JP2001269566A - Supercritical water reaction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supercritical water reaction apparatus capable of stably treating a liquid to be treated in which an inorganic salt is dissolved in addition to organic matter. SOLUTION: The supercritical water reaction apparatus is constituted so as to treat the liquid to be treated in which the inorganic salt is dissolved in addition to organic matter and has the same constitution as a conventional supercritical water reaction apparatus excepting the constitution of an inlet nozzle. This apparatus has a principal part 10 equipped with an inlet nozzle 18 piercing a flange 16 closing the upper opening 14 of a vertical reactor 12 to communicate with the interior of the reactor 12 and connected to an inflow pipe 72 and a cooling jacket 20 provided as an annular opening part, which surrounds the periphery of the inlet nozzle 18, along the inlet nozzle 18 to cool the inlet nozzle 18. A supply pipe 24 for supplying a cooling medium to the cooling jacket 20 is connected to the lower end of the cooling jacket 20 and a discharge pipe 26 for discharging the cooling medium from the cooling jacket 20 is connected to the upper end of the cooling jacket 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercritical water reactor, and more particularly, to a supercritical water reactor which stably dissolves an inorganic salt in addition to an organic substance for a long period of time. The present invention relates to a supercritical water reactor capable of performing a treatment by a water reaction.

[0002]

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

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

The liquid to be treated containing an organic chlorine compound such as dioxin includes an inorganic salt which is a compound of an inorganic acid and an alkali metal or an alkaline earth metal, and a metal ion (hereinafter simply referred to as an inorganic salt). Is often dissolved. When treating a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance by a supercritical water reaction, in consideration of the extremely small inorganic salt dissolving ability of the supercritical water, a two-zone supercritical water is usually used. A reactor is used.

Here, referring to FIG. 5, a liquid to be treated containing an inorganic salt in addition to an organic substance is treated by a supercritical water reaction.
The basic configuration of a conventional supercritical water treatment device will be described. FIG. 5 is a flow sheet showing the configuration of a conventional supercritical water treatment apparatus, and FIG. 6 is a sectional view showing the configuration of an inlet nozzle. FIG.
The supercritical water treatment apparatus 60 shown in FIG. 1 is a so-called modal process type apparatus having a two-zone pressure-resistant closed vertical reactor 62 as a reactor for performing a supercritical water reaction. It has been evaluated as an optimal apparatus as a supercritical water reactor for treating a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance, or a liquid to be treated in which an inorganic salt is precipitated during supercritical water treatment.

In the upper part of the reactor 62, conditions above the critical point of water, that is, supercritical conditions are maintained, a supercritical water area 64 for retaining supercritical water is formed, and a virtual interface 66 with the supercritical water area 64 is formed. In the lower part of the reactor 62 through the sub-critical water region 68 is formed at a temperature lower than the critical temperature of water, and the sub-critical water is retained. In the upper part of the reactor 62,
An inflow pipe 72 that allows the liquid to be treated and the oxidant to flow into the supercritical water zone 64 through the inlet nozzle 70 is connected to the supercritical water area 64. As shown in FIG. 6, the inlet nozzle 70 is provided with a flange 7 for closing the upper opening of the reactor 62.
3 is provided. The flange 73 is
It is flange-connected to the body flange 62a of the reactor 62 by bolting (not shown) or the like. In FIG. 6, 70a
Is a joint for connecting the inlet nozzle 70 and the inflow pipe 72.

The inflow pipe 72 is supplied with a liquid to be treated 74 in which an inorganic substance is dissolved in addition to the organic substance to be treated by the supercritical water reaction, and air is supplied as an oxidizing agent for oxidizing the organic substance. And a supercritical water line 7 for feeding supercritical water or makeup water for producing supercritical water.
8 have joined.

A neutralizing agent line 80 for supplying an alkali neutralizing agent for neutralizing hydrochloric acid generated by the organic chlorine compound in the liquid to be treated is connected to the liquid to be treated line 74. The liquid to be treated and the neutralizing agent are introduced into the supercritical water zone 64 in the reactor 62 through the inflow pipe 72 and the inlet nozzle 70. Organochlorine compounds and other organic substances in the liquid to be treated are instantaneously oxidized and decomposed in the supercritical water area 64.
In the course of the supercritical water reaction, the chlorine of the organic chlorine compound contained in the liquid to be treated is neutralized with an alkali neutralizing agent to form a salt,
The supercritical water area 64 shifts to the subcritical water area 68. Also,
The inorganic salt dissolved in the liquid to be treated also precipitates in the supercritical water area 64 and moves to the subcritical water area 68.

