JP7437659B2 - Combustion system and method - Google Patents

Description

The present invention relates to a combustion system and combustion method for burning materials to be combusted such as fossil fuels and waste using an oxidizing agent, and in particular for suppressing carbon dioxide emissions and reducing the amount of exhaust gas released into the atmosphere. Regarding technology.

When combustible materials such as fossil fuels and waste are combusted using an oxidizing agent, carbon contained in the combustible materials is oxidized and carbon dioxide is generated.

Since releasing carbon dioxide into the atmosphere causes global warming, it is strongly desired to suppress the release of carbon dioxide into the atmosphere due to the combustion of materials to be combusted.

As a technique for suppressing the release of carbon dioxide into the atmosphere, a technique has been developed that uses oxygen as an oxidizing agent and separates carbon dioxide from the generated combustion exhaust gas (Patent Document 1).

Japanese Patent Application Publication No. 2010-84962

According to the invention disclosed in Patent Document 1, by using oxygen as an oxidizing agent, the main components of the combustion exhaust gas generated during combustion are carbon dioxide and water. By selectively separating only carbon dioxide from the combustion exhaust gas, the main component of the combustion exhaust gas released into the atmosphere is water, and compared to the normal combustion method, the amount of carbon dioxide released into the atmosphere is can be significantly reduced. Moreover, the amount of exhaust gas discharged can also be reduced accordingly.

However, even if carbon dioxide could be separated from combustion exhaust gas, huge equipment would be required to store the separated carbon dioxide.

In addition, equipment to produce oxygen used as an oxidizing agent is also required, but if a water electrolyzer is used as the equipment to produce oxygen, for example, hydrogen will be produced at the same time as oxygen is produced. will not be used for other equipment and will be released into the atmosphere. In that case, the problem arises that the water electrolyzer generates wasted parts as equipment, and it is not possible to reduce the amount of exhaust gas released into the atmosphere.

The present invention was made in view of these problems, and is capable of suppressing carbon dioxide emissions and reducing the amount of exhaust gas released into the atmosphere. The aim is to provide a combustion system with no waste.

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 a garbage incinerator that burns waste using an oxidizing agent, a water electrolyzer that electrolyzes water, and a garbage incinerator that uses oxygen generated in the water electrolyzer as an oxidizing agent. a carbon dioxide separation means that separates carbon dioxide from the combustion exhaust gas generated in the waste incinerator ; and a carbon dioxide separation means that separates the hydrogen generated in the water electrolysis device from the combustion exhaust gas by the carbon dioxide separation means. A combustion system is provided, comprising: a methane gas generating means for synthesizing methane gas to generate methane gas;

According to the invention according to the first feature, since the oxygen generated in the electrolyzer is supplied to the waste incinerator as an oxidizing agent, the main components of the combustion exhaust gas generated when waste is burned are carbon dioxide and water. and excess oxygen. Therefore, compared to the case where air is used as an oxidizing agent, the separation efficiency of carbon dioxide in the carbon dioxide separation means can be improved, and the amount of nitrogen oxides generated can be suppressed.

Since carbon dioxide is separated by the carbon dioxide separation means, the amount of carbon dioxide released into the atmosphere can be reduced.

In addition, the hydrogen generated in the water electrolysis device is synthesized with carbon dioxide separated from the combustion exhaust gas to generate methane gas, making it possible to effectively utilize the hydrogen generated in the water electrolysis device and to The amount of exhaust gas released into the atmosphere can be reduced to 1/2 or less compared to when combustion is performed using air.

Since methane gas that can be used as fuel can be synthesized using carbon dioxide, it becomes possible to reuse it as a resource and energy source.

Further, the invention according to the first feature uses a garbage incinerator that burns waste as the combustion device.

By using a waste incinerator as a combustion device, it is possible to recover the waste heat from the flue gas generated when incinerating waste and generate electricity to operate the water electrolysis device, which is an energy recycling perspective. You can build a lean system from this.

Furthermore, the invention according to the first feature further includes an exhaust gas recirculation means for recirculating a part of the combustion exhaust gas to the waste incinerator, and a flow rate adjustment means for adjusting the flow rate of the combustion exhaust gas to be recirculated, and the oxygen supply The means mixes the combustion exhaust gas, the flow rate of which is adjusted by the flow rate adjusting means, with oxygen and supplies the mixture to the waste incinerator.

