JP3812135B2 - Method for supercritical and hydrothermal reaction treatment of organic matter and treatment plant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a supercritical / hydrothermal reaction treatment method for organic matter and a treatment plant therefor.
[0002]
[Prior art]
As a technique for decomposing organic substances harmful to human livestock with water under supercritical conditions to make them harmless, Technical Example 1: Japanese Patent Application Laid-Open No. 07-275870 “Supercritical Hydroxylation Apparatus and Treatment Method for Harmful Organic Substances” Also, Technical Example 2: Japanese Patent Application Laid-Open No. 07-275871 “Supercritical water oxidation treatment method and treatment apparatus for harmful substances” has been proposed.
[0003]
The technical example 1 includes a reactor that decomposes harmful organic substances under a supercritical condition of water, and a gas-liquid separator that performs gas-liquid separation of decomposition products, and separately from the object to be processed. The first pressure feeding means for pressurizing and feeding water to the reactor, and a return means for returning the separated liquid of the gas-liquid separator to the first pressure feeding means, and The technical example 2 includes a preheater, a reactor and a cooler, and a gas-liquid separator, and performs a gas-liquid separation of the decomposition product after decomposing a harmful substance under supercritical conditions of water. In this method, the aqueous solution is supplied to the preheater for preheating, and the preheated aqueous solution and the harmful substance are mixed at the inlet of the reactor.
[0004]
[Problems to be solved by the invention]
However, since the material to be treated (liquid organic material to be treated) that undergoes supercritical / hydrothermal reaction treatment is often a heterogeneous liquid with properties, the inorganic content (inorganic suspension) is separated after the reaction treatment. It is necessary to take measures against the phenomenon of accumulation and blocking of piping and valves and the phenomenon of narrowing the flow path.
[0005]
This invention is made | formed in view of such a subject, and achieves the following objectives.
(1) Depressurize the reaction product after supercritical / hydrothermal reaction treatment to precipitate inorganic components and chlorides, and efficiently separate inorganic particles from the liquid.
(2) To improve the separability by separating the reaction product in stages.
(3) Suppressing the rising phenomenon of the inorganic component during the separation process and reducing the downstream flow of the inorganic component.
[0006]
[Means for Solving the Problems]
In the supercritical / hydrothermal reaction processing method for organic matter, the first stage of the process (a) is carried out in a supercritical / hydrothermal reaction, and the reaction product thus produced is separated in the separator (4B, 4C). The inorganic component in the reaction product is precipitated by a step of performing jetting by the diffusers (44A to 44C) set in multiple stages by changing the direction alternately up and down in the downward direction, and by reducing the pressure based on the increase in the cross-sectional area at the time of jetting. And a step of separating into an inorganic component and a liquid component.
The supercritical / hydrothermal reaction processing plant for organic matter includes supercritical / hydrothermal reaction processing means (3A, 3B) for subjecting the object (a) to supercritical / hydrothermal reaction, and the supercritical / hydrothermal reaction processing means. A separator (4B, 4C) that separates the reaction-treated product produced by being separated into an inorganic component and a liquid component, the first stage (44A) being set downward , The second stage (44B) for transferring the reaction product in the upward direction is arranged around and at the tip, and the reaction treatment product is ejected into the separator and reacted by depressurization based on an increase in the cross-sectional area at the time of ejection. A diffuser (44A, 44B) for precipitating inorganic components in the treated product was provided.
In addition, the diffusers (44A to 44C) are arranged in three or more stages by alternately changing the direction vertically.
In addition, a throttle part (46) for bringing the flow of the reaction product to the center inside the separators (4B, 4C) is disposed at the outlet of the final stage diffuser (44C).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a supercritical / hydrothermal reaction processing plant according to the present invention will be described with reference to FIGS.
FIG. 1 shows the overall configuration of a supercritical / hydrothermal reaction processing plant.
