WO2004044102A1

WO2004044102A1 - Slurry production and storage system utilizing waste heat

Info

Publication number: WO2004044102A1
Application number: PCT/JP2003/014394
Authority: WO
Inventors: Satoru Suetake; Takeshi Yamaguchi; Shoji Nagai
Original assignee: The Tokyo Electric Power Company, Incorporated
Priority date: 2002-11-13
Filing date: 2003-11-12
Publication date: 2004-05-27
Also published as: JP2004161972A; AU2003280755A1

Abstract

A slurry production and storage system utilizing waste heat, characterized in that it comprises a reactor (102) in a subcritical water for forming a solid waste slurry fuel (110) from a solid waste (109), an internal combustion engine (105) discharging a hot exhaust gas (112), heat exchangers (106, 107) for heating a heat transfer oil (108) by the exhaust gas (112) discharged from the internal combustion engine (105), wherein the heat of the heat transfer oil (108) is utilized in the heat treatment of the solid waste (109) in the reactor (102) in a subcritical water. The system allows the improvement of the efficiency in the formation of a slurry fuel from a solid waste.

Description

Specification

Slurry production storage system using waste heat

The present invention relates to a slurry production and storage system that utilizes waste heat and is suitable for use when treating solid waste as slurry fuel. Background art

Conventionally, organic solid waste such as wood, agricultural and sewage sludge has been incinerated in an incinerator.

Recently, a technology has been studied to convert organic solid waste such as wood, agricultural, and sewage sludge into a slurry and use it as boiler fuel by hydrothermal reaction. On the other hand, biomass is generated by performing anaerobic treatment with methane bacteria from waste liquids containing organic substances, and fuel technologies used for boiler fuel and gas engine power generation have been studied in the past.

In fact, biogas subjected to anaerobic treatment with methane bacteria is burned by a boiler and used for heat supply, and power generation and heat and power supply systems using biogas for gas engines are becoming widespread. Here, the thermoelectric supply system is a system that supplies electric power and heat at the same time.For example, a device that recovers retained heat contained in exhaust gas from an internal combustion engine generates steam or hot water and uses it for heating. There is a power generation system.

As described above, various systems have been developed as systems for processing slurry fuel. For example, in Patent Document 1 below, a method for treating an organic solid that can recover water-insoluble organic solids with high efficiency and generate no harmful substances can be achieved. An organic solid processing apparatus suitable for carrying out this method is disclosed.

Further, for example, Patent Document 2 below discloses an organic matter treatment system capable of detoxifying and reducing the amount of slurry and reducing operating costs. (Patent Document 1)

Japanese Patent Application Laid-Open Publication No. 2002-66607

(Patent Document 2)

Japanese Patent Application Laid-Open No. 2000-2012

However, the conventional system as described above has a problem that the total energy efficiency is low.

For example, in the past, organic solid waste was incinerated, and the heat was used as unused energy, or power generation was performed by a steam turbine.

However, in such treatment of organic solid waste, the power generation efficiency of converting the energy of raw materials into electric power is low, and much of the energy is discharged as heat energy. In the vicinity of the waste generation point, there was a problem that the heat demand was smaller than the waste heat energy generated, and it was difficult to use energy effectively.

In addition, a large amount of fossil fuel or electric power is used in the process of heating the waste because the reaction in the subcritical water or supercritical water is generally used to slurry the organic solid waste. It is hoped that the heating process will be more efficient. Here, a reaction in subcritical water refers to a reaction at a temperature and pressure below the critical point, and a reaction in supercritical water refers to a reaction at a temperature and pressure above the critical point.

On the other hand, when biogas is generated by performing anaerobic treatment with methane bacteria from waste liquid containing organic matter, the biogas is generated continuously, but the amount generated varies depending on external conditions, and all the biogas is used effectively To do so, excessive engine equipment or large-scale gas compressors and buffer tanks are required.

Therefore, when investing in a system that generates pigas by performing anaerobic treatment with methane bacteria from wastewater containing organic matter, it is desired to further improve the efficiency and improve profitability.

However, also in the thermoelectric supply system, the organic solid waste treatment system and the biogas generation system are being considered as separate systems. It has a problem that it does not spread from the viewpoint of investment recovery. W

Three

Disclosure of the invention

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to reduce waste heat capable of improving efficiency in producing slurry fuel from solid waste. The purpose of the present invention is to provide a slurry manufacturing and storage system using the slurry.

