JP2002355697A - Supercritical water oxidative decomposition apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supercritical water oxidative decomposition apparatus for sewage sludge or the like capable of eliminating the defect of a conventional supercritical water oxidative decomposition apparatus for sewage sludge or the like, generating no pressure loss even if scale adheres and enabling the easy peeling of scale and stable continuous operation. SOLUTION: In the apparatus wherein organic matter containing inorganic matter is reacted with an oxidizing agent in supercritical water to be subjected to supercritical water oxidative decomposition, pressure supply means 26 and 28 for supplying organic matter, water and an oxidizing agent under pressure not less than the critical pressure of water, a reactor 10 for performing the supercritical water oxidation reaction of a mixed fluid to be treated consisting of the organic matter, water and the oxidizing agent supplied under pressure from the pressure supply means, a cooling means 16 for cooling the treated fluid after reaction flowing out of the reactor and taking-out means 20 and 22 for taking out the treated fluid flowing out of the reactor are provided. A preheating means 12 for preheating the mixed fluid to be treated to <200 deg.C is provided to the front stage of the reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercritical hydroxylation / decomposition apparatus effective for preventing scale.

[0002]

2. Description of the Related Art Heretofore, as a method of oxidizing sewage sludge and the like, a method of mainly incineration has been generally used. However, since the sewage sludge has a high water content of 97 to 98%, in order to incinerate the sewage sludge, the sewage sludge is previously dehydrated by a dehydration means such as a screw press type dehydrator.
It was necessary to reduce the water content to the extent that it could be incinerated.

On the other hand, in recent years, a method of directly oxidizing sewage sludge using water in a supercritical state has been proposed.

[0004] However, when the sewage sludge is subjected to the supercritical water oxidation treatment, if the inorganic substances contained in the sludge settle as solids, there is a possibility that the pipe of the supercritical water oxidation apparatus may be clogged, and the supercritical water may be stably superposed. Oxidation treatment cannot be performed. To prevent blockage, ensure that solids do not settle,
It is necessary to make the flow velocity of the mixed fluid of the object to be processed at least a certain value. Therefore, the flow path of the fluid needs to have a certain thickness including the reactor.

[0005] Further, sewage sludge has a low concentration of organic substances contained therein and does not generate a large amount of heat. Therefore, in order to oxidize sewage sludge with supercritical water, it is necessary to preheat the sewage sludge.

Referring to FIG. 7, a conventional supercritical water oxidation apparatus for supercritical water oxidation of sewage sludge will be described. FIG. 7 is a flow sheet showing a configuration of a conventional supercritical water oxidation apparatus. As shown in FIG. 7, the conventional supercritical water oxidation apparatus 50 includes a tubular long pressure-resistant closed reactor 51 as a reactor for performing a supercritical water oxidation reaction, and upstream of the reactor 51, A sewage sludge pump 59 for supplying sewage sludge, an air compressor 60 for supplying oxygen, and a double-pipe heat exchanger 52 for preheating the reactants are provided downstream of the reactor 51. A vessel 53 and a cooler 54 are provided. By cooling the reaction product in the heat exchanger 53, the temperature of the heat medium becomes high, and the heat medium is used as a heat source in the double-tube heat exchanger 52 for preheating the mixed fluid to be processed. Further, the supercritical water oxidation device 50 includes a pressure control valve 55 for controlling the pressure in the reactor 51.
Downstream of the cooler 54, a gas-liquid separator 56 for gas-liquid separation of the reaction product into gas and slurry, downstream of the pressure control valve 55, and solid-liquid separation of the slurry-like reaction product, A solid-liquid separator 57 for separating an inorganic solid from a reaction product is provided. The inorganic solid separated by the solid-liquid separator 57 is
It is mainly contained in the reaction product and has not contributed to the reaction, and may additionally contain a salt generated by the supercritical hydroxylation reaction.

[0007] As shown in FIG. 7, the reactor including the preheating section is a pipe having the same diameter.
Is used, a mixture to be treated of sewage sludge and oxygen flows through the inner tube, and a high-temperature heat medium flows through the outer tube.

In this case, the double tube heat exchanger 52 of the preheating section is used.
Since a high-temperature heat medium flows through the outer tube, a thermal gradient is generated in the inner tube in the radial direction, and the temperature near the inner wall of the inner tube is the highest.

