JP2005133156A - Metallic material for hydrothermal-reaction treatment apparatus, and hydrothermal-reaction treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic material for a hydrothermal-reaction treatment apparatus, which controls an extent of corrosion caused by a hydrothermal oxidation reaction in a supercritical state or a subcritical state, to a corrosion loss of 1 mm or less per year, and to provide the hydrothermal-reaction treatment apparatus. <P>SOLUTION: The metallic material for the hydrothermal-reaction treatment apparatus, which composes the hydrothermal-reaction treatment apparatus used for the hydrothermal reaction in the supercritical state or the subcritical state, is made of a Ni-based alloy including Ni as a main component, 14-30 mass% Cr, and 2 mass% or less Mo or substantially 0 mass% Mo. The hydrothermal-reaction treatment apparatus 1 is composed of the above metallic material for the hydrothermal-reaction treatment apparatus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a metal material for a hydrothermal reaction treatment apparatus and a hydrothermal reaction treatment apparatus.

  In recent years, in a supercritical state exceeding the critical point of water (temperature: 374 ° C., pressure: about 22 MPa) and in a subcritical state adjacent to the supercritical state, water containing an object to be treated and an oxidizing agent. Is caused to cause a hydrothermal oxidation reaction including combustion, and a hydrothermal reaction process (hereinafter referred to as “hydrothermal oxidation reaction process”) that decomposes harmful organic substances in the object to be processed almost completely in a short time. ) Is attracting attention. In this way, when the material to be treated is treated by hydrothermal oxidation in a supercritical or subcritical state of water in the reaction vessel, harmful organic substances are oxidatively decomposed, resulting in high temperature and high pressure consisting of water and carbon dioxide. This hydrothermal reaction treatment is attracting attention as a treatment method that converts toxic substances such as dioxins, PCBs (Poly Chlorinated Biphenyls), and chlorofluorocarbons into oxidatively decomposed substances into non-polluting substances. Has been.

  In decomposing the harmful organic substances that are to be treated in the hydrothermal reaction treatment, the environment in the hydrothermal reaction treatment is a strong oxidizing environment, and further, Cl (chlorine) contained in the treated material. , S (sulfur), P (phosphorus), etc. form an acid, or generate a highly corrosive substance such as an alkali, which is harsh for materials for equipment that performs such hydrothermal reaction treatment. It was a highly corrosive environment.

  Conventionally, Ni-based alloy materials have been typical as corrosion-resistant device materials, and they are widely used as device materials for hydrothermal reaction treatment as corrosion-resistant metal materials, particularly high-temperature corrosion-resistant materials, oxidation-resistant materials, and crevice corrosion-resistant materials. Ni-based alloy materials such as Inconel 625 (for example, Ni-20Cr-10Mo-Nb) and Hastelloy C276 (for example, Ni-16Cr-16Mo) have been used. However, since these materials corrode at a level of several tens of millimeters per year in the above-mentioned highly corrosive environment, they are inferior in corrosion resistance as materials for devices applied in a supercritical state or a subcritical state, and are appropriate. It was not a thing.

  In addition, depending on the composition of the inorganic substance contained in the material to be treated, water in the supercritical state has low salt solubility, so an inorganic salt is generated during the reaction, and the surface of the component material is formed inside (inner surface) of the reaction vessel. It was supposed to deposit and deposit. In addition, in anticipation of the degree of acid and alkali formed during the reaction to the hazardous organic substance that is the object to be treated, if acid is formed, alkali is added to the object to be treated, and alkali is formed. In such a case, an acid has been added to the material to be treated and neutralized during the reaction. In this case, the corrosion of the device material is reduced to some extent, but the inorganic substance is deposited as a neutralized salt in the reaction vessel and adheres to the surface of the device material.

  In this way, if salt adheres to the surface of the device material, the material will still be exposed to a strong corrosive environment due to the presence of such salt and the interaction of high temperature and strong oxidizing environment. become. For this reason, when salt is present in the aforementioned Ni-based metal material, the amount of corrosion of about 10 mm per year is inevitable, which is insufficient as a material used in the apparatus.

  On the other hand, for Ni-based alloy materials, desired corrosion resistance can be derived by adding a plurality of types of alloy elements to Ni as the main component. For example, Cr (chromium) can be included as an alloy element. In order to improve local corrosion resistance against hydrochloric acid and chloride aqueous solution, Mo (molybdenum) is added, and other components include W (tungsten), Co (cobalt), Nb (niobium), Ta (tantalum), Ti ( Elements such as titanium), Al (aluminum), Cu (copper), Fe (iron), and Si (silicon) were appropriately added as alloy elements. Among these, the Cr component and the Mo component are typical alloy elements contained in the Ni-based corrosion resistant material, but as described above, the Ni-based alloy materials such as conventional Inconel 625 and Hastelloy C276 have corrosion resistance. As such, it was insufficient, and further studies were desired.

