JP6016114B2 - Fluid purification device - Google Patents

Description

  The present invention provides a fluid purification system including a cylindrical reaction tank that purifies a purification target fluid by decomposing an organic substance in the purification target fluid by an oxidation reaction while heating and pressurizing a mixed fluid of the purification target fluid and an oxidizing agent. It relates to the device.

  Conventionally, as a method for purifying wastewater such as human waste, sewage, settlement wastewater, livestock manure, food factory wastewater, a method of performing biological treatment using activated sludge has been generally used. However, with this method, it has been impossible to treat high-concentration organic solvent wastewater that hinders the activity of microorganisms in activated sludge at the same concentration or wastewater containing plastic fine particles that cannot be biodegraded. In addition, it has not been possible to treat wastewater containing a large amount of hardly decomposable organic substances, such as oil, which are slow to decompose by microorganisms.

  On the other hand, in recent years, a fluid purification device has been developed that purifies wastewater by oxidizing and decomposing organic matter in the mixed fluid while heating and pressurizing a mixed fluid of wastewater as a treatment target fluid and an oxidant such as air. became. In this type of fluid purification device, the organic substance in the mixed fluid is chemically oxidized and decomposed by heating and pressurizing the mixed fluid of the wastewater and the oxidizing agent in the reaction tank. Thereby, highly concentrated organic solvent waste water, plastic fine particle-containing waste water, hardly decomposable organic matter-containing waste water, etc., which could not be obtained by biological treatment, can be purified well.

  As a fluid purification device for purifying wastewater in this way, the one described in Patent Document 1 is known. In this fluid purification device, a catalyst for promoting oxidative decomposition of organic substances is disposed in a reaction tank. The catalyst has a honeycomb-like honeycomb structure. Then, oxidative decomposition of the organic matter in the mixed fluid of the waste water and the oxidant received in the plurality of tubes in the honeycomb structure is promoted. According to such a configuration, by promoting the oxidative decomposition of the organic substance by the honeycomb structure catalyst, even the hardly decomposable organic substance can be oxidatively decomposed satisfactorily.

  Patent Document 2 describes a fluid purification device in which a granular catalyst is filled in a reaction tank in which a mixed fluid is pressurized and heated to cause oxidative decomposition of organic matter. In this fluid purification device, even a hardly decomposable organic substance can be oxidatively decomposed satisfactorily by promoting the oxidative decomposition of the organic substance with a granular catalyst.

  However, the present inventors have found through experiments that the fluid purification device described in Patent Document 1 causes a problem that it takes time to clean the reaction tank. Specifically, the present inventors prototyped an experimental machine having the same configuration as the fluid purification device described in Patent Document 1, and arranged a catalyst 950 having a honeycomb structure as shown in FIG. 1 in the experimental machine. Set up. In the figure, the arrow X direction indicates the transport direction of the mixed fluid in the experimental machine. A running test was conducted to oxidatively decompose the organic matter in the mixed fluid while flowing the mixed fluid in the direction of arrow X in the experimental machine. Then, with the passage of time, the granular inorganic solid started to adhere to the catalyst 950. This inorganic solid is a substance in which inorganic substances such as alumina, silica, zirconia, and phosphorus dissolved in the waste water are deposited under high temperature and high pressure and are fixed to the surface of the catalyst 950. As shown in FIG. 2, the inorganic solid material 960 is intensively adhered to the upstream end face (hereinafter referred to as the upstream end face) of the catalyst 950 in the fluid conveyance direction (arrow X direction). The catalyst 950 is also adhered to the inner wall of the pipe, but the amount is considerably smaller than the amount adhered to the upstream end face. When the running test is further continued from the state shown in FIG. 2, as shown in FIG. 3, as shown in FIG. 3, the inorganic solid material 960 adhered to the upstream end surface of the catalyst 950 is directed toward the centers of the plurality of openings formed in the catalyst 950. Growing up. Then, as shown in FIG. 4, the plurality of openings are respectively closed to block the flow of the mixed fluid into the catalyst 950. In the fluid purification device described in Patent Document 1, it is necessary to frequently perform a cleaning operation of removing the inorganic solid matter fixed to the upstream end face of the catalyst in the reaction tank in order to avoid the occurrence of such blockage. Therefore, it takes a lot of effort.

  Further, the fluid purification device described in Patent Document 2 also seems to cause a problem that it takes time to clean the reaction tank. Specifically, in a reaction tank filled with granular catalyst particles, a mixed fluid flows in an intergranular space formed between individual catalyst particles. If the waste water contains a lot of inorganic substances, among the countless catalyst particles packed in the reaction tank, the inorganic solids are intensively fixed to the catalyst particles located on the most upstream side in the fluid conveyance direction. Will grow. Eventually, the intergranular space around the catalyst particles located on the most upstream side is clogged. For this reason, it is necessary to frequently perform a cleaning operation of removing the inorganic solid matter fixed to the catalyst particles on the most upstream side, and a great effort is required.

  This invention is made | formed in view of the above background, The place made into the objective is providing the fluid purification apparatus which can reduce the effort of the cleaning operation | work of a reaction tank.