A treatment liquid line 86 is further connected to the upper part of the reactor 62, and organic substances in the liquid to be treated are mainly converted into water and carbon dioxide by a supercritical water reaction, and together with the treatment liquid, a supercritical water area 64 is formed. From the processing solution line 86. Although not shown, the processing liquid line 86 is provided with a cooler for cooling the processing liquid, a pressure control valve for controlling the pressure in the reactor 62, a gas-liquid separator, and the like. If necessary, an auxiliary fuel line for supplying auxiliary fuel to a supercritical water area may be connected to the inflow pipe 72.

On the other hand, a subcritical water line 82 and a subcritical drainage line 84 are connected to a lower portion of the reactor 62. The subcritical water line 82 supplies subcritical water to the subcritical water area 68, The line 84 discharges the subcritical water in which the salt generated by the supercritical water reaction and the neutralization reaction is dissolved from the subcritical water area 68 as wastewater. Although not shown, the subcritical drain line 84 is provided with a cooler for lowering the temperature of the subcritical wastewater to a predetermined temperature, a decompression device for reducing the pressure to a predetermined pressure, a gas-liquid separation / solid-liquid separation device, and the like.

[0011]

However, in the above-mentioned conventional supercritical water reaction apparatus, when a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance is to be treated by a supercritical water reaction, an inlet nozzle of the reactor is required. However, there is a problem that it is difficult to continuously perform a stable supercritical water treatment for a long time because the clogging is performed in a relatively short time. For example, supernatant water obtained when throwing fly ash collected from a combustion furnace or the like for burning municipal garbage into water contains inorganic chlorides such as calcium chloride and calcium sulfate in addition to organochlorine compounds such as dioxin by 0.5%. It dissolves about by weight%. When this supernatant water is treated by the supercritical water reaction, calcium sulfate and calcium chloride in the liquid to be treated precipitate at the inlet nozzle of the reactor, and close the inlet nozzle in a relatively short time.

When a supercritical water reaction treatment is performed on a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance, a decomposition reaction of the organic substance may be carried out without introducing a gas oxidizing agent such as air or oxygen gas. However, at this time, particularly, the inorganic salt in the liquid to be treated tends to precipitate.

Accordingly, an object of the present invention is to provide a supercritical water reactor capable of stably treating a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance for a long time.

[0014]

The present inventors have studied the causes of the precipitation of inorganic salts and as a result found the following. That is, the temperature of the upper part of the reactor, which is in contact with the supercritical water region having a high temperature in the reactor, almost rises to a temperature close to the supercritical water, and becomes, for example, about 400 ° C. Accordingly, the temperature of the inlet nozzle provided to penetrate the upper wall of the reactor is also extremely high. As a result, it was found that as the liquid to be treated passes through the inlet nozzle, the temperature of the liquid to be treated increases and the solubility of the inorganic salt in the liquid to be treated decreases, so that inorganic salts precipitate. It has also been found that by cooling the inlet nozzle to 350 ° C. or lower, the precipitation of inorganic salts can be substantially suppressed.

In order to achieve the above object, a supercritical water reactor according to the present invention (hereinafter referred to as a first invention) includes a vertical reactor containing supercritical water, and a vessel wall of the reactor. In a supercritical water reactor for introducing a liquid to be treated into the supercritical water in the reactor from the inlet nozzle of the liquid to be treated, which is provided through, and performing a supercritical water reaction, the inlet nozzle along the inlet nozzle A cooling jacket for cooling the inlet nozzle, a supply pipe connected to one end of the cooling jacket for supplying a cooling medium to the cooling jacket, and a cooling jacket for cooling the inlet nozzle. And a discharge pipe connected to the cooling jacket to discharge the cooling medium from the cooling jacket.

The wall thickness between the inlet nozzle and the cooling jacket should be strong enough to resist the pressure difference between the pressure in the reactor and the cooling medium. In a preferred embodiment of the first invention, the supply pipe is connected to the lower end of the cooling jacket, and the discharge pipe is connected to the upper end of the cooling jacket. As a result, the cooling medium supplied from the supply pipe to the lower end of the jacket flows upward as the temperature of the cooling medium rises by cooling the inlet nozzle, and flows out from the upper end. As long as the cooling medium can cool the inlet nozzle, for example, water and air can be used as the cooling medium regardless of the type and composition. If water is used, it may be vaporized in the jacket, and the heat of vaporization may be used for cooling. Desirably, the temperature near the inlet nozzle outlet of the nozzle wall interposed between the inlet nozzle and the cooling jacket is measured, and the flow rate of the cooling medium is set so that the temperature of the nozzle wall near the inlet nozzle outlet is 350 ° C. or less. And a temperature control device for controlling the temperature of the nozzle wall. Thereby, precipitation of the inorganic salt can be suppressed more reliably, and a stable supercritical water reaction can be performed for a long period of time.