[0008]
As shown in FIG. 1, the supercritical / hydrothermal reaction treatment plant X is a stock solution for supplying the liquid organic substance a to be treated in a state in which it is pressurized to a pressure necessary for the supercritical / hydrothermal reaction treatment, for example, up to 20 MPa. A supply means 1, a preheater 2 connected to the stock solution supply means 1 for preheating in advance, and a superheater connected to the preheater 2 for performing a hydrothermal reaction with the liquid organic substance a to be treated as a supercritical condition atmosphere. The critical / hydrothermal reaction treatment means 3A, 3B, the superheater / hydrothermal reaction treatment means 3A, 3B connected to the preheater 2 and the supercritical / hydrothermal reaction treatment means 3A, 3B are separated into solid (suspension) and liquid components. And separators 4A, 4B, and 4C for separating the suspensions, and discharge means 5 connected to the separators 4A, 4B, and 4C for returning the suspension (solid content) to a reduced pressure state and discharging the suspensions. In the most downstream separator 4C, the liquid is taken up and processed. Processing water treatment unit 6 is connected.
[0009]
The liquid organic substance a to be treated is, for example, an appropriate amount necessary for supercritical / hydrothermal reaction treatment to harmful organic substances such as chlorofluorocarbon and PCB described in Technical Examples 1 and 2 and organic waste such as sludge and pulp sludge. The water is added and adjusted.
[0010]
As shown in FIG. 1, the undiluted solution supply means 1 sucks the untreated liquid organic material a from the undiluted solution tank 11 for storing the untreated liquid organic material a at, for example, atmospheric pressure or relatively low pressure. For example, it has the supply pump 12 for pressurizing and supplying to the above-mentioned pressure of about 20 MPa.
[0011]
As shown in FIG. 1, the preheater 2 is interposed between the stock solution supplying means 1 and the supercritical / hydrothermal reaction processing means 3A to preheat the liquid organic substance a to be treated to about 200 ° C., for example. Thus, in a normal case, it is sent to the supercritical / hydrothermal reaction treatment means 3A, and when the inorganic content is large, the liquid organic substance a to be treated is sent to the downstream separator 4A.
[0012]
The supercritical / hydrothermal reaction processing means 3A, 3B includes a first reaction tank 31A and a second reaction tank 31B arranged in series downstream of the preheater 2, and the first reaction tank 31A and the first reaction tank 31A. A heating furnace 32 for generating a hydrothermal reaction by heating the second reaction tank 31B to a temperature of, for example, about 350 ° C. and setting the liquid organic substance a to be treated as a supercritical condition atmosphere.
[0013]
As shown in FIG. 1, the separator 4A is connected to the downstream side of the preheater 2 and the upstream side of the first reaction tank 31A, and the separator 4B is connected to the downstream side of the first reaction tank 31A and the second side. The separator 4C is connected to the downstream of the second reaction tank 31B.
[0014]
Details of the separators 4A, 4B, and 4C will be described with reference to FIGS. As shown in FIG. 2, the separators 4A, 4B, and 4C are directly connected to the preheater 2 and the first and second supercritical / hydrothermal reaction processing means 3A and 3B to receive a high-pressure fluid. A pressure vessel 41, an outer wall portion 42 surrounding the pressure vessel 41, a heat insulating material 43 interposed between the pressure vessel 41 and the outer wall portion 42, and a first stage arranged in an inserted state inside the pressure vessel 41, The second-stage and third-stage diffusers 44A, 44B, 44C are arranged between the inner bottom of the pressure vessel 41 and the base of the second-stage diffuser 44B, and support the second-stage diffuser 44B. A member having a support member 45 for setting the position and a throttle portion 46 arranged at the tip of the third-stage diffuser 44C and in which the jet outlet at the tip is narrowed is applied.
[0015]
The pressure vessel 41 has an inlet 4a for receiving the reaction product and feeding it to the first stage diffuser 44A, an outlet 4b for taking out the inorganic part, and a third stage diffuser 44C. An outflow passage 4c and a drainage port 4d are provided for sending the reaction product (liquid component) passing through to the next supercritical / hydrothermal reaction treatment means 3A, 3B or treated water treatment means 6.
[0016]
The first-stage diffuser 44A has a front-end jet outlet set downward, and has a bottom lid (bottom plate) at the periphery and at the front end for transferring the reaction processing product upward and then jetting it upward. A stage diffuser 44B is arranged, and further, around the tip of the second stage diffuser 44B, the flow of the reaction product is reversed at the ceiling of the pressure vessel 41 and transferred downward. A third-stage diffuser 44C to be ejected is arranged.
