JP2006231119A - Waste heat recovery device for wet oxidation decomposition equipment of organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat recovery device for wet oxidation decomposition equipment of organic waste capable of recovering a heat of product from an oxidation decomposition furnace for wet oxidation decomposition equipment, cooling the product up to a desirable post-cooling temperature, heating liquid organic waste supplied to the oxidation decomposition furnace up to a desirable prescribed supply temperature with the recovery heat and, at the same time, preventing scale production due to carbonization etc. in a supply line of the liquid organic waste. <P>SOLUTION: The waste heat recovery device for wet oxidation decomposition equipment having the oxidation decomposition furnace by which the liquid organic waste is subjected to wet oxidation decomposition in a subcritical state is provided with: a cooler which cools the product discharged from the oxidation decomposition furnace up to the prescribed post-cooling temperature through thermal exchange with heat medium; a preheater which raises the temperature of the liquid organic waste supplied to the oxidation decomposition furnace up to the prescribed supply temperature through thermal exchange with the heat medium; a heat medium circuit through which the heat medium is circulated between the cooler and the preheater; and a cooler which is inserted into the heat medium circuit and cools the heat medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wet oxidative decomposition apparatus that oxidizes and decomposes organic waste in a subcritical state and processes harmlessly in a low cost and in a short time without giving a load to the environment, and in particular, waste heat recovery for recovering the waste heat. Relates to the device.

  Conventionally, organic waste derived from animals and plants, such as food industry wastewater, and organic waste as biomass organic matter have been treated by returning to farmland (spreading upland), concentrating and drying, converting to livestock feed, recovering energy through methane fermentation, dumping into the ocean, etc. However, in recent years, new processing methods and processing apparatuses have been demanded due to problems such as environmental secondary contamination, processing costs, and disposal prohibition measures.

  Therefore, for example, a treatment system for organic waste and organic waste water as disclosed in Japanese Patent Application Laid-Open No. 2003-290738 (Patent Document 1) has been proposed, and reuse is also performed. The outline of the description will be described below with reference to the schematic diagram of FIG.

  In FIG. 2, reference numeral 101 denotes a crusher, which includes a cutter (blade) that rotates at high speed and cuts organic waste, and a stirrer. Reference numeral 104 denotes a cracking furnace composed of a cylindrical hermetic high-pressure vessel, and the outer shell is provided with a heating means using an electric heater. 105 is a cylindrical closed high-pressure vessel similar to the cracking furnace 104, and is a catalyst furnace in which titania and alumina are loaded with a noble metal such as ruthenium or palladium, or a catalyst such as platinum or zeolite. is there.

  Reference numeral 108 denotes a carbon dioxide concentrator comprising an adsorption tower or the like enclosing zeolite that selectively adsorbs carbon dioxide. Reference numeral 109 denotes a carbon dioxide gas reduction device including a reaction tube, a heater and the like in which a catalyst (ruthenium catalyst) is enclosed. Reference numeral 110 denotes an impurity adsorption apparatus including an adsorption tower in which zeolite for removing metal ion components (cation components) and inorganic nutrient salts (anion components) or reducing the concentration thereof is enclosed. 111 is an advanced water purifier equipped with a filter (reverse osmosis membrane) comprising a polyamide polymer membrane and a polysulfone membrane. Reference numeral 114 denotes a power generation device that generates methane gas as fuel. Reference numeral 115 denotes a plant cultivating apparatus or the like that produces vegetables, fruit trees, etc. by hydroponics. The cracking furnace 104, the catalyst furnace 105, and the carbon dioxide gas reduction device 108 are connected to a waste heat recovery system including a heat pump and the recovered heat is reused in the heat exchanger 103.

  The system further includes a high-pressure pump 102, an air addition device 106, a back pressure valve 107, a gas-liquid separation device 113, and the like.

  The main steps of treating and reusing organic waste and organic wastewater by the system configured as described above have been proposed as follows.

