JP3887941B2 - 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 inorganic content contained in the product during the supercritical / hydrothermal reaction and the inorganic content contained in the raw material subjected to the supercritical / hydrothermal reaction treatment include many inorganic substances that are easily deposited, When supercritical / hydrothermal reaction treatment is performed, take measures against the phenomenon that inorganic components (inorganic suspensions, etc.) in raw materials and reaction products are separated and deposited and block piping and valves. There is a need.
[0005]
This invention is made | formed in view of such a subject, and achieves the following objectives.
(1) To reduce the influence on the supercritical / hydrothermal reaction treatment in the presence of inorganic components in the raw materials and reaction products.
(2) Smooth and continuous treatment without substantially stopping the supercritical / hydrothermal reaction.
(3) To separate inorganic components from the hydrothermal reaction processing plant and discharge them out of the system.
(4) Separating and collecting useful and unnecessary materials in inorganic content.
[0006]
[Means for Solving the Problems]
A liquefied object to be treated containing an organic substance is sent to a supercritical / hydrothermal reaction treatment means, and subjected to a hydrothermal reaction in a supercritical atmosphere, and a reaction treatment product generated in the supercritical / hydrothermal reaction treatment means is obtained. In the state separated from the supercritical / hydrothermal reaction treatment means after being sent to the separator, it is separated into an inorganic component and a liquid component, and the separator is connected to a discharge means to intermittently take out the separated inorganic component. Technology is used.
A superheater that preheats the workpiece, and a separator that is connected to the preheater and removes the inorganic component separated during the preheating. A supercritical / hydrothermal reaction treatment is performed by supplying the treatment means.
Between the supercritical and hydrothermal reaction treatment means, the separator can be placed in an interposed state, and the object to be treated with the inorganic component removed can be sent again to the supercritical and hydrothermal reaction treatment means for treatment. Repeat as necessary.
A control valve is arranged between the separator and the discharge means to control intermittent connection.
In the discharge means, a suspension processing means for receiving the inorganic component and a gas processing means for receiving the separated gas component are arranged in a connected state, and these processes are performed as necessary.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a supercritical / hydrothermal reaction treatment method and treatment plant for organic matter according to the present invention will be described with reference to the drawings.
1 and 2 show the overall configuration of a liquid organic supercritical / hydrothermal reaction treatment plant.
[0008]
As shown in FIGS. 1 and 2, the supercritical / hydrothermal reaction treatment plant X supplies the liquid organic substance a to be treated in a state of being pressurized to a pressure necessary for the supercritical / hydrothermal reaction treatment: for example, 20 MPa. The raw solution supplying means 1 for the preheating, the preheater 2 connected to the raw solution supplying means 1 for preheating in advance, and the liquid organic substance a to be treated connected to the preheater 2 as the supercritical condition atmosphere is subjected to the hydrothermal reaction. Supercritical / hydrothermal reaction treatment means 3A, 3B for the purpose of the process and the supercritical / hydrothermal reaction treatment means 3A, 3B connected to the preheater 2 and the supercritical / hydrothermal reaction treatment means 3A, 3B are treated as inorganic components (inorganic suspension) And separators 4A, 4B and 4C for separating them into liquid components, and discharge means 5 connected to the separators 4A, 4B and 4C for returning the inorganic components (inorganic suspension) to a reduced pressure state and discharging them. And is connected to the discharging means 5 and takes up the inorganic content for processing. Suspension processing means 6 for processing, and treated water treatment means 7 connected to the separator 4C at the most downstream position for collecting and treating the liquid, and the discharge means 5 includes cooling water supply means. 8A, the cooling water treatment means 8B and the gas treatment means 9 are 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]
As shown in FIG. 1, the discharge means 5 is arranged in a connected state downstream of the separators 4A, 4B, 4C, and intermittently returns the inorganic content (inorganic suspension) to a reduced pressure state to about atmospheric pressure. It has a function to discharge.
[0015]
Details of the discharging means 5 will be described with reference to FIG.