On the other hand, sewage sludge contains various scale components as inorganic substances. Among them, Ca salts and the like have a property of decreasing in solubility with increasing temperature and precipitating. Therefore, deposition of the scale component proceeds most on the inner wall of the inner tube. When the dissolved scale component precipitates on the inner wall of the pipe, it adheres to the inner wall of the pipe as a scale, and the pipe diameter decreases. Furthermore, the attached scale becomes a seed crystal,
Further, it promotes deposition and adhesion of scale components.

[0010] As described above, scale is easily formed and adhered in the preheating portion of the supercritical water oxidation apparatus, and as a result, the heat transfer efficiency is reduced and the pipe pressure loss is increased due to the decrease in the pipe diameter. It becomes difficult to continuously operate the critical water oxidation apparatus.

It is also conceivable to add a scale inhibitor to the sewage sludge, but when the scale inhibitor is added,
The generation of scale cannot be prevented only when the temperature at which the scale is generated slightly increases.

[0012]

The problem to be solved by the present invention is to solve the problems of the conventional supercritical water oxidation apparatus such as sewage sludge, to prevent the adhesion of scale, and to prevent the adhesion of scale. An object of the present invention is to provide a supercritical water oxidation apparatus for sewage sludge or the like that can easily remove scale without pressure loss and that can be stably operated continuously.

[0013]

Means for Solving the Problems The present inventors have studied the mechanism of scale formation in the method of supercritical water oxidation of sewage sludge, and have found that the liquid temperature is less than 20 in the preheating section.
It has been found that scale is intensively generated in a portion of about 0 to 350 ° C.

The scale is formed mainly by dissolving scale components which precipitate on the pipe wall. For scale components that have already been deposited, depending on their adhesion,
Since it is suspended as a suspension in the fluid, it does not easily adhere to the pipe as a scale.

At 350 ° C., since almost all of the scale components are precipitated, they do not adhere to the inner tube wall as scale.
It is considered that scale formation was not remarkable at a temperature exceeding 350 ° C.

The present invention has been made on the basis of the above-described findings, and is intended to prevent the formation of scale by suppressing the heating in the preheating portion to less than 200 ° C. and to reduce the heating in the preheating portion to less than 200 ° C. After the suppression, a portion for pre-heating or holding at 200 to 350 ° C. to positively precipitate the scale is provided.

That is, in order to solve the above-mentioned problem, the present invention is directed to an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically hydrolyze the organic substance. Pressurizing and supplying means for pressurizing water and an oxidizing agent at a pressure equal to or higher than the critical pressure of water; A supercritical hydroxylation decomposition apparatus comprising: a reactor for performing an oxidation reaction; cooling means for cooling the processed fluid flowing out of the reactor after the reaction; and take-out means for removing the cooled processing fluid flowing from the cooling means. The mixed fluid to be treated is placed at a stage before the reactor for 200 hours.
The present invention relates to an apparatus for supercritically hydrolyzing and decomposing an organic substance containing an inorganic substance, which is provided with a preheating means for preheating the organic substance to a temperature lower than 0 ° C.

According to a second aspect of the present invention, there is provided an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically hydrolyze the organic substance. Supply means for pressurizing and supplying an oxidizing agent and a scale inhibitor to a pressure higher than the critical pressure of water, and an object to be treated comprising an organic substance, water, an oxidizing agent and a scale inhibitor supplied by pressure from the pressure supplying means A reactor for performing a supercritical water oxidation reaction of the mixed fluid, cooling means for cooling the processed processing fluid flowing out of the reactor, and removing means for taking out the cooled processing fluid flowing out of the cooling means are provided. A supercritical hydroxylation / decomposition apparatus, wherein a pre-heating means for preheating the mixed fluid to be treated to a temperature of less than 300 ° C. is provided in a preceding stage of the reactor. Seki Is shall.

According to a third aspect of the present invention, there is provided an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically hydrolyze the organic substance. Supply means for pressurizing and supplying an oxidizing agent at a pressure equal to or higher than the critical pressure of water, and a supercritical water oxidation reaction of a mixture fluid to be treated comprising an organic substance, water and an oxidizing agent pressurized and supplied from the pressurizing supply means And a cooling means for cooling the reaction fluid after the reaction flowing out of the reactor,
A supercritical hydroxylation decomposition apparatus comprising a take-out means for taking out a cooled processing fluid flowing out of the cooling means,
A pre-heating means for preheating the mixed fluid to be treated to a temperature of less than 200 ° C. in a stage preceding the reactor; The present invention relates to an apparatus for supercritically decomposing organic substances including inorganic substances, which is provided with a scale component precipitation means for preheating to 350 ° C. to deposit scale components.