(1) Crushing process:
Organic waste and organic waste water are put into a crusher 101, cut with a cutter, mixed with a stirrer, then turned into a slurry, and sent to a heat exchanger 103 via a valve 112 using a high-pressure pump 102. After being preheated by the exchanger 103, it is sent to the cracking furnace 104.

(2) Oxidative decomposition process:
In order to increase the oxidation efficiency in the cracking furnace 104, a predetermined amount of air (may be oxygen) is added to the slurry-like substance sent in by the decomposition furnace 104, and a high temperature (250 to 300 ° C.) is added. ), And the contained organic matter is oxidatively decomposed to be converted into an intermediate product comprising carbon dioxide and an aqueous solution containing a small amount of organic matter that could not be decomposed. The aqueous solution containing carbon dioxide and a small amount of organic matter that could not be decomposed is continuously sent to the catalyst furnace 105 as a mixed solution mixed with each other by the pressure of the high-pressure pump 102. Note that the waste heat generated in the cracking furnace 104 is recovered by the heat exchanger 103.

(3) Mineralization process:
The organic matter contained in the mixed aqueous solution flowing into the catalyst furnace 105 is circulated and contacted with the catalyst using the air addition device 106 (or oxygen supply device) and further oxidatively decomposed, and the mixed solution is converted into water, carbon dioxide gas, nitrogen gas or the like. It is decomposed and completely mineralized. The mineralized aqueous solution is reduced in pressure by the back pressure valve 107 through the heat exchanger 103 and introduced into the gas-liquid separator 113 to be separated into the aqueous solution and carbon dioxide gas. Sent to the device 108. Note that the waste heat generated in the catalyst furnace 105 is recovered by the heat exchanger 103. The back pressure valve 107 is used to maintain the cracking furnace 104 and the catalyst furnace 105 at a predetermined high pressure.

(4) Water purification process:
In the mineralized aqueous solution, a certain amount of metal components (cations) are removed by the negatively charged zeolite by the impurity adsorption device 110, and inorganic nutrient salts (anions) are fixed by the positively charged zeolite. The amount is removed and sent to the advanced water purifier 111 as purified water.

(5) Reuse process:
The carbon dioxide gas separated from the aqueous solution by the gas-liquid separation device 113 is separated and concentrated by adsorption and separation by the carbon dioxide gas concentration device 108, sent to the carbon dioxide gas reduction device 109, added with hydrogen gas, and then reduced to methane gas. And converted to water. The methane gas is sent to the power generation device 114 as fuel. In addition, carbon dioxide gas generated from the power generation device 114 is sent to the plant cultivation device 115 of the plant factory, and is used for plant growth by photosynthesis. In the plant cultivation apparatus 115, the inorganic nutrients recovered by the impurity adsorption apparatus 110 can be reused as fertilizer.

  As shown in FIG. 2, an example of a basic concept of a treatment system for organic waste and organic wastewater has been shown conventionally, but wet oxidation decomposition treatment at high temperature and high pressure, in particular, oxidation characteristics and dissolution characteristics of subcritical water. In order to actively utilize the high price, if an organic wastewater or a slurried organic waste (hereinafter referred to as “liquid organic waste”) is subjected to a wet oxidative decomposition process in a subcritical state, for example, FIG. It is necessary to maintain the inside of the oxidation decomposition reaction furnace such as the decomposition furnace 104 and the catalyst furnace 105 at a high temperature and high pressure (for example, approximately 310 ° C. and 14 MPa) under the desired subcritical conditions. The high pressure is obtained by setting a high pressure pump (for example, the high pressure pump 102 in FIG. 2) and a pressure regulator (for example, the back pressure valve 107 in FIG. 2) for feeding organic waste. In order to obtain a high temperature, the oxidation decomposition reactor is heated to the reaction start temperature (for example, 180 ° C.) with a heater installed in the outer shell at the start of the reaction treatment. Therefore, the heat of the reaction product is recovered and the liquid organic waste before being supplied to the oxidative decomposition reactor is converted into a reaction start temperature (for example, 180 by a heat exchanger (for example, the heat exchanger 103 in FIG. 2)). Preheating is performed up to ° C).