The discharge means 5 is connected to the separators 4A, 4B, and 4C, and discharges the inorganic component (inorganic suspension) in a supercritical and high pressure (for example, pressure of about 20 MPa) state through the workpiece inlet 5a. A tank 51, a jacket 52 surrounding the discharge tank 51, a heat exchange chamber 53 formed in an interposed state between the discharge tank 51 and the jacket 52, and an inorganic component disposed under the discharge tank 51. A suspension discharge port 5b dropped into the suspension treatment means 6, a cooling water inlet 5c connected to the cooling water supply means 8A and receiving cooling water, and a cooling water after heat exchange for sending the cooling water to the cooling water treatment means 8B A cooling water outlet 5d and a gas discharge port 5e for sending the gas component separated inside the discharge tank 51 to the gas processing means 9 are provided.
[0016]
The suspension treatment means 6 is connected to the suspension discharge port 5b of each discharge means 5, and when the inside of the discharge tank 51 is in a reduced pressure state such as atmospheric pressure, the inorganic matter is taken and processed. What has the function to do is applied.
[0017]
As shown in FIG. 1, the treated water treatment means 7 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.
[0018]
As shown in FIG. 2, the cooling water supply means 8A and the cooling water treatment means 8B are connected to the cooling water inlet 5c and the cooling water outlet 5d, and supply cooling water to the heat exchange chamber 53 in the discharge means 5, By cooling the discharge tank 51, the inorganic content stored in the discharge tank 51 is lowered to, for example, about room temperature, and the cooling water after heat exchange is recovered.
[0019]
The gas processing means 9 is connected to the gas discharge port 5e of the discharge means 5, and has a function of sucking and collecting the gas content inside the discharge tank 51, and a function of storing or necessary processing of the collected gas. Applies.
[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 supercritical state. After heating (preheating) to (for example, about 200 ° C.), it is sent to the supercritical / hydrothermal reaction processing means 3A to generate the desired supercritical / hydrothermal reaction.
[0022]
At this time, when the inorganic substance is separated or precipitated from the liquid organic substance to be treated a, or when the amount of inorganic components to be separated is large, the liquid organic substance a to be treated preheated in the separator 4A is changed by switching the switching valve b. A process is adopted in which the inorganic component is precipitated by feeding in and only the liquid part is fed into the supercritical / hydrothermal reaction processing means 3A.
In the case where there is little or no separation of the inorganic content, a step of directly feeding the preheated liquid organic substance a to be processed to the supercritical / hydrothermal reaction treatment means 3A without sending it to the separator 4A is adopted. .
[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 processing 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 substances, the supercritical / hydrothermal reaction processing means The supercritical / hydrothermal reaction processing is performed by switching the switching valve b downstream of 3A and sending the liquid component from the separator 4B to the supercritical / hydrothermal reaction processing means 3B of the next stage.
Therefore, the supercritical / hydrothermal reaction treatment means 3A, 3B can be three or more stages.
[0025]
The product generated by the supercritical / hydrothermal reaction is sent to the separators 4B and 4C to be in a reduced pressure state, and inorganic substances (silica content, salt content, etc.) in the supercritical water are precipitated, and the separator Deposited at the bottom of 4B and 4C.
The supernatant water separated at this time is sent to the next-stage separator 4C or treated water treatment means 7 to be processed.
[0026]
The inorganic substances separated and deposited by the separators 4A, 4B, and 4C are controlled between the discharge means 5 in a state where the switching valve b upstream of the separators 4A, 4B, and 4C is closed and separated from the high-pressure environment. By opening the valve c, it is transferred to the discharge means 5.
In the discharge means 5, the control valve c between the separators 4A, 4B, and 4C is closed and disconnected, and then returned to a low-pressure environment of, for example, about atmospheric pressure, and the cooling water supply means 8A and the cooling water The storage in the discharge tank 51 is cooled by the operation of the processing means 8B.
[0027]
Thereafter, the control valve c downstream of the gas discharge port 5e in the discharge means 5 is opened, and CO ₂ , methane gas, water vapor and the like are sent to the gas processing means 9 for recovery, and the control valve c downstream of the discharge tank 51 is set. It is opened and the inorganic substance is sent to the suspension treatment means 6 and collected.
In addition, by adjusting the internal temperature of the discharge tank 51, it is possible to redissolve useful substances (or unnecessary substances) in the inorganic substance and separate and recover the useful substances and unnecessary substances.
