JP2023175328A - Intermittently operated incineration facility and method for operating the same - Google Patents

Abstract

To provide an intermittently operated incineration facility provided with an incinerator that operates intermittently and capable of effectively utilizing a waste heat generated when a material to be incinerated is burned in the facility without wasting the waste heat.SOLUTION: An intermittently operated incineration facility of the present invention includes: an incinerator provided with a combustion chamber that burns a material to be incinerated, by performing a combustion operation, a start-up operation, a shutdown state, and a start-up operation during a day; a power generating unit installed in the combustion chamber to generate electric power by converting the heat generated by the combustion of the material to be incinerated into electric energy; electric power supplying means for supplying the electric power generated by the power generating unit to the water electrolysis device; carbon dioxide separating means for separating carbon dioxide from combustion exhaust gas discharged from the incinerator; and methane gas generating means for generating methane gas by synthesizing hydrogen generated in the water electrolysis device and carbon dioxide separated in the carbon dioxide separating means.SELECTED DRAWING: Figure 1

Description

The present invention relates to an intermittent operation incineration facility having an incinerator that incinerates materials to be incinerated such as general waste and industrial waste using an oxidizing agent, and a method of operating the same, and in particular, to suppress carbon dioxide emissions and efficiently. Concerning technology for recovering energy.

Conventionally, so-called stoker-type incinerators have been used to process municipal waste and industrial waste. A stoker-type incinerator is a relatively simple incinerator that gradually dries and burns garbage as it moves forward due to the back-and-forth movement of multiple fire grates arranged in the front and back or left and right directions. Despite its structure, it is able to process a large amount of waste regardless of the moisture content or calorific value of the waste being thrown in, so it has been adopted by many incineration facilities.

By the way, the Ministry of Health, Labor and Welfare has established guidelines regarding dioxins contained in the flue gas emitted from waste incineration facilities. There is a need to collect fly ash by decomposing precursors of dioxins and cooling the temperature of combustion exhaust gas to approximately 200° C. or less.

In addition, the above guidelines recommend fully continuous combustion incinerators in which the incinerator operates 24 hours a day. In this case, it is possible to stably suppress the generation of dioxins by operating the incinerator all day long, but when the incinerator is shut down, it is necessary to perform a burnout operation that does not leave any unburned materials in the incinerator. required to do so.

Although it is possible to adopt a fully continuous combustion type that operates 24 hours a day in urban areas where the processing capacity is large and it is relatively easy to secure workers, it is possible to use a fully continuous combustion type that operates 24 hours a day. This is difficult to achieve in areas where it is not easy to secure. In such areas, incinerators that operate intermittently may be used, such as mechanized batch furnaces that operate for about eight hours a day, or semi-continuous combustion systems that operate for 16 hours a day.

Incinerators that operate intermittently have start-up operations, combustion operations, shut-down operations, and pauses during the day, so the frequency of start-up and shutdown is higher than in incinerators that operate continuously. When the incinerator is started up, an auxiliary burner is used to burn auxiliary fuel to raise the temperature inside the combustion chamber, and after the materials to be incinerated begin to be fed, the auxiliary burner continues to be used until steady operation is reached at 850℃ or higher. do. In addition, even during shutdown operation, the auxiliary combustion burner is ignited after the material to be incinerated has been put into the combustion chamber, and the auxiliary combustion burner is stopped after the auxiliary fuel has been burned and the material to be incinerated has been completely burnt out. .

Fossil fuels such as heavy oil and natural gas are used as auxiliary fuels for such auxiliary combustion burners, and carbon dioxide emissions associated with the use of fossil fuels pose a problem. In addition, carbon dioxide is emitted not only during combustion, but also when purchasing fossil fuels and transporting them to facilities, so the total amount of carbon dioxide emitted from burning fossil fuels with auxiliary burners is enormous. becomes.

In addition, in incineration facilities that perform intermittent operation, a so-called DSS (DSS) is used to describe an operation method in which normal combustion operation is performed during the day, the operation is suspended at night, and the operation is restarted the next morning. This is called "Daily Startup and Shutdown" operation.

With the promotion of a recycling-oriented society and a low-carbon society, there is a strong demand for heat recovery using waste heat from incineration at incineration facilities. , does not have an exhaust heat recovery boiler to recover waste heat. This is because having an exhaust heat recovery boiler that has a large heat capacity and cannot always recover heat causes a state of overcapacity. Therefore, in incinerators that operate intermittently, there is no effective means to recover the heat generated by the combustion of the materials to be incinerated, and in such a case, the heat is wasted.

Therefore, in recent years, as one of the means to recover the heat generated by the combustion of the materials to be incinerated, an emitter disposed on the inner wall of the combustion chamber and a photoelectric conversion cell disposed outside the combustion chamber are provided. A TPV (ThermoPhotovoltaic) power generation unit has been proposed (Patent Document 1).

Patent No. 6824500

According to the invention disclosed in Patent Document 1, light is emitted outward from an emitter disposed on the inner wall of a combustion chamber by receiving radiant heat of combustion gas generated as the material to be incinerated is burned. A photoelectric conversion cell receives the light emitted from the emitter, and the photoelectric conversion cell generates electric power. This is the principle by which electric power is generated from the TPV power generation unit.