FIG. 3 shows a conventional example A of a preheater as a waste heat recovery apparatus in a wet oxidative decomposition apparatus for organic waste. In FIG. 3, reference numeral 1 denotes an oxidative decomposition treatment furnace of a wet oxidative decomposition treatment apparatus. The oxidative decomposition treatment furnace 1 is formed of a high-pressure sealed container that performs wet oxidative decomposition treatment under subcritical conditions of approximately 310 ° C. and 14 MPa, and is liquid with organic waste a is supplied, there is also a case of supplying oxygen O ₂ in the high pressure is supplied (air to be sufficient amount of oxygen to the oxidizing action from the air supply device under high pressure from a suitable oxygen supply unit 2 ), Solid organic matter is solubilized under high temperature and high pressure in a subcritical state, and the organic matter is completely oxidatively decomposed, and contains inorganic carbon dioxide CO ₂ , nitrogen gas N ₂ , and water H ₂ O as main components. Is taken off as product b with residual oxygen O ₂ .

In this conventional example, the oxidative decomposition treatment furnace 1 has a configuration in which a reaction tower 1a is connected upstream and a catalyst tower 1b is connected in series downstream. The reaction tower 1a is supplied with liquid organic waste a to be treated and high-pressure oxygen O ₂ and performs wet oxidative decomposition treatment in a subcritical state to solubilize solid organic matter and decompose about 70% of organic matter. Similarly, the catalytic tower 1b performs wet oxidative decomposition treatment by catalytic oxidation in the subcritical state, and is suitable for wet oxidative decomposition and mineralization in the subcritical state of organic waste, depending on the material and catalytic action, etc. The catalyst is charged with high pressure oxygen O _{2, and} is brought into contact with the catalyst, whereby the remaining about 30 containing intermediate products such as acetate ions are obtained by the oxidative decomposition reaction involving the catalyst in the catalyst tower 1b. % Organic matter is almost completely oxidatively decomposed and mineralized, and nitrate ions, nitrite ions, etc. contained in intermediate products are also completely oxidized and decomposed to low molecules, so that carbon dioxide CO ₂ , nitrogen gas N ₂ , water The product b is harmless to the environment mainly composed of H ₂ O and residual oxygen O ₂ (when air is supplied, other gases constituting the air are also included).

  Further, both the reaction tower 1a and the catalyst tower 1b constituting the oxidative decomposition treatment furnace 1 are provided with a heater such as an electric type or a hot oil type not shown in the outer shell, and the oxidative decomposition treatment furnace 1 at the start-up of the oxidative decomposition process. As soon as possible, a sub-critical wet oxidative decomposition reaction is possible.

  In this conventional example, the preheater is composed of a heat exchanger 3 that heats the liquid organic waste a supplied to the oxidative decomposition treatment furnace 1 at the same time as recovering heat from the product b exiting the oxidative decomposition treatment furnace 1. Functions as a waste heat recovery device. In addition, the product b is pressure-reduced by the pressure regulator which is not shown in the downstream after heat exchange. The pressure adjusting device also holds the upstream side at a desired high pressure (approximately 14 MPa).

  In the example shown in FIG. 3, when the intended temperature and pressure of the subcritical reaction in the oxidative decomposition treatment furnace 1 are about 310 ° C. and 14 MPa, the liquid organic waste a entering the heat exchanger 3 is not shown in advance. The pressure is increased to approximately 14 MPa by a high-pressure pump, the temperature is room temperature (for example, 30 ° C.), and the temperature is heated by the heat exchanger 3 to approximately 180 ° C. and 14 MPa. In the oxidative decomposition treatment furnace 1, the temperature is raised to about 310 ° C. in a subcritical state by the reaction heat of the oxidative decomposition reaction, and the product b decomposed into inorganic substances enters the heat exchanger 3 at about 310 ° C. and is liquid organic waste as described above. It is contemplated that heat is recovered in the object a and cooled to a post-cooling temperature close to room temperature at the outlet of the heat exchanger 3. Further, the pressure is reduced to atmospheric pressure by a pressure adjusting device.

  However, when the heat exchanger 3 that directly exchanges heat between the product b and the liquid organic waste a as in this example is used, the heat generation amount of the oxidative decomposition reaction of the organic waste is high. In the oxidative decomposition furnace 1, the liquid organic waste a at 180 ° C. is heated to the product b at 310 ° C. Even if the liquid organic waste a is heated from room temperature to 180 ° C. in the heat exchanger 3, The product b at 310 ° C. has not been cooled to a normal temperature (preferably about 40 ° C.) after cooling at the outlet of the heat exchanger 3, and there has been a problem in handling on the downstream side.

On the other hand, if the heat exchanger 3 is set so that the temperature t ₀ after cooling of the product b at the outlet of the heat exchanger 3 is about 40 ° C., the temperature of the liquid organic waste a at the outlet of the heat exchanger 3 is 210, for example. It has been found that there is a possibility that the temperature will rise to above ℃ and scale will be generated in the heat exchanger 3, which may hinder continuous operation.

That is, as a result of the study by the present inventors, when the high-pressure (approximately 14 MPa) liquid organic waste a is heated, only endotherm is obtained up to about 210 ° C., but decomposition exceeds about 210 ° C., and oxygen O ₂ Is not sufficient, but oxidative decomposition occurs, and a preferable subcritical oxidative decomposition reaction is obtained at a high temperature of about 310 ° C. However, it has been discovered that when oxygen O ₂ is insufficient above about 210 ° C., organic carbonization occurs.

Accordingly, when the liquid organic waste a exceeds about 210 ° C. in the heat exchanger 3, oxygen O ₂ is not supplied in the heat exchanger 3, so that fine particles are formed on the liquid organic waste a side of the heat exchanger 3. As a result, not only the heat exchange failure but also the liquid organic waste a could be blocked.

  On the other hand, there is an example of a preheater in a wet oxidative decomposition apparatus for organic waste, such as Conventional Example B shown in FIG. In FIG. 4, reference numeral 1 denotes an oxidative decomposition treatment furnace, which is the same as the above-described oxidative decomposition treatment furnace 1 in FIG.

  In this conventional example, the preheater 4 is provided alone in the supply line 5 to the oxidative decomposition treatment furnace 1 of the liquid organic waste a, and according to the example shown in FIG. 3, it is liquid at room temperature (approximately 30 ° C.) and 14 MPa. The organic waste a is heated to a supply temperature of about 180 ° C. by the preheater 4 and sent to the oxidative decomposition treatment furnace 1. The heating (preheating) of the liquid organic waste a is performed by an appropriate means such as electric heating or steam.

The liquid organic waste a undergoes an oxidative decomposition reaction in the oxidative decomposition treatment furnace 1 to be decomposed into inorganic substances, and is discharged as a product b that has been heated to about 310 ° C. by reaction heat. The discharge line 6 is provided with a cooler 7 to cool the product b to a preferable post-cooling temperature t ₀ (for example, 40 ° C.) close to normal temperature. Cooling is performed by connecting a cooler 8 to the cooler 7 and cooling with water or air. The cooler 8 includes a cooling tower, a radiator, and the like.

In the case of this conventional example, since the preheater 4 and the cooler 7 are separately provided and can be set and controlled, a preferable supply temperature (for example, approximately 180 ° C. of the reaction start temperature) is set at the outlet of the preheater 4. Therefore, it is possible to avoid the occurrence of a scale problem such as carbonization due to an increase in the preheating temperature of the liquid organic waste a as in the above-mentioned conventional example A. Moreover, it is possible to set so that the product b of about 310 ° C. and 14 MPa may be cooled to a preferable post-cooling temperature t ₀ (for example, 40 ° C.) in the cooler 7. Therefore, the problem found in the conventional example A can be avoided.

  However, since preheating and cooling are performed separately, it is necessary to provide a heating source and a cooling source. In particular, since the liquid organic waste a is preheated up to the reaction start temperature with a separate heat source, the heat to the liquid organic waste a Even if recovery is not performed and a separate heat recovery destination is provided, the apparatus becomes complicated, energy efficiency is reduced, and it is difficult to achieve a function as a heat recovery apparatus. Further, when the cooler 7 is to cool the product b of about 310 ° C. to a room temperature of about 40 ° C., there is a problem that the cooling capacity is large for both water cooling and air cooling, and the apparatus must be enlarged.

JP 2003-290738 (pages 3 to 5, FIG. 1)

  The invention of the present application is a wet oxidative decomposition treatment apparatus for organic waste, in which the heat of the product from the oxidative decomposition treatment furnace of the wet oxidative decomposition treatment apparatus can be recovered and cooled to a preferable post-cooling temperature. Liquid organic waste supplied to the furnace can be heated to a preferred predetermined supply temperature, and scale generation due to carbonization, etc. in the liquid organic waste supply line is prevented, and heat recovery of the wet oxidative decomposition treatment apparatus for organic waste It is an object to provide an apparatus.

  The present invention has been made to solve the above-described problems, and provides the following means (1) to (4), which will be described below in the order of the claims.

  (1) As a first means, in a waste heat recovery apparatus of a wet oxidative decomposition treatment apparatus provided with an oxidative decomposition treatment furnace that performs wet oxidative decomposition treatment of liquid organic waste in a subcritical state, the liquid organic waste is discharged from the oxidative decomposition treatment furnace. A cooler that cools the product to be cooled to a predetermined temperature after heat exchange with the heat medium, and a predetermined supply by heat exchange with the heat medium for the liquid organic waste supplied to the oxidation decomposition treatment furnace. A preheater that raises the temperature, a heat medium circuit that circulates the heat medium between the cooler and the preheater, and a cooler that is interposed in the heat medium circuit and cools the heat medium. The present invention provides a waste heat recovery apparatus for a wet oxidative decomposition treatment apparatus for organic waste.

  (2) As the second means, in the waste heat recovery apparatus of the wet oxidative decomposition apparatus for organic waste of the first means, the predetermined supply temperature does not exceed 210 ° C. The waste heat recovery device of the wet oxidative decomposition treatment apparatus of

  (3) Further, as a third means, in the waste heat recovery apparatus of the wet oxidative decomposition apparatus for organic waste of the first means or the second means, the subcritical state is about 310 ° C. and 14 MPa. A waste heat recovery apparatus for a wet oxidative decomposition treatment apparatus for organic waste is provided.

  (4) As a fourth means, in the waste heat recovery apparatus of the wet oxidative decomposition apparatus for organic waste according to any one of the first means to the third means, the cooler is configured so that the heat medium is supplied from the cooler. The wet oxidation of organic waste, characterized in that the heating medium circuit in the flow toward the preheater and the heating medium circuit in the flow from the preheater to the cooler are provided respectively. A waste heat recovery apparatus for a decomposition processing apparatus is provided.

  (1) According to the invention of claim 1, the waste heat recovery apparatus of the wet waste oxidative decomposition apparatus for organic waste is configured as the first means, so that the oxidative decomposition treatment furnace Heat can be recovered while obtaining a predetermined post-cooling temperature of the product from, and by the recovered heat, the temperature of the liquid organic waste supplied to the oxidative decomposition treatment furnace can be preheated to a supply temperature sufficient to start the reaction, The heat cooled by the cooler in the heat medium circuit is the remaining residual heat recovered for preheating the liquid organic waste to be treated, and energy loss can be greatly reduced. It is also possible to add further heat recovery from the cooler.