  On the other hand, as an example in which a Ni-based alloy material containing Cr or Mo is applied as a device material for a hydrothermal oxidation reaction in a supercritical state or the like, the Cr content is more than 30% by mass and less than 50% by mass. In addition, a material for a supercritical water / subcritical water utilization device in which the Mo content is 20% by mass or less and the Ni content is 45% by mass or more is provided (for example, Patent Document 1). Also, a supercritical water reaction field member constituting a device for handling supercritical water, comprising a base material, and a build-up layer for preventing corrosion that covers the surface of the base material in contact with the supercritical water, The build-up layer is composed of a Ni-Cr-Mo type metal-plated material containing 20 to 40 wt% Cr and 2.5 to 12 wt% Mo, with the balance being Ni and irreversible impurities. There is a disclosure about a member for a supercritical water reaction field (for example, Patent Document 2).

Japanese Patent Laid-Open No. 2002-3971 JP 2000-334595 A

  The materials disclosed in the above-mentioned documents showed improved corrosion resistance in a hydrothermal oxidation environment as compared with Ni-based alloy materials such as Inconel 625 and Hastelloy C276. On the other hand, in the supercritical state environment, if the annual corrosion amount is about 1 mm, it is judged that there is no practical problem, and such performance is required, but in practice, hydrothermal oxidation in the supercritical state In a highly corrosive environment where there is a reaction treatment, particularly where inorganic salts are present, even the materials disclosed in the above-mentioned literature, a corrosion amount of several millimeters per year is recognized. I was not satisfied.

  The object of the present invention has been proposed in view of the above-mentioned problems of the prior art, and by making the contents of Cr and Mo, which are additive metal elements in the Ni-based alloy material, into a specific range, supercriticality is achieved. To provide a metal material for a hydrothermal reaction treatment device and a hydrothermal reaction treatment device capable of suppressing the degree of corrosion associated with the hydrothermal oxidation reaction in a state or subcritical state to 1 mm or less in terms of the annual corrosion amount. is there.

  The metal material for a hydrothermal reaction treatment device according to claim 1 of the present invention is a metal material for a hydrothermal reaction treatment device constituting a hydrothermal reaction treatment device used in a hydrothermal reaction in a supercritical state or a subcritical state. It is characterized by comprising a Ni-based alloy containing Ni as a main component and having a Cr content of 14 to 30% by mass and a Mo content of 2.0% by mass or less.

  The metal material for a hydrothermal reaction treatment device according to claim 2 of the present invention is a metal material for a hydrothermal reaction treatment device constituting a hydrothermal reaction treatment device used in a hydrothermal reaction in a supercritical state or a subcritical state. It is characterized by being made of a Ni-based alloy containing Ni as a main component and having a Cr content of 14 to 30% by mass and substantially not containing Mo.

  A hydrothermal reaction treatment apparatus according to claim 3 of the present invention is characterized in that the metal material for a hydrothermal reaction treatment apparatus according to claim 1 or 2 is used.

  In the metal material for a hydrothermal reaction treatment device according to claim 1, the Cr content in the Ni-based alloy material is in the range of 14 to 30% by mass, and the Mo content is in the range of 2.0% by mass or less. Therefore, in the hydrothermal oxidation reaction treatment in the supercritical state or the subcritical state, it is possible to provide a metal material for a hydrothermal reaction treatment apparatus that is superior in corrosion resistance as compared with conventional corrosion resistant materials at a low cost. Specifically, it is possible to provide a metal material that can suppress the degree of corrosion associated with the above-described hydrothermal oxidation reaction treatment to 1 mm or less in terms of the annual corrosion amount.

  In the metal material for a hydrothermal reaction treatment device according to claim 2, since the Cr content in the Ni-based alloy material is in the range of 14 to 30% by mass and does not substantially contain Mo, this also In the hydrothermal oxidation reaction treatment in the supercritical state or subcritical state, it is possible to provide metal materials for hydrothermal reaction treatment equipment superior in corrosion resistance compared to conventional corrosion resistant materials at low cost, and for hydrothermal oxidation reaction treatment The metal material which can suppress the grade of the accompanying corrosion to 1 mm or less in terms of an annual corrosion amount can be provided.

  In the hydrothermal reaction processing apparatus of claim 3, since the metal material for hydrothermal reaction processing apparatus described in claim 1 or claim 2 is used, the above-mentioned action and effect are enjoyed, and supercriticality is achieved. Even if it is used in a state or a subcritical state, it is possible to suitably provide a hydrothermal reaction treatment apparatus having excellent corrosion resistance and high reliability. Moreover, since the metal material for a hydrothermal reaction treatment apparatus described above can be provided at a low cost, the cost reduction of the hydrothermal reaction treatment apparatus itself can be promoted.

