 14 and the neutralization mixer 1
6 is thin and economical.

Embodiment 6 This embodiment is still another example of the embodiment of the supercritical water treatment apparatus of the first invention, and FIG. 7 is an essential view of the supercritical water treatment apparatus of this embodiment. 6 is a flow sheet showing a configuration of a unit.
The supercritical water treatment apparatus of the present embodiment and its main part 80 are:
Except for being configured to circulate and use the cooling water, it has the same configuration as the fifth embodiment. This modification is different from the fifth embodiment in that the cooling water outlet pipe 74 is provided with a cooling water cooler 82, and the cooling water that has exited the internal cooler 84 is cooled by another low-temperature cooling water. At 78, the pressure is made the same as the pressure inside the outer cylindrical body 12a, and then returned to the suction side of the cooling water supply pump 17 at a high pressure and circulated. In addition, a part of the cooling water is blown, and fresh water is replenished instead.

Therefore, in this embodiment, the coil 8
Since the pressure of the cooling water in the container 84b of the internal cooler 84 having 4a is the same as the pressure in the outer cylindrical body 12a of the reactor 12, it is not necessary to form the container 84b as a pressure container. Note that the technical idea of the fifth embodiment and the modified example thereof can be easily applied to the second embodiment as well as the first embodiment.

In the first to sixth embodiments, when titanium and tantalum are used as the material of the internal cooler and the neutralization mixer, a titanium alloy and a tantalum alloy may be used, respectively. Further, as shown in Embodiment Examples 1 to 6, it is not always necessary to use titanium and a titanium alloy, and tantalum and a tantalum alloy for the entire flexible tube of the internal cooler, the entire container, and the entire container of the neutralization mixer. In the case of an internal cooler, titanium and a titanium alloy are used only for the inner surface layer of the pipeline in which the reaction product contacts, and in the case of a neutralization mixer, a vessel in which a mixed fluid of the reaction product and an aqueous NaOH solution contacts. Tantalum and a tantalum alloy may be used only for the inner surface layer of the wall.

Embodiments 2 and 4 are applicable to the embodiments in which the reaction product flows out from the bottom of the reaction cartridge as shown in FIGS. 3 and 5, respectively. Although not shown, the present invention can also be applied to a configuration in which the reaction cartridge flows out from an upper portion or a side portion of the reaction cartridge. Also,
Embodiments 2 and 4 can also be applied to a reactor having no reaction cartridge, in which case it is not necessary that the reactor flows out from the bottom of the reactor, and the reaction product is not supplied to the reactor. The present invention can be applied to a configuration that flows out from an upper portion or a side portion. Further, the fifth and sixth embodiments correspond to the second and fourth embodiments.
Similarly to the above, the reaction can be performed outside the outer cylindrical body 12a of the reactor 12.

[0067]

According to the first and second aspects of the present invention, the reaction product is cooled by the cooling means to a temperature range lower than the second predetermined temperature, which is the application temperature range of tantalum, and then neutralized by the neutralization cooling means. And maintaining the cooling means at a temperature equal to or lower than the reaction temperature and equal to or higher than the second predetermined temperature, by using titanium or a titanium alloy, and maintaining the neutralizing cooling means at a temperature lower than the second predetermined temperature. By using tantalum or a tantalum alloy, the problem of corrosion of a supercritical water treatment apparatus for treating a liquid to be treated containing a high-concentration organic chlorine compound such as PCB can be solved. Therefore, the first and second aspects of the invention
A supercritical water treatment apparatus capable of stably treating a liquid to be treated containing a high-concentration organic chlorine compound such as CB over a long period of time and satisfying a discharge standard of 3 ppb or less is realized.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a configuration of a supercritical water treatment apparatus of a first embodiment.

FIG. 2 is a flow sheet showing a configuration of a main part of a supercritical water treatment apparatus of Embodiment 1, that is, a configuration of a lower part of a reactor and a cooling / neutralizing part.

FIG. 3 is a flow sheet showing a configuration of a main part of a supercritical water treatment apparatus according to a second embodiment, that is, a configuration of a lower part of a reactor and a cooling / neutralizing part.

FIG. 4 is a flow sheet showing a configuration of a main part of a supercritical water treatment apparatus according to a third embodiment, that is, a configuration of a reactor lower part and a cooling / neutralizing part.

FIG. 5 is a flow sheet showing a main part of a supercritical water treatment apparatus according to a fourth embodiment, that is, a configuration of a lower part of a reactor and a cooling / neutralizing part.