Therefore, since a mixed gas of oxygen and combustion exhaust gas with a controlled flow rate is supplied to the waste incinerator as an oxidizing agent, only a small amount of nitrogen is contained when air is used as an oxidizing agent, suppressing the generation of thermal NOx. At the same time, it is possible to prevent the temperature inside the waste incinerator from rising too much, and it is also possible to suppress the generation of fuel NOx.

The invention according to the second characteristic is the invention according to the first characteristic, comprising a heat recovery means for generating steam by recovering the heat of combustion exhaust gas, and a steam rotationally driven by the steam generated by the heat recovery means. It includes a turbine and a generator driven by the steam turbine, and uses the electric power generated by the generator to operate the water electrolyzer.

According to the invention according to the second feature, the electric power required to operate the water electrolyzer can be provided by the electric power generated by using the heat of the flue gas generated when burning waste. Therefore, there is no need for separate power supply equipment, and there is no waste in the system configuration.

Further, the power left over when the water electrolyzer is operated can be used as power for operating auxiliary equipment at various locations within the plant, and can be supplied outside the plant.

The invention according to the third characteristic is an invention according to the first or second characteristic, which
The power supplied to the decomposer is controlled by the amount of oxygen required in the waste incinerator.

According to the invention according to the third feature, in order to control the amount of power supplied to the water electrolyzer in accordance with the amount of oxygen required for oxidation in the waste incinerator, when burning waste, There is no need for oxygen to be supplied from equipment, and extra equipment can be omitted.

The invention according to the fourth 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 fourth 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.

Advantageous Effects of Invention According to the present invention, a combustion system and a combustion method are provided that are capable of suppressing carbon dioxide emissions and reducing the amount of exhaust gas released into the atmosphere, and that do not waste any equipment. can do.

FIG. 1 is a schematic diagram of a combustion system according to this embodiment. FIG. 2 is a flow diagram of a combustion method using the combustion system according to this 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.

[Combustion system configuration]
The configuration of the combustion system according to this embodiment will be explained using FIG. 1.

FIG. 1 shows a schematic system diagram of a combustion system according to the present embodiment, and the combustion system includes a combustion device 1, a heat recovery means 2, a bag filter 3, an induced blower 4, and a carbon dioxide Separation means 5, exhaust gas recirculation means 6, chimney 7, water electrolyzer 8, oxygen supply means 9, methane gas generation means 10, steam turbine 11, generator 12, condenser 13, , and a control device (not shown).

The combustion device 1 burns, or oxidizes, fossil fuels such as pulverized coal, heavy oil and natural gas, or wastes such as amorphous general waste and industrial waste using an oxidizing agent. .

In this embodiment, oxygen generated in an electrolyzer 7, which will be described later, is used as the oxidizing agent supplied to the combustion device 1. Note that when oxygen is not sufficiently generated in the electrolyzer 7, such as at the start of operation, air is used as an oxidizing agent, and the proportion of oxygen increases as time passes from the start of operation.

The heat recovery means 2 generates steam by recovering heat contained in high-temperature combustion exhaust gas generated when fossil fuel or waste is burned in the combustion device 1 and heating boiler feed water. The heat recovery means 2 includes a heat exchanger tube wall (not shown) formed by combining heat exchanger tubes through which boiler feed water flows, and a steam generator that separates steam generated when boiler feed water is heated within the heat exchanger tube wall into brackish water. It consists of a drum, a superheater that further heats the steam, etc., but the format is not limited to these. In addition, although the combustion device 1 and the heat recovery means 2 are shown as separate bodies in FIG. 1, they may be an integrated type in which the walls constituting the combustion device 1 are heat transfer tube walls. .

The bag filter 3 includes a filter cloth that filters the exhaust gas whose temperature has been reduced by the heat recovery means 2, and removes soot and harmful components contained in the 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 exhaust gas on the filter cloth of the bag filter 3, thereby purifying the exhaust gas.

The induced blower 4 is a blower disposed downstream of the bag filter 3, and is for sucking the exhaust gas from which soot and harmful components have been removed by the bag filter 3, and releasing the exhaust gas from the chimney 7 into the atmosphere. be.

The carbon dioxide separation means 5 selectively separates carbon dioxide contained in the combustion exhaust gas from the combustion exhaust gas discharged from the combustion device 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.