  The metal material for a hydrothermal reaction treatment apparatus of the present invention (hereinafter sometimes simply referred to as “metal material”) is a Ni-based alloy material whose main component is Ni (nickel). By using such Ni as a main component, the metal material of the present invention has excellent toughness of the metal material, and can be a metal material having small brittleness and resistance to stress corrosion cracking.

  The metal material of the present invention contains Cr (chromium) as an additive metal element for the Ni-based alloy material. Here, the addition of Cr to the Ni-based alloy material causes a Cr oxide layer to be a protective film to be formed on the surface of the alloy material, and the progress of corrosion can be suppressed by the protective film. Furthermore, such a protective film is particularly stable in an oxidizing atmosphere, and is suitable as an alloy element for a metal material used in a harsh oxidizing environment such as a hydrothermal oxidation reaction.

  In the present invention, the Cr content is in the range of 14 to 30% by mass, and preferably in the range of 20 to 30% by mass. By setting the Cr content within such a range, the above-described Cr oxide layer is suitably formed, and the metal material exhibits excellent corrosion resistance even in a hydrothermal oxidation reaction treatment in a supercritical state or a subcritical state. .

  On the other hand, when the Cr content is less than 14% by mass, the corrosion resistance effect due to the formation of the protective film of Cr in the alloy material may not be obtained. If the Cr content exceeds 30% by mass, Cr is a brittle element, so if the content is excessive, the relative content of Ni as the main component is reduced. Therefore, the ductility of Ni is hindered, the brittle material having low toughness as a whole metal material is obtained, and the material is inferior in terms of manufacturability and workability, leading to high cost of the metal material.

  Next, Mo (molybdenum) as an additive metal element is widely used in a general corrosive environment because it has an effect of improving local corrosion resistance against hydrochloric acid or a chloride aqueous solution. On the other hand, excessive addition has the property of weakening the oxidation resistance of the metal material. In particular, as a metal material for a hydrothermal oxidation treatment apparatus exposed to a harsh oxidizing environment, an excessive amount of Mo in the alloy is used. Addition impairs the oxidation resistance of the alloy itself and may lead to the occurrence of significant corrosion. Therefore, in the present invention, Mo is not substantially contained in the metal material (content = 0), Even when it is added, it is necessary to make the content 2.0% by mass or less, preferably 1.5% by mass or less.

  The metal material for a hydrothermal reaction treatment apparatus of the present invention is based on the above-described alloy component, and other alloy components such as W (tungsten), Co (cobalt), Nb (niobium), Ta (tantalum), Components such as Ti (titanium), Al (aluminum), Cu (copper), Fe (iron), and Si (silicon) can be added, but such as Fe, Al, and Si that do not impair oxidation resistance It is desirable to be an element. In that case, the total of alloy elements other than Ni and Cr is preferably 16% by mass or less.

  In carrying out the present invention, the Ni-based alloy composed of the above-described components can be used as it is as the metal material for the hydrothermal reaction processing apparatus, and the Ni-based alloy composed of the above-described components can be applied to the surface of a predetermined substrate. You may use what coat | covered the base alloy as a metal material for hydrothermal reaction processing apparatuses.

  The metal material for a hydrothermal reaction treatment device of the present invention is preferably applied as a material constituting a hydrothermal reaction treatment device used in a hydrothermal reaction treatment in a supercritical state or a subcritical state. It is applicable to the hydrothermal reaction treatment apparatus 1 shown in the embodiment.

[Configuration of Hydrothermal Reaction Treatment Apparatus 1]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an embodiment of a hydrothermal reaction treatment apparatus using a metal material for a hydrothermal reaction treatment apparatus of the present invention as a constituent material. In FIG. 1, reference numeral 1 denotes a hydrothermal reaction processing apparatus, a hydrothermal reaction processing container 11, a supply pipe 2 that supplies an object to be processed to the hydrothermal reaction processing apparatus 1, a movable shaft 41, and this movable shaft 41. For example, a shaft holding mechanism 51 that rotatably holds the hydrothermal reaction processing vessel 11, a drive mechanism 61 that rotates the movable shaft 41, and a seal between the hydrothermal reaction processing vessel 11 in close contact with the movable shaft 41. The basic configuration includes a sealing member 71 to be performed, a scraper 81 as scraping means attached to the movable shaft 41, and fluid supply holes 23, 24, and 27. In addition, since this structure shows the one aspect | mode of a hydrothermal reaction processing apparatus, it cannot be overemphasized that this invention is not limited to this structure.