In order to achieve the above object, the present invention provides a cylinder for purifying a purification target fluid by decomposing an organic substance in the purification target fluid by an oxidation reaction while heating and pressurizing a mixed fluid of the purification target fluid and an oxidant. In the fluid purification apparatus including a reaction tank, a corrosion-resistant layer made of a material superior in corrosion resistance to the substrate, an intermediate layer, and an oxidative decomposition of organic matter on the inner peripheral surface of the cylindrical substrate in the reaction tank sequentially laminating a catalyst layer made of a material encouraging, as the material of the intermediate layer, and exhibits excellent fixation property than the catalyst layer with respect to the corrosion-resistant layer, and the corrosion-resistant layer to the catalyst layer than Is also characterized by using a material that exhibits excellent adhesion .

  In the present invention, if the fluid to be purified contains a large amount of an inorganic substance, an inorganic solid is present on the upstream end surface of the catalyst phase laminated on the inner surface of the reaction tank or the catalyst member disposed in the inner space of the reaction tank. Fix things. The diameter of the catalyst phase laminated on the inner surface of the reaction tank or the cylindrical catalyst member having a size that can be accommodated in only one space in the reaction tank is the diameter of each of the plurality of tubes in the conventional honeycomb structure catalyst. In addition, it is much larger than the diameter of the intergranular space in the granular catalyst. For this reason, the period until the clogging of the reaction tank or the catalyst member due to the inorganic substance fixed to the catalyst phase or the catalyst member is much longer than the period during which the catalyst of the conventional honeycomb structure or the granular catalyst is clogged. Become. Thereby, since the frequency of the maintenance operation of the reaction tank is greatly reduced, the labor of the maintenance operation of the reaction tank can be reduced.

The perspective view which shows the catalyst of the honeycomb structure arrange | positioned in the reaction tank. The enlarged schematic diagram which shows the upstream end surface of the catalyst, and the inorganic solid substance adhering to the upstream end surface. The enlarged schematic diagram which shows the same upstream end surface and the inorganic solid substance grown rather than the state of FIG. The expanded block diagram which shows the inorganic solid substance which obstruct | occluded the inlet_port | entrance of the pipe | tube of the same catalyst. The schematic block diagram which shows the fluid purification apparatus which concerns on 1st Embodiment. The longitudinal cross-sectional view which shows the reaction tank of the fluid purification apparatus. The cross-sectional view which shows the heterogeneous reaction tank used for experiment. The longitudinal cross-sectional view which shows the reaction tank of the fluid purification apparatus which concerns on a reference form.

Hereinafter, a fluid purification device according to a first embodiment to which the present invention is applied will be described.
FIG. 5 is a schematic configuration diagram illustrating the fluid purification device according to the first embodiment. The fluid purification apparatus according to the first embodiment includes a raw water tank 1, a stirrer 2, a raw water supply pump 3, a raw water pressure gauge 4, a raw water inlet valve 5, an oxidant pressure feed pump 6, an oxidant pressure gauge 7, and an oxidant inlet valve 8. Etc. In addition, the heat exchanger 9, the heat medium tank 10, the heat exchange pump 11, the outlet pressure gauge 12, the outlet valve 13, the gas-liquid separator 14, the reaction tank 20, the heater 23, the solid matter separation device 30, and the reaction tank thermometer 24. Further, an oxidant preheater 43, a raw water preheater 44, and the like are also provided. Furthermore, a gas chromatograph 41, a TOC analyzer 42, a control unit (not shown), and the like are also provided.

  The control unit has a power feeding circuit composed of a combination of an earth leakage breaker, a magnet switch, a thermal relay, and the like corresponding to each drive system device. And the on / off of the power supply with respect to each drive system apparatus is controlled separately by turning on / off the magnet switch of a feed circuit with the control signal from a programmable sequencer.

  The raw water pressure gauge 4, the oxidant pressure gauge 7, and the outlet pressure gauge 12 each output a voltage having a value corresponding to the pressure detection result. The reaction vessel thermometer 24 outputs a voltage corresponding to the temperature detection result. The voltages output from these measuring devices are individually converted into digital data by an A / D converter (not shown) and then input to the programmable sequencer as sensing data. The programmable sequencer controls driving of various devices based on the sensing data.

  In the raw water tank 1, waste water W, which is a purification target fluid containing organic substances, is stored in an unpurified state. There is a possibility that the waste water W contains a hardly decomposable organic substance.

  The agitator 2 agitates the waste water W stored in the raw water tank 1 to uniformly disperse suspended solids contained in the waste water, thereby achieving a uniform organic substance concentration. The waste water W in the raw water tank 1 is continuously pumped toward the reaction tank 20 by the raw water supply pump 3. The waste water W sent from the raw water supply pump 3 flows into the raw water inlet valve 5. The raw water inlet valve 5 plays a role of a check valve, and allows the waste water W sent from the raw water supply pump 3 to flow from the raw water supply pump 3 side to the reaction tank 20 side while flowing in the reverse direction. To prevent. The waste water W that has passed through the raw water inlet valve 5 is preheated by the raw water preheater 44.