FIG. 6 is a flow sheet showing a main part of a supercritical water treatment apparatus of a fifth embodiment, that is, a configuration of a lower part of a reactor and a cooling / neutralizing part.

FIG. 7 is a flow sheet showing a main part of a supercritical water treatment apparatus of a sixth embodiment, that is, a configuration of a lower part of a reactor and a cooling / neutralizing part.

FIG. 8 is a flow sheet showing a configuration of a main part of a conventional supercritical water treatment apparatus.

FIG. 9 is a longitudinal sectional view showing a configuration of a pressure balanced reactor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Supercritical water treatment apparatus of Embodiment 1 2 Treatment liquid pipe 3 Secondary cooler 4 Pressure control valve 5 Gas-liquid separator 6 Liquid to be treated pump 7 Air compressor 8 Liquid to be treated 9 Air inlet pipe 10 Pressure Air inlet pipe for balance 11 Main temperature control device 12 Reactor 12a Outer cylinder 12b Reaction cartridge 12c Annular part 13 Thermometer 14 Internal cooler 14a Serpentine pipe 14b Container 15 Reactor outlet pipe 16 Neutralization mixer 17 Cooling water supply pump Reference Signs List 18 electric furnace type heating furnace 19 thermometer 20 first temperature control device 21 thermometer 22 second temperature control device 23 cooling water supply pipe 24 static mixer 25 neutralization mixer inflow pipe 26 neutralization mixer outflow pipe 28 NaOH aqueous solution Supply pipe 30 NaOH aqueous solution supply pump 32 Fresh water supply pump 34 Thermometer 36 Third temperature control device 37 Cooling water outlet pipe 40 Embodiment example Main part of supercritical water treatment apparatus 42 Cooler 44 Neutralization mixer 50 Main part of supercritical water treatment apparatus of Embodiment 3 52 Cooler 54 Static mixer 56 Thermometer 60 Supercritical water of Embodiment 4 Main part of treatment apparatus 62 Cooler 64 Neutralization mixer 70 Main part of supercritical water treatment apparatus of Embodiment 5 72 Heat exchanger 74 Cooling water outlet pipe 76 Cooling water cooler 78 Self-standing pressure control valve 80 Embodiment Principal part of supercritical water treatment apparatus of modified example of Example 5 82 Cooling water cooler 84 Internal cooler 86 Supercritical water treatment apparatus 87 Reactor 88 Supercritical water area 89 Virtual interface 90 Subcritical water area 91 Inflow pipe 92 Treated Liquid line 93 Air line 94 Supercritical water line 95 Neutralizer line 96 Treatment liquid line 97 Subcritical water line 98 Subcritical drainage line 100 Pressure balanced reactor 101 Pressure vessel 10 2 Reaction cartridge 103 Inlet nozzle 104 Reaction zone 105 Air inlet for pressure balance 106 Annular part 107 Gap 108 Reactor outflow pipe

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C02F 1/58 C02F 1/58 A 1/66 510 1/66 510L 521 521B 530 530D 540 540H // A62D 3/00 A62D 3/00 (72) Inventor Tomoyuki Iwamori 1-8-2 Shinsuna, Koto-ku, Tokyo, Japan Organo Corporation (72) Inventor Shinichiro Kawasaki 1-2-8, Shinsuna, Koto-ku, Tokyo Organo Corporation F Terms (reference) 2E191 BA12 BD11 4D038 AA08 AA10 AB14 BA02 BA06 BB01 BB13 BB16 BB20 4D050 AA12 AA20 AB19 BB01 BC01 BC02 BD02 BD08 CA13 CA20 4G075 AA13 AA37 AA53 AA62 AA63 BA05 BA06 BA10 CA02 CA03

Claims (8)