Here, the hydrothermal reaction processing container 11 has a cylindrical cylindrical space 12 in which a cylindrical space for reaction is formed and a lower end portion narrows toward the center in a funnel shape. The base 15 is made up of. A circular hole 13 that penetrates substantially the center of the cylindrical portion 12 in the vertical direction is provided in the lower portion of the cylindrical portion 12. In the present apparatus 1, since the hydrothermal oxidation reaction process is performed in the cylindrical portion 12, the metal material for the hydrothermal reaction processing apparatus of the present invention is applied as the constituent material of the cylindrical portion 12.

  The supply pipe 2 supplies an object to be processed into the hydrothermal reaction processing container 11 and is arranged toward the center or the vicinity of the center of the above-described hydrothermal reaction processing container 11.

  In this embodiment, the movable shaft 41 is rotatably supported by the shaft holding mechanism 51 that includes the bushes 52 and 53 and the thrust washer 54 that supports the lower surface of the movable shaft 41 with respect to the base 15 described above. To be formed. On the upper side of the movable shaft 41, the reaction product is pulverized and stirred, and the reaction product is pushed out from the center of the movable shaft 41 by centrifugal force to assist the conveyance to the discharge port 22. Fins 43 as means are provided radially. Although not shown, a gear is provided at a height corresponding to the opening 29 of the movable shaft 41, and a motor disposed outside the hydrothermal reaction processing vessel 11 and the motor And a chain 62 stretched around the gear of the movable shaft 41 constitutes a drive mechanism 61. In addition, it is preferable that the drive mechanism 61 is provided with the safety mechanism which act | operates at the time of overtorque.

  The movable shaft 41 is provided with a nozzle 44, and one end communicates with the fluid supply hole 27 through a communication hole 42 provided in the nozzle 44 and the movable shaft 41, and the supplied fluid is radiated. It is made to eject toward the hole 13. In the present embodiment, the communication hole 42 communicates with the fluid supply hole 27 via the seal member 71. The seal member 71 has an annular shape whose longitudinal section is a vertically long rectangle, for example, an outer periphery of a metal ring. It is configured to be coated with Teflon (registered trademark) or the like.

  The scraper 81 is formed in a shape along the inner surface of the container 11 from the lower side to the upper side so as to scrape off the deposits inside the hydrothermal reaction processing container 11. The scraper 81 may have, for example, a rod-like shape that is attached around the movable shaft 41 at a predetermined interval, for example, 60 °, and has a cylindrical shape with openings at a plurality of locations on the cylindrical surface. A shape in which a blade is formed can be used. And in this apparatus 1, since the scraper 81 is provided in the inside of the hydrothermal reaction processing container 11 in which a hydrothermal oxidation reaction process is performed, the hydrothermal reaction process of this invention is used as the constituent material of the said scraper 81. An apparatus metal material may be applied.

  In the present embodiment, the base 15 on which the cylindrical portion 12 is mounted shows an aspect in which, in the case of the present embodiment, the base is divided into three layers of the base divided portions 16, 17, and 18. The base divided portions 16, 17, and 18 are also provided with a hole 21 concentric with the hole 13 and communicating with the hole 13, and the movable shaft 41 is accommodated in the hole 21.

  Here, the top base divided portion 16 includes a reaction product discharge port 22 communicating with the hole 13, a fluid supply hole 23 for assisting discharge of the reaction product, a base 15, and a movable shaft 41. A fluid supply hole 24 for supplying fluid to the space formed between the two is provided.

  Further, a step portion 25 having a lower surface concentric with the hole 21 is provided in the circumferential direction in the base split portion 16, and the step portion 25 and the upper surface of the base split portion 17 described later are integrated into a movable shaft. A recess is formed around the outside of 41, and a seal member 71 communicating with the fluid supply hole 27 is accommodated in the recess.

  Next, in the second base divided portion 17, a recess 28 is formed in which the inside is opened in the hole 21 and circulates, and the bush 52 is accommodated in the recess 28.

  The bottom base divided portion 18 is provided with an opening 29 into which a chain 62 or the like for driving the movable shaft 41 is inserted, and a recess 30 that opens around the hole 21 and circulates. A bush 53 is accommodated in the interior.

  The fluid supply holes 23, 24, and 27 are connected to a pump (not shown) that pressurizes and sends a fluid, for example, water, through a pipe provided with a valve, and each of the fluid supply means constitutes a fluid supply means. ing. The fluid supplied from the fluid supply holes 23, 24, and 27 has a reaction in the supercritical state or the subcritical state of several hundred degrees Celsius. May be water. In addition, the pumps, pipes and valves of each fluid supply means are not shown, but since water is used as each fluid, the pumps of each means are shared by one unit, or the valves are shared by one unit. It may be.