  The oxidant pressure feed pump 6 composed of a compressor sends out the air A taken as an oxidant to the oxidant inlet valve 8 while compressing the air A to a pressure similar to the inflow pressure of the waste water W. The oxidant inlet valve 8 serves as a check valve, and allows the air A fed from the oxidant pressure feed pump 6 to flow from the oxidant pressure feed pump 6 side to the reaction tank 20 side. Block the reverse flow. The air A that has passed through the oxidant inlet valve 8 is preheated by the oxidant preheater 43.

  The waste water W preheated by the raw water preheater 44 and the air A preheated by the oxidant preheater 43 merge in the middle to become a mixed fluid, and are then sent into the reaction tank 20.

  The delivery pressure of the waste water W driven by the raw water supply pump 3 is detected by the raw water pressure gauge 4 disposed on the upstream side of the raw water inlet valve 5 and is input to the programmable sequencer of the control unit as sensing data. Moreover, the delivery pressure of the air A by the oxidant pressure pump 6 is detected by the oxidant pressure gauge 7 on the upstream side of the oxidant inlet valve 8, and the detection result is input to the programmable sequencer. The delivery pressure of the waste water W and the delivery pressure of the air A are almost the same as the pressure in the reaction tank 20. The programmable sequencer determines whether or not the pressure in the reaction tank 20 is appropriate based on the detection result by the raw water pressure gauge 4 and the detection result by the oxidant pressure gauge 7 when the raw water supply pump 3 and the oxidant pressure feed pump 6 are driven. To do.

  The amount of air pumped by driving the oxidant pump 6 is determined based on the stoichiometric amount of oxygen required to completely oxidize the organic matter in the wastewater W. More specifically, COD (Chemical Oxygen Demand) of wastewater, total nitrogen (TN), total phosphorus (TP), etc. are necessary for complete oxidation of organic matter based on organic matter concentration, nitrogen concentration, phosphorus concentration, etc. in wastewater W The amount of oxygen is calculated. And based on the result, the pumping amount of air is set.

  The inflow of air is set by the worker, but the type of organic matter contained in the wastewater W is stable over time, and the physical properties such as turbidity, light transmittance, electrical conductivity, specific gravity, etc. When the correlation with the amount of oxygen is relatively good, the following may be performed. That is, the programmable sequencer may be configured to perform the process of automatically correcting the above-described control range based on the result of detecting the physical property by a sensor or the like.

  As the oxidizing agent, in addition to air, any one of oxygen gas, ozone gas, hydrogen peroxide water, or a mixture of two or more of them can be used.

  The outer peripheral surface of the reaction tank 20 is covered with a heater 23 for heating the mixed fluid in the reaction tank 20. In addition to increasing the temperature of the mixed fluid in the reaction tank 20 by being heated by the heater 23, the temperature of the mixed fluid is also increased by heat generated by the oxidative decomposition of the organic matter. When the wastewater W contains organic matter at a high concentration, the mixed fluid may be heated to a desired temperature only by a large amount of heat generated when a large amount of organic matter is decomposed by oxidation. In this case, heating by the heater 23 is performed only when the apparatus is started up, and the power supply to the heater 23 can be turned off after the oxidative decomposition is started.

  Examples of the pressure applied to the mixed fluid in the reaction tank 20 include a range of 0.5 to 30 MPa (desirably 2 to 30 MPa). The pressure in the reaction tank 20 is adjusted by an outlet valve 13 described later. When the pressure in the reaction tank 20 becomes higher than the threshold value, the outlet valve 13 automatically opens the valve and discharges the mixed fluid in the reaction tank 20 to the outside, thereby maintaining the pressure in the reaction tank 20 near the threshold value. To do.

  Examples of the temperature of the mixed fluid in the reaction tank 20 include 100 to 600 ° C. (desirably 200 to 550 ° C.). The temperature is adjusted by turning on / off the heater 23 described above and turning on / off the operation of the heat exchanger 9 described later.

  When temperature = 374.2 ° C. or higher and pressure = 21.8 MPa or higher are adopted as temperature and pressure conditions, the critical temperature and critical pressure of water are exceeded, and the critical temperature and critical pressure of air are also exceeded. State. For this reason, the mixed fluid becomes a supercritical fluid having an intermediate property between liquid and gas. In such a supercritical fluid, the organic matter is well dissolved in the supercritical fluid and is in good contact with air, so that the oxidative decomposition of the organic matter proceeds rapidly.

  As a condition of temperature and pressure, a relatively high pressure of temperature = 200 ° C. or higher (desirably 374.2 ° C. or higher) and pressure = 21.8 MPa (desirably 10 MPa or higher) is adopted in the reaction vessel 20. The waste water in the mixed fluid may be superheated steam.

  The temperature of the mixed fluid in the reaction vessel 20 is 100 to 700 ° C, desirably 200 to 550 ° C. When the operation of the fluid purification device is started, the mixed fluid in the reaction tank 20 is under pressure, but the temperature is not so high. Therefore, at the start of operation, the programmable sequencer causes the heater 23 to generate heat, and the temperature of the mixed fluid in the reaction vessel 20 is increased to 200 to 550 ° C.

  In the reaction tank 20, the mixed fluid is brought to a high temperature and high pressure state to promote oxidative decomposition of organic matter and ammonia nitrogen in the mixed fluid. The mixed fluid that has moved to the downstream end in the fluid conveyance direction of the reaction tank 20 in the reaction tank 20 is in a state in which organic substances and inorganic compounds are almost completely oxidized and decomposed. A solids separation device 30 is connected to the downstream end of the reaction tank 20 through a pipe branched into two. In addition, although the heat exchanger 9 is attached to the pipe branched into the two described above, this will be described in detail later.