In order to achieve the above object, a slurry production and storage system using waste heat according to the present invention includes: a reaction unit that generates slurry fuel from solid waste; a combustion unit that discharges heated waste gas; A heat exchange means for heating a heat medium with the exhaust gas discharged from the combustion means, wherein heat of the heat medium is used in the heating treatment of the solid waste in the reaction means.

Further, the slurry production and storage system using waste heat according to the present invention includes: a reaction unit that generates slurry fuel from solid waste; a storage unit that stores the slurry fuel generated by the reaction unit; A combustion means for discharging the fuel, wherein the storage means is heated by heat from the combustion means, and the slurry fuel inside the storage means is agitated by heat convection.

Further, the slurry production and storage system using waste heat according to the present invention includes a heat exchange unit that heats a heat medium with exhaust gas having heat discharged from the combustion means, and further includes: It is characterized by heating using heat.

Further, the slurry production and storage system using waste heat according to the present invention includes: a reaction unit that generates slurry fuel from solid waste; a storage unit that stores slurry fuel generated by the reaction unit; and a cooling medium. A combustion unit to be cooled; and a biogas generation unit for generating biogas, wherein the heat of the cooling medium when the combustion unit is cooled by a cooling medium is transferred to the storage unit and the biogas generation. It is characterized in that it is used for heating means.

In the slurry production / storage system using waste heat according to the present invention, the combustion means is an internal combustion engine, an external combustion engine, or a fuel cell.

Here, the slurry fuel produced from solid waste (hereinafter also referred to as solid waste slurry fuel) refers to the carbonization of organic matter by reaction in subcritical water or supercritical water using biomass as a raw material. After that, adjust the water content (if necessary, A fuel that is in a slurry state.

A slurry is generally a highly fluid substance obtained by mixing water and a solid.

The combustion means refers to an internal combustion engine, an external combustion engine, and a fuel cell. An internal combustion engine is an engine that converts the chemical energy of a mixture of fuel and air into thermal energy by combustion, and directly uses the work of expanding the combustion products. An external combustion engine is a boiler An engine that gives heat to a working material through a heat transfer wall, and uses the work when the working material expands.A fuel cell is obtained by supplying fuel from the outside and reforming it. A battery that directly generates electrical energy by electrochemically reacting hydrogen and oxygen in the air.

The reaction means is a means for producing solid waste slurry fuel from solid waste. This reaction means produces solid waste slurry fuel by, for example, reforming solid waste into high calorie fuel using dehydration and deoxidation at high temperature and pressure. Further, as such a reaction means, for example, a coal slurry technology can be mentioned.

The biogas generation means is not limited to an anaerobic digestion tank, including, for example, biogas generated from the underground of a landfill site for waste, such as an anaerobic digestion tank.

Further, the cooling medium is a medium for cooling the combustion means, and may be, for example, cooling water, but is not limited to cooling water. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of a first embodiment of a slurry production / storage system using waste heat according to the present invention.

FIG. 2 is a block diagram of a second embodiment of a slurry production and storage system using waste heat according to the present invention.

FIG. 3 is a block diagram of a third embodiment of a slurry production and storage system using waste heat according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are intended to limit the scope of the invention to only those components. Not something.

(First Embodiment)

First, a first embodiment of a slurry production and storage system using waste heat according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a first embodiment of a slurry production and storage system using waste heat according to the present invention.

As shown in FIG. 1, a first embodiment of a slurry production and storage system using waste heat according to the present invention includes a factory 101 for discharging solid waste 109.

The solid waste 109 is, for example, organic solid waste of wood, organic solid waste discharged from agricultural systems, food waste, plant waste, animal waste, and the like.

In addition, the slurry production and storage system using waste heat of the present embodiment is a subcritical fuel that generates a solid waste slurry fuel 110 from a solid waste 109 through at least a heating step of the solid waste 109. Equipped with a reactor 102 in water.

The reactor 102 in this subcritical water is a device that generates solid waste slurry fuel 110 from solid waste 109 by heating under pressure and holding for a certain period of time. In addition, the slurry production and storage system using waste heat according to the present embodiment includes a dehydrator 103 for removing excess moisture from the solid waste slurry fuel 110. This dehydrator 103 produces a solid waste slurry fuel 111 from which excess water has been removed.