In this embodiment, since the oxygen generated in the water electrolyzer 8 is supplied to the combustion device 1 as an oxidizing agent, the main components of the combustion exhaust gas generated in the combustion device 1 are carbon dioxide, water (steam), and excess oxygen. Therefore, it does not contain much of the nitrogen that is contained when air is used as an oxidizing agent. Therefore, the concentration of carbon dioxide in the combustion exhaust gas is high, and carbon dioxide can be efficiently separated.

The exhaust gas recirculation means 6 recirculates a part of the combustion exhaust gas discharged from the combustion apparatus 1 and purified by the bag filter 3 to the combustion apparatus 1, and recirculates the combustion exhaust gas that is branched from the exhaust gas flue and reaches the combustion apparatus 1. The damper 6b is installed in the flow path 6a, the exhaust gas flue, and the recirculation flow path and whose opening degree can be adjusted. Note that the damper 6b is an embodiment of the flow rate adjusting means of the present invention.

By adjusting the opening degree of the damper 6b, it is possible to adjust the ratio of the flow rate of the combustion exhaust gas flowing into the exhaust gas flue and the combustion exhaust gas recirculating to the combustion device 1 through the recirculation flow path 6a.

Further, an oxygen supply passage supplied from an oxygen supply means 9 described later is connected to the recirculation passage 6a, and a mixture of combustion exhaust gas and oxygen can be supplied to the combustion device 1 as an oxidizing agent. can.

The chimney 7 is for releasing combustion exhaust gas from which carbon dioxide has been separated into the atmosphere.

The water electrolyzer 8 electrolyzes water to generate oxygen and hydrogen. The water electrolyzer 8 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 oxygen supply means 9 supplies oxygen generated by the water electrolyzer 8 to the combustion device 1, and is constituted by a blower or the like that supplies oxygen. Further, the oxygen supply means 9 mixes the combustion exhaust gas, which has been recirculated by the exhaust gas recirculation means 6 and whose flow rate is adjusted by the damper 6b, with oxygen, and supplies the mixture to the combustion apparatus 1.

The methane gas generation means 10 synthesizes methane gas using carbon dioxide separated from the combustion exhaust gas by the carbon dioxide separation means 5 and hydrogen generated by the water electrolysis device 8. 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 synthesized by the methane gas generating means 10 is stored through a pipeline (not shown) or used as a fuel gas at a desired location. Alternatively, it can be used in-house as auxiliary fuel.

The steam turbine 11 is driven to rotate by high-temperature, high-pressure steam generated by the heat recovery means 2, and as the steam turbine 11 is driven, a generator 12 coaxially connected to the steam turbine 11 is driven.

The electric power generated by the generator 12 is converted into AC/DC and used as operating power for the water electrolyzer 8 and driving power for auxiliary machines such as blowers in the plant.

The condenser 13 condenses exhaust steam discharged from the steam turbine 11 to form condensate water. The condensate condensed in the condenser 13 is stored in a condensate tank (not shown) and is again supplied to the heat recovery means 2 as boiler feed water.

Although not shown, the combustion system according to this embodiment has a control device that controls the entire system, and the control device controls each part of the system based on physical quantities measured by various measuring instruments. do.

In this embodiment, the amount of oxygen that is supplied to the combustion device 1 is controlled such that the amount of oxygen necessary for oxidation is generated in the water electrolyzer 8 according to the weight and properties of the material to be combusted that is supplied to the combustion device 1. Recirculation flow rate control is performed to control the recirculation flow rate of exhaust gas mixed with oxygen so that the oxygen concentration of the oxidizing agent becomes a desired oxygen concentration.

[Combustion method using combustion system]
Next, a combustion method using the combustion system according to this embodiment will be explained using FIG. 2.

In FIG. 2, the operating procedure of a combustion system using a garbage incinerator as an embodiment of the combustion apparatus 1 according to the present invention will be described.

[Step S100: Start-up of garbage incinerator]
First, when starting combustion in the garbage incinerator 1, auxiliary fuel is used to ignite waste, which is a material to be combusted. At that time, air is used as the oxidizing agent supplied to the waste incinerator 1. As the auxiliary fuel, methane gas generated and stored by the methane gas generating means 10 described later may be used, or auxiliary fuel such as heavy oil may be used.