[Claims] 1. A pressure-balanced reactor formed as a double cylinder comprising an outer cylinder formed as a pressure vessel and a reaction cartridge disposed in the outer cylinder and comprising an inner cylinder communicating with each other. A liquid to be treated containing an organic chlorine compound is introduced into supercritical water in a reaction cartridge,
A supercritical water treatment apparatus which oxidatively decomposes with an oxidizing agent at a temperature of not less than 650 ° C. and a second reaction product flowing out of the reaction cartridge by a cold fluid having a temperature of not less than a first predetermined temperature and not more than a second predetermined temperature. A cooling means for cooling directly or indirectly to a predetermined temperature or higher and a third predetermined temperature or lower, and a neutralizing agent aqueous solution is injected into the reaction product cooled by the cooling means to neutralize the reaction product. Means for cooling is provided in the outer cylinder downstream of the reaction cartridge, and the temperature region equal to or higher than the first predetermined temperature is included in a temperature region where the corrosion rate of the titanium or titanium alloy material is low, and The temperature region below the predetermined temperature is a temperature region where the corrosion rate of the tantalum or tantalum alloy material is low, and at least the surface layer of the member wall which contacts the reaction product among the members constituting the cooling means is made of titanium or titanium. At least the surface layer of a member wall that is in contact with a mixed fluid of a reaction product and a neutralizing agent aqueous solution is formed of tantalum or a tantalum alloy material among members constituting neutralization and cooling means. A supercritical water treatment apparatus, characterized in that: 2. A cooler provided as a cooling means includes a pipe through which a reaction product flows, and a container accommodating the pipe and flowing cooling water, wherein at least an inner surface layer of the pipe is made of titanium or titanium. A heat exchanger formed of an alloy material, wherein the neutralization mixer provided as a neutralization and cooling means is a container having at least an inner surface layer formed of tantalum or a tantalum alloy material. 2. The supercritical water treatment apparatus according to 1. 3. A cooler provided as a cooling means is a cooling water mixing type cooler having a container having at least an inner surface layer made of titanium or a titanium alloy material, and provided as a neutralization and cooling means. The supercritical water treatment apparatus according to claim 1, wherein the neutralization mixer is a container in which at least an inner surface layer is formed of tantalum or a tantalum alloy material. 4. A reactor containing supercritical water is provided, a liquid to be treated containing an organic chlorine compound is introduced into supercritical water in the reactor, and oxidized with an oxidizing agent at a temperature of 550 ° C. or more and 650 ° C. or less. In a decomposing supercritical water treatment apparatus, a reaction product flowing out of a reactor is cooled by a cold fluid having a temperature equal to or higher than a first predetermined temperature and equal to or lower than a second predetermined temperature. Cooling means for cooling directly or indirectly to the temperature of the reaction solution, and means for injecting a neutralizing agent aqueous solution into the reaction product cooled by the cooling means and performing neutralization cooling downstream of the reactor. The temperature range above the first predetermined temperature is included in the temperature range where the corrosion rate of titanium or titanium alloy material is low, and the temperature range below the third predetermined temperature is the corrosion rate of tantalum or tantalum alloy material. Is in the low temperature range, At least the surface layer of the member wall which comes into contact with the reaction product among the members constituting the means is formed of titanium or a titanium alloy material, and the reaction product and the neutralizer aqueous solution among the members constituting the neutralization and cooling means A supercritical water treatment apparatus, wherein at least a surface layer of a member wall in contact with a mixed fluid is formed of tantalum or a tantalum alloy material. 5. A cooler provided as a cooling means includes a pipe through which a reaction product flows, and a pressure vessel accommodating the pipe and through which cooling water flows, and at least an inner surface layer of the pipe is made of titanium or A heat exchanger formed of a titanium alloy material, wherein the neutralization mixer provided as the neutralization cooling means is a pressure vessel having at least an inner surface layer formed of tantalum or a tantalum alloy material. Item 5. A supercritical water treatment apparatus according to item 4. 6. A cooler provided as a cooling means is a cooling water mixing type cooler having a pressure vessel at least whose inner surface layer is formed of titanium or a titanium alloy material, and is provided as a neutralization cooling means. The supercritical water treatment apparatus according to claim 4, wherein the neutralization mixer is a pressure vessel in which at least an inner surface layer is made of tantalum or a tantalum alloy material. 7. The first predetermined temperature is 380 ° C., the second predetermined temperature is 400 ° C., and the third predetermined temperature is 450 ° C., and the inlet temperature of the cooling water supplied to the heat exchange type cooler is 380 ° C
A first temperature control device for controlling the temperature of the cooling water, and a second temperature control device for controlling the flow rate of the cooling water at the outlet of the cooler to 400 ° C. by adjusting the flow rate of the cooling water. The supercritical water treatment apparatus according to claim 2 or 5, wherein 8. The cooling water inlet temperature, wherein the first predetermined temperature is 380 ° C., the second predetermined temperature is 400 ° C., and the third predetermined temperature is 450 ° C. 38
A first temperature controller for controlling the temperature to 0 ° C .; and a second temperature controller for controlling the flow rate of the cooling water at the outlet of the cooler to 400 ° C. by adjusting the flow rate of the cooling water. The supercritical water treatment apparatus according to claim 3 or 6, wherein: