JP2002113348A - Treating apparatus of organic waste from animal and vegetable residue by hydrothermal reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating apparatus of organic waste from animal and vegetable residues, which is capable of decreasing the areas of heat-transfer surfaces in a hydrothermal reactor. SOLUTION: This has the hydrothermal reactor 25 which subjects the organic wastes, such as the animal and vegetable residues by pressurizing and heating the wastes to a subcritical state and executes hydrothermal reaction and a subcritical water supplying means 19 which supplies the subcritical water previously heated and pressurized up to hydrothermal conditions in the hydrothermal reactor 25 together with the organic wastes to the hydrothermal reactor 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for treating organic waste such as animal and plant residues by hydrothermal reaction for treating organic waste such as garbage and the like as animal and plant residues by hydrothermal reaction.

[0002]

2. Description of the Related Art Conventionally, animal and plant residues, such as garbage, have been treated by specialists by methods such as collection, incineration, and landfilling. In recent years, various types of refuse treatment apparatuses have been developed.

For example, JP-A-10-328699 discloses that hydrous organic waste is oxidatively decomposed by a supercritical water oxidation reaction.

[0004] However, in the decomposition method using supercritical fluid, the pressure and temperature of hydrated organic waste are raised to a supercritical state to increase oxidative decomposition and treatment capacity. The problem becomes bigger.

Accordingly, the present inventor has previously disclosed in Japanese Patent Application No. Hei 11-3
In No. 30,000 (Title of Invention; Apparatus for treating animal and plant residues by hydrothermal reaction), the organic waste is subjected to a hydrothermal reaction under a subcritical pressure state, and then the organic waste decomposed by the hydrothermal reaction is oxidized. Proposed to be processed.

The basic configuration of the prior application will be described with reference to FIG.

In FIG. 3, a raw material from a raw material tank 60 is supplied to a raw material supply line 61 and a raw water tank 6 is supplied.
2 is supplied to the raw material supply line 61, the raw material and water are mixed, the pressure is raised to a subcritical pressure state by the booster pump 63, and the water is preheated by the heat exchanger 64.
5 is circulated to the hydrothermal reactor 65 together with the hydrothermal treatment liquid from the hydrothermal reactor 65 by the circulating pump 67 connected to the circulating line 66 and connected to the circulating line 66 to perform the hydrothermal reaction. From 68, it is discharged to a post-processing device and mineralized.

[0008]

In the invention of the prior application, the hydrothermal reactor 65 is formed by a heat exchanger such as a double tube, in which the raw material slurry flows into the inner tube, and the heat transfer oil is contained in the outer tube. When the temperature difference between the heating medium oil and the raw material slurry is large, the raw material slurry is scorched in the tube, so that it is necessary to take into consideration the prevention of scorching.

For this reason, the temperature difference is reduced, the heat transfer area is increased accordingly, and the circulation amount of the slurry relative to the supply amount of the raw material slurry is increased to several tens of times, so that the heat transfer efficiency is increased and the scorch is prevented. While preventing this, the raw material slurry is heated to the hydrothermal condition of 300 ° C.

However, increasing the heat transfer area in the hydrothermal reactor 65 in a state in which a large amount of the raw material slurry is raised to a subcritical pressure requires an increase in the size of the hydrothermal reactor 65, and in addition to the load of the heat medium. There is a problem that the load on the boosting pump 63 and the circulation pump 67 also increases, and the cost increases as a whole.

Accordingly, an object of the present invention is to solve the above problems and to provide an apparatus for treating organic waste such as animal and plant residues, which can reduce the heat transfer area in a hydrothermal reactor.

[0012]

Means for Solving the Problems In order to achieve the above object, the invention of claim 1 provides a hydrothermal reaction in which organic wastes such as animal and plant residues are pressurized and heated to a subcritical state and subjected to a hydrothermal reaction. Animal and plant residues by hydrothermal reaction, comprising: a reactor and subcritical water supply means for supplying subcritical water heated and pressurized in advance to the hydrothermal condition to the hydrothermal reactor together with organic waste to the hydrothermal reactor. An organic waste treatment device.

According to a second aspect of the present invention, the subcritical water supply means includes:
It consists of a water tank, a pressure pump for increasing the pressure of the water in the water tank, and a heating means for heating the pressurized water to about 100 to 300 ° C. The apparatus for treating organic waste such as animal and plant residues according to claim 1, wherein a circulation line for circulating the material repeatedly to the hydrothermal reactor is connected, and the heating means is connected to the circulation line.