In addition, the slurry production and storage system using waste heat of the present embodiment includes a slurry fuel tank 104 for storing the solid waste slurry fuel 111 generated by the dehydrator 103. .

The slurry production and storage system using waste heat of the present embodiment includes an internal combustion engine 105 that performs combustion using the solid waste slurry fuel 111 stored in the slurry fuel tank 104 as fuel. Prepare. Examples of the internal combustion engine 105 include a gas turbine, a diesel engine, a gas engine, and the like. Further, the internal combustion engine 105 burns the solid waste slurry fuel 111 and emits exhaust gas 112 having heat.

The fuel-burning engine 105 mixes and burns kerosene, light oil, city gas, natural gas, heavy oil, and other fuels as necessary to ensure stable operation.

In addition, the slurry production and storage system using the exhaust heat of the present embodiment uses the high-temperature exhaust gas 112 discharged from the internal combustion engine 105 to heat the reactor 102 in subcritical water. Heat exchangers 106 and 107 are provided.

The heat exchanger 106 and the heat exchanger 107 exchange heat between the internal combustion engine 105 and the reactor 102 in subcritical water by the heat transfer oil 108.

That is, the heat exchanger 106 heats the heat transfer oil 108 with the exhaust gas 112 discharged from the internal combustion engine 105.

Then, the heat exchanger 106 circulates the heated heat transfer oil 108 with the heat exchanger 107.

The heat exchanger 107 heats the reactor 102 in subcritical water by giving the heat from the heat transfer oil 108 to the reactor 102 in subcritical water.

As described above, in the first embodiment of the slurry production / storage system using waste heat according to the present invention, the reaction in sub-critical water is performed using the high-temperature exhaust gas 112 discharged from the internal combustion engine 105. Heat vessel 102.

The reactor 102 in the subcritical water uses the heating of the exhaust gas by the internal combustion engine 105 described above to generate the solid waste slurry fuel 110 from the solid waste 109.

Therefore, in the present embodiment, since the heat of the exhaust gas 112 from the internal combustion engine 105 is used for producing the solid waste slurry fuel 110 in the reactor 102 in sub-critical water, The heat exhausted from the engine 105 as the exhaust gas 112 can be used effectively, and the efficiency of the entire slurry production and storage system using the exhaust heat can be improved.

Here, in the present embodiment, the internal combustion engine 105 burns the solid waste slurry fuel 111 stored in the slurry fuel tank 104, but the present invention is limited to such a case. The internal combustion engine 105 is a slurry fuel tank The fuel other than the solid waste slurry fuel 111 stored in 4 may be burned to emit exhaust gas 112.

Although the present embodiment uses the internal combustion engine 105 as an engine that emits high-temperature exhaust gas 112, the present invention is not limited to such a case, and uses an external combustion engine and a fuel cell. You may.

Examples of the external combustion engine include a boiler and a Stirling engine.

In the present embodiment, heat exchangers 106 and 107 for exchanging heat between the internal combustion engine 105 and the reactor 102 in subcritical water use a heat transfer oil 108. However, the present invention is not limited to such a case, and the heat exchangers 106 and 107 exchange heat using an appropriate medium other than the heat transfer oil. May be performed.

Further, the heat exchange may be performed not only with the energy in the exhaust gas but also with the heat of the internal combustion engine body.

(Second embodiment)

Next, a second embodiment of a slurry production and storage system using waste heat according to the present invention will be described with reference to FIG. FIG. 2 is a block diagram of a second embodiment of a slurry production and storage system using waste heat according to the present invention.

As shown in FIG. 2, the second embodiment of the slurry production / storage system using waste heat according to the present invention includes a factory 201 for discharging solid waste 209.

This solid waste is, for example, organic solid waste from wood, organic solid waste from agriculture, forestry, fisheries, and livestock industries, food waste, plant waste, animal waste, and construction waste. Organic solid waste such as waste.

In addition, the slurry production and storage system using the waste heat of the present embodiment generates the solid waste slurry fuel 210 from the solid waste 209 through at least the heating step of the solid waste 209. The reactor is provided with sub-critical water in subcritical water. The reactor 202 in subcritical water is the same as the reactor 102 in subcritical water in the first embodiment described above.