The temperature range in which the TPV power generation unit operates is relatively high, around 800°C, so by recovering the electricity generated by the TPV power generation unit during normal operation, the combustion heat generated from the combustion of incinerated materials can be converted into electricity. and can be used.

Here, if the power generated by the TPV power generation unit is not large enough to be supplied to other facilities via the power grid, it is desired that the power be used effectively within the facility.

The present invention has been made in view of these problems, and is an object of the present invention to effectively utilize waste heat generated when incinerating materials in an intermittent operation type incinerator facility without wasting it. An object of the present invention is to provide an intermittent operation incineration facility and an operating method thereof, which are capable of reducing carbon dioxide emissions during startup and shutdown operations.

The inventors of the present invention focused on a technique for synthesizing methane gas from carbon dioxide and hydrogen, and arrived at the present invention.

The present invention provides the following solution.

The invention according to the first feature provides an incinerator equipped with a combustion chamber that performs combustion operation, shut-down operation, hibernation state, and start-up operation during the day and burns materials to be incinerated, and an incinerator disposed in the combustion chamber, A power generation unit that converts the heat generated by the combustion of the incinerated material into electrical energy to generate power, a power supply means that supplies the power generated by the power generation unit to the water electrolyzer, and a power generation unit that converts the heat generated by the combustion of the incineration material into electrical energy. It includes a carbon dioxide separation means that separates carbon dioxide from combustion exhaust gas, and a methane gas generation means that generates methane gas by synthesizing hydrogen generated by the water electrolyzer and carbon dioxide separated by the carbon dioxide separation means.

According to the invention according to the first feature, in an incinerator that operates intermittently, a power generation unit is provided in a combustion chamber and converts heat generated by combustion of materials to be incinerated into electrical energy to generate electric power. Since waste heat is used to generate electricity, even small and medium-sized incinerators that do not have a waste heat recovery boiler can recover waste heat as electricity.

The recovered waste heat is converted into electrical energy and used as electric power to operate the water electrolyzer, so the recovered electric power can be effectively utilized.

Furthermore, it is equipped with a methane gas generation means that generates methane gas by synthesizing the hydrogen generated by the water electrolyzer and the carbon dioxide separated from the combustion exhaust gas using the carbon dioxide separation means, so it can be used as a fuel gas and can be used in various ways. It is possible to recover energy by converting it into a shape that can be supplied to various locations.

The invention according to the second characteristic is the invention according to the first characteristic, in which the power generation unit includes an emitter and a photoelectric conversion cell arranged on the inner wall of a combustion chamber, and generates thermophotovoltaic power. A TPV (ThermoPhotoVoltaic) power generation unit is used.

According to the invention according to the second feature, since the power generation unit is a TPV (ThermoPhotovoltaic) power generation unit that performs thermophotovoltaic power generation and includes an emitter and a photoelectric conversion cell arranged on the inner wall of the combustion chamber, Heat can be converted into electrical energy in a combustion chamber located in a high temperature region.

The invention according to the third characteristic is the invention according to the second characteristic, in which, in addition to the TPV power generation unit, the power generation unit is installed in an area lower in temperature and downstream than the position where the TPV power generation unit is installed. A thermoelectric power generation unit using a thermoelectric element installed in the system is also used.

According to the invention according to the third feature, power generation is possible by combining power generation with a thermoelectric power generation unit that can operate in a lower temperature range than the TPV power generation unit in addition to the TPV power generation unit that operates only in a high temperature range. This expands the temperature range, making it possible to convert heat into electrical energy over a wider temperature range.

The invention according to the fourth feature is the invention according to any one of the first to third features, which includes: an auxiliary combustion burner that burns auxiliary fuel in a combustion chamber; The apparatus further includes a methane gas supply means, which supplies the electric power generated by the power generation unit to the water electrolyzer, and supplies the methane gas generated by the methane gas generation means to the auxiliary combustion burner during startup operation and/or shutdown operation. do.

According to the invention according to the fourth feature, the generated electric power is supplied to the water electrolyzer to generate hydrogen and oxygen, and the methane gas generating means generates methane gas, and the generated methane gas is used during startup operation. And/or by supplying the auxiliary fuel to the auxiliary combustion burner during the start-up operation, the auxiliary fuel required to raise the temperature in the combustion chamber during the start-up operation can be provided within the plant. Therefore, it is possible to provide an intermittent operation incineration facility that can reduce the cost of purchasing and transporting fossil fuels such as heavy oil and reduce carbon dioxide emissions during transport.

Further, the power left over when the water electrolyzer is operated can be used as power for operating auxiliary equipment in various parts of the facility, or can be supplied outside the facility.

The invention according to the fifth characteristic is the invention according to any one of the first to third characteristics, in which oxygen generated in the water electrolyzer is supplied to the combustion chamber as an oxidizing agent during start-up operation.

According to the invention according to the fifth feature, by using oxygen instead of air as an oxidizing agent during start-up operation, the flame temperature increases, and the temperature inside the combustion chamber can be quickly raised to a predetermined temperature. Moreover, since the oxygen generated in the water electrolyzer is used as the oxygen used as the oxidizing agent, no other supply source such as an oxygen cylinder is required. Therefore, the cost associated with purchasing and transporting oxygen can be reduced, and the amount of carbon dioxide emissions generated accordingly can also be reduced.