  The solid substance separation device 30 has a first separation system and a second separation system. The first separation system includes a first branch valve 31, a first separation tank 32, a first drain valve 33, a first gate valve 34, and the like. The second separation system includes a second branch valve 35, a second separation tank 36, a second drain valve 37, a second gate valve 38, and the like.

  The first separation system and the second separation system are used alternately. When the first separation system is used, the second branch valve 35 and the second partition of the second separation system are opened with the first branch valve 31 and the first gate valve 34 of the first separation system opened, respectively. Each valve 38 is closed. On the other hand, when the second separation system is used, the first branch valve 31 of the first separation system is opened with the second branch valve 35 and the second gate valve 38 of the second separation system opened. And the 1st gate valve 34 is closed.

  In the first separation system, the purified fluid sent from the reaction tank 20 enters the first separation tank 32 via the first branch valve 31. In the first separation tank 32, the solid matter in the purified fluid settles toward the tank bottom by its own weight. The purified fluid from which the solid matter has been separated in this way is discharged from the first separation tank 32 and then flows into the purified fluid transport pipe 16 through the first gate valve 34. A filter may be provided at the fluid discharge port of the first separation tank 32 for the purpose of favorably separating solids from the fluid in the first separation tank 32. When the solid content contained in the waste water W is relatively small, only the filter may be provided instead of the first separation tank 32 and the second separation tank 36.

  When the first separation system is used, since the second branch valve 35 and the second gate valve 38 are closed in the second separation system, the reaction tank 20 → the first separation system → the purified fluid transport pipe 16 It is cut off from the route. In this state, by opening the second drain valve 37 existing immediately below the second separation tank 36, the solid matter accumulated at the bottom of the second separation tank 36 can be discharged from the second separation tank 36. it can. At this time, the pressure in the second separation tank 36 decreases as the solid matter is discharged, but since the second separation system is shut off from the above path, the high pressure is maintained in the above path. For this reason, it is possible to remove the solid matter from the second separation tank 36 without stopping the purification process in the entire apparatus.

  On the other hand, when the second separation system is used, the purified fluid that has passed through the second branch valve 35 reaches the second separation tank 36 and is subjected to a solid separation process. Then, after being discharged from the second separation tank 36, it passes through the second gate valve 38 and then flows into the purified fluid transport pipe 16. Further, in the first separation system, the solid matter is discharged from the first separation tank 32 by opening the first drain valve 33.

  In the purified fluid transport pipe 16, the moisture of the purified fluid is cooled to change the state from the supercritical state or the superheated steam state to the liquid state. On the other hand, oxygen and nitrogen in the mixed fluid change the mode from the supercritical state to the gas state. The mixed fluid that has passed through the purified fluid transport pipe 16 is separated into treated water and gas by the gas-liquid separator 14.

  The composition of the gas separated by the gas-liquid separator 14 is detected by the gas chromatograph 41. When an undecomposed substance is detected by the gas chromatograph 41, a programmable sequencer that receives an output signal from the gas chromatograph 41 issues an alarm. Further, the TOC (total organic carbon) concentration of the liquid separated by the gas-liquid separator 14 is detected by the TOC analyzer 42. When the total organic carbon having a concentration exceeding the threshold is detected by the TOC analyzer 42, a programmable sequencer that receives an output signal from the TOC analyzer 42 issues an alarm.

  Purified water contains almost no suspended solids or organic matter because organic substances of very low molecular weight that cannot be removed by biological treatment with activated sludge are almost completely oxidized and decomposed. It contains only a small amount of inorganic material that could not be oxidized. Even as it is, it can be reused as industrial water depending on the application. Further, if a filtration process using an ultrafiltration membrane is performed, it can be diverted to an LSI cleaning liquid or the like. The gas separated by the gas-liquid separator 14 is mainly composed of carbon dioxide, nitrogen gas, and oxygen.

  The heat exchanger 9 is attached to two branched pipes (hereinafter referred to as “two-branched pipes”) extending from the reaction tank 20 toward the solid matter separation device 30. The main body of the heat exchanger 9 is composed of an outer tube that covers the outer surface of the purified fluid transport pipe 16, and a space between the outer tube and the outer surface of the purified fluid transport pipe 16 is filled with a heat exchange fluid such as water. Then, heat exchange is performed between the outer surface of the two-branch pipe and the heat exchange fluid. When the reaction tank 20 is operated, a very high-temperature liquid flows inside the two-branch pipe, so that heat is transferred from the two-branch pipe to the heat exchange fluid in the heat exchanger 9, and the heat exchange fluid is heated. The transfer direction of the heat exchange fluid in the heat exchanger 9 is opposite to the transfer direction of the liquid in the two-branch pipe so as to perform so-called countercurrent heat exchange. That is, the heat exchange fluid is sent from the reaction tank 20 side toward the solids separation device 30 side. This is performed by the heat exchange pump 11 that sends the heat exchange fluid in the heat medium tank 10 to the heat exchanger 9 while sucking the heat exchange fluid.