[Operation of Hydrothermal Reaction Treatment Apparatus 1]
Next, operation | movement of the hydrothermal reaction processing apparatus 1 is demonstrated. When an object to be treated (for example, a toxic organic substance) is supplied from the supply pipe 2 into the hydrothermal reaction treatment apparatus 1 configured as described above and in a supercritical state, the object is produced in the hydrothermal reaction treatment apparatus 1. The treated product undergoes an oxidation reaction, and the reaction product is discharged from the discharge port 22 through the hole 13.

  On the other hand, if this operation is continued, as the operating time of the hydrothermal reaction treatment apparatus 1 elapses, the amount of salt attached to the inside of the hydrothermal reaction treatment vessel 11 increases, the reaction region becomes narrower, Since the reaction product is deposited, the drive mechanism 61 is operated together with the operation of the hydrothermal reaction processing apparatus 1. Specifically, when the movable shaft 41 is rotated at a low speed (for example, about 1 rpm), the salt attached to the inside of the hydrothermal reaction processing vessel 11 is scraped off by the rotating scraper 81, and the fin of the rotating movable shaft 41 is rotated. The reaction product is pulverized or stirred by 43 so as to be easily discharged and conveyed toward the discharge port 22.

  In addition, when water is supplied to the fluid supply hole 27, the water ejected from the nozzle 44 toward the hole 13 prevents the accumulated reaction product from forming a bridge and assists the conveyance to the discharge port 22. Discharge. Furthermore, when water is supplied to the fluid supply hole 23, the supplied water conveys the reaction product to the discharge port 22 and makes it easier to discharge. When water is supplied to the fluid supply holes 23 and 27 in this way, a part of the accumulated salt dissolves, or the salt or reaction product is slurried or even in the form of granules or powder even if it does not dissolve. Salt and reaction products are fluidized.

  When water is supplied to the fluid supply hole 24, the water rises from the lower side to the upper side in the space formed between the hole 21 of the base 15 and the movable shaft 41 and closed at one end by the seal member 71. Then, it flows out to the discharge port 22.

  In the hydrothermal reaction processing apparatus 1 described above, in the present embodiment, the metal material for the hydrothermal reaction processing apparatus of the present invention is used as the constituent material of the hydrothermal reaction processing container 11, so that the hydrothermal reaction process is performed in a supercritical state. Even when the above is performed, since the corrosion amount of the container 11 is about 1 mm per year, the corrosion resistance is extremely excellent. And the hydrothermal reaction processing apparatus 1 which is excellent in corrosion resistance and highly reliable can be provided suitably.

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the embodiment shown in FIG. 1 described above, an example in which the metal material for a hydrothermal reaction treatment device of the present invention is applied as a constituent material of the hydrothermal reaction treatment vessel 11 in the hydrothermal reaction treatment device 1 is shown. However, it is not limited to this, It is good also as an aspect applied as the lining material 14 of the said container 11 formed with the predetermined base material, as shown in FIG.

FIG. 2 shows the hydrothermal reaction processing apparatus of FIG. 1 in which the metal material for a hydrothermal reaction processing apparatus of the present invention is applied to the inner surface of the cylindrical portion 12 of the hydrothermal reaction processing container 11 formed of a predetermined base material. It is the longitudinal cross-sectional view which showed the aspect arrange | positioned as the lining material.
In the present embodiment, the metal material for a hydrothermal reaction treatment device of the present invention is used as the lining material 14 for the cylindrical portion 12 of the hydrothermal reaction treatment vessel 11 formed of a predetermined base material in this way. Since the hydrothermal reaction processing apparatus 1 is formed by application, the entire hydrothermal reaction processing container 11 shown in FIG. 1 can be enjoyed by the apparatus 1 composed of the metal material for hydrothermal reaction processing apparatus of the present invention. In addition to actions and effects, material costs can be reduced.
Furthermore, the metal material for a hydrothermal reaction processing apparatus of the present invention may be applied as a constituent material of the supply pipe 2, and a thermocouple (not shown) for measuring the temperature inside the hydrothermal reaction processing vessel 11 is protected. The metal material for a hydrothermal reaction treatment device of the present invention may be applied to a protective tube (not shown).

  In the above-described embodiment, the base 15 is configured by the divided portions 16, 17, and 18 having three layers, and the fluid supply holes 23, 24, and 27 are provided in the base 15. The configuration of 15 is not limited to this, and there is no problem even if it is formed integrally. Further, for the fluid supply holes 23, 24, and 27, for example, the fluid may be supplied only from the fluid supply hole 27. Furthermore, the fluid is supplied from the fluid supply hole 24 to the space where one end side is closed by the seal member 71 and the other end side communicates with the interior of the hydrothermal reaction processing vessel 11 and is discharged to the discharge port 22. A discharge port different from the outlet 22 may be provided in the base 15 and the fluid may be discharged from the discharge port.