The invention according to the sixth feature is the invention according to any one of the first to third features, which includes a water vapor separation means for separating water vapor from the combustion exhaust gas, and a water vapor separated by the water vapor separation means to condense and recover the water vapor. The apparatus further includes a condenser that converts water into water, and a condensate supply means that supplies the condensate condensed in the condenser to the water electrolyzer.

According to the invention according to the sixth feature, water separated from combustion exhaust gas can be used as water to be electrolyzed in the water electrolyzer, and not only electric power for electrolyzing water but also water can be used. This can be done within the same facility, making it a useful intermittent operation incineration facility with no waste.

The invention according to the seventh feature is the invention according to any one of the first to third features, wherein the carbon dioxide separation means removes carbon dioxide from the combustion exhaust gas by a membrane separation method, an adsorption method, or a cryogenic separation method. To separate.

According to the invention according to the seventh feature, high purity carbon dioxide can be recovered by separating carbon dioxide from the combustion exhaust gas using a membrane separation method or an adsorption method.

According to the present invention, as an intermittent operation incineration facility equipped with an incinerator that operates intermittently, waste heat generated when incinerating materials is not wasted and can be effectively used within the facility. An operational incineration facility and a method for operating the same can be provided.

FIG. 1 is a schematic system diagram of an intermittent operation incineration facility according to the first embodiment. FIG. 2 is a flow diagram of a combustion method using an intermittent operation incineration facility according to the first embodiment. FIG. 3 is a schematic system diagram of an intermittent operation incineration facility according to the second embodiment. FIG. 4 is a schematic system diagram of an intermittent operation incineration facility according to the fourth embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that this is just an example, and the technical scope of the present invention is not limited to this.

[Configuration of intermittent operation incineration facility]
The configuration of an intermittent operation incineration facility according to this embodiment will be explained using FIG. 1.

FIG. 1 shows a schematic system diagram of an intermittent operation incineration facility according to the first embodiment, and the intermittent operation incineration facility includes an incinerator 1, an exhaust gas cooling device 2, a bag filter 3, and an induced blower. 4, carbon dioxide separation means 5, chimney 6, water electrolyzer 7, hydrogen supply means 8, oxygen supply means 9, methane gas generation means 10, methane gas supply means 11, control device 12, It is constituted by a power generation unit 13.

The incinerator 1 burns, or oxidizes, waste such as amorphous general waste or industrial waste using an oxidizing agent.

In this embodiment, the incinerator 1 is applied to a vertical garbage incinerator that incinerates waste such as general waste and industrial waste, and a filtration type dust collector as exhaust gas treatment equipment. Although shown in the figure, the type of incinerator 1 may be other types such as a stoker furnace or a fluidized bed furnace, and other treatment methods such as a catalytic reaction tower may be added to the exhaust gas treatment equipment. But that's fine.

The incinerator 1 includes a combustion chamber 1a for burning materials to be incinerated, a primary combustion air supply means 1b for supplying primary combustion air, a secondary combustion air supply means 1c for supplying secondary combustion air, and a combustion chamber 1a for burning materials to be incinerated. A charging device 1d for charging the fuel into the fuel tank 1a, an auxiliary combustion burner 1e for burning the auxiliary fuel, and the like are provided. These are configured so that their respective operating conditions can be changed by signals from a control device 12, which will be described later.

The primary combustion air supply means 1b supplies primary combustion air to the combustion chamber 1a. The primary combustion air supply means 1b includes a blower, a ventilation passage (not shown), an air preheater, etc.

The secondary combustion air supply means 1c supplies secondary combustion air to the combustion chamber 1a. The secondary combustion air supply means 1c includes a blower, a ventilation passage (not shown), etc., and supplies secondary combustion air to the combustion chamber 1a, thereby burning combustible gas components that could not be completely combusted by combustion using the primary combustion air.

The charging device 1d is a device for charging the material to be incinerated into the combustion chamber 1a, and is composed of, for example, a hopper and multiple gates for temporarily storing waste, which is the material to be incinerated. The materials to be incinerated are supplied by a garbage crane from a garbage pit (not shown) and can be temporarily stored using a charging device 1d, and can be intermittently charged into the combustion chamber 1a.

The auxiliary combustion burner 1e performs combustion by burning auxiliary fuel when the temperature of the combustion chamber 1a is low, such as during startup and/or shutdown operation in intermittent operation or after long-term maintenance. This is to raise the temperature inside the chamber 1a and assist the operation. Although the use of such additional fuel can easily raise the temperature within the combustion chamber 1a, it also increases carbon dioxide emissions and facility operating costs, so it is desirable to avoid using it as much as possible.

The exhaust gas cooling device 2 has a temperature at which the combustion exhaust gas discharged from the incinerator 1 can be supplied to the bag filter 3, and is approximately 200 degrees Celsius or less as specified in the "Guidelines for Prevention of Dioxins Generation Related to Garbage Treatment". It reduces the temperature, and is composed of, for example, a cooling tower that cools the combustion exhaust gas by spraying cooling water.

The bag filter 3 includes a filter cloth that filters the combustion exhaust gas whose temperature has been reduced by the exhaust gas cooling device 2, and removes soot and harmful components contained in the combustion exhaust gas. A chemical supply device (not shown) for blowing a chemical into the bag filter is disposed in the exhaust gas flue at the bag filter inlet. The alkaline chemical supplied from the chemical supply device causes a neutralization reaction with acidic components in the combustion exhaust gas on the filter cloth of the bag filter 3, thereby purifying the combustion exhaust gas.