When air is used as the oxidizing agent, the main components of the combustion exhaust gas generated from the waste incinerator 1 are carbon dioxide, nitrogen, surplus oxygen, etc., but as described later, the combustion exhaust gas is recycled to the garbage using the exhaust gas recirculation means 6. By recirculating to the incinerator 1, nitrogen is gradually reduced.

Further, the heat recovery means 2 does not generate steam until a predetermined time has elapsed from the start of operation. That is, in the early stage of combustion, although the combustion exhaust gas can heat the boiler feed water in the heat recovery means 2, it cannot immediately generate steam. By continuing to incinerate waste in the garbage incinerator 1, the amount of heat recovered in the heat recovery means 2 gradually increases, leading to the generation of steam.

[Step S110: Recirculation of exhaust gas]
The combustion exhaust gas generated by the start of combustion in step S100 is purified by the bag filter 3, and then recirculated to the waste incinerator 1 using the exhaust gas recirculation means 6 (step S110).

At the beginning of combustion in the waste incinerator 1, air is used as an oxidizer, so nitrogen is contained in the combustion exhaust gas, but by recirculating the combustion exhaust gas to the waste incinerator 1, nitrogen is gradually removed. The percentage decreases.

[Step S120: Generation of steam]
When the amount of heat recovered in the heat recovery means 2 increases, steam is generated in the heat recovery means 2 (step 120). When a sufficient amount of steam is generated in the heat recovery means 2, the generated steam is sent to the steam turbine 11 and drives the steam turbine 11. Here, the steam turbine 11 is generally coaxially connected to a generator 12, and as the steam turbine 11 rotates, the generator 12 is rotated to generate electric power.

After driving the steam turbine 11, the steam is discharged from the steam turbine 11 and then condensed in the condenser 13 to become condensate, stored in a condensate tank (not shown), and sent to the heat recovery means 2 again as boiler feed water. be done.

[Step S130: Water electrolysis]
When electric power is generated by the generator 12 in step S120, the water electrolyzer 8 is operated using the generated electric power to electrolyze water (step S130).

Since the electric power generated in the generator 12 is alternating current, it is converted to direct current using an AC/DC converter (not shown), and the water electrolyzer 8 is operated.

In the water electrolyzer 8, 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.

In this embodiment, water electrolysis is controlled by the amount of oxygen required for combustion. In other words, as will be described later, oxygen generated in the water electrolyzer 8 is used as an oxidizing agent in the waste incinerator 1, but depending on the amount of oxygen required to oxidize the waste in the waste incinerator 1. , the amount of water electrolysis is controlled.

[Step S140: Combustion with oxygen]
When oxygen is generated in the water electrolyzer 8 in step S130, the generated oxygen is used as an oxidizing agent to cause a combustion reaction in the waste incinerator 1 (step S140). Note that even if oxygen is generated in the water electrolyzer 8, the amount of oxygen generated is small at the initial stage of operation, so the ratio of oxygen to air in the oxidizer is gradually increased, and eventually the air Control is performed so that only oxygen is used by cutting off the supply of oxygen.

In addition, the amount of oxygen supplied to the waste incinerator 1 in a steady state is greater than the amount to completely burn the waste supplied to the waste incinerator 1 (1.2 to 1.5 times the theoretical air amount). degree). Therefore, excess oxygen that cannot be reacted is discharged from the waste incinerator 1 as combustion exhaust gas.

By using oxygen as an oxidizing agent in the garbage incinerator 1, the main components of the generated combustion exhaust gas are carbon dioxide, water (steam), and surplus oxygen, and the amount of nitrogen oxides generated is significantly reduced.

Harmful components such as hydrogen chloride and sulfur oxides and soot are removed in the bag filter 3, and highly purified carbon dioxide, water and oxygen flow through the exhaust gas flue as combustion exhaust gas.

Further, a part of the combustion exhaust gas purified by the bag filter 3 is recirculated to the waste incinerator 1 using the exhaust gas recirculation means 6.

By recirculating the combustion exhaust gas using the exhaust gas recirculation means 6, a mixed gas of oxygen, carbon dioxide, and water is supplied to the waste incinerator 1 as an oxidizing agent. Then, by adjusting the opening degree of the damper 6b according to the detection result of the oxygen concentration detection means (not shown) in the supply path that supplies the mixed gas to the waste incinerator 1, the oxygen concentration in the oxidizer can be adjusted to 18 to 24%, for example. The concentration can be adjusted to a desired level.