  Further, in the above-described embodiment, the base 15 is provided on the lower side of the cylindrical portion 12, but the base 15 may be provided on the upper side of the cylindrical portion 12, and in this case, the discharge port 22 and the discharge assisting The fluid supply hole 23 may be provided separately on the lower side. The movable shaft 41 has been described as rotating. However, the movable shaft 41 is rotated in the forward and reverse directions, moved up and down, and the movable shaft 41 is rotated or rotated, for example, using a cam mechanism. It may be moved up and down or vibrated using a vibrator.

  Further, the movable shaft 41 is formed to be supported rotatably with respect to the base 15 by a shaft holding mechanism 51 including bushes 52 and 53 and a thrust washer 54 that supports the lower surface of the movable shaft 41. Although the configuration is shown, the configuration of the movable shaft 41 is not particularly limited to the above configuration as long as the movable shaft 41 is rotatable.

  And although the fin 43 was provided in the movable shaft 41 as a grinding | pulverization means, a stirring means, and a conveyance means, you may provide any one or more of the means which have the other structure which functions similarly. Furthermore, if a transfer means such as a screw is provided at the discharge port 22, the salt and the reaction product can be discharged from the discharge port 22 more efficiently. Of course, the reaction product includes inorganic solids such as ash contained in the reaction object.

In addition, the best configuration for carrying out the present invention is disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. In other detailed configurations, those skilled in the art can make various modifications.
Accordingly, the description limiting the shape and the like disclosed above is an example for easy understanding of the present invention and does not limit the present invention. The description in the name of the member excluding a part or all of the limitation is included in the present invention.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by these Examples.

[Examples 1 to 5 and Comparative Examples 1 to 7]
Preparation of test piece:
A metal material (Ni-based alloy material) for hydrothermal reaction treatment equipment having the prescriptions of Examples 1 to 5 and Comparative Examples 1 to 7 consisting of chemical components shown in Table 1 has a thickness of 1.6 mm and a length of 10 cm. A test piece was prepared by polishing the surface of the wire with # 1200 emery paper. As other components, W (tungsten), Co (cobalt), Nb (niobium), Ta (tantalum), Ti (titanium), Al (aluminum), Cu (copper), Fe (iron), Si ( Silicon).

(Components of Ni-based alloy materials)

[Test Example 1]
Corrosion test (1):
FIG. 3 shows a schematic diagram of the test apparatus 100 used for the corrosion test. This test example was obtained from the chemical components shown in Table 1 in a highly corrosive environment in which Na ₂ SO ₄ (sodium sulfate) was present as an inorganic salt in a supercritical hydrothermal oxidation reaction system using the test apparatus 100 shown in FIG. The corrosion behavior of the test piece (metal material for hydrothermal reaction treatment equipment) is confirmed, and the corrosion resistance of the test piece is compared and evaluated.

The apparatus shown in FIG. 3 includes a reaction vessel 110 including an outer vessel 111 and an inner vessel 112, a reaction furnace 120 that heats the reaction vessel 110, a liquid feed pump 130 that feeds fluid into the reaction vessel 110, and a fluid heating device. The preheating furnace 140 is provided as a basic configuration. Further, the reaction vessel 110 is provided with a pressure gauge 150 for measuring the pressure in the vessel and thermocouples 115 and 116 for measuring the temperature in the vessel. The pressure in the reaction vessel 110 is controlled by a connected pressure regulating valve 160. In addition, a cooler 170 is provided between the reaction vessel 110 and the pressure adjustment valve 160, and high-temperature steam and oxygen (described later) discharged from the reaction vessel 110 are cooled before being sent to the pressure adjustment valve 160. .
Of the reaction vessels 110, the inner vessel 112 is made of a material made of Ti having excellent corrosion resistance, the outer vessel 111 is made of a material made of SUS316, and the capacity of the reaction vessel 110 is about 370 mL.

Hereinafter, the procedure of Test Example 1 will be described. In this test example, 5 g of Na ₂ SO ₄ (sodium sulfate) is used as the salt 200 used for the evaluation, and the depth is filled in the lower part of the inner container 112 from the bottom of the inner container 112 to 50 mm, and is subject to corrosion evaluation. The test piece A was embedded in the Na ₂ SO ₄ so as to contact the bottom of the inner container 112 as shown in FIG. Then, the inner container 112 into which the test piece A was inserted was mounted in the outer container 111 to form the reaction container 110.