The induced blower 4 is a blower disposed downstream of the bag filter 3, and is used to suck the combustion exhaust gas from which soot and harmful components have been removed by the bag filter 3, and to release the combustion exhaust gas into the atmosphere from the chimney 6. It is something.

The carbon dioxide separation means 5 selectively separates carbon dioxide contained in the combustion exhaust gas from the combustion exhaust gas discharged from the incinerator 1 and purified by the bag filter 3 . The means for separating carbon dioxide from the combustion exhaust gas may be separation using a separation membrane, chemical adsorption, physical adsorption, or cryogenic separation.

The chimney 6 is for releasing combustion exhaust gas from which carbon dioxide has been separated into the atmosphere.

The water electrolyzer 7 electrolyzes water to generate oxygen and hydrogen. The water electrolyzer 7 in this embodiment includes an electrolytic cell for storing water, a power source, an anode connected to the positive electrode of the power source, a cathode connected to the negative electrode of the power source, and the like.

The hydrogen supply means 8 supplies hydrogen produced by the water electrolyzer 7 to a methane gas generation means 10, which will be described later.

The oxygen supply means 9 temporarily stores oxygen generated in the water electrolyzer 7 and supplies it to the primary combustion air supply means 1b and other supply destinations.

The methane gas generating means 10 synthesizes carbon dioxide separated from the combustion exhaust gas by the carbon dioxide separating means 5 and hydrogen generated by the water electrolyzer 7 to generate methane gas. As described above, methods for synthesizing methane gas using carbon dioxide and hydrogen include those utilizing the Sabatier reaction occurring through a catalyst, but are not limited thereto.

The methane gas supply means 11 is for temporarily storing the methane gas synthesized by the methane gas generation means 10 and for using it as fuel at a desired location inside or outside the facility. Using the methane gas supply means 11, it can also be used as auxiliary fuel in the auxiliary burner 1e disposed in the combustion chamber 1a, as will be described later.

In addition, the intermittent operation incineration facility according to the present embodiment has a control device 12 that controls the entire facility, and the control device 12 controls the incineration process to incinerate materials to be incinerated in the incinerator 1 depending on the situation. Controls combustion operation, shutdown operation, hibernation state, and intermittent operation that performs startup operation to resume combustion operation after returning from hibernation.

That is, the incinerator 1 of this embodiment has a combustion operation in which the materials to be incinerated are combusted by supplying primary combustion air and secondary combustion air into the high-temperature combustion chamber 1a, and a combustion operation in which the materials to be incinerated are combusted by supplying primary combustion air and secondary combustion air into the high-temperature combustion chamber 1a. There is a hibernation state in which the supply of fuel is substantially stopped and the material to be incinerated is not combusted, the period from combustion operation to hibernation state is defined as shutdown operation, and the state from hibernation state to combustion operation is defined as start-up operation.

The control device 12 in this embodiment controls the primary combustion air supply means 1b, the secondary combustion air supply means 1c, and the incineration material input device 1d according to predetermined conditions, thereby starting the combustion operation and starting the combustion operation. It repeats operation, hibernation, and start-up operation, and controls intermittent operation.

Further, the control device 12 controls each part of the intermittent operation incineration facility based on physical quantities measured by various measuring instruments.

The power generation unit 13 in this embodiment is constituted by a TPV power generation unit including an emitter 13a and a photoelectric conversion cell 13b.

The emitter 13a is an element that converts heat into light energy, and is disposed on the inner wall of the combustion chamber 1a. As the emitter 13a in this embodiment, a wavelength selective emitter on a flat plate made of a high melting point metal and having a light emitting surface (not shown) is used. In this embodiment, the combustion chamber 1a is provided with a plurality of openings, and the emitter 13a is fitted into each opening, thereby disposing the emitter 13a on the inner wall of the combustion chamber 1a. The emitter 13a receives heat from the combustion chamber 1a and emits light energy from a light emission surface facing away from the inner wall of the combustion chamber 1a. A shutter device (not shown) that controls the open/close state of the emitter 13a is installed on the light emitting surface of the emitter 13a, and the control device 12 controls the open/close state of the shutter device to emit light energy from the emitter 13a. can be controlled.

The photoelectric conversion cell 13b is an element that converts light energy into electrical energy, and is disposed outside the combustion chamber 1a. As the photoelectric conversion cell 13b in this embodiment, a GaSb cell used as a solar cell is used. The photoelectric conversion cell 13b is arranged in pairs with a plurality of emitters 13a, and the light receiving surface of each photoelectric conversion cell 13b is arranged to face the light emitting surface of the emitter 13a.

[Energy recovery method using intermittent operation incineration facility]
Next, an energy recovery method using the intermittent operation incineration facility according to the first embodiment will be described using FIG. 2.

FIG. 2 is a flow diagram illustrating the energy recovery procedure in the intermittent operation incineration facility according to the first embodiment.