Another supercritical water reactor according to the present invention (hereinafter referred to as a second invention) includes a vertical reactor containing supercritical water, and penetrates a vessel wall of the reactor. In a supercritical water reactor for introducing the liquid to be treated into the supercritical water in the reactor from the provided liquid inlet nozzle and performing a supercritical water reaction, the inlet nozzle has an inner cylinder nozzle and an inner cylinder. A two-fluid nozzle composed of an outer cylinder nozzle surrounding the outside of the nozzle in a double tubular manner, the inner cylinder nozzle is used as an inflow path of the liquid to be treated, and an annular portion between the inner cylinder nozzle and the outer cylinder nozzle is an inner cylinder nozzle. And a cooling medium inflow path for cooling the cooling medium.

In the second invention, water is introduced into the reactor by using a liquid, for example, water as a cooling medium,
Used as part of the supercritical water makeup water. Further, by separately introducing a low-temperature liquid to be treated as a cooling medium, it is possible to additionally perform a treatment by a supercritical water reaction in the reactor.

In a preferred embodiment of the second invention, the outlet of the inner cylinder nozzle is inside the outer cylinder nozzle. Thus, the liquid to be treated and the cooling medium can be mixed and introduced into the reactor, so that the temperature distribution in the reactor is not disturbed. In a further preferred embodiment of the second invention, the temperature of the inner cylinder nozzle near the outlet of the inner cylinder nozzle is measured, and the flow rate of the cooling medium is controlled so that the temperature of the inner cylinder nozzle becomes 350 ° C. or lower. A two-fluid nozzle temperature controller. Thereby, the precipitation of the inorganic salt can be more reliably suppressed, and a stable supercritical water reaction can be performed for a long period of time.

The first and second aspects of the present invention can be applied to a two-zone reactor or a reactor in which the entire reactor is a supercritical water zone.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment 1 This embodiment is an example of an embodiment of the supercritical water reactor according to the first invention, and FIG. 1 shows an inlet nozzle and a main part of the supercritical water reactor of this embodiment. FIG. 2 is a longitudinal sectional view showing the configuration of the cooling jacket provided in the vicinity thereof, and FIG. 2 is a transverse sectional view of the inlet nozzle and the cooling jacket taken along line II in FIG. The supercritical water reactor of the present embodiment is an apparatus for treating a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance by a supercritical water reaction. It has the same configuration as the critical water reactor 60.

As shown in FIGS. 1 and 2, a supercritical water reactor of the present embodiment has a vertical type reactor having the same structure as a reactor 62 provided in a conventional supercritical water reactor 60 as shown in FIGS. An inlet nozzle 18 comprising the reactor 12, connected at one end to the inlet pipe 72, through a flange 16 closing the upper opening 14 of the reactor 12 and communicating at the other end into the reactor 12;
A cooling jacket 20 is provided along the inlet nozzle 18 and is provided as an annular opening surrounding the inlet nozzle 18 and cools the inlet nozzle 18. An annular wall 21 is interposed between the inlet nozzle 18 and the cooling jacket 20. The flange 16 is provided at the upper body flange 2 of the reactor 12.
2 is flanged by bolting (not shown). In FIG. 1, reference numeral 23 denotes an inlet nozzle 18 connected to the inflow pipe 7.
2 is a joint to be connected.

A supply pipe 24 for supplying a cooling medium to the cooling jacket 20 is connected to a lower end of the cooling jacket 20, and a discharge pipe 26 for discharging the cooling medium from the cooling jacket 20 is provided at an upper end of the cooling jacket 20. It is connected. In the present embodiment, water is used as a cooling medium, and water is supplied at a flow rate set so that the temperature of the inlet nozzle 18 does not rise to 350 ° C. or higher.

Water is introduced into the cooling jacket 20 from the supply pipe 24 and discharged from the discharge pipe 26 while cooling the annular wall 21 between the cooling jacket 20 and the inlet nozzle 18, so that the processing target flowing through the inlet nozzle 18 is processed. Liquid temperature is 35
Does not rise above 0 ° C. Therefore, the precipitation of the inorganic salt in the liquid to be treated is remarkably reduced as compared with the related art.
No blockage of the inlet nozzle 18 occurs.