[0028]
【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) By separating the reaction product produced by the supercritical / hydrothermal reaction treatment of the material to be treated into an inorganic component and a liquid component in a state separated from the supercritical / hydrothermal reaction treatment means, Even when there is an inorganic component in the reaction product, it is possible to carry out the supercritical / hydrothermal reaction treatment in a state in which the influence is reduced, and to reliably perform the decomposition work of the organic matter.
(2) By adopting a technique for intermittently taking out the inorganic content by connecting the discharging means to the separator, the supercritical / hydrothermal reaction can be smoothly and continuously processed without substantially stopping.
(3) By preheating the material to be processed and separating it into an inorganic component and a liquid component at that time, the supercritical / hydrothermal reaction treatment is performed, thereby reducing the burden on the supercritical / hydrothermal reaction treatment means. It is possible to increase the operability of the plant by reducing the amount of inorganic components and preventing clogging.
(4) By repeatedly supercritical / hydrothermal reaction treatment of the object to be treated with inorganic content removed, it is possible to ensure the decomposition of organic substances and contribute to the detoxification of harmful organic substances such as chlorofluorocarbon and PCB. Can do.
(5) By arranging a control valve between the separator and the discharge means to perform connection and disconnection control, connection and disconnection between the plant and the outside of the system are facilitated, and the discharge and removal of inorganic substances are ensured. be able to.
(6) By separating the inorganic component from the gas component, it is possible to improve the separation and recovery of useful and unnecessary materials.
[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 together with a block diagram showing the discharging means of FIG. 1;
[Explanation of symbols]
X Supercritical / hydrothermal reaction processing plant a Object to be processed (liquid organic substance to be processed)
DESCRIPTION OF SYMBOLS 1 Stock solution supply means 2 Preheater 3A, 3B Supercritical / hydrothermal reaction treatment means 4A, 4B, 4C Separator 5 Discharge means 6 Suspension treatment means 7 Treated water treatment means 8A Cooling water supply means 8B Cooling water treatment means 9 Gas treatment means 11 Stock solution tank 12 Supply pump 31A First reaction tank 31B Second reaction tank 32 Heating furnace 51 Discharge tank 52 Jacket 53 Heat exchange chamber b Switching valve c Control valve d Back pressure valve

Claims (6)

A preheating step of preheating the workpiece using a preheater;
A removal step of removing inorganic components from the workpiece preheated by the preheater by using the first separator connected to the preheater;
A reaction step of hydrothermally reacting an object to be treated after the inorganic content has been removed by using a supercritical / hydrothermal reaction treatment means connected to the first separator in a supercritical atmosphere ;
Separation process of separating the reaction product produced by the supercritical / hydrothermal reaction treatment means into an inorganic component and a liquid component by using a second separator connected to the supercritical / hydrothermal reaction treatment means. and,
A discharge step of intermittently discharging inorganic components separated by the first and second separators by using discharge means connected to the first and second separators, respectively . Supercritical hydrothermal reaction processing method. 2. The organic supercritical / hydrothermal reaction treatment method according to claim 1, wherein the second supercritical / hydrothermal reaction treatment means is used to repeat the reaction step on the reaction treatment product after the separation step . A preheater for preheating the workpiece;
A first separator connected to the preheater for removing inorganic components from the workpiece preheated by the preheater;
A supercritical / hydrothermal reaction processing means connected to the first separator and hydrothermally reacting an object to be processed output from the first separator in a supercritical atmosphere;
A second separator connected to the supercritical / hydrothermal reaction processing means and separating the reaction product produced by the supercritical / hydrothermal reaction processing means into an inorganic component and a liquid component;
Discharging means connected to the first and second separators respectively for intermittently discharging inorganic components separated by the first and second separators;
An organic supercritical / hydrothermal reaction treatment plant characterized by comprising: The second separator is provided between the supercritical / hydrothermal reaction treatment means in order to supply the object to be treated with the inorganic content removed and repeat the supercritical / hydrothermal reaction treatment. The organic matter supercritical / hydrothermal reaction processing plant according to claim 3 . 5. The organic supercritical / hydrothermal reaction processing plant according to claim 3 or 4, wherein a control valve for intermittently connecting discharge means to the first and second separators is provided . 6. The organic supercritical / hydrothermal reaction processing plant according to claim 5, wherein the discharging means includes a suspension processing means for receiving an inorganic content and a gas processing means for receiving a gas content separated from the inorganic content .

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