[Step S100: Detection of combustion chamber temperature]
During combustion operation, startup operation, and shutdown operation, heat is generated as the material to be incinerated is combusted using the oxidizing agent supplied to the combustion chamber 1a. temperature increases. Therefore, the temperature inside the combustion chamber 1a is detected by a temperature detection means (not shown) (step S100).

[Steps S110 to S120: Extraction of electric power during combustion operation]
When the temperature detection means (not shown) detects that the temperature inside the combustion chamber 1a is equal to or higher than a predetermined value (for example, 800° C.) (Y in step S110), the control device 12 generates power using the power generation unit 13 (step S120). ).

Specifically, when the control device 12 detects that the temperature inside the combustion chamber 1a is 800° C. or higher using a temperature detection means (not shown), it controls the shutter device provided in the emitter 13a to open. conduct. Then, thermal radiation is generated from the light emitting surface of the emitter 13a that has received heat, and enters the light receiving surface of the photoelectric conversion cell 13b. Then, the light energy is photoelectrically converted into electric energy by the photovoltaic effect in the photoelectric conversion cell 13b that receives the thermal radiation light. In this way, by using the power generation unit 13, the heat generated by burning the material to be incinerated in the combustion chamber 1a can be converted into electrical energy and extracted as electric power.

On the other hand, if the temperature inside the combustion chamber 1a is not higher than a predetermined value (for example, 800° C.) (N in step S110), the power generation unit 13 does not generate power and continues operation.

[Step S130: Water electrolysis]
When electric power is generated in the power generation unit 13 in step S120, the generated electric power is supplied to the water electrolyzer 7 by a power supply means such as a power transmission line, and the water electrolyzer 7 is operated to electrolyze water ( Step S130).

In the water electrolyzer 7, as water is electrolyzed, a reduction reaction occurs at the cathode to generate hydrogen, and an oxidation reaction occurs at the anode to generate oxygen.

[Step S140: Separation of carbon dioxide]
A part of the combustion exhaust gas generated in the incinerator 1 due to the combustion of the materials to be incinerated flows through the exhaust gas flue and is supplied to the carbon dioxide separation means 5, where the carbon dioxide is removed. It is separated (step S140).

In the carbon dioxide separation means 5, carbon dioxide is selectively separated from the combustion exhaust gas by a method using a separation membrane, an adsorption method such as chemical adsorption or physical adsorption, or cryogenic separation.

[Step S150: Generation of methane gas]
The carbon dioxide separated by the carbon dioxide separation means 5 in step S140 is supplied to the methane gas generation means 10 together with the hydrogen generated in the water electrolyzer 7 in step S130, and methane gas is generated in the methane gas generation means 10 (step S150 ). Alternatively, the carbon dioxide may be supplied to a desired location outside the site through a pipeline (not shown) or by means such as liquefying it and transporting it by lorry.

Methane gas generated by the methane gas generation means 10 is stored in a tank (not shown) through the methane gas supply means 11, and is provided for internal use, such as as auxiliary fuel when starting up or shutting down the incinerator 1. Alternatively, it may be supplied to a desired location outside the site through a pipeline (not shown) or by means such as liquefying and transporting by lorry.

In this way, the methane gas stored in the tank through the methane gas supply means 11 is supplied to the auxiliary combustion burner 1e as auxiliary fuel during the start-up operation on the same day and during the start-up operation the next morning.

In other words, in the incinerator 1 that performs intermittent operation, the startup operation is performed after a predetermined downtime (for example, about 8 hours), so at the start of the startup operation, the temperature in the combustion chamber 1a is 300. ℃ or lower, and even if the material to be incinerated is directly put into the combustion chamber 1a, it cannot be ignited successfully.

Therefore, during start-up operation, auxiliary fuel is supplied to the auxiliary combustion burner 1e and the auxiliary fuel is combusted within the combustion chamber 1a to increase the temperature within the combustion chamber 1a, but in this embodiment, in step S150 Methane gas generated by the methane gas generation means 10 is supplied to the auxiliary combustion burner 1e using the methane gas supply means 11 during start-up operation and is combusted.

Normally, fossil fuels such as heavy oil would be combusted in the auxiliary combustion burner 1e, but in this embodiment, methane gas generated when an intermittent operation incineration facility is operated is combusted.

Therefore, the cost of purchasing and transporting fossil fuels such as heavy oil and the amount of carbon dioxide emissions generated at that time can be reduced.

In this way, by using a configuration in which electricity is extracted using the power generation unit 13, which is disposed in the combustion chamber 1a and generates electricity by converting the heat generated by the combustion of materials to be incinerated into electrical energy, the exhaust heat can be extracted. Even in a small to medium-sized incinerator 1 that does not include a recovery boiler, waste heat can be recovered as electricity.

Since the recovered waste heat is converted into electrical energy and used to operate the water electrolyzer 7 installed within the plant, there is no power transmission loss that occurs when transmitting power to other locations, and the recovered power is effectively used. It can be used for

Furthermore, it is equipped with a methane gas generation means 10 that generates methane gas by synthesizing the hydrogen generated by the water electrolyzer 7 and the carbon dioxide recovered from the combustion exhaust gas using the carbon dioxide separation means 5, so that it can be used as fuel gas. It is possible to recover energy by converting it into a shape that can be supplied to various locations.