In addition, the slurry production and storage system using waste heat according to the present embodiment includes a dehydrator 203 for removing excess water from the solid waste slurry fuel 210. This dehydrator 203 produces a solid waste slurry fuel 211 from which excess water has been removed.

In addition, the slurry production and storage system using waste heat according to the present embodiment includes a slurry fuel tank 204 for storing the solid waste slurry fuel 211 generated from the dehydrator 203.

In addition, the slurry production and storage system using waste heat of the present embodiment includes an internal combustion engine 205 that burns using the solid waste slurry fuel 211 stored in the slurry fuel tank 204 as fuel. .

The internal combustion engine 205 mixes and burns kerosene, light oil, city gas, natural gas, heavy oil, and other fuels as necessary to ensure stable operation.

Examples of the internal combustion engine 205 include a gas turbine, a diesel engine, and a gas engine. The internal combustion engine 205 emits high-temperature exhaust gas 212.

In addition, the slurry production and storage system using the exhaust heat of the present embodiment includes a heat exchanger for heating the slurry fuel tank 204 using the high-temperature exhaust gas 212 discharged from the internal combustion engine 205. It is equipped with 206,207.

The heat exchanger 206 and the heat exchanger 207 exchange heat between the internal combustion engine 205 and the slurry fuel tank 204 using the heat medium oil 208.

That is, the heat exchanger 206 heats the heat transfer oil 208 with the exhaust gas 212 discharged from the internal combustion engine 205.

Then, the heat exchanger 206 circulates the heated heat medium oil 208 between the heat exchanger 208 and the heat exchanger 206.

The heat exchanger 207 heats the slurry fuel tank 204 by applying heat from the heat transfer oil 208 to the slurry fuel tank 204.

As described above, in the second embodiment of the slurry production and storage system using the exhaust heat according to the present invention, the slurry-based fuel tank 200 is prepared by using the high-temperature exhaust gas 212 discharged from the internal combustion engine 205. Heat 4

In the heated slurry fuel tank 204, heat convection 2 13 of the solid waste slurry fuel 2 11 is generated therein. Conventional slurry fuels have been stabilized by mixing additives to prevent separation of liquid and solid.

However, in the slurry production and storage system using the exhaust heat of this embodiment, the heat generated from the internal combustion engine 205 is used for heating the slurry fuel tank 204, and the heat convection in the slurry fuel tank 204 By generating 13 and stirring the solid waste slurry fuel 2 11, separation of liquid and solid in the solid waste slurry fuel 2 11 is prevented.

Therefore, in this embodiment, since the heat of the exhaust gas 212 from the internal combustion engine 205 is used for stirring the solid waste slurry fuel 211 in the slurry fuel tank 204, the internal combustion engine 105 The heat discharged as exhaust gas 212 from the wastewater can be effectively used, and the efficiency of the entire slurry production and storage system using the discharged heat can be improved.

Here, in the present embodiment, the internal combustion engine 205 burns the solid waste slurry fuel 211 stored in the slurry fuel tank 204, but the present invention is limited to such a case. Instead, the internal combustion engine 205 may burn the fuel other than the solid waste slurry fuel 211 stored in the slurry fuel tank 204 and discharge the exhaust gas 212.

Although the present embodiment utilizes the internal combustion engine 205 as an engine that emits high-temperature exhaust gas, the present invention is not limited to such a case, and as described in the first embodiment. Alternatively, an external combustion engine or a fuel cell may be used.

In the present embodiment, the heat exchangers 206 and 207 for exchanging heat between the internal combustion engine 205 and the slurry fuel tank 204 use heat transfer oil 208 to exchange heat. However, the present invention is not limited to such a case, and the heat exchangers 206 and 207 may exchange heat using an appropriate medium other than the heat transfer oil. good.

Further, in the present embodiment, the heat discharged from the internal combustion engine 205 is given to the slurry fuel tank 204 using the heat exchangers 206 and 207 and the heat medium oil 208. However, the present invention is not limited to such a case.

That is, the slurry fuel tank 204 and the internal combustion engine 205 are brought into close contact with each other, and the heat discharged other than the exhaust gas discharged from the internal combustion engine 205 is transferred directly or by a heat medium. It may be provided directly to the slurry fuel tank 204.