According to a fourth aspect of the present invention, there is provided a preheating means for preheating the mixed fluid flowing out of the scale component precipitation means to 350 ° C. or higher. The present invention relates to a supercritical hydroxylation decomposition apparatus according to claim 3.

According to a fifth aspect of the present invention, there is provided an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically decompose the organic substance, the method comprising the steps of: And an oxidizing agent for pressurizing the oxidizing agent to a pressure equal to or higher than the critical pressure of water, and a supercritical water of a mixed fluid of the treating object comprising the organic substance, water, and the oxidizing agent pressurized and supplied from the object supplying unit. A reactor for performing an oxidation reaction;
A supercritical hydroxylation cracking apparatus comprising: a cooling means for cooling a process fluid after reaction flowing out of the reactor, and a take-out means for taking out a cooled process fluid flowing from the cooling means, wherein Preheating means for preheating the mixed fluid to be processed to less than 200 ° C., and flowing the mixed fluid flowing out of the preheating means as a downward flow through a flow path having a large diameter to maintain the temperature around 200 ° C. A scale component depositing means for depositing a scale component and a preheating means for preheating a mixture fluid to be processed flowing out of the scale component depositing means to a predetermined temperature. It relates to a critical hydroxylation decomposition apparatus.

According to a sixth aspect of the present invention, there is provided the present invention, wherein the scale component depositing means is provided with a scale scraping means for scraping scale deposited on the inner wall. Any one of claims 3 to 5
The present invention relates to the supercritical hydroxylation decomposition apparatus described in the section.

According to a seventh aspect of the present invention, there is provided a method for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically decompose the organic substance. A supercritical hydroxylation decomposition method in which a mixed fluid of an organic substance, water and an oxidizing agent is supercritically hydroxylated in a reactor by pressurizing and supplying an oxidizing agent at a pressure higher than the critical pressure of water. The present invention relates to a method for supercritically hydrolyzing an organic substance containing an inorganic substance, which comprises pre-heating a pressure-supplied mixed fluid to be processed before a reaction to less than 200 ° C.

[0024] In order to solve the above-mentioned problem, the present invention as set forth in claim 8, is characterized in that the premixed pre-heated mixed fluid of the object is mixed with 2 fluids.
The supercritical hydroxylation decomposition method according to claim 7, wherein a supercritical hydroxylation reaction is performed in a reactor after preserving or preheating at 00 to 350C to precipitate scale components. .

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The supercritical hydroxylation decomposition apparatus of the present invention is provided with a reactor for oxidatively decomposing organic substances including inorganic substances in the presence of supercritical water and an oxidizing agent. The supercritical hydroxylation reaction performed in the reactor is not particularly limited as long as the temperature and pressure conditions bring water into a supercritical state.
The temperature may be in the range of 00 to 650 ° C. and the pressure of 22 MPa or more, preferably 22 to 25 MPa. Examples of the oxidizing agent include air, pure oxygen, hydrogen peroxide, and liquid oxygen. These oxidizing agents may be used in a stoichiometrically required amount or more. The reactor for performing the supercritical hydroxylation decomposition may be any of a pipe (tubular) type and a vessel type.

Since water is a good solvent for organic substances and gaseous substances in the supercritical state, the supercritical water, organic substances and oxidizing agent form a homogeneous phase in the reactor, and the supercritical water oxidation reaction The organic matter is oxidatively decomposed in a very short time.

(First Embodiment) In the first embodiment, a preheating means for preheating a mixed fluid to be processed to less than 200 ° C. is provided before a reactor for oxidizing an organic substance containing an inorganic substance in supercritical water. It is characterized by having been provided. By setting the heating temperature in the preheating section to less than 200 ° C., the generation of scale is suppressed, and the scale is prevented from adhering to the preheating means. The temperature of the mixed fluid in the pre-heating means is less than 200 ° C., preferably 150 to
180 ° C. Set the heating temperature in the preheating means to 20
By setting the temperature to less than 0 ° C., remarkable scale generation is suppressed, a decrease in heat transfer efficiency and an increase in pressure loss are suppressed, and a long-time continuous operation becomes possible.

The temperature of the mixture fluid to be processed flowing in the flow path changes due to fluctuations in pressure, concentration of the processing object, and the like.
It is difficult to control the temperature exactly. Therefore,
The term “less than 200 ° C.” in the present invention may be a temperature at which the temperature of the mixed fluid to be treated is generally less than 200 ° C., for example, less than 200 ± 20 ° C.

[0029] The mixed fluid of the object to be treated is 200
There is no particular limitation on the method of heating the mixture to a temperature lower than ℃, but for example, the heat of the processing fluid flowing out of the reactor may be recovered by a heat exchanger and used.