Moreover, by supplying the generated methane gas to the auxiliary combustion burner 1e and burning it during start-up operation, auxiliary fuel for start-up operation can be generated in-house, making it possible to purchase and transport fossil fuels such as heavy oil. It is possible to provide an intermittent operation incineration facility that can reduce costs and carbon dioxide emissions during transportation.

[Configuration of intermittent operation incineration facility according to second embodiment]
The configuration of an intermittent operation incineration facility according to the second embodiment will be explained using FIG. 3. Note that the description of the points common to the intermittent operation incineration facility according to the first embodiment will be omitted, and only the characteristic points of the intermittent operation incineration facility according to the second embodiment will be explained.

FIG. 3 shows a schematic system diagram of an intermittent operation incineration facility according to the second embodiment, and the intermittent operation incineration facility includes an incinerator 1, an exhaust gas cooling device 2, a bag filter 3, and an induced blower. 4, carbon dioxide separation means 5, chimney 6, water electrolyzer 7, hydrogen supply means 8, oxygen supply means 9, methane gas generation means 10, methane gas supply means 11, control device 12, It is constituted by a power generation unit 13.

The difference between the intermittent operation incineration facility according to the second embodiment and the intermittent operation incineration facility according to the first embodiment is that the power generation unit 13 includes a TPV power generation unit consisting of an emitter 13a and a photoelectric conversion cell 13b; The point is that a thermoelectric power generation unit using a thermoelectric element 13c that converts the difference into electromotive force is also used. Note that the thermoelectric element 13c is located in an area downstream in the flow of combustion exhaust gas that is lower in temperature than the position where the emitter 13a of the TPV power generation unit is disposed, for example, the inner wall of the exhaust gas cooling device 2 which has a medium temperature range of about 500°C, It is arranged on the inner wall of the exhaust gas flue downstream of it.

A thermoelectric element is constructed by electrically connecting a p-type semiconductor and an n-type semiconductor that generate positive and negative thermoelectromotive force.It can be removed from heat by keeping one end at a high temperature and the other end at a low temperature. Although it is possible to extract power directly, the operating temperature is lower compared to TPV power generation units. Therefore, in the intermittent operation incineration facility according to the second embodiment that uses both the TPV power generation unit and the thermoelectric power generation unit, power is generated by the TPV power generation unit in the combustion chamber 1a which is a high temperature area, and the TPV power generation unit is disposed. Power generation is performed by a thermoelectric power generation unit in the exhaust gas cooling device 2 and the exhaust gas flue downstream thereof, which are downstream of the combustion exhaust gas flow and have a low temperature region, for example, a medium temperature region of about 500° C.

Regarding the TPV power generation unit, as shown in FIG. 2, the control device 12 performs switching so that power is generated when the temperature inside the combustion chamber 1a is higher than a predetermined value (for example, 800° C.). Furthermore, the thermoelectric power generation unit installed in the exhaust gas cooling device 2 and the exhaust gas flue downstream thereof generates power in a temperature range lower than the temperature range in which the TPV power generation unit generates power.

Then, a step of electrolyzing water in the water electrolyzer 7 using the electric power generated by the power generation unit 13 to generate hydrogen and oxygen, a step of separating carbon dioxide from the combustion exhaust gas with the carbon dioxide separation means 5, and a step of water electrolysis. A step of synthesizing hydrogen generated by the device 7 and carbon dioxide separated by the carbon dioxide separation means 5 to generate methane gas, and using the generated methane gas as auxiliary fuel during startup and/or shutdown operation. It is similar to the flow diagram of the first embodiment shown in FIG. 2 in that it includes the step of supplying to the burner.

In this way, by combining power generation with a thermoelectric power generation unit that can operate in a medium temperature range in addition to a TPV power generation unit that operates only in a high temperature range, the temperature range in which power can be generated is expanded, and the combustion of materials to be incinerated is It is possible to recover more of the heat generated due to this, and it is possible to provide an energy recovery method with high energy efficiency.

Furthermore, even if the generated methane gas cannot be used completely by the auxiliary combustion burner 1e, it can be supplied as fuel elsewhere through the methane gas supply means 11, so that energy is not wasted. Alternatively, methane gas may not be generated and may be supplied elsewhere as carbon dioxide.

[Configuration of intermittent operation incineration facility according to third embodiment]
In the intermittent operation incineration facility according to the third embodiment, oxygen generated in the water electrolyzer 7 is supplied to the combustion air supply means and used as an oxidizing agent for burning the material to be incinerated.

In intermittent operation in which combustion operation, startup operation, hibernation state, and start-up operation are performed in one day, it is important to shorten the temperature rise time in the combustion chamber 1a during the start-up operation.

Therefore, during start-up operation, by using oxygen instead of air as the oxidizing agent, the flame temperature increases, and the temperature in the combustion chamber 1a can be quickly raised to a predetermined temperature.

As the oxygen used at this time, the oxygen generated in the water electrolyzer 7 in step S130 in FIG. 2 is supplied to the primary combustion air supply means 1b by the oxygen supply means 9 shown in FIGS. 1 and 3. This eliminates the need for other sources such as oxygen cylinders. Therefore, the cost associated with purchasing and transporting oxygen can be reduced, and the amount of carbon dioxide emissions generated accordingly can also be reduced.