According to a third aspect of the present invention, there is provided an apparatus for treating organic waste such as animal and plant residues according to the second aspect, wherein an oxidation tank for oxidizing the decomposed and decompressed organic waste residues is connected to the circulation line. is there.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing a basic configuration of the present invention.

The raw material tank 10 contains raw materials for organic wastes such as garbage and other animal and plant residues, and the raw materials are supplied to a sub-critical pressure of water (about 10 MPa) by a booster pump 16 connected to a raw material supply line 15. Up to 25
Is supplied to a circulation line 26 connected to

The hydrothermal reactor 25 comprises a heat exchanger such as a double tube, which will be described in detail later. The raw material is supplied to the inner tube, and the heat transfer oil is supplied to the outer tube to exchange heat. The circulation line 26 is connected to the inner pipe. A circulation pump 31 is connected to the circulation line 26, and the raw material supply line 1 is connected to a suction side thereof.
5 is connected.

The sub-critical water supply means 19 is connected to the suction side of the circulation pump 31.

The subcritical water supply means 19 includes the water tank 12
Pump 17 for increasing the pressure of the water from the water tank 12 to a subcritical pressure, and a line 18a of the pressure pump 17
And heating means 19a for heating pressurized tap water to about 100 to 300 ° C.

The heating means 19a comprises a heat exchanger 42 for preheating by using the heat of the processing liquid, which will be described later, and a hot water boiler 18 for heating the preheated tap water to about 300 ° C., which is a hydrothermal condition. , Line 18 from the hot water boiler 18
a is connected to the discharge side of the circulation pump 31.

A decomposed product line 33 is connected to the circulation line 26 on the outlet side of the hydrothermal reactor 25. The decomposed product in the hydrothermal reactor 25 is decompressed as described later, and It is supplied to 22 and mineralized.

In FIG. 1, raw material containing only organic waste is supplied from a raw material supply line 15 to a hydrothermal reactor 25, and water mixed with the organic waste is supplied to a hot water boiler 1.
By separately supplying the subcritical water supply means 19 comprising the hydrothermal reactor 8, the hydrothermal reactor 25 only needs to handle the temperature rise of the raw material alone, and the heat transfer surface can be greatly reduced.

Next, the overall configuration of the present invention will be described with reference to FIG.

In FIG. 2, reference numeral 10 denotes a raw material tank for storing an organic waste raw material 11 consisting of animal and plant residues such as garbage, 12 denotes a water supply tank for performing a hydrothermal reaction with subcritical water, 13 Reference numeral denotes a chemical solution tank containing caustic soda and the like, and reference numeral 14 denotes a processing liquid tank for storing a processing liquid after processing animal and plant residues.

The raw material tank 10 has a raw material supply line 15
Is connected, and a boosting pump 16
Is connected.

A booster pump 17 is connected to the water supply tank 12, and a heating means 19a comprising a heat exchanger 42 and a hot water boiler 18 is connected to the booster pump 17 to constitute a subcritical water supply means 19. The subcritical water supply line 18 a from the hot water boiler 18 is supplied to the hydrothermal reactor 25 together with the organic waste in the raw material supply line 15.

The raw material tank 10 includes a chemical solution tank 13.
Is connected to a chemical solution supply line 20, and a chemical solution pump 21 is connected to the line 20.

A double tube heat exchanger 24 is connected to the raw material supply line 15, and the raw material supply line 15 is connected to a circulation line 26 of the hydrothermal reactor 25.

The hydrothermal reactor 25 has a heating medium circulation line 27
The heating medium circulation line 27 is connected to a heating medium circulation pump 28 and a heating medium heater 29.

The hydrothermal reactor 25 comprises a double tube or the like,
The raw material flows inside the inner tube 30, and the heat medium flows between the outer tube 32 and the inner tube 30.

The circulation line 26 connects the outlet and the inlet of the inner tube 30 of the hydrothermal reactor 25, and is constituted by connecting a circulation pump 31 therebetween.

The material supply line 15 and the subcritical water supply means 19 are connected to the circulation line 26 on the discharge side of the circulation pump 31. The material supply line 15 and the subcritical water supply means 19 will be described with reference to FIG. As described above, it may be connected to the suction side of the circulation pump 31.