As the pre-heating means, a double-pipe heat exchanger can be mentioned, and the cooling means provided at the latter stage of the reactor is also a double-pipe heat exchanger, both of which are connected by piping, and the heat medium is supplied. Heat exchange may be performed by flowing the fluid to preheat the mixture fluid to be treated and cool the treated fluid after the reaction.

The first embodiment of the present invention will be described with reference to the flowchart of FIG.

As shown in FIG. 1, the supercritical water oxidation apparatus of the present invention comprises a long tubular pressure-resistant closed reactor 10 as a reactor for performing a supercritical water oxidation reaction.
Upstream of 0, an object supply pump 26 for supplying an object fluid such as sewage sludge under pressure, an oxidant supply pump 28 for supplying an oxidant under pressure, and a double pipe for preheating the object mixture fluid A preheater 12 of the type heat exchanger is provided, and a downstream heat exchanger 14 of a double tube type and a cooler 16 for cooling the processing fluid are provided downstream of the reactor 10. Further, the supercritical hydroxylation decomposition apparatus includes a pressure control valve 18 for controlling the pressure in the reactor 10 downstream of the cooler 16 and a gas-liquid separator 20 for gas-liquid separation of the processing fluid into gas and slurry. A solid-liquid separator 22 is provided downstream of the control valve 18 and separates a solid reaction product from the reaction product by solid-liquid separation of a slurry-like reaction product. The inorganic solid separated by the solid-liquid separator 22 is mainly contained in the reaction product and has not contributed to the reaction, and may also contain a salt generated by the supercritical water oxidation reaction. is there.

The pre-heater 12 is a double-pipe heat exchanger comprising an inner pipe through which a mixed fluid of the processing object and an oxidant flows, and an outer pipe for heating the mixed fluid of the processing object. In the pre-heater 12, in order to suppress the generation of scale,
It is necessary to control the temperature of the mixture fluid to be processed to less than 200 ° C.

The mixed fluid pre-heated to less than 200 ° C. is supercritically hydroxylated in the reactor 10. In the case where the object to be treated is sewage sludge, etc., when the calorific value is insufficient and the temperature does not reach the critical temperature in the reactor 10, an organic substance as an auxiliary fuel is added to the object to be treated in advance, so that supercritical water oxidation proceeds. Good.

In supercritical water, in the presence of an oxidizing agent, organic substances in the object to be treated are quickly oxidized and decomposed into carbon dioxide, water and the like. A processing fluid consisting of decomposition products, inorganic substances and supercritical water flows out of the reactor 10.

A part of the heat of the high-temperature and high-pressure processing fluid is recovered by a double-pipe heat exchanger 14 provided downstream of the reactor 10. The heat exchanger 14 and the preliminary preheater 12 are connected to the pipe 2
4, the heating medium is circulated, and the heated heating medium is supplied to the pre-heater 12 and the mixed fluid at 200 ° C.
Heat to less than.

The processing fluid from which part of the heat has been recovered is cooled by the cooler 16 to room temperature. The cooled processing fluid is extracted as a processing liquid, an inorganic solid, and an exhaust gas by an extracting unit. Examples of the extracting means include a pressure control valve 18 for controlling the pressure of the cooled processing fluid, a gas-liquid separator 20 for separating the processing fluid released to the atmospheric pressure, and a solid-liquid separator 22.

If the temperature of the mixed fluid flowing out of the preheating means exceeds 200 ° C., scale is generated, and if it is too low, a larger amount of auxiliary fuel is required.
It is necessary to strictly control the temperature of the mixed fluid flowing out of the preheating means to about 200 ° C.

An example for controlling the temperature of the fluid mixture to be processed to less than 200 ° C. is shown in the flow chart of FIG.

Since the mixed fluid to be processed is not heated to a temperature higher than the temperature of the heat medium, first, the maximum temperature of the heat medium is set to 200 ° C.
It is effective to increase the maximum temperature of the heat medium according to the heat transfer efficiency and the heat transfer due to the scale. In order to control the temperature of the heat medium, water is used as the heat medium, and its pressure and flow rate are controlled.

Since a large amount of latent heat of evaporation is required for water to evaporate, it is relatively easy to control the maximum temperature of the heating medium in the pre-heater 12 to be close to the boiling point. When the temperature is higher than near the boiling point, the flow rate may be increased, and when the temperature is lower than the boiling point, the flow rate may be decreased. Further, the boiling point can be controlled by the pressure.