In this way, by adjusting the oxygen concentration of the oxidizing agent supplied into the waste incinerator 1, it is possible to control the temperature inside the furnace, which increases with the combustion reaction. Thereby, the temperature inside the furnace can be prevented from rising too much, and the amount of fuel NOx generated due to clinker generation and nitrogen in the fuel can be suppressed.

[Step S150: Separation of carbon dioxide]
Of the combustion exhaust gas generated due to combustion with oxygen in step S140, the combustion exhaust gas that is not recirculated is supplied to the carbon dioxide separation means 5 through the exhaust gas flue, and carbon dioxide is separated in the carbon dioxide separation means 5. (Step S150).

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.

By separating carbon dioxide in this manner, the main components of the combustion exhaust gas are water and excess oxygen, and the emission of carbon dioxide, which causes global warming, is significantly reduced.

[Step S160: Synthesis of methane gas]
The carbon dioxide separated by the carbon dioxide separation means 5 in step S150 is supplied to the methane gas generation means 10 together with the hydrogen produced in the water electrolyzer 8 in step S120, and methane gas is synthesized in the methane gas generation means 10 (step S160 ).

The methane gas synthesized by the methane gas generating means 10 is supplied to a desired location through a pipeline, and a portion is stored for internal use, such as as auxiliary fuel when starting up the waste incinerator 1.

By combusting the combustible material using the combustion system according to the present embodiment in the steps described above, the combustion exhaust gas discharged from the chimney 7 is composed of carbon dioxide, water, and excess oxygen generated by combustion. This excludes the combustion exhaust gas to be recirculated and the carbon dioxide separated for methane gas synthesis, and can reduce the amount to 1/2 or less of the normal combustion exhaust gas.

In addition, by using a garbage incinerator as combustion system 1, it is possible to generate fuel from waste that would otherwise be disposed of and incinerated, making it possible to construct an extremely superior system from the point of view of energy recycling. .

Such a system is particularly useful as an emergency facility in times of disaster. In other words, in emergency situations such as disasters, people may be forced to live in temporary housing or the like. In such cases, temporary housing generates waste associated with daily life, and it may be difficult to secure emergency power sources and fuel for heating and hot water supply.

In such an environment, by burning waste using the combustion system according to this embodiment, the amount of combustion exhaust gas can be suppressed to less than half, while the emissions of carbon dioxide and nitrogen oxides can be significantly reduced. It is possible to dispose of waste generated as a result of daily life in a state where the amount of waste is reduced to .

Furthermore, by driving the generator 12 using the heat generated during combustion, the electricity necessary for daily life can be provided.

Then, the water electrolyzer 8 is operated using the surplus electricity, and a synthesis reaction is caused in the methane gas generating means 10 using the hydrogen generated in the water electrolyzer 8 and the carbon dioxide separated by the carbon dioxide separating means 5. By doing so, it is possible to generate methane gas that can be used as gas fuel for hot water supply and space heating.

Furthermore, the amount of methane gas that can be generated by the entire system can be increased by collecting and fermenting human waste generated in houses to generate methane gas and using it together with the methane gas generated by the methane gas generation means 10. It is possible to build a leaner system.

In this way, by using the combustion system according to this embodiment, waste treatment equipment can be used as an energy infrastructure supply base in the event of a disaster.

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

The present invention provides a combustion device that burns a substance to be combusted using an oxidizing agent, a water electrolyzer that electrolyzes water, and an oxygen supply means that supplies oxygen generated in the water electrolyzer to the combustion device as an oxidizing agent. , a carbon dioxide separation means that separates carbon dioxide from the combustion exhaust gas generated by the combustion device, and methane gas is produced by synthesizing the hydrogen generated in the water electrolysis device and the carbon dioxide separated from the combustion exhaust gas by the carbon dioxide separation means. This is a combustion system equipped with a methane gas generating means.

Since the oxygen generated in the water electrolyzer is supplied to the combustion device as an oxidizing agent, the main components of the combustion exhaust gas generated when the combustion target is combusted are carbon dioxide and water. Therefore, compared to the case where air is used as an oxidizing agent, the amount of nitrogen generated can be suppressed, and the efficiency of separating carbon dioxide in the carbon dioxide separation means can be improved.