These diffusers 44A, 44B, and 44C are arranged concentrically, and eject the reaction product in the up and down direction.
And the cross-sectional area of the jet outlet of each diffuser 44A, 44B, 44C is set so that it may become large gradually.
[0017]
As the support member 45, a member having a communication hole 45 a for sending an inorganic substance or the like to the discharge port 4 b at least in the vicinity of the inner bottom portion of the pressure vessel 41 is employed.
[0018]
As shown in FIG. 1, the discharge means 5 is arranged in a connected state downstream of the separators 4A, 4B, 4C, and is in a supercritical and high pressure (for example, a pressure of about 20 MPa) state inorganic content (solid content). And a suspension outlet 5b for intermittently returning the inorganic content (inorganic suspension) to a reduced pressure state of about atmospheric pressure and delivering it to the downstream suspension processing means, It has a gas discharge port 5c for sending the separated gas component to an appropriate gas processing means.
[0019]
As shown in FIG. 1, the treated water treatment means 6 is connected to the separator 4C located at the most downstream position, and sucks liquid components such as treated water generated by separation by the separator 4C. What has a pump function to perform is applied, and what has the function to store the taken-up liquid component is applied.
[0020]
1 and 2, b indicates a switching valve, c indicates a control valve, and d indicates a back pressure valve.
[0021]
In such a hydrothermal reaction processing plant X, the raw liquid supply means 1 is operated to supply the liquid organic substance a to be processed having a desired pressure of about 20 MPa to the preheater 2, for example, a temperature before becoming a critical state (for example, After heating (preheating) to about 200 ° C., it is sent to the supercritical / hydrothermal reaction treatment means 3A to generate the desired supercritical / hydrothermal reaction.
[0022]
At this time, when the inorganic component is separated or precipitated from the liquid organic material to be processed a, or when the amount of separation of the inorganic component is large, the preheated liquid organic material a to be processed is separated by switching the switching valve b. And the step of separating the inorganic component from the liquid organic material to be treated a is employed.
Since the preheater 2 does not reach a high temperature until it reaches a supercritical state, for example, the connection flow path 4b, the ejection sleeve 44, and the outflow path are formed in the separator 4A so as to reduce the pressure drop. The inner diameter of 4c is increased so that a large amount of the liquid organic substance a to be processed is gently inserted.
[0023]
The preheated liquid organic substance a in the preheated state sent to the supercritical / hydrothermal reaction processing means 3A is heated to a supercritical / hydrothermal reaction generation temperature (for example, 350 ° C. under the above-mentioned 20 MPa condition) by the operation of the heating furnace 32. To a certain temperature).
When these high-temperature and high-pressure conditions overlap with the conditions in which water is present (mixed) in the liquid organic material a to be treated, a hydrothermal reaction occurs in a supercritical environment, and the organic matter is decomposed compositionally. The phenomenon of dissolving in water is promoted.
At this time, the mixture of the organic matter (carbon compound such as chlorofluorocarbon, PCB, sludge, pulp sludge and the like) and water is in a state of being almost uniformly dissolved in water in a supercritical environment.
[0024]
In the first-stage supercritical / hydrothermal reaction treatment means 3A, if a sufficient temperature cannot be obtained and the critical state is not reached, or if there is a lot of decomposition and precipitation of inorganic components, supercritical / hydrothermal reaction treatment The supercritical / hydrothermal reaction treatment is performed by switching the switching valve b downstream of the means 3A and sending the liquid component from the separator 4B to the next supercritical / hydrothermal reaction treatment means 3B.
Therefore, the supercritical / hydrothermal reaction treatment means 3A, 3B can be three or more stages.
[0025]
In the preheater 2 and the supercritical / hydrothermal reaction processing means 3A, 3B, the reaction product generated by heating or supercritical / hydrothermal reaction processing is transferred into the pressure vessel 41 in the separators 4A, 4B, 4C. Then, as shown by the arrow in FIG. 3, the first stage diffuser 44 </ b> A is ejected downward and is in a reduced pressure state.