As shown in FIG. 2, in order to control the temperature of the fluid mixture to be processed to less than 200.degree.
Thermometer 31 that measures the temperature of the mixed fluid flowing out of the processing object, thermometer 32 that measures the temperature of the heat medium at the inlet of the pre-heater 12, and temperature that measures the temperature of the heat medium at the outlet of the pre-heater 12. A pressure control valve 37 for controlling the pressure of the heat medium, a heat medium tank 38 for pooling the heat medium,
A heat medium circulation pump 39 for circulating the heat medium, a thermometer 33 for measuring the temperature and pressure at the inlet of the heat medium circulation pump 39, a pressure gauge 36, and a pressure for measuring the pressure at the outlet of the heat medium circulation pump 39. The total 35 includes a flow meter for measuring the flow rate of the heat medium.

Specifically, the pressure of the heat medium discharged from the heat medium circulation pump 39 is measured by the pressure gauge 35, and the temperature of the heat medium at the inlet of the pre-heater 12 is measured by the thermometer 32. When the inlet temperature of the preheater 12 is lower than the boiling point at the discharge pressure of the heat medium, the discharge amount of the heat medium circulation pump 39 is reduced, and when it is higher, the discharge amount of the heat medium circulation pump 39 is increased. Further, a thermometer 31
The preheater outlet temperature of the mixture to be treated measured in
If it is lower than 200 ° C., the discharge pressure of the heat medium circulation pump 39 is increased, and if it exceeds 200 ° C., the discharge pressure is reduced. Such control enables strict temperature control.

In this embodiment, when a scale inhibitor such as an acrylic acid polymer, a maleic acid polymer, or a phosphonic acid derivative is added to the object to be treated, the temperature of the preheater 12 is raised to less than 300 ° C. It is possible.

Although the temperature at which scale is generated increases to some extent due to the dispersing effect of the addition of the scale inhibitor, scale generation cannot be fundamentally prevented. For example, when an acrylic acid polymer having a molecular weight of 10,000 or less is used, 25
The scale generation temperature rises to 0 ° C., and when an acrylic acid polymer having a molecular weight exceeding 10,000 is used, the scale generation temperature rises to nearly 300 ° C. Therefore, the temperature of the pre-heater 12 may be set according to the performance of the scale inhibitor used.

(Second Embodiment) FIG. 3 shows a flowchart of a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The second embodiment is different from the first embodiment in that the mixed fluid flowing out of the pre-heater 12 between the pre-heat exchanger 12 and the reactor 10 is a downward flow,
This is the point that a scale component deposition means (scale component deposition section) 11 for heating to 00 to 350 ° C. and depositing the scale component is provided.

The method of preheating to less than 200 ° C. by the preliminary preheating means and the method of preheating to 200 to 350 ° C. in the scale component precipitation section are not particularly limited. For example, the heat of the processing fluid flowing out of the reactor is transferred to the heat exchanger. It can be collected and used.

It is difficult to strictly control the temperature of the mixed fluid flowing through the scale component deposition section to 200 to 350 ° C. In the present invention, 200 to 350 ° C. refers to the temperature of the mixed mixed fluid. Is about 200 to 350 ° C., for example, 200 ± 20 to 350 ± 35 ° C.

The pipe portion of the supercritical hydroxylation decomposition apparatus has a pipe diameter capable of securing a flow rate of 0.5 m / s or more at room temperature in order to prevent sedimentation of inorganic solids. On the other hand, it is preferable that the pipe diameter of the portion of the preheating means where the scale component is deposited (hereinafter, abbreviated as the scale component deposition portion) is made 50 mm or more larger than the above-mentioned pipe diameter. By increasing the flow path diameter of the mixture fluid to be treated in the scale component deposition means, even if the scale adheres to the scale component deposition portion, an increase in pressure loss can be suppressed.

As shown in FIG. 3, the scale component precipitation means 11 is a double-pipe heat exchanger, in which the diameter of the heated portion is increased, and the scale component deposition section is used as a downward flow. As shown in FIG. 3, it is preferable that the outlet side of the pre-heater 11 for the mixed fluid to be treated has a cone shape in order to eliminate the portion where the inorganic solid matter is deposited. After the outlet of the preheater 11, a constant flow rate can be secured by making the pipe diameter the same as or close to the original pipe diameter in order to prevent sedimentation of the inorganic solid matter in the pipe. Thereby, the blockage of the pipe due to the sedimentation of the inorganic solid can be prevented.

The pre-heater 12, the pre-heater 11, and the heat exchanger 14 are connected to each other by a pipe 24, and the temperature is controlled by circulating a heat medium.