Modification of Embodiment 1 In this modification, as a main part 30, in addition to the structure of Embodiment 1, a temperature for controlling the temperature of the annular wall 21 between the inlet nozzle 18 and the cooling jacket 20 is set. It has a control system. As shown in FIG. 3, the temperature control system includes a thermometer 32 for measuring the temperature of the annular wall 21 between the inlet nozzle 18 and the cooling jacket 20, a flow control valve 34 provided on the discharge pipe 26, The cooling jacket 2 is adjusted by adjusting the flow control valve 34 so that the temperature of the annular wall 21 becomes a set value, for example, 350 ° C., based on the temperature measurement value output from the meter 32.
And a temperature control device 36 for adjusting the amount of water flowing through zero. FIG. 3 is a schematic diagram showing a configuration of a modification of the first embodiment. In the present modification, by providing the temperature control system, it is possible to more reliably suppress the temperature rise of the liquid to be treated and prevent the precipitation of the inorganic salt in the liquid to be treated.

Embodiment 2 This embodiment is an example of an embodiment of the supercritical water reactor according to the second invention, and FIG. 4 is a main part of the supercritical water reactor of this embodiment. It is a partial fracture side view showing composition of a two-fluid nozzle provided as an entrance nozzle. The supercritical water reactor of the present embodiment is an apparatus for treating a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance by a supercritical water reaction. It has the same configuration as the critical water reactor 60. As shown in FIG. 4, the supercritical water reactor of the embodiment of the present embodiment penetrates the flange 16 for closing the upper opening 14 of the vertical reactor 12 as shown in FIG. The two-fluid nozzle 42 is provided so as to penetrate the critical water area, and is connected at the other end to the inflow pipe 72 and the cooling medium supply pipe 24. The flange 16 is connected to the upper body flange (not shown) of the reactor 12 by bolting (not shown).

The two-fluid nozzle 42 of the present embodiment comprises an inner cylinder nozzle 44 and an outer cylinder nozzle 46 surrounding the inner cylinder nozzle 44 in a double cylinder shape. The inside of the inner cylinder nozzle 44 is used as an inflow path of the liquid to be treated, and the annular portion 48 between the inner cylinder nozzle 44 and the outer cylinder nozzle 46 is connected to the supply pipe 24 for the cooling medium. It is an inflow path of a cooling medium for cooling the liquid to be processed flowing in the inner cylinder nozzle 44. In the two-fluid nozzle 42, the outlet of the inner cylinder nozzle 44 is connected to the outer cylinder nozzle 46.
It is configured to be inside.

In this embodiment, water is used as a cooling medium, and water is supplied to the annular portion 48 at a flow rate set so that the temperature of the inner cylinder nozzle 44 does not rise to 350 ° C. or more. Water is introduced from the supply pipe 24 into the annular portion 48 to cool the inner cylinder nozzle 44, mix with the liquid to be treated flowing in the inner cylinder nozzle 44 at the outlet of the outer cylinder nozzle 46, and introduce the water into the reactor 12. As a result, the temperature of the liquid to be processed flowing through the inner cylinder nozzle 44 is not raised to 350 ° C. or higher. Therefore, compared to the past,
Precipitation of inorganic salts in the liquid to be treated is remarkably reduced, and the inlet nozzle is not blocked as in the related art.

As a modification of the second embodiment, similarly to the first modification of the first embodiment, a temperature control system for controlling the temperature of the nozzle wall of the inner cylinder nozzle 44 is provided. The temperature rise of the nozzle wall of the inner cylinder nozzle 44, that is, the temperature of the liquid to be treated can be suppressed, and the precipitation of inorganic salts in the liquid to be treated can be prevented.

The first and second embodiments can be applied to a two-zone type reactor including a modified example thereof, and also to a type of reactor in which the entire area inside the reactor is a supercritical water area. Further, when performing a decomposition treatment by a supercritical water reaction on a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance, a gas oxidizing agent such as air or oxygen gas may not be introduced together with the liquid to be treated.
At this time, the inorganic salt in the liquid to be treated is easily precipitated at the inlet nozzle. However, by applying the first and second embodiments and the modifications thereof, the precipitation of the inorganic salt in the liquid to be treated is greatly reduced. be able to.