At this time, since the bottom portion of the second-stage diffuser 44B is almost closed, the direction of the flow of the reaction treatment product is changed, as shown by the arrows in FIG. Guided upward. In the example of FIG. 2, since the outer peripheral surface of the first stage diffuser 44A has a tapered shape, the reaction product is depressurized inside the second stage diffuser 44B.
Since the ceiling portion of the pressure vessel 41 and the base of the third-stage diffuser 44C are arranged at the tip of the second-stage diffuser 44B, the direction of the flow of the reaction treatment product guided up is changed. Then, as shown by the arrow in FIG.
Even in the third-stage diffuser 44C, the reaction product is decompressed because the cross-sectional area is set to gradually increase.
[0026]
In this manner, the supercritical state disappears by repeating the depressurization of the reaction treatment product in a plurality of stages, the inorganic content (silica content, salt content, etc.) in the reaction treatment product precipitates and gradually settles, and the pressure vessel 41 It is thought that it accumulates on the inner bottom of this.
The liquid component from which the inorganic component has been separated (most of the reaction product) is sent downstream from the drain port 4d.
[0027]
On the other hand, since each of the diffusers 44A to 44C at each stage changes the ejection direction and increases the cross-sectional area each time, separation based on precipitation of inorganic components is repeated, so that the second stage diffuser It is also effective to arrange a slit or the like for dropping and removing the settled inorganic component without impairing the induction of the reaction product at the base (lower bottom) of 44B.
[0028]
In the case where the reaction product has passed through the supercritical / hydrothermal reaction treatment means 3A, 3B, the inorganic components generated by the supercritical / hydrothermal reaction are mainly precipitated and settled and separated.
In the case where the reaction product is sent from the preheater 2, based on the fact that it does not go through the supercritical / hydrothermal reaction process, the inorganic component mixed in the material to be treated is necessarily deposited and separated. Although there is no limitation, if there is a solid content or a part of the inorganic content deposited (or separated) without undergoing a supercritical / hydrothermal reaction, these precipitate.
These inorganic components and the like are transferred further downstream from the discharge port 4b of the pressure vessel 41 by opening the control valve c.
In addition, since the throttle 46 is arranged at the tip (jet outlet) of the third-stage diffuser 44C, which is the final stage, the flow of the reaction product is separated by the throttle 46 from the separator. 4A, 4B, 4C is brought to the center of the inside, and it is avoided that it interferes with the liquid component sent downstream from the drainage port 4d, and the occurrence of the rising phenomenon of the precipitated inorganic component is suppressed. it can.
[0029]
The inorganic components separated and deposited by the separators 4A, 4B, and 4C are transferred to the discharge means 5 by opening the control valve c between the separators 4A, 4B, and 4C.
In the discharge means 5, after the control valve c between the separators 4A, 4B, and 4C is closed and disconnected, the necessary treatment of the inorganic content is performed by returning to a low pressure environment of about atmospheric pressure, for example. Do.
In the discharge means 5, gas components such as CO ₂ and water vapor generated by the pressure drop are processed by the gas processing means in the above-described example.
[0030]
4 and 5 show a second embodiment of the parts of the separators 4A, 4B, 4C.
In the second embodiment, the first-stage diffuser 44A, the second-stage diffuser 44B, and the third-stage diffuser 44C are formed in a right cylindrical shape instead of the tapered shape.
In the example of FIG. 4 as well, the outlet of each diffuser 44A, 44B, 44C is set so that the cross-sectional area gradually increases as it goes to the next stage (for example, the third stage diffuser 44C As the inner diameter of the pressure vessel 41 is larger than that of the jet port), as shown by arrows in FIG. 5, the flow of the reaction product spreads, and separation based on precipitation of inorganic components is repeated based on reduced pressure.
[0031]
6 and 7 show a third embodiment of the parts of the separators 4A, 4B, 4C.
In the third embodiment, as shown in FIG. 6, only the first-stage diffuser 44A is used. However, in the case where the separators 4A, 4B, 4C are connected in series and the number of stages can be increased. As shown by the arrows in FIG. 7, the fluid is expanded and the pressure is reduced based on the deceleration, so that the inorganic content is deposited.
[0032]
【The invention's effect】
According to the supercritical / hydrothermal reaction processing method for organic matter and its processing plant according to the present invention, the following effects can be obtained.