As described above, the type of the scale component deposition means for precipitating the scale component by preheating to 200 to 350 ° C. has a large pipe diameter, and the mixed fluid of the object to be treated flows downward.
There is no particular limitation as long as there is no portion where inorganic solid matter is deposited, the outlet is the same as or close to the original pipe diameter, and the flow rate of the mixed fluid flowing out of the preheating means is secured.

In FIG. 3, a double tube heat exchanger is exemplified as the preheater, but the present invention is not limited to this, and a coil heat exchanger, a multi-tube heat exchanger, or the like may be used.

Since the precipitation of scale components is almost completed at the portion heated to 200 to 350 ° C., if preheating at 350 ° C. or more is required, the scale may be set to the same or close to that of the other portions. There is no adverse effect due to precipitation.

Since the scale component deposition section of the preheater 11 is for the purpose of depositing scale components, the scale component deposition section may deposit scale without performing heat exchange.

(Third Embodiment) FIG. 4 shows a flowchart of a third embodiment of the present invention. The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

The third embodiment of the present invention is characterized in that a preheating means for preheating the mixed fluid flowing out of the scale component deposition section to a predetermined temperature or more is further provided in the second embodiment. And

The predetermined temperature in the present embodiment is, for example, around 350 ° C., and the scale hardly adheres at the portion exceeding 350 ° C. Therefore, even if the preheating means 13 for preheating to a predetermined temperature or more is provided, There is no hindrance to continuous operation.

FIG. 4 shows a flowchart of the third embodiment of the present invention. The same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The third embodiment is different from the second embodiment in that, after the scale component deposition section 11, the preheating of the mixed fluid flowing out of the scale component deposition section 11 to a predetermined temperature or higher is performed. The point is that the means 13 is provided.

In the case where an object to be treated having a small calorific value is to be subjected to the supercritical hydroxylation decomposition treatment without adding an auxiliary fuel, it is necessary to preheat the fluid mixture to be treated to a predetermined temperature or higher. In such a case, the present embodiment is effective.

The structure of the preheating means 13 is not particularly limited as long as the solid matter does not settle, but may be the same as the structure of the preheating means 12.

In the third embodiment, the preheating means 1
2. The method of preheating the scale component precipitation means 11 and the preheating means 13 is not particularly limited. However, similarly to the second embodiment, for example, the heat of the processing fluid flowing out of the reactor 10 is recovered by a heat exchanger. Just use it. In order to efficiently recover heat, a plurality of heat exchangers are provided, the heat medium of the first heat exchanger closest to the reactor outlet is circulated to the preheating means 13, and the second heat exchanger is provided downstream of the first heat exchanger. A heat exchanger is provided and the heat medium is circulated to the scale component precipitation means 11. Further, a third heat exchanger is provided after the second heat exchanger and the heat medium is supplied to the preliminary preheating means 12.
Should be circulated.

(Fourth Embodiment) FIG. 5 shows a flowchart of a fourth embodiment of the present invention. The same components as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

The fourth embodiment of the present invention is the same as the third embodiment, except that the scale component deposition means 11 for preheating to 200 to 350 ° C. to deposit the scale component comprises a 200 ° C.
It is characterized in that it is replaced by a scale component deposition means 11 ′ that deposits a scale component while keeping it in the vicinity.

The scale is generally formed by precipitation of components that are dissolved at a low temperature as the temperature increases and the solubility decreases. The temperature of the fluid heated from the outside of the flow channel is highest on the tube wall, and scale component precipitation is remarkable in this part.As a result, scale component deposition increases near the tube wall, and the scale is deposited on the tube wall. Adhere to. In a typical calcium salt of a scale, precipitation becomes remarkable at 200 ° C. or higher.

On the other hand, as compared with the case where the dissolved scale component is deposited, the scale component deposited in advance is less likely to adhere to the tube wall and the scale is not easily formed.

Therefore, by preserving the fluid to be treated at around 200 ° C. and precipitating the scale component, even when preheating is performed in a subsequent stage, scale formation in the preheating section is suppressed. There is no need to make the shape of the part special.

The time for maintaining the temperature around 200 ° C. by the scale component deposition means 11 ′ may be appropriately selected, for example, from 30 seconds to 1 minute.

(Fifth Embodiment) The fifth embodiment of the present invention relates to an apparatus for removing scale deposited on a scale component deposition section during operation.

The scale component deposition part of the above-mentioned preheating means is:
Since the pipe diameter is increased, a means for scraping the scale can be provided inside.