  (2) According to the invention of claim 2, since the waste heat recovery device of the wet oxidative decomposition treatment apparatus for organic waste is configured as the second means, in addition to the function and effect of the invention of claim 1, The temperature of the liquid organic waste supplied to the oxidative decomposition furnace is kept high enough to start the reaction, and to a temperature that can avoid the problem of scale generation due to carbonization in the heat recovery device of the wet oxidative decomposition apparatus for organic waste. It can be preheated.

  (3) According to the invention of claim 3, since the waste heat recovery device of the wet oxidative decomposition apparatus for organic waste is configured as the third means, the operation of the invention of claim 1 or claim 2 is achieved. In addition to the effect, in the subcritical state at approximately 310 ° C. and 14 MPa, the property of high oxidation and dissolution properties of subcritical water can be fully utilized, and a more preferable oxidative decomposition reaction can be obtained.

  (4) According to the invention of claim 4, the waste heat recovery device of the wet oxidative decomposition apparatus for organic waste is configured as the fourth means, and therefore any one of claims 1 to 3. In addition to the effects of the invention, the temperature condition of the heat medium, the cooling condition of the cooler, and the preheating condition of the preheater can be easily set.

  Example 1 will be described below as the best mode for carrying out the present invention.

  Based on FIG. 1, a waste heat recovery apparatus of an organic waste wet oxidative decomposition treatment apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic diagram of a main part configuration of a waste heat recovery apparatus of a wet oxidative decomposition apparatus for organic waste according to the present embodiment.

In FIG. 1, reference numeral 1 denotes an oxidative decomposition treatment furnace of a wet oxidative decomposition treatment apparatus. The oxidative decomposition treatment furnace 1 is formed of a high-pressure sealed container that performs wet oxidative decomposition treatment under subcritical conditions of approximately 310 ° C. and 14 MPa. Liquid organic waste a such as waste liquid or slurried organic waste is supplied, and high-pressure oxygen O ₂ from the oxygen supply device ₂ is supplied, and solid organic matter is acceptable under high temperature and high pressure in a subcritical state. While being solubilized, the organic matter is completely oxidized and decomposed and taken out as a product b containing inorganic carbon dioxide CO ₂ , nitrogen gas N ₂ , and water H ₂ O as main components and the remaining oxygen O ₂ . The wet oxidative decomposition treatment in the subcritical state is intended to positively utilize the properties with high oxidation and dissolution properties of subcritical water. The properties can be fully utilized in the subcritical state at approximately 310 ° C. and 14 MPa. More preferable oxidative decomposition reaction can be obtained.

  Note that an air supply device may be provided instead of the oxygen supply device 2 to supply air having an oxygen amount sufficient for the oxidizing action under high pressure. However, in the present embodiment, hereinafter, oxygen is supplied. explain. In the case of supplying air, the product b contains other gas constituting the air.

  The oxidative decomposition treatment furnace 1 of the present embodiment has the same configuration and action as the oxidative decomposition treatment furnace 1 described in the above-described conventional example A, and therefore, the same portions are denoted by the same reference numerals and description thereof is omitted. To do. In this embodiment, the oxidative decomposition treatment furnace 1 has a structure in which the reaction tower 1a is connected upstream and the catalyst tower 1b is connected in series downstream, but the structure of the oxidative decomposition treatment furnace 1 is not limited thereto. Other configurations may be used.

  In this embodiment, the preheater 10 is provided alone in the supply line 5 of the liquid organic waste a to the oxidation decomposition treatment furnace 1, and the cooler 11 is provided in the discharge line 6 of the product b from the oxidation decomposition treatment furnace 1. It is provided alone.

  On the other hand, a heat medium circuit 13 is provided in which the heat medium c passes from the preheater 10 through the cooler 11 and circulates through the cooler 12 to the preheater 10. As will be described later, the cooler is not the cooler 12 interposed in the illustrated heat medium circuit 13a from the cooler 11 to the preheater 10, but the heat medium circuit 13b in the flow from the preheater 10 to the cooler 11. The cooler 12 'may be provided in both the circuits 13a and 13b of the heat medium circuit 13, and the coolers 12 and 12' may be provided. Here, the heat medium circuit 13 includes a heat medium circulation pump for circulating the heat medium c and the like, but the heat medium circulation pump and the like are not shown. As the heat medium c, one having a high boiling point in accordance with a temperature range of approximately 310 ° C. or higher, for example, a mixture of glycol and water is used.