(Third embodiment)

Next, a third embodiment of a slurry production and storage system using waste heat according to the present invention will be described with reference to FIG. FIG. 3 is a block diagram of a third embodiment of a slurry production and storage system using waste heat according to the present invention.

As shown in FIG. 3, the third embodiment of the slurry production / storage system using waste heat according to the present invention includes a factory 301 for discharging solid waste 308.

The solid waste 308 is, for example, organic solid waste such as wood organic solid waste, organic solid waste discharged from agricultural systems, food waste, plant waste, and animal waste.

In addition, the slurry production and storage system using waste heat of the present embodiment is a subcritical fuel that generates a solid waste slurry fuel 309 from the solid waste 308 through a heating process of the solid waste 308. Equipped with a reactor 302 in water. The reactor 302 in subcritical water is the same reactor as the reactor 102 in subcritical water in the first embodiment described above.

In addition, the slurry production and storage system using waste heat according to the present embodiment includes a dehydrator 303 for removing excess water from the solid waste slurry fuel 309.

The dehydrator 303 produces a solid waste slurry fuel 310 from which excess water has been removed.

In addition, the slurry production and storage system using waste heat of the present embodiment includes a slurry fuel tank 304 for storing the solid waste slurry fuel 310 generated from the dehydrator 303.

In addition, the slurry production and storage system using waste heat according to the present embodiment includes an anaerobic digestion tank 306 that generates biogas 312 using waste liquid 313 discharged from the factory 301. Anaerobic digester 306 requires heat to produce biogas 312.

The biogas 312 generated from the aerobic digester 306 is used in the heater 307.

The heater 307 uses biogas 312 generated from the anaerobic digester 306 The reactor 302 is heated in subcritical water.

In addition, the slurry production and storage system using waste heat of the present embodiment includes an internal combustion engine 350 that burns using solid waste slurry fuel 310 stored in the slurry fuel tank 304 as fuel. .

The internal combustion engine 305 mixes and burns kerosene, light oil, city gas, natural gas, heavy oil, and other fuels as necessary to ensure stable operation.

Examples of the internal combustion engine 305 include a gas turbine, a diesel engine, and a gas engine. The internal combustion engine 2005 is cooled by the cooling water 311.

The temperature of the cooling water 311 rises after cooling the internal combustion engine 2005. In the present embodiment, the slurry fuel tank 304 and the anaerobic digestion tank 310 are heated using the cooling water 311 whose temperature has been increased by cooling the internal combustion engine 2005.

That is, as shown in FIG. 3, in the present embodiment, after cooling the internal combustion engine 300, the cooling water 311 having heat is supplied to the slurry fuel tank 304 and the anaerobic digestion tank 310. To heat the slurry fuel tank 304 and the anaerobic digestion tank 303. The circulation of the cooling water 311 is performed by, for example, a circulation device including a pipe, a pressurizing device, and the like (not shown).

In the conventional system, heating of the slurry fuel tank 304 and the anaerobic digestion tank 306 is performed by steam, and seawater, river water, cooling towers, etc. are used to cool the internal combustion engine 305. I was

However, in the present embodiment, since the heat of the cooling water 311 when the internal combustion engine 2005 is cooled is used for heating the slurry fuel tank 304 and the anaerobic digestion tank 310, excessive heat is used. No equipment is required, and the investment cost of the slurry production and storage system using waste heat can be reduced.

Further, in the heated slurry fuel tank 304, heat convection 314 of the solid waste slurry / fuel 310 is generated therein.

Conventional slurry fuels have been stabilized by mixing additives to prevent separation of liquid and solid. However, in the slurry production and storage system using the exhaust heat of the present embodiment, the heat of the cooling water 311 when cooling the internal combustion engine 350 is used for heating the slurry fuel tank 304 and the slurry fuel tank By generating heat convection 314 inside 304 and stirring the solid waste slurry fuel 310, separation of liquid and solid in the solid waste slurry fuel 310 is prevented.

Further, the cooling water 311 after cooling the internal combustion engine 304 is used for heating the anaerobic digestion tank 310 for generating the pyrogas 312.

In general, heating the slurry fuel tank 304 and the anaerobic digestion tank 306 does not require so much heat, so the temperature rises after cooling the internal combustion engine 305. Even the heat of the cooling water 311 can be used to heat the slurry fuel tank 304 and the anaerobic digestion tank 310.