FIG. 6A shows the scale component deposition section 11.
It is explanatory drawing which provided the scale scraper 40 inside (11 '), and FIG.6 (b) is explanatory drawing of the scale scraper 40. FIG.

The scale scraper 40 is provided with a ring-shaped scraper 42 that is in close contact with the inner wall of the scale component deposition unit 11.
And a support body 44 for supporting the scraping section 42, a connecting body 46 for connecting the scraping section 42 and the support body, and a movable support body 48 for moving the scale scraping machine 40 up and down. The number of the movable supports 48 is not particularly limited as long as the movable supports 48 can be shifted from the center of the flow path diameter and can support the scraping section 42.

By moving the end of the movable support 48 out of the scale component deposition section 11, the movable support 48 can be moved up and down, and the scale attached to the inner wall of the scale support is scraped. It is physically dropped by the taking part 42. Therefore, even during operation, if there is a pressure loss due to scale adhesion, the scale can be removed by the scale scraper 40, and continuous operation can be performed.

As a member constituting the scale scraping machine 40, a steel bar having a diameter that does not cause an increase in pressure loss may be used.

[0077]

According to the first aspect of the present invention, the provision of the pre-heating means for pre-heating at less than 200 ° C., where the scale is small, is provided, so that the scale formation is suppressed and the supercritical hydroxylation is continuously performed. be able to.

As described in claim 2, the temperature of the preliminary preheating means can be set slightly higher by adding a scale inhibitor, and when the temperature in the reactor is increased, the temperature is increased. The burden of raising the temperature of the reactor can be reduced.

According to a third aspect of the present invention, there is provided a pre-heating means for pre-heating at a temperature of less than 200 ° C., at which scale generation is small, and a scale component precipitation means at 200 to 350 ° C. at which scale generation is remarkable. By increasing the path diameter and causing the mixture fluid to be treated to flow downward, it is possible to prevent the deposition of inorganic solids deposited at the scale component deposition section, and to reduce the pressure even if the scale adheres to the scale component deposition section. The increase in loss can be suppressed, and supercritical hydroxylation can be continuously performed.

According to the fourth aspect of the present invention, the temperature can be raised to a predetermined preheating temperature without increasing the pressure even when the scale is formed.

According to the fifth aspect of the present invention, scale formation can be suppressed without using a special structure for the preheating portion.

According to the invention of claim 6, in addition to the above-mentioned effects, even if the scale adheres to the scale component deposition portion, the scale can be removed during operation, so that the supercritical hydroxylation decomposition can be continuously performed. It can be performed.

According to the seventh aspect of the invention, by preheating at a temperature of less than 200 ° C. where the generation of scale is small, the generation of scale can be suppressed and the supercritical hydroxylation decomposition can be continuously performed.

As described in claim 8, the preheating is performed at less than 200 ° C. where the scale formation is small, and the scale formation is remarkable.
By precipitating scale components at 00 to 350 ° C., supercritical hydroxylation can be continuously performed.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment of the present invention.

FIG. 2 is a flowchart of temperature control of a preheater according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a second embodiment of the present invention.

FIG. 4 is a flowchart showing a third embodiment of the present invention.

FIG. 5 is a flowchart showing a fourth embodiment of the present invention.

FIG. 6A is an explanatory view showing a fifth embodiment of the present invention,
(B) is a partially enlarged view.

FIG. 7 is a flowchart showing a conventional supercritical water oxidation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reactor 11 Scale component deposition part 12 Preheater 14 Heat exchanger 16 Cooler 18 Pressure control valve 20 Gas-liquid separator 22 Solid-liquid separator 24 Piping 26 Workpiece pressurized supply pump 28 Oxidant pressurized supply Pumps 31 to 34 Thermometer 35, 36 Pressure gauge 37 Pressure control valve 38 Heat medium tank 39 Heat medium circulation pump 40 Scraper

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Suzugaki 1-2-8 Shinsuna, Koto-ku, Tokyo Organo Corporation (72) Inventor Shinji Ito 1-2-8 Shinsuna, Koto-ku, Tokyo Olga (72) Inventor Akira Suzuki 1-2-8 Shinsuna, Koto-ku, Tokyo Organo Corporation F-term (reference) 4D059 AA05 BC01 BC02 BK30 CB18 DA44 DA47 DB11 EA06 EA20 EB06 EB08

Claims (8)