Next, the reactor 120 was heated so that the temperature became 650 ° C. By setting the reaction furnace to 650 ° C., the inside of the reaction vessel 110 can be brought into a supercritical state together with the pressure described later. In addition, one thermocouple 115, 116 is inserted into the reaction vessel 110 heated by the reaction furnace 120 from above and below the outer vessel 111, respectively, and the thermocouple 115 inserted from above is sent later. The thermocouple 116 inserted from the lower side of the temperature of the fluid fed from the liquid pump 130 contacts the bottom surface of the inner container 112, thereby burying the test piece A in the salt 200 (Na ₂ SO ₄ ) in the inner container 112. The temperature is measured at the location. Moreover, since the temperature in the location where the test piece A was buried in the salt 200 is required to perform the test, the temperature control of the reaction furnace 120 was performed by the thermocouple 116 inserted from the lower side.

  When the temperature of the reaction furnace 120 reached 650 ° C., water was fed into the reaction vessel 110 from the liquid feed pump 130. Regarding the amount of water to be fed, while checking the temperature measured by the thermocouple 115 inserted from above, keep the temperature at this position below 400 ° C., for example, so that the temperature does not fall below the critical temperature of water. And I tried to send water.

  When water is supplied by the liquid feed pump 130 in this way, the water becomes steam in the upper part of the preheating furnace 140 and the reaction furnace 120 and is supplied into the reaction furnace 120, and the pressure is increased according to the supply amount of water. It rises. The pressure regulating valve 160 connected to the reaction vessel 110 is set so that the pressure can be controlled to 25 MPa, which is the critical pressure of water. When the set pressure is reached, the pressure regulating valve 160 holds the reaction furnace 120 at a constant pressure, and the reaction vessel 110 reaches a supercritical state in this state.

  When the inside of the reaction vessel 110 reached a supercritical state, the fluid sent by the liquid feed pump 130 was switched from water to diluted hydrogen peroxide solution (a 45% concentration hydrogen peroxide solution reagent was diluted four times with water). Here, the hydrogen peroxide solution is used as an oxidation source, and when heated through the preheating furnace 140, most of it is separated into oxygen and water and supplied into the reaction vessel 110. In this test example, when a corrosion phenomenon occurs in the reaction vessel 110, oxygen is consumed. Therefore, it is necessary to continue supplying a certain amount of oxygen into the reaction vessel 110. Therefore, the diluted hydrogen peroxide solution was supplied at 1 mL / min.

  The diluted hydrogen peroxide solution is kept in the supercritical state as described above and continuously supplied for 100 hours, and then the fluid to be supplied is returned to water, and further, the supply of water is stopped and the pressure is removed in an open state. 110 was cooled. After cooling, the test piece A was taken out from the reaction vessel 110, and the corrosion amount of the test piece A was calculated and compared / evaluated according to the following measurement method. The results are shown in Table 2.

(Measurement method of corrosion amount)
The test piece A after the test was cut at a position corresponding to 25 mm from the bottom of the inner container 112 and embedded with an epoxy resin for microscope observation, and then the observation surface was polished to a mirror surface to obtain an observation sample. . This observation sample is set on a table that can be slightly moved with a micrometer in the X-axis and Y-axis directions, and an optical microscope is used to check the remaining radius of the uncorroded portion of the sample while performing a microscopic examination. The difference from the radius of the test piece A before the test was evaluated as the amount of corrosion.

  For evaluation of the corrosion amount, a corrosion amount of 1 mm per year, which is considered to be practical as an apparatus material, was used as a reference value. Assuming that the corrosion progresses linearly, this value (1 mm / 1 year) corresponds to 11.4 μm at 100 hours, which is the test time of this test example. Evaluation was made using the standard value.

(Result)

As can be seen from the results in Table 2, the metal materials for hydrothermal reaction treatment apparatuses of Examples 1 to 5 have a very small amount of corrosion per 100 hours, which is a level far below the standard value of 11.4 μm. It was. On the other hand, all of the metal materials of Comparative Examples 1 to 7 greatly exceeded the reference value and were inferior in corrosion resistance.
Specifically, in the case where the Mo component is not added (Examples 1 to 4, Comparative Example 1), the corrosion resistance is improved with the increase of the Cr component content, and the Cr content is 14% by mass or more. If it exists, it became a level which is less than the reference value (11.4 μm) of the corrosion amount, and it was confirmed that the corrosion resistance was extremely excellent.

Moreover, in what added Mo component (Example 5, Comparative Examples 2-7), although corrosion resistance worsens with the increase in content of Mo component, content of Mo is 2. If it was 0 mass%, it became a level which is less than the reference value (11.4 μm) of the corrosion amount, and it was confirmed that the corrosion resistance was extremely excellent.
From the above results, in the metal material for a hydrothermal treatment apparatus used in a highly corrosive environment such as a hydrothermal reaction in a supercritical state or a subcritical state, the content of Cr is 14 with Ni as a main component. By setting the content to -30% by mass and substantially not containing Mo, or 2.0% by mass or less, the degree of corrosion associated with the hydrothermal reaction in the highly corrosive environment can be suppressed to about 1 mm or less per year. It was confirmed that a metal material for a hydrothermal reaction treatment apparatus could be provided.