  This embodiment shows the configuration of the present invention in a range corresponding to the heat exchanger 103, the cracking furnace 104, the catalyst furnace 105, and the air addition device 106 of the conventional example shown in FIG. However, as in the system of FIG. 2, the addition of peripheral processing devices and playback devices may be made as appropriate, and is not limited to the configuration shown in FIG.

  In the waste heat recovery apparatus of the wet oxidative decomposition apparatus for organic waste according to the present embodiment as described above, heat recovery is performed as follows.

The liquid organic waste a undergoes an oxidative decomposition reaction in the oxidative decomposition treatment furnace 1 to be decomposed into inorganic substances, and is discharged as a product b that has been heated to about 310 ° C. by reaction heat. The discharge line 6 is provided with a cooler 11, and the product b is cooled in the cooler 11 by heat exchange with the heat medium c of the heat medium circuit 13, and a preferable predetermined post-cooling temperature t ₀ close to room temperature (for example, 40 ° C.). ).

On the other hand, the heating medium c is heated from the temperature t ₂ to t ₃ in the cooler 11, but the product b at about 310 ° C. is cooled to a temperature t ₀ after cooling near room temperature, and the heating medium temperature t ₃ is near 310 ° C. Therefore, when the refrigerant circuit 13a is circulated as it is and directly introduced into the preheater 10 to exchange heat with the liquid organic waste a, the wet oxidative decomposition treatment of the organic waste is the same as in the heat exchanger 3 of the conventional example A. There is a possibility that scale problems such as carbides peculiar to the heat recovery apparatus of the apparatus may occur.

Therefore, a cooler 12 is provided in the refrigerant circuit 13a, which is preferable for heating the liquid organic waste a in the supply line 5 from a substantially normal temperature (for example, 30 ° C.) to a supply temperature, preferably approximately 180 ° C., and avoids problems such as carbonization. The heat medium c is cooled to the heat medium temperature t ₁ (for example, approximately 200 ° C.). Cooling in the cooler 12 may be performed by appropriate means such as water cooling or air cooling.

The heat medium c having the heat medium temperature t ₁ heats the liquid organic waste a from a normal temperature (for example, 30 ° C.) to a predetermined supply temperature, preferably a reaction start temperature of about 180 ° C. by heat exchange in the preheater 10. It is cooled to medium temperature _{t 2.} The supply temperature is set so as not to exceed 210 ° C. so that at least the above carbonization problem can be avoided. Thereafter, the heat medium c circulates through the heat medium circuit 13b and is introduced into the cooler 11, and cools the product b from the oxidative decomposition treatment furnace 1 as described above.

Here, when it is difficult to cool the product b to the predetermined temperature t ₀ after cooling in the cooler 11 depending on the heat medium c having the heat medium temperature t _2, the cooler 12 ′ is also provided in the heat medium circuit 13 b. Then, the heat medium c is cooled to the heat medium temperature t ₂ ′ at which a predetermined post-cooling temperature t ₀ of the product b is obtained, and then circulated through the cooler 11. Cooling of the cooler 12 'may be performed by appropriate means such as water cooling or air cooling. If the heat medium circuit 13a and the heat medium circuit 13b are provided with the coolers 12 and 12 ', the temperature condition of the heat medium c, the cooling condition of the cooler 11, and the preheating condition of the preheater 10 can be easily set.