[Configuration of intermittent operation incineration facility according to fourth embodiment]
The configuration of an intermittent operation incineration facility according to the fourth embodiment will be explained using FIG. 4. Note that the description of the points common to the intermittent operation incineration facility according to the first embodiment will be omitted, and only the characteristic points of the intermittent operation incineration facility according to the fourth embodiment will be explained.

FIG. 4 shows a schematic system diagram of an intermittent operation incineration facility according to the fourth embodiment, which includes an incinerator 1, an exhaust gas cooling device 2, a bag filter 3, and an induced blower. 4, carbon dioxide separation means 5, chimney 6, water electrolyzer 7, hydrogen supply means 8, oxygen supply means 9, methane gas generation means 10, methane gas supply means 11, control device 12, It is composed of a power generation unit 13, a steam separation means 14, a condenser 15, and a condensate supply means 16.

In other words, in the intermittent operation incineration facility according to the fourth embodiment, water vapor is extracted from the combustion exhaust gas that is discharged from the incinerator 1, passes through the exhaust gas cooling device 2 and the bag filter 3, and the temperature is lowered, and acidic components and impurities are filtered. A water vapor separation means 14 is provided for separating the water vapor. Further, a condenser 15 is provided which condenses the water vapor separated by the water vapor separation means 14 to form condensate. Furthermore, a condensate supply means 16 for supplying condensate condensed in the condenser to the water electrolyzer 7 is provided.

By doing this, the water separated from the combustion exhaust gas can be used as the water to be electrolyzed in the water electrolyzer 7, and not only the electric power for electrolyzing water but also the water can be used with the same equipment. It will be a useful intermittent operation incineration facility with no waste.

In summary, the effects of the present invention are as follows.

The present invention provides an incinerator equipped with a combustion chamber that performs intermittent operation that performs combustion operation, shutdown operation, hibernation state, and start-up operation during the day and burns materials to be incinerated; A power generation unit that converts the heat generated by the combustion of the incineration material into electrical energy to generate electricity, a power supply means that supplies the electricity generated by the power generation unit to the water electrolyzer, and combustion discharged from the incinerator. An intermittent operation incineration facility equipped with a carbon dioxide separation means that separates carbon dioxide from exhaust gas, and a methane gas generation means that generates methane gas by synthesizing hydrogen generated by a water electrolysis device and carbon dioxide separated by the carbon dioxide separation means. It is.

In incinerators that operate intermittently, waste heat recovery is used to generate electricity using a power generation unit that is installed in the combustion chamber and converts the heat generated from the combustion of the materials to be incinerated into electrical energy to generate electricity. Even small and medium-sized incinerators without a boiler can recover waste heat as electricity. The recovered waste heat is converted into electrical energy and used as electric power to operate the water electrolyzer, so the recovered electric power can be effectively utilized. Furthermore, it is equipped with a methane gas generation means that generates methane gas by synthesizing the hydrogen generated by the water electrolyzer and the carbon dioxide separated from the combustion exhaust gas using the carbon dioxide separation means, so it can be used as a fuel gas and can be used in various ways. It is possible to recover energy by converting it into a shape that can be supplied to various locations.

In addition, since the power generation unit uses a TPV (ThermoPhotovoltaic) power generation unit that is equipped with an emitter and a photoelectric conversion cell arranged on the inner wall of the combustion chamber and performs thermophotovoltaic power generation, the combustion chamber is located in a high temperature range. can convert heat into electrical energy.

Here, in a high temperature state such as during combustion operation, the TPV power generation unit generates electricity and supplies it to the water electrolyzer to generate hydrogen and oxygen, and the methane gas generation means generates methane gas. By supplying fuel to the auxiliary combustion burner during startup and/or shutdown, the auxiliary fuel required to raise the temperature in the combustion chamber during startup can be supplied within the plant. Therefore, it is possible to provide an intermittent operation incineration facility that can reduce the cost of purchasing and transporting fossil fuels such as heavy oil and reduce carbon dioxide emissions during transport. Further, the power left over when the water electrolyzer is operated can be used as power for operating auxiliary equipment in various parts of the facility, or can be supplied outside the facility.

In addition, as a power generation unit, in addition to the TPV power generation unit, a thermoelectric power generation unit using a thermoelectric element located downstream and at a lower temperature than the location where the TPV power generation unit is installed is used in combination, making it possible to generate electricity. This expands the temperature range, making it possible to convert heat into electrical energy over a wider temperature range.

Here, the TPV power generation unit generates electric power in a temperature range where the temperature inside the combustion chamber exceeds a predetermined value, and the thermoelectric power generation unit generates power in a temperature range downstream of the location where the TPV power generation unit is installed and where the temperature is low. By generating electric power, it is possible to generate electric power not only in the combustion chamber in the high temperature range, but also in the exhaust gas cooling chamber and the exhaust gas flue, which are in a medium temperature state of about 500° C., for example. Then, the electricity generated in a wide temperature range is supplied to the water electrolyzer to generate hydrogen and oxygen, and the methane gas generation means generates methane gas, and the generated methane gas is used during startup and/or shutdown. By supplying the fuel to the auxiliary burner during operation, the auxiliary fuel required to raise the temperature in the combustion chamber during start-up operation can be provided within the plant. Therefore, it is possible to provide an intermittent operation incineration facility that can reduce the cost of purchasing and transporting fossil fuels such as heavy oil and reduce carbon dioxide emissions during transport.