[0031]

According to the first invention, a cooling jacket is provided around an inlet nozzle for introducing a liquid to be treated into a reactor,
By cooling the inlet nozzle and the liquid to be processed flowing in the inlet nozzle by the cooling medium flowing through the cooling jacket, precipitation of inorganic salts at the inlet nozzle is prevented. Second
According to the invention, a double tubular two-fluid nozzle is provided as an inlet nozzle for introducing the liquid to be treated into the reactor, the inner cylinder nozzle is used as an inflow path of the liquid to be treated, and the inner cylinder nozzle and the outer cylinder nozzle Precipitation of inorganic salts at the inlet nozzle by cooling the inner cylinder nozzle and the liquid to be processed flowing through the inner cylinder nozzle by the cooling medium flowing through the annular part, and using the annular part as an inflow path of a cooling medium for cooling the inner cylinder nozzle. Has been prevented. By applying the first and second inventions, a liquid to be treated in which an inorganic salt is dissolved in addition to an organic substance can be stably and continuously subjected to a supercritical water reaction treatment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an inlet nozzle, which is a main part of a supercritical water reactor of Embodiment 1, and a jacket provided near the inlet nozzle.

FIG. 2 is a cross-sectional view of the inlet nozzle taken along line II of FIG. 1;

FIG. 3 is a schematic diagram illustrating a configuration of a modification of the first embodiment.

FIG. 4 is a partially broken side view showing a configuration of a two-fluid nozzle provided as an inlet nozzle, which is a main part of the supercritical water reactor of Embodiment 2.

FIG. 5 is a flow sheet showing a configuration of a conventional supercritical water treatment apparatus.

FIG. 6 is a sectional view showing a configuration of an inlet nozzle.

[Explanation of symbols]

 Reference Signs List 60 Conventional supercritical water treatment apparatus 62 Reactor 62a Body flange 64 Supercritical water area 66 Virtual interface 68 Subcritical water area 70 Inlet nozzle 70a Joint 72 Inflow pipe 73 Flange 74 Liquid line to be treated 76 Air line 78 Supercritical water line 80 Neutralizer line 82 Subcritical water line 84 Subcritical drainage line 86 Treatment liquid line 10 Main part of supercritical water reactor of Embodiment 1 12 Reactor 14 Upper opening 16 Flange 18 Inlet nozzle 20 Cooling jacket 21 Annular wall 22 Body flange 23 Joint 24 Supply pipe 26 Discharge pipe 30 Principal part of supercritical water reactor of modified example of Embodiment 1 32 Thermometer 34 Flow control valve 36 Temperature controller 40 Supercritical water reactor of Embodiment 2 Main part 42 Two-fluid nozzle 44 Inner cylinder nozzle 46 Outer cylinder nozzle 48 Annular part

Claims (8)

[Claims] 1. A vertical reactor containing supercritical water is provided.
In a supercritical water reactor for introducing a liquid to be treated into supercritical water in the reactor and performing a supercritical water reaction from an inlet nozzle for the liquid to be treated provided through the vessel wall of the reactor, A cooling jacket provided in a double tubular shape around the inlet nozzle and cooling the inlet nozzle, a supply pipe connected to one end of the cooling jacket and supplying a cooling medium to the cooling jacket, A discharge pipe connected to the other end and discharging a cooling medium from a cooling jacket. 2. The supercritical water reactor according to claim 1, wherein the supply pipe is connected to a lower end of the cooling jacket, and the discharge pipe is connected to an upper end of the cooling jacket. 3. The temperature of the nozzle wall interposed between the inlet nozzle and the cooling jacket near the inlet nozzle outlet is measured, and the temperature of the nozzle wall near the inlet nozzle outlet is 350 ° C.
The supercritical water reactor according to claim 1 or 2, further comprising a temperature control device for the nozzle wall, which controls the flow rate of the cooling medium as follows. 4. The supercritical water reactor according to claim 1, wherein the cooling medium is water or air. 5. A vertical reactor containing supercritical water,
In a supercritical water reactor for introducing a liquid to be treated into supercritical water in the reactor and performing a supercritical water reaction from an inlet nozzle for the liquid to be treated provided through the vessel wall of the reactor, Is configured as a two-fluid nozzle composed of an inner cylinder nozzle and an outer cylinder nozzle that surrounds the outside of the inner cylinder nozzle as a double tube. The inner cylinder nozzle is used as an inflow path of the liquid to be treated, and the inner cylinder nozzle and the outer cylinder nozzle A supercritical water reactor characterized in that the annular portion between the two is used as an inflow path of a cooling medium for cooling the inner cylinder nozzle. 6. The supercritical water reactor according to claim 5, wherein the outlet of the inner cylinder nozzle is inside the outer cylinder nozzle. 7. A two-fluid nozzle which measures the temperature of the inner cylinder nozzle near the outlet of the inner cylinder nozzle and controls the flow rate of the cooling medium so that the temperature of the inner cylinder nozzle becomes 350 ° C. or less. The supercritical water reactor according to claim 5, further comprising a temperature controller. 8. The supercritical water reactor according to claim 5, wherein the cooling medium is water or a liquid to be treated having a low temperature.