[Claims] In an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water and supercritically decomposing the organic substance by supercritical water, the organic substance, water and the oxidizing agent are supplied under pressure higher than the critical pressure of water. A pressure supply means, a reactor for performing a supercritical hydroxylation reaction of the mixed fluid of the processing object comprising the organic substance, water and the oxidant supplied under pressure from the pressure supply means, and a reaction after the reaction flowing out of the reactor. A supercritical hydroxylation decomposition apparatus comprising: a cooling means for cooling a processing fluid; and a take-out means for taking out a cooled processing fluid flowing out of the cooling means. An apparatus for supercritically hydrolyzing an organic substance containing an inorganic substance, wherein a preheating means for preheating the organic substance to a temperature lower than a predetermined value is provided. 2. In an apparatus for reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water to supercritically decompose the organic substance, the organic substance, water, the oxidizing agent and the scale inhibitor are added to a pressure higher than the critical pressure of the water. Pressurized supply means for supplying pressure, a reactor for performing a supercritical water oxidation reaction of a mixed fluid to be processed comprising an organic substance, water, an oxidizing agent and a scale inhibitor supplied under pressure from the pressurized supply means, A supercritical hydroxylation cracking apparatus comprising a cooling means for cooling the processed processing fluid flowing out of the reactor and a take-out means for taking out the cooled processing fluid flowing out of the cooling means. A supercritical water oxidation decomposition apparatus for an organic substance containing an inorganic substance, comprising a pre-heating means for pre-heating a mixed fluid to be processed to less than 300 ° C. 3. An apparatus for reacting an organic substance containing an inorganic substance and an oxidant in supercritical water and supercritically decomposing the organic substance by supercritical water to supply the organic substance, water and the oxidant under a pressure higher than the critical pressure of water. A pressure supply means, a reactor for performing a supercritical hydroxylation reaction of the mixed fluid of the processing object comprising the organic substance, water and the oxidant supplied under pressure from the pressure supply means, and a reaction after the reaction flowing out of the reactor. A supercritical hydroxylation decomposition apparatus comprising: a cooling means for cooling a processing fluid; and a take-out means for taking out a cooled processing fluid flowing out of the cooling means. A pre-heating means for pre-heating to less than, and a scale for flowing the mixed fluid to be treated flowing out of the pre-heating means as a downward flow through a flow path having a large flow path diameter to pre-heat to 200 to 350 ° C. to precipitate scale components. Success An apparatus for supercritically decomposing organic substances including inorganic substances, the apparatus comprising analysis means. 4. The apparatus of claim 3, further comprising a preheating means for preheating the mixed fluid flowing out of the scale component precipitation means to 350 ° C. or higher. 5. An apparatus for reacting an organic substance containing an inorganic substance and an oxidant in supercritical water and supercritically decomposing the organic substance by supercritical water to supply the organic substance, water and the oxidant under a pressure higher than the critical pressure of water. A treated material supply unit, a reactor for performing a supercritical hydroxylation reaction of a mixed fluid of the treated material composed of an organic substance, water, and an oxidant supplied under pressure from the treated material supply unit, and a reaction flowing out of the reactor A supercritical hydroxylation cracking device comprising a cooling means for cooling the subsequent processing fluid, and a take-out means for taking out the cooled processing fluid flowing out of the cooling means, wherein the mixed fluid to be processed is provided at a stage preceding the reactor. 200
A pre-heating means for pre-heating at a temperature of less than ℃, and a scale for allowing the mixed fluid flowing out of the pre-heating means to flow as a downward flow through a flow path having a large flow path diameter and keeping it at about 200 ° C. to precipitate scale components An apparatus for supercritical water oxidation and decomposition of organic substances including inorganic substances, comprising: a component precipitating means; and a preheating means for preheating a mixed fluid to be processed flowing out of the scale component precipitating means to a predetermined temperature. 6. The supercritical apparatus according to claim 3, wherein said scale component deposition means is provided with a scale scraping means for scraping scale deposited on an inner wall. Hydrolysis device. 7. A method of reacting an organic substance containing an inorganic substance and an oxidizing agent in supercritical water and supercritically decomposing the organic substance, wherein the organic substance, water and the oxidizing agent are pressurized and supplied to a pressure higher than the critical pressure of water. A supercritical hydroxylation decomposition method in which a mixed fluid of an organic substance, water, and an oxidizing agent is subjected to a supercritical hydroxylation reaction in a reactor. A method for supercritically hydrolyzing an organic substance containing an inorganic substance, which comprises preheating the organic substance to a temperature lower than the preheating temperature. 8. The pre-heated mixed fluid of the object to be pre-heated,
The supercritical hydroxylation decomposition method according to claim 7, wherein a supercritical hydroxylation reaction is performed in a reactor after preserving or preheating at 200 to 350 ° C to precipitate scale components.