The circulating pump 31 branches off from the circulating line 26 on the suction side, is connected to a decomposition line 33, the heat exchanger 24 is connected to the decomposition line 33, and the oxidation tank 22 is connected downstream thereof.

A trim cooler 34 and a back pressure regulating valve 35 are connected to a decomposition line 33 between the heat exchanger 24 and the oxidation tank 22.

The oxidizing tank 22 is connected to an oxidizing agent supply line 36 for burning and oxidizing the supplied decomposition product, and the outlet thereof is connected to the gas-liquid separator 23 and the liquid-side discharge line. A return line 39 for returning a part of the oxidized decomposition product to the oxidation tank 22 and a pump 40 are connected to 37.

A condenser 38, a separation pot 51, and a back pressure adjusting valve 52 are connected to the gas-phase side discharge line 50 of the gas-liquid separator 23, and a separation pot 51 is provided between the separation pot 51 and the gas-liquid separator 23. A line 53 for returning the condensed water separated by the process to the gas-liquid separator 23 is connected.

The liquid-side discharge line 37 has a return line 3
9, a discharge line 41 for returning the processing liquid to the processing liquid tank 14 is connected, and the discharge line 41 is connected to a heat exchanger 42 as a heating means 19a for heating clean water. The regulating valve 43 is connected, and its back pressure regulating valve 4
The processing liquid returned to normal pressure in step 3 is returned to the processing liquid tank 14.

The processing liquid tank 14 has a decomposition gas exhaust line 44 connected to its upper part, and a sewage line 45 formed to its lower part.
Is connected. The decomposition exhaust line 44 is connected to a deodorizing device 46 made of activated carbon or the like, and the sewage line 45 is connected to a line 47 for returning a part of the liquid to the raw material tank 10 and a pump 48.

The gas gasified in the raw material tank 10 is connected to the exhaust line 44 via a gas line 49.

The trim cooler 34 and the condenser 38 are
Although not shown, cold water w from a cold water tower or the like is supplied,
The chilled water w cooled by the trim cooler 34 and the condenser 38 is air-cooled by the cooling water tower, and is again cooled by the trim cooler 34 and the condenser 38.
It is supplied to.

The raw material 1 supplied to the raw material tank 10
In the case where the water content is low, the water tank 12
Water is supplied as appropriate.

Next, the treatment of organic waste such as animal and plant residues in FIG. 2 will be described.

A raw material 11, which is an organic waste, is charged into a raw material tank 10, and a chemical solution tank 13 is placed in the raw material tank 10.
Is introduced into the raw material tank 10 through the chemical liquid line 20 by the chemical liquid pump 21 so that the liquid can be pumped. In this case, tap water is supplied from the tap water tank 12 through the line 51 to adjust the viscosity of the raw material.

The raw material adjusted in the raw material tank 10 is boosted to a subcritical pressure by a booster pump 16 and supplied to a heat exchanger 24 through a raw material supply line 15 where the decomposed product from a hydrothermal reactor 25 Then, after being heated by exchanging heat, it is supplied to the hydrothermal reactor 25 through the circulation line 26.

At the same time, the pressure of the subcritical water supply means 19, that is, the water in the water tank 12 is raised to a subcritical pressure by the pressure increasing pump 17, and this is heated by the heating means 19a, that is, by the heat exchanger 42. The pre-heating is performed by exchanging heat with the processing liquid separated by the gas-liquid separator 23, and the heated sub-critical water is heated to 100 to 300 ° C. by the hot water boiler 18 to make the sub-critical water substantially circulating line 26. To the hydrothermal reactor 25 via

As described above, by producing subcritical water separately from the raw material and supplying it to the hydrothermal reactor 25, the hydrothermal reactor 25 heats the raw material by an amount required for the hydrothermal reaction. Therefore, the heat transfer area can be reduced, the temperature difference between the heat medium and the raw material does not need to be increased, and the problem of burning can be solved.

In the hydrothermal reactor 25, the supplied subcritical water (300 ° C., 10 MPa) is used to supply
Organic waste, hydrocarbon is decomposed into H ₂ and the like. In this hydrothermal reaction, the raw material is repeatedly circulated through the circulation line 26 to the hydrothermal reactor 25 to secure the flow rate of the liquid and promote heat transfer in the hydrothermal reactor 25. Further, since the raw material contains a chemical solution such as caustic soda, the decomposition of the raw material is promoted.