As described above, in the present embodiment, the heat of the cooling water 311 that has cooled the internal combustion engine 300 is effectively used, and the efficiency of the entire slurry production and storage system using the exhaust heat is improved. be able to.

Here, in the present embodiment, the internal combustion engine 300 burns the solid waste slurry fuel 310 stored in the slurry fuel tank 304, but the present invention is limited to such a case. Instead, the internal combustion engine 305 may burn fuel other than the solid waste slurry fuel 310 stored in the slurry fuel tank 304.

Further, the present embodiment utilizes the internal combustion engine 305 as the engine cooled by the cooling water 311.However, the present invention is not limited to such a case. An external combustion engine or a fuel cell as shown may be used.

Further, in the present embodiment, the cooling of the internal combustion engine 305 is performed by the cooling water 311, but the present invention is not limited to such a case, and the cooling of the internal combustion engine 305 is performed. Any medium other than water can be used as long as it can be performed and circulated.

Further, in this embodiment, the biogas 312 generated from the anaerobic digestion tank 106 is used for heating the reactor 302 in subcritical water, so that the biogas 312 is effective. It can be used. Further, in the present embodiment, the factory 301 is described as an example for discharging the waste liquid 3 13, but the present invention is not limited to such a case, and the methane gas In the present invention, any place, component, or the like that discharges waste liquid for producing 312 can be used in place of a factory that discharges waste liquid in the present invention.

In each of the above embodiments, a factory is described as an example of discharging solid waste.However, the present invention is not limited to such a case, and organic solid waste of wood and waste discharged from an agricultural system are used. Any place, member, etc., which discharges or accumulates organic solid waste such as organic solid waste, food waste, plant waste, animal waste, etc., discharges organic solid waste in the present invention. It can replace the factory in each of the above embodiments.

In each of the above embodiments, an external combustion engine and a fuel cell may be used instead of the internal combustion engine.

In each of the above embodiments, there is a mode in which boiler steam of an external combustion engine is used instead of the heat transfer oil.

In each of the above embodiments, a reactor in subcritical water is used as a reactor, but this reactor can be replaced with a reactor in supercritical water.

As described above, according to the present invention, since the heat generated from the combustion means is used for the heat treatment in the reaction means, the efficiency of the slurry production and storage system using the exhaust heat can be improved. .

Further, in the present invention, since the heat generated from the combustion means is used for agitation by thermal convection of the slurry fuel stored in the storage means, the efficiency of the slurry production and storage system using waste heat can be improved. .

Further, in the present invention, since the combustion means is cooled by the cooling medium, and the heat of the cooling medium which has risen at that time is used for heating for heat convection in the storage means and heating for the biogas generation means, The heat of the cooling medium when the combustion means is cooled can be effectively used.

Claims

The scope of the claims

1. A reaction means for producing slurry fuel from solid waste;

Combustion means for discharging exhaust gas having heat,

Heat exchange means for heating a heat medium by the exhaust gas discharged from the combustion means,

In the heat treatment of the solid waste in the reaction means, heat of the heat medium is used, and the slurry production and storage system using exhaust heat is provided.

2. A reaction means for producing slurry fuel from solid waste;

Storage means for storing the slurry fuel generated by the reaction means, and combustion means for discharging heat,

A slurry manufacturing and storage system using exhaust heat, wherein the storage means is heated by heat from the combustion means, and the slurry fuel inside the storage means is agitated by heat convection.

3. Heat exchange means for heating a heat medium with exhaust gas having heat discharged from the combustion means,

The slurry production / storage system using waste heat according to claim 2, wherein the storage means is heated using heat of the heat medium.

4. A reaction means for producing slurry fuel from solid waste;

Storage means for storing the slurry fuel generated by the reaction means, combustion means cooled by a cooling medium,

And a biogas generating means for generating biogas,

A slurry production / storage system using waste heat, wherein heat of the cooling medium when the combustion means is cooled by a cooling medium is used for heating the storage means and the biogas generation means.

5. The combustion means is:

The slurry production and storage system using exhaust heat according to any one of claims 1 to 4, wherein the system is an internal combustion engine, an external combustion engine, or a fuel cell.