(1) The reaction product after supercritical / hydrothermal reaction treatment is ejected from the diffuser of the flow divider to reduce the pressure, thereby precipitating inorganic components and chlorides and efficiently removing inorganic components from the reaction product. Can be separated.
(2) Separation of the reaction product in multiple stages step by step can improve the separability and suppress the occurrence of a clogging phenomenon during transfer of the reaction product due to deposition of inorganic components.
(3) By arranging the diffuser concentrically and guiding the reaction product from the center to the outside, an increase in the length of the diffuser can be suppressed, and the overall size can be reduced.
(4) At the time of the above, it becomes easy to set the cross-sectional area of the diffuser jets to be gradually increased by jetting the reaction treatment products up and down, and the precipitation of inorganic components is repeated inside one separator. be able to.
(5) By restricting the flow of the reaction product to the center by arranging a constriction part at the jet port of the diffuser, it is possible to suppress the rising phenomenon of the deposited inorganic component and reduce the downstream feed of the inorganic component. it can.
[Brief description of the drawings]
FIG. 1 is a connection diagram illustrating a first embodiment of a supercritical / hydrothermal reaction treatment method and treatment plant for organic matter according to the present invention.
FIG. 2 is a front sectional view showing a detailed structure of the separator shown in FIG.
FIG. 3 is a front sectional view schematically showing a pressure reduction state by the separator of FIG. 2;
FIG. 4 is a front sectional view showing a second embodiment of a separator portion.
FIG. 5 is a front sectional view schematically showing a pressure reduction state by the separator of FIG. 4;
FIG. 6 is a front sectional view showing a third embodiment of the separator portion.
7 is a front cross-sectional view schematically showing a depressurization state by the separator of FIG. 6. FIG.
[Explanation of symbols]
X Supercritical / hydrothermal reaction treatment plant a Processed liquid organic substance 1 Stock solution supply means 2 Preheater 3A, 3B Supercritical / hydrothermal reaction treatment means 4A, 4B, 4C Separator 4a Inlet 4b Outlet 4c Outlet 4d Drain Liquid outlet 5 Discharge means 5a Workpiece inlet 5b Suspension discharge outlet 5c Gas exhaust 6 Treated water treatment means 11 Raw liquid tank 12 Supply pump 31A First reaction tank 31B Second reaction tank 32 Heating furnace 41 Pressure vessel 42 Outer wall part 43 Insulating material 44A, 44B, 44C Diffuser 45 Support member 45a Communication hole 46 Restriction part b Switching valve c Control valve d Back pressure valve

Claims (4)

A supercritical / hydrothermal reaction of the workpiece (a);
In the separator (4B, 4C), the step of ejecting the produced reaction treatment product by the diffusers (44A to 44C) set in multiple stages by changing the direction alternately up and down with the first stage downward;
A step of precipitating the inorganic component in the reaction product by depressurization based on the increase in the cross-sectional area at the time of ejection and separating the inorganic component and the liquid component;
A method for supercritical / hydrothermal reaction treatment of an organic substance, comprising: The supercritical / hydrothermal reaction treatment means (3A, 3B) for reacting the object to be treated (a) with the supercritical / hydrothermal reaction means, and the reaction treatment product produced by being connected to the supercritical / hydrothermal reaction treatment means are treated with an inorganic component. And a separator (4B, 4C) that separates into a liquid component,
In the separator, the first stage (44A) is set in the downward direction , and the second stage (44B) for transferring the reaction process product in the upward direction is arranged around and at the tip, and the reaction process product is separated. Supercritical water of organic matter, characterized by having a diffuser (44A, 44B) that is ejected into the vessel and deposits inorganic components in the reaction product by decompression based on the increase in the cross-sectional area at the time of ejection Thermal reaction processing plant.   The supercritical / hydrothermal reaction processing plant for organic substances according to claim 2, wherein the diffusers (44A to 44C) are arranged in three or more stages while alternately changing the direction. The ejection port of the final-stage diffuser (44C), claims, characterized in that the flow of the reaction treated separator (4B, 4C) throttle portion for lapping inside the center of (46) disposed 3. A supercritical / hydrothermal reaction treatment plant for organic matter according to 3 .

Images