Thereafter, the cracked raw material is discharged from the cracking line 33 to the heat exchanger 24 and heated, then cooled through the trim cooler 34, reduced in pressure by the back pressure regulating valve 35, and then transferred to the oxidation tank 22. Then, the combustibles and unreacted carbides are burned and oxidized there, pass through the gas-liquid separator 23, and a part is returned to the oxidation tank 22 again in the return line 39, and the unoxidized components are oxidized again. .

The raw material thus decomposed and the hydrothermal reactor 2
By performing heat recovery by exchanging heat with the raw material supplied to 5,
The heating medium supply amount in the heating medium heater 29 can be reduced.

Thereafter, the oxidized decomposed material is separated into gas and liquid by the gas-liquid separator 23, and the treated liquid is separated into a discharge line 41.
Then, the tap water is heated and cooled in the heat exchanger 42, lowered to the atmospheric pressure by the back pressure adjusting valve 43, and then discharged to the processing liquid tank 14.

The gas separated by the gas-liquid separator 23 is introduced into the condenser 38 from the gas-phase discharge line 50 and cooled, and is supplied to the separation pot 51. The gas is returned to the gas-liquid separator 23, and the gas component is reduced in pressure by the back pressure adjusting valve 52 and supplied to the processing liquid tank 14.

In the processing liquid tank 14, a gas component is exhausted from an exhaust line 44 through a deodorizing device 46.
Drained from the sewage line 45.

As described above, in the present invention, by reducing the reaction temperature and pressure as compared with the conventional supercritical treatment, the decomposition ability of raw materials (reduction of COD) is reduced, but the problem of corrosion of piping and the like is reduced. Can be reduced. In addition, a sufficient decomposition ability can be obtained as a result of performing the oxidation treatment by the oxidation reaction process in the oxidation tank 22 after the hydrothermal reaction treatment.

Further, when decomposing in the hydrothermal reaction tube 25, by supplying subcritical water separately from the raw material, the heat transfer area of the hydrothermal reaction tube 25 can be greatly reduced, and the hydrothermal reaction The load of the heat medium can be reduced while preventing the tube 25 from sticking.

[0056]

In summary, according to the present invention, the organic waste alone is supplied to the hydrothermal reactor through the raw material, and the water mixed with the organic waste is supplied to the subcritical water supply means comprising a hot water boiler. By supplying it separately, the hydrothermal reactor only needs to handle the temperature rise of the raw material, and the heat transfer surface can be significantly reduced.

Further, by treating the raw material in two stages of a subcritical hydrothermal reaction and a subsequent oxidation reaction, it is possible to discharge sewage of organic waste. In addition, there is no emission of CO ₂ and no harmful substances are generated, and the effects of eliminating the need for a waste disposal site are exhibited.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic schematic configuration showing an embodiment of the present invention.

FIG. 2 is a diagram showing an overall configuration showing an embodiment of the present invention.

FIG. 3 is a diagram showing a schematic configuration of the invention of the prior application.

[Explanation of symbols]

 Reference Signs List 10 raw material tank 18 hot water boiler 19 subcritical water supply means 19a heating means 22 oxidation tank 25 hydrothermal reactor

Claims (3)

[Claims] 1. A hydrothermal reactor for hydrothermally reacting an organic waste such as animal and plant residues to a subcritical state by pressurizing and heating the waste.
Sub-critical water supply means for supplying sub-critical water heated and pressurized to hydrothermal conditions in advance to the hydrothermal reactor together with organic waste to the hydrothermal reactor Organic waste treatment equipment such as residue. 2. The sub-critical water supply means comprises a water tank, a booster pump for increasing the pressure of the water in the water tank, and a heating means for heating the boosted water to about 100 to 300 ° C. The organic waste such as animal and plant residues according to claim 1, wherein a circulation line for repeatedly circulating the organic waste to the hydrothermal reactor is connected to the hydrothermal reactor, and the heating means is connected to the circulation line. Processing equipment. 3. The apparatus for treating organic waste such as animal and plant residues according to claim 2, wherein an oxidation tank for oxidizing the organic waste residues decomposed and decompressed is connected to the circulation line.