  The heat exchange fluid heated through the heat exchanger 9 is sent to a thermal energy utilization facility through a pipe (not shown). A generator can be illustrated as an example of a thermal energy utilization facility. In the generator, power generation is performed by rotating the turbine with an air flow generated when the heat exchange fluid that has been heated to increase the pressure from a liquid to a gas state. A part of the heat exchange fluid that has passed through the heat exchanger 9 may be sent to the raw water preheater 44 or the oxidant preheater 43 through a branch pipe and used for preheating the waste water W or air A.

  A thermometer (not shown) that detects the temperature of the two-branch pipe or the temperature of the fluid in the two-branch pipe is provided in the vicinity of the inlet of the two-branch pipe. The programmable sequencer of the control unit controls the drive of the heat exchange pump 11 so that the detection result by the outlet thermometer is maintained within a predetermined numerical range. Specifically, when the detection result by the thermometer reaches a predetermined upper limit temperature, the amount of heat exchange fluid supplied to the heat exchanger 9 is increased by increasing the drive amount of the heat exchange pump 11, thereby exchanging heat. The cooling function by the vessel 9 is enhanced. On the other hand, when the detection result by the thermometer reaches a predetermined lower limit temperature, the amount of heat exchange fluid supplied to the heat exchanger 9 is reduced by reducing the drive amount of the heat exchange pump 11 to thereby reduce the heat exchanger. 9 reduces the cooling function. In such a configuration, the temperature of the liquid in the two-branch pipe can be maintained in a certain range by appropriately adjusting the heat exchange amount. The heat exchanger 9 may be attached to the reaction tank 20 in addition to or instead of being attached to the two-branch pipe.

  When the organic matter concentration in the wastewater W is relatively high, a large amount of heat is generated by oxidative decomposition of the organic matter. For this reason, although the heater 23 is operated at the initial stage of operation, after the oxidative decomposition of the organic substance is started, the temperature of the mixed fluid of the waste water W and the air A is set to a desired value by the heat generated by the oxidative decomposition of the organic substance. In some cases, the temperature can be naturally increased to the temperature. Therefore, the programmable sequencer of the control unit turns off the heater 23 as a heating means when the detection result by the reaction vessel thermometer 24 that detects the temperature of the reaction vessel 20 becomes higher than a predetermined temperature. Thereby, useless energy consumption can be suppressed.

Next, a characteristic configuration of the fluid purification device according to the first embodiment will be described.
FIG. 6 is a longitudinal sectional view showing the reaction tank 20. The reaction tank 20 includes a cylindrical substrate 20a, a corrosion-resistant layer 20b coated on the inner peripheral surface of the substrate 20a, an intermediate layer 20c coated thereon, and a catalyst phase coated thereon. 20d.

  The base material 20a is made of a metal material having excellent pressure resistance. In the fluid purification device according to the first embodiment, stainless steel (SUS304, SUS316), Inconel 625, or nickel alloy is used as the metal material. The pressure inside the reaction tank 20 is controlled to a high pressure of 0.5 to 30 [Mpa], preferably 2 to 30 [Mpa]. The thickness of the base material 20a is thick so that it can withstand such a high pressure.

  The corrosion resistant layer 20b is made of a material excellent in corrosion resistance using titanium, titanium alloy, nickel, nickel alloy, tantalum, or platinum. In the reaction vessel 20, hydrochloric acid derived from the chloro group of the organic chloride and sulfuric acid derived from the sulfonyl group such as amino acid may be generated to make the mixed fluid strongly acidic. Depending on the case, it may become so acidic that the metal of the base material 20a is dissolved in a very short time. If the metal of the base material 20a is melted, there is a risk that it will not withstand high pressure and may burst. Therefore, the inner wall of the base material 20a is covered with a corrosion-resistant layer 20b having excellent corrosion resistance. The corrosion resistant layer 20b can prevent the base material 20a from being melted.

  The catalyst phase 20d promotes oxidative decomposition of organic substances such as Au, Pd, Ag, Pt, Ru, Co, Ni, Cu, Mn, Fe, V, Cr, or a compound containing at least one of them. Made of material. The intermediate layer 20c is made of a material that exhibits better adhesion to the corrosion-resistant layer 20b than the catalyst phase 20d and also exhibits better adhesion to the catalyst phase 20d than the corrosion-resistant layer 20b. In the fluid purification device according to the first embodiment, titanium is used as the material of the corrosion-resistant layer, and palladium is used as the material of the catalyst phase 20d. As the material for the intermediate layer 20c, gold is used which exhibits better adhesion to titanium than palladium while exhibiting better adhesion to palladium than titanium. By interposing the intermediate layer 20c between the corrosion-resistant layer 20b and the catalyst phase 20d, the catalyst phase 20d made of a material excellent in catalytic property for oxidative decomposition of organic matter on the corrosion-resistant layer 20b made of material excellent in corrosion resistance. Can be stably fixed over a long period of time. Thereby, it is possible to avoid the loss of the catalyst capacity due to the dropping of the catalyst phase 20d.