In addition, by supplying oxygen generated in the water electrolyzer to the combustion chamber as an oxidizing agent during start-up operation, the temperature of the combustion chamber increases, making it possible to start up quickly. Moreover, since the oxygen generated in the water electrolyzer is used as the oxygen used as the oxidizing agent, no other supply source such as an oxygen cylinder is required. Therefore, the cost associated with purchasing and transporting oxygen can be reduced, and the amount of carbon dioxide emissions generated accordingly can also be reduced.

Furthermore, a water vapor separation means for separating water vapor from the combustion exhaust gas, a condenser for condensing the water vapor separated by the water vapor separation means to condensate, and supplying the condensed water in the condenser to the water electrolyzer. Since the water electrolyzer further includes a condensate supply means, water separated from combustion exhaust gas can be used as the water to be electrolyzed in the water electrolyzer, and not only the electric power for electrolyzing water but also the water can be used. can be done within the same facility, making it a useful intermittent operation incineration facility with no waste.

Further, the carbon dioxide separation means can recover highly pure carbon dioxide by separating carbon dioxide from the combustion exhaust gas by a membrane separation method, an adsorption method, or a cryogenic separation method.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments described above. Furthermore, the effects described in the embodiments of the present invention are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. isn't it.

Further, the above-described embodiments have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. . Furthermore, some of the configurations of each embodiment may be added, deleted, or replaced with other configurations.

For example, in FIG. 3, an example is described in which a TPV power generation unit and a thermoelectric power generation unit are used together as the power generation unit 13, but the power generation unit 13 may include only a thermoelectric power generation unit.

The intermittent operation incineration facility and its operating method of the present invention can be applied to incineration facilities in general that burn various materials to be incinerated.

1 Incinerator 1a Combustion chamber 1b Primary combustion air supply means 1c Secondary combustion air supply means 1d Charge device 1e Assist burner 2 Exhaust gas cooling device 3 Bag filter 4 Induced blower 5 Carbon dioxide separation means 6 Chimney 7 Water electrolyzer 8 Hydrogen supply Means 9 Oxygen supply means 10 Methane gas generation means 11 Methane gas supply means 12 Control device 13 Power generation unit 13a Emitter 13b Photoelectric conversion cell 13c Thermoelectric element 14 Steam separation means 15 Condenser 16 Condensate supply means

Claims (8)

an incinerator equipped with a combustion chamber that performs combustion operation, shut-down operation, hibernation state, and start-up operation during the day and burns materials to be incinerated;
a power generation unit that is disposed in the combustion chamber and generates electric power by converting heat generated as a result of combustion of materials to be incinerated into electric energy;
power supply means for supplying the power generated by the power generation unit to the water electrolyzer;
carbon dioxide separation means for separating carbon dioxide from combustion exhaust gas discharged from the incinerator;
Methane gas generation means for generating methane gas by synthesizing hydrogen generated by the water electrolyzer and carbon dioxide separated by the carbon dioxide separation means;
Intermittent operation incineration facility equipped with As the power generation unit, a TPV (ThermoPhotovoltaic) power generation unit is used, which is equipped with an emitter and a photoelectric conversion cell disposed on the inner wall of the combustion chamber and performs thermophotovoltaic power generation.
The intermittent operation incineration facility according to claim 1. As the power generation unit, in addition to the TPV power generation unit, a thermoelectric power generation unit using a thermoelectric element disposed in a region downstream and lower in temperature than the position where the TPV power generation unit is disposed is used in combination;
The intermittent operation incineration facility according to claim 2. an auxiliary combustion burner that burns auxiliary fuel in the combustion chamber;
Further comprising a methane gas supply means for supplying the methane gas generated by the methane gas generation means to the auxiliary combustion burner,
Supplying electric power generated by the power generation unit to the water electrolyzer, and supplying methane gas generated by the methane gas generating means to the auxiliary combustion burner during startup operation and/or shutdown operation.
The intermittent operation incineration facility according to any one of claims 1 to 3. supplying oxygen generated in the water electrolyzer to the combustion chamber as an oxidizing agent during start-up operation;
The intermittent operation incineration facility according to any one of claims 1 to 3. water vapor separation means for separating water vapor from the combustion exhaust gas;
a condenser that condenses the steam separated by the steam separation means to condensate;
further comprising a condensate supply means for supplying condensate condensed in the condenser to the water electrolyzer;
The intermittent operation incineration facility according to any one of claims 1 to 3. The carbon dioxide separation means separates carbon dioxide from the combustion exhaust gas by membrane separation, adsorption, or cryogenic separation.
The intermittent operation incineration facility according to any one of claims 1 to 3. a step of burning the to-be-incinerated material using an oxidizing agent in an incinerator equipped with a combustion chamber that performs combustion operation, shut-down operation, hibernation state, and start-up operation during the day and burns the incinerated material;
generating electricity by converting heat generated as a result of combustion of the incineration material into electrical energy using a power generation unit disposed in the combustion chamber;
electrolyzing water using the electric power generated in the step of generating electric power;
separating carbon dioxide from the flue gas discharged from the incinerator;
generating methane gas by synthesizing the hydrogen generated in the step of electrolyzing the water and the carbon dioxide separated in the step of separating the carbon dioxide;
How to operate an intermittent operation incineration facility equipped with