[Test Example 2]
Corrosion test (2):
In the test example 1 described above, a corrosion test was performed using the same method as in the test example 1 except that the salt used was changed from sodium sulfate (Na ₂ SO ₄ ) to the same amount of Na ₂ CO ₃ (sodium carbonate). Performed and evaluated. The results are shown in Table 3.

(Result)

  As can be seen from the results in Table 3, even when the salt is sodium sulfate, the metal materials for the hydrothermal reaction processing devices of Examples 1 to 5 are at a level significantly lower than the standard value of 11.4 μm. It was confirmed that the metal material was excellent in corrosion resistance in a highly corrosive environment. From this result, as described in Test Example 1, in the metal material for a hydrothermal reaction processing apparatus used in a highly corrosive environment such as a hydrothermal reaction such as a supercritical state, Ni is the main component, Cr By making the content of 14-30% by mass and substantially not containing Mo, or 2.0% by mass or less, the degree of corrosion associated with the hydrothermal reaction in the highly corrosive environment is about annually. It has been confirmed that a metal material for a hydrothermal reaction treatment apparatus that can be suppressed to 1 mm or less can be provided.

[Test Example 3]
Corrosion test (3):
In Test Example 1 described above, the salt used was changed from sodium sulfate (Na ₂ SO ₄ ) to 5 g of a mixed salt of Na ₂ SO ₄ (sodium sulfate) and Na ₂ CO ₃ (sodium carbonate) (mass ratio 1: 1). Evaluation was performed using the same method as in Test Example 1 except that. The results are shown in Table 4.

(Result)

  As can be seen from the results in Table 4, even when the salt is a mixed salt of sodium sulfate and sodium carbonate, the metal material for the hydrothermal reaction treatment apparatus of Examples 1 to 5 is the standard value of 11.4 μm. It was confirmed that the metal material was excellent in corrosion resistance in a highly corrosive environment. From these results, as described in Test Example 1 and Test Example 2, Ni is mainly used in the metal material for hydrothermal reaction processing equipment used in a highly corrosive environment such as a hydrothermal reaction in a supercritical state or the like. As a component, the content of Cr is set to 14 to 30% by mass, and the content of Mo is not substantially contained or is set to 2.0% by mass or less, so that the corrosion caused by the hydrothermal reaction in the highly corrosive environment is reduced. It was confirmed that a metal material for a hydrothermal reaction processing apparatus capable of suppressing the degree to about 1 mm or less per year can be provided.

  The metal material for a hydrothermal reaction treatment device and the hydrothermal reaction treatment device of the present invention are hydrothermal reaction treatments performed in a supercritical state or subcritical state exceeding the critical point of water, for example, dioxin, PCB, chlorofluorocarbon, etc. It can be used as a metal material for hydrothermal reaction treatment equipment used in hydrothermal treatment systems that perform hydrothermal reaction treatment for the purpose of decomposition of hazardous waste, energy generation or chemical production, and hydrothermal reaction treatment equipment it can.

The longitudinal cross-sectional view which shows schematic structure of one Embodiment of the hydrothermal reaction processing apparatus of this invention. The longitudinal cross-sectional view which shows schematic structure of other embodiment of the hydrothermal reaction processing apparatus of this invention. Schematic which shows the testing apparatus used in Test Example 1-Test Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hydrothermal reaction processing apparatus, 11 ... Hydrothermal reaction processing container, 12 ... Cylindrical part, 14 ... Lined material, 15 ... Base, 23, 24, 27 ... Fluid supply hole, 41 ... Movable shaft, 44 ... Nozzle , 81 ... scraper

Claims (3)

    A metal material for a hydrothermal reaction treatment device constituting a hydrothermal reaction treatment device used in a hydrothermal reaction in a supercritical state or a subcritical state, wherein Ni is a main component and the content of Cr is 14-30. A metal material for a hydrothermal reaction treatment apparatus, characterized in that the metal material is made of a Ni-based alloy having a Mo content of 2.0% by mass or less.     A metal material for a hydrothermal reaction treatment device constituting a hydrothermal reaction treatment device used in a hydrothermal reaction in a supercritical state or a subcritical state, wherein Ni is a main component and the content of Cr is 14-30. A metal material for a hydrothermal treatment apparatus, characterized in that it is made of a Ni-based alloy that is mass% and does not substantially contain Mo.     A hydrothermal reaction treatment device (1), characterized in that the metal material for a hydrothermal reaction treatment device according to claim 1 or 2 is used.

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