  As a method for coating the corrosion resistant layer 20b on the inner peripheral surface of the base material 20a, an explosion pressure welding method can be exemplified. The explosive welding method is a processing technique in which different materials are collided at high speed by the explosive force of an explosive and the materials are firmly bonded. Moreover, you may coat | cover the catalyst phase 20d directly with respect to the corrosion-resistant layer 20b. In this case, the material of the catalyst phase 20d is laminated on the surface of the corrosion-resistant layer 20b by a processing method such as a CVD method, an impregnation method, a reduction method, a plating method, or a thermal spraying method. However, it is more desirable to provide the intermediate layer 20c in order to prevent the catalyst phase 20d from falling off.

  In the figure, straight arrows indicate the transport direction of the mixed fluid of the wastewater W and the air A. A coupling packing for connecting the reaction tank 20 and a feed pipe (not shown) for feeding the mixed fluid toward the reaction tank 20 is pressed against the upstream end surface S in the fluid conveyance direction of the catalyst phase 20d. . For this reason, basically, the mixed fluid sent toward the reaction tank 20 by the feeding pipe does not hit the upstream end surface S. However, depending on the dimensional error of the packing and the reaction tank 20, a part of the upstream end surface S protrudes toward the center side of the packing in the radial direction of the cylinder, and the mixed fluid collides with the protruding portion (hereinafter referred to as a protruding portion). It is also possible. Even if the mixed fluid collides in this way, since the mixed fluid has not yet been heated to a predetermined temperature because it has not yet entered the reaction vessel 20, the inorganic solid matter is precipitated so much. Not. For this reason, the sticking of the inorganic solid matter to the protruding portion does not occur so much. Moreover, even if very few inorganic solids adhere, the growth rate is very slow. In addition, the inner diameter of the catalyst phase 20d at the upstream end in the fluid conveyance direction of the reaction vessel 20 is larger than the diameters of a plurality of tubes in the conventional honeycomb structure catalyst and the diameter of the intergranular space in the conventional granular catalyst. , Much bigger. For this reason, the period until the reaction tank 20 is clogged by the inorganic substance fixed to the inner wall of the catalyst phase 20d is much longer than the period during which the conventional catalyst having a honeycomb structure or the granular catalyst is clogged. Thereby, since the frequency of the cleaning operation | work of the reaction tank 20 falls significantly, the effort of the cleaning operation | work of the reaction tank 20 can be reduced.

  The inventors prepared a test apparatus having the same configuration as the fluid purification apparatus according to the first embodiment. Moreover, the reaction tank (henceforth a different structure reaction tank) of the structure different from the reaction tank 20 of the fluid purification apparatus which concerns on 1st Embodiment was prepared. As shown in FIG. 7, the heterogeneous reaction tank 200 includes a cylindrical base material 200 a and a corrosion-resistant layer 200 b covered on the inner peripheral surface thereof. Inside the heterogeneous reaction tank 200, only seven tube catalysts 201 having a tube shape are arranged. The diameter of the tube catalyst 201 is slightly smaller than 1/3 of the internal diameter of the heterogeneous reaction tank 200. It is a value.

The present inventors performed a running test by setting the test apparatus to various conditions. As the purification target fluid, organic waste water (hereinafter referred to as raw water) containing solid content of 10 wt% or more was used. Then, the COD (chemical oxygen demand) of the purified water purified by the test apparatus was measured, and it was examined whether or not the value satisfies the river discharge standard. Further, the presence or absence of clogging of the catalyst due to the sticking of the inorganic solid matter was examined. The experimental results are shown in Table 1 below.

  As shown in Table 1, in the running tests of Experiment Nos. 1, 2, 3, 4, 5, and 6, the same catalyst as the reaction tank 20 of the fluid purification device according to the first embodiment is used as the reaction tank. What provided the phase was used. On the other hand, in the running test of Experiment No. 7, the above-described heterogeneous reaction tank 200 was used as a reaction tank. In the running tests of Experiment Nos. 1, 2, 3, 4, 5, and 6 using the reaction tank provided with the catalyst phase, although the inorganic solid was fixed on the inner wall of the catalyst phase, the fixed region was spread over the entire inner wall. No intensive sticking at the entrance occurred. For this reason, the reaction tank was not clogged with inorganic solids. On the other hand, in the running test of Experiment No. 7 using the seven catalyst tubes 201 shown in FIG. 7 as the catalyst, one of the seven catalyst tubes 201 has the middle inlet fixed with the inorganic solid matter. Completely clogged. Further, in the remaining six, the inorganic solids were intensively fixed on the upstream end face, so it was clear that if the running test was further continued, they were also clogged with the inorganic solids. From this experimental result, it was proved that clogging with inorganic solids can be effectively suppressed in the reaction tank provided with the catalyst phase as in the fluid purification device according to the first embodiment.

  In the running tests of Experiment Nos. 5 and 6, the water quality (COD) of the treated water did not satisfy the river discharge standard, while the other running tests satisfied the river discharge standard. While the reaction temperature in the running tests of Experiment Nos. 5 and 6 is 300 ° C or lower, the reaction temperature in other running tests is 400 ° C or higher. It is desirable that the temperature be 400 ° C. or higher.