  Therefore, according to the waste heat recovery apparatus of the wet waste oxidative decomposition apparatus of the present embodiment, a predetermined post-cooling temperature to of the product b from the oxidative decomposition furnace 1 can be obtained in the discharge line 6. Heat can be recovered as a product, and by the recovered heat, the temperature of the liquid organic waste a supplied to the oxidative decomposition treatment furnace 1 is high enough to start the reaction in the supply line 5 and wet oxidative decomposition of the organic waste. Preheating can be performed at a temperature at which scale generation due to carbonization, which is a problem specific to the heat recovery apparatus of the processing apparatus, can be avoided (at least not exceed 210 ° C., preferably approximately 180 ° C.).

  In addition, the heat cooled by the cooler 12 (12 ') in the heat medium circuit 13 is the remaining heat recovered completely for preheating the liquid organic waste a to be treated in the wet oxidative decomposition apparatus for organic waste. The energy loss can be greatly reduced. It is also possible to add further heat recovery from the cooler 12 (12 ').

The arrangement of the cooler 12, 12 'of the present embodiment, the temperature, the heat balance and the like are merely examples, to a temperature t ₀ after a predetermined cooling the product b from the oxidative decomposition treatment furnace 1 at the discharge line 6 The temperature of the liquid organic waste a supplied to the oxidative decomposition treatment furnace 1 in the supply line 5 is high enough to start the reaction and the scale generation due to carbonization can be avoided by cooling and recovering the heat. What is necessary is just to set it so that the preheating can be suppressed to at least 210 ° C., preferably about 180 ° C., and these settings include the setting of the temperature conditions before and after, the reaction conditions, the heat exchange amount between the cooler and the preheater, It may be appropriately selected and set depending on the processing flow rate, the refrigerant flow rate, and the like.

  Although the present invention has been described with reference to the illustrated embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made to the specific structure within the scope of the present invention. . For example, as described above, air may be supplied instead of oxygen from the oxygen supply device 2.

It is a principal part structure schematic diagram of the waste heat recovery apparatus of the wet oxidation decomposition processing apparatus of the organic waste which concerns on one Example of this invention. It is a structure schematic diagram of the processing system of the conventional organic waste and organic wastewater. It is a structure schematic diagram which shows the prior art example A of the waste heat recovery apparatus of the wet oxidation decomposition processing apparatus of organic waste. It is a structure schematic diagram which shows the prior art example B of the waste heat recovery apparatus of the wet oxidation decomposition processing apparatus of organic waste.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oxidation cracking furnace 2 Oxygen supply apparatus 5 Supply line 6 Discharge line 10 Preheater 11 Cooler 12, 12 'Cooler 13, 13a, 13b Heat transfer circuit a Liquid organic waste b Product c Heat transfer medium

Claims (4)

  In a waste heat recovery apparatus of a wet oxidative decomposition treatment apparatus equipped with an oxidative decomposition treatment furnace that performs wet oxidative decomposition treatment of liquid organic waste in a subcritical state, the product discharged from the oxidative decomposition treatment furnace is heated with a heat medium. A cooler for cooling to a predetermined post-cooling temperature by exchange, a preheater for raising the temperature of the liquid organic waste to be supplied to the oxidative decomposition treatment furnace to a predetermined supply temperature by heat exchange with the heat medium, and A wet type organic waste comprising: a heat medium circuit for circulating the heat medium between a cooler and the preheater; and a cooler interposed in the heat medium circuit for cooling the heat medium. Waste heat recovery equipment for oxidative decomposition treatment equipment.   The waste heat of the wet oxidative decomposition treatment apparatus for organic waste according to claim 1, wherein the predetermined supply temperature does not exceed 210 ° C. Recovery device.   The waste heat recovery apparatus of the organic waste wet oxidative decomposition treatment apparatus according to claim 1 or 2, wherein the subcritical state is approximately 310 ° C and 14MPa. Waste heat recovery equipment for processing equipment.   The wet oxidative decomposition apparatus for organic waste according to any one of claims 1 to 3, wherein the cooler is the same as the heat medium circuit in which the heat medium flows from the cooler to the preheater. A waste heat recovery apparatus for a wet oxidative decomposition treatment apparatus for organic waste, wherein the heat medium is provided in each of the heat medium circuits flowing from the preheater to the cooler.

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