Next, the fluid purification apparatus according to the reference embodiment will be described. Unless otherwise specified below, the configuration of the fluid purification device according to the reference embodiment is the same as that of the first embodiment.
FIG. 8 is a longitudinal sectional view showing the reaction tank 20 of the fluid purification device according to the reference embodiment. In the fluid purification device according to the reference embodiment, a catalyst member configured separately from the reaction tank 20 is used. Specifically, the reaction tank 20 includes a base material 20a and a corrosion-resistant layer 20b coated on the inner peripheral surface thereof, but does not include an intermediate layer or a catalyst phase. Instead, the catalyst member 21 is disposed in the reaction tank 20.

  The reaction tank 20 has a cylindrical shape. And the catalyst member 21 arrange | positioned in the reaction tank 20 is also cylindrical. Further, the size of the catalyst member 21 is such that only one of the catalyst members 21 can be accommodated in the inner space of the reaction tank 20 in a posture extending in the longitudinal direction of the reaction tank 20.

  The catalyst member 21 includes a cylindrical substrate 21a, a catalyst phase 21b coated on the outer peripheral surface thereof, and a catalyst phase 21b coated on the inner peripheral surface of the substrate 21a. The feeling 21a is made of a material such as stainless steel, nickel, or a nickel alloy. The catalyst phase 21b is made of Au, Pd, Ag, Pt, Ru, Co, Ni, Cu, Mn, Fe, V, Cr, etc., and includes CVD, impregnation, reduction, plating, thermal spraying, etc. The outer peripheral surface and inner peripheral surface of the base material 21a are coated by a processing method.

  The diameter of the catalyst member 21 having a size that can accommodate only one in the inner space of the reaction tank 20 is larger than the diameter of a plurality of tubes in a conventional honeycomb structure catalyst and the diameter of an intergranular space in a granular catalyst. , Much bigger. For this reason, the period until the inorganic solid substance fixed to the upstream end face of the catalyst member 21 grows toward the center of the diameter of the catalyst member 21 and closes the inlet of the catalyst member 21 is a conventional honeycomb-structure catalyst or granular shape. This is much longer than the period during which the catalyst is clogged. Thereby, since the implementation frequency of the cleaning operation | work which removes the inorganic solid substance adhering to the catalyst member 21 of the reaction tank 20 falls significantly, the effort of the cleaning operation | work of the reaction tank 20 can be reduced.

The inventors prepared a test apparatus having the same configuration as that of the fluid purification apparatus according to the reference embodiment, and performed a running test by setting the test apparatus to various conditions. The experimental results are shown in Table 2 below.

As shown in Table 2, in any of Experiment Nos. 8, 9, 10, and 11, a reaction tank provided with a catalyst member similar to the reaction tank 20 of the fluid purification device according to the reference embodiment was used. In any running test, although the inorganic solid matter was fixed to the inner wall of the catalyst member, the fixed region was spread over the entire inner wall, and intensive fixing at the inlet of the catalyst member did not occur. For this reason, the catalyst member was not clogged with inorganic solids. From this experimental result, it was proved that clogging with inorganic solids can be effectively suppressed in a reaction tank provided with a catalyst member as in the fluid purification device according to the reference embodiment.

  In the running tests of Experiment Nos. 10 and 11, the water quality (COD) of the treated water did not satisfy the river discharge standard, while in other running tests, the river discharge standard was satisfied. While the reaction temperature in the running tests of Experiment Nos. 10 and 11 is 300 ° C or lower, the reaction temperature in other running tests is 400 ° C or higher. It is desirable that the temperature be 400 ° C. or higher.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
[Aspect A]
Aspect A purifies the fluid to be purified by decomposing organic matter in the fluid to be purified by an oxidation reaction while heating and pressurizing a fluid mixture of the fluid to be purified (for example, waste water W) and an oxidant (for example, air A). In the fluid purification device including a cylindrical reaction tank (for example, reaction tank 20), a catalyst phase (for example, catalyst phase 20d) made of a material that promotes oxidative decomposition of organic substances is laminated on the inner surface of the reaction tank. It is what.

[Aspect B]
Aspect B is a cylindrical reaction tank that purifies the purification target fluid by decomposing organic matter in the purification target fluid by oxidation reaction while heating and pressurizing the mixed fluid of the purification target fluid and the oxidant, and the reaction In a fluid purification apparatus comprising a catalyst member (for example, catalyst member 21) made of a material that is disposed in a tank and promotes oxidative decomposition of organic matter, in a tank internal space of the reaction tank, in a longitudinal direction of the reaction tank The catalyst member is formed in a cylindrical shape having a size that can accommodate only one in an extended posture.

[Aspect C]
Aspect C is the aspect A wherein, on the inner peripheral surface of the cylindrical base material (for example, the base material 20a), a corrosion-resistant layer (for example, the corrosion-resistant layer 20b) made of a material superior in corrosion resistance to the base material, and the corrosion-resistant material An intermediate layer (for example, the intermediate layer 20c) made of a material that exhibits superior adhesion to the catalyst phase and exhibits superior adhesion to the catalyst phase than the corrosion-resistant material, and the catalyst The phase is laminated in order. In such a configuration, the intermediate layer is interposed between the corrosion-resistant layer and the catalyst phase, so that the catalyst phase can be effectively prevented from falling off.

[Aspect D]
Aspect D is characterized in that in Aspect B, the shape of the catalyst member is the same as the shape of the reaction vessel. In such a configuration, the catalyst member can be disposed in the reaction tank with the catalyst member having a larger diameter than when the catalyst member has a shape different from that of the reaction tank. The frequency of the member cleaning operation can be further reduced.

[Aspect E]
Aspect E is characterized in that, in aspect C, titanium, titanium alloy, nickel, nickel alloy, tantalum, iridium or platinum is used as the material of the corrosion-resistant layer. In such a configuration, corrosion of the substrate can be effectively suppressed by the corrosion-resistant layer made of titanium, titanium alloy, nickel, nickel alloy, tantalum, iridium, or platinum.

[Aspect F]
Aspect F is characterized in that, in aspect C or E, the substrate is made of stainless steel or nickel alloy. In such a configuration, the pressure resistance excellent in the reaction tank can be exhibited by the base material made of stainless steel or nickel alloy.

[Aspect G]
The aspect G is any one of the aspects A to F. As the material of the catalyst phase or the surface material of the catalyst member, Au, Pd, Ag, Pt, Ru, Co, Ni, Cu, Mn, Fe, V , Cr, or a compound comprising a compound containing at least one of them is used. In such a configuration, the oxidative decomposition of the organic matter is excellent due to the catalytic action of Au, Pd, Ag, Pt, Ru, Co, Ni, Cu, Mn, Fe, V, Cr, or a compound containing at least one of them. Can be encouraged.

[Aspect H]
Aspect H is characterized in that in any one of Aspects A to G, an oxidant pumping means for pumping air, oxygen, liquid oxygen, ozone, or hydrogen peroxide as the oxidant to the reaction vessel is provided. It is. In such a configuration, the purification target fluid can be mixed with air, oxygen, liquid oxygen, ozone, or hydrogen peroxide in the reaction tank to enable oxidative decomposition of organic substances in the purification target fluid.

[Aspect I]
Aspect I recovers with a heat exchange medium in order to use the heat of the reaction tank or the transporting means for transporting the purified fluid discharged from the reaction tank as thermal energy in any of aspects A to H. A heat exchanger (for example, heat exchanger 9) is provided. In such a configuration, the heat generated in the reaction vessel due to the oxidative decomposition of the organic matter can be extracted and used as thermal energy.

[Aspect J]
Aspect J is any one of aspects A to I, comprising heating means for heating the mixed fluid in the reaction tank to 100 to 600 ° C., and pressure maintaining means for maintaining the pressure of the mixed fluid at 2 to 30 MPa. It is characterized by providing. In such a configuration, the organic fluid in the mixed fluid can be oxidatively decomposed by heating and pressurizing the mixed fluid to a high temperature and a high pressure.

W: Wastewater (Purified fluid)
A: Air (oxidizer)
3: Raw water supply pump (part of pressure maintenance means)
6: Oxidant pump (oxidant pump)
9: Heat exchanger 13: Outlet valve (part of pressure maintaining means)
20: Reaction tank 20a: Base material 20b: Corrosion resistant layer 20c: Intermediate layer 20d: Catalyst phase 21: Catalyst member 23: Heater (heating means)

JP 2001-205279 A JP 2001-321786 A

Claims (7)

In a fluid purification apparatus comprising a cylindrical reaction tank that purifies a purification target fluid by decomposing an organic substance in the purification target fluid by an oxidation reaction while heating and pressurizing a mixed fluid of the purification target fluid and an oxidizing agent.
On the inner peripheral surface of the cylindrical base material in the reaction vessel, a corrosion-resistant layer made of a material having better corrosion resistance than the base material, an intermediate layer, and a catalyst layer made of a material that promotes oxidative decomposition of organic matter are sequentially laminated. and,
As the material of the intermediate layer, a material that exhibits better adhesion to the corrosion resistant layer than the catalyst layer and that exhibits better adhesion to the catalyst layer than the corrosion resistant layer was used . A fluid purification device characterized by the above. The fluid purification device according to claim 1 ,
A fluid purification apparatus using titanium, titanium alloy, nickel, nickel alloy, tantalum, iridium or platinum as a material of the corrosion-resistant layer. The fluid purification device according to claim 1 ,
A fluid purification apparatus using a material made of stainless steel or nickel alloy as the substrate. The fluid purification device according to any one of claims 1 to 3 ,
As a wood charge of the catalyst layer, use Au, Pd, Ag, Pt, Ru, Co, Ni, Cu, Mn, Fe, V, Cr, or of those ones made of a compound containing at least one A fluid purification device characterized by that. The fluid purification device according to any one of claims 1 to 4 ,
A fluid purification apparatus comprising an oxidant pumping means for pumping air, oxygen, liquid oxygen, ozone, or hydrogen peroxide as the oxidizer to the reaction tank. The fluid purification device according to any one of claims 1 to 5 ,
Fluid purification comprising a heat exchanger for recovering with a heat exchange medium in order to use heat of the reaction tank or a purified fluid discharged from the reaction tank as heat energy apparatus. The fluid purification device according to any one of claims 1 to 6 ,
A fluid purification apparatus comprising: a heating unit that heats the mixed fluid in the reaction tank to 100 to 600 ° C .; and a pressure maintaining unit that maintains a pressure of the mixed fluid at 2 to 30 MPa.

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