Since carbon dioxide is separated by the carbon dioxide separation means, the release of carbon dioxide into the atmosphere can be reduced.

Furthermore, since methane gas is generated by synthesizing the hydrogen generated in the water electrolysis device with carbon dioxide separated from the combustion exhaust gas, the hydrogen generated in the water electrolysis device can be effectively used. As a result, the amount of exhaust gas released into the atmosphere from the entire system can be reduced to 1/2 or less of that when combustion is performed using air.

Since methane gas that can be used as fuel can be synthesized using carbon dioxide, it becomes possible to reuse it as a resource and energy source.

Furthermore, the apparatus further includes an exhaust gas recirculation means for recirculating a part of the combustion exhaust gas to the combustion device, and a flow rate adjustment means for adjusting the flow rate of the combustion exhaust gas to be recirculated, so as to generate a mixed gas of oxygen and the combustion exhaust gas whose flow rate has been adjusted. Since it is supplied to the combustion equipment as an oxidizer, nitrogen in the mixed gas is significantly reduced, making it possible to suppress the generation of thermal NOx and prevent the temperature inside the combustion equipment from rising too much. It is also possible to suppress the generation of gas and fuel NOx.

It also includes a heat recovery means that recovers the heat contained in the combustion exhaust gas to generate steam, a steam turbine that is rotationally driven by the steam generated by the heat recovery means, and a generator that is driven in conjunction with the drive of the steam turbine. By operating the water electrolyzer using the electricity generated by the generator, the electricity required to operate the water electrolyzer can be generated by using the heat of the flue gas generated when the material to be combusted is combusted. Since it can be covered by the electricity generated by the system, there is no need for separate power supply equipment, and there is no waste in the system configuration.

In addition, the power left over when the water electrolyzer is operated can be used as power for operating auxiliary equipment at various locations within the plant, and can also be supplied outside the plant.

In addition, in order to control the amount of power supplied to the water electrolyzer according to the amount of oxygen required for oxidation in the combustion equipment, oxygen is supplied from equipment other than the water electrolyzer when burning the material to be combusted. It is not necessary and extra equipment can be omitted.

Furthermore, high-purity carbon dioxide can be recovered by separating carbon dioxide from the combustion exhaust gas by membrane separation, adsorption, cryogenic separation, or the like.

By using a waste incinerator that burns waste as a combustion device, waste heat from the combustion exhaust gas generated when waste is incinerated is recovered to generate electricity to operate the water electrolysis device. This makes it possible to build a system with no waste from an energy recycling perspective.

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.

For example, the heat recovery means 2 does not need to be separate from the combustion device 1, and the present invention may include a boiler structure in which the furnace wall of the combustion device 1 is constructed of water tubes.

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.

The combustion system and combustion method of the present invention can be applied to all equipment that burns various materials to be combusted.

1 Combustion device (garbage incinerator)
2 Heat recovery means 3 Bag filter 4 Induced blower 5 Carbon dioxide separation means 6 Exhaust gas recirculation means 6a Recirculation channel 6b Damper 7 Chimney 8 Water electrolyzer 9 Oxidizing agent supply means 10 Methane gas generation means 11 Steam turbine 12 Generator 13 condenser

Claims (2)

A garbage incinerator that burns waste using an oxidizing agent;
a heat recovery means for generating steam by recovering heat contained in the combustion exhaust gas generated in the garbage incinerator;
a steam turbine rotationally driven by the steam generated by the heat recovery means;
a generator that is driven as the steam turbine is driven;
a water electrolyzer that operates using electric power generated by the generator to electrolyze water;
an oxygen supply means for supplying oxygen generated in the water electrolyzer to the waste incinerator as an oxidizing agent;
carbon dioxide separation means for separating carbon dioxide from the combustion exhaust gas generated in the garbage incinerator;
Methane gas generation means for generating methane gas by synthesizing hydrogen generated by the water electrolyzer and carbon dioxide separated from the combustion exhaust gas by the carbon dioxide separation means ;
Exhaust gas recirculation means for recirculating a part of the combustion exhaust gas purified by the bag filter supplied with an alkaline agent to the garbage incinerator;
and a flow rate adjustment means for adjusting the flow rate of the combustion exhaust gas recirculated by the exhaust gas recirculation means,
The oxygen supply means mixes the combustion exhaust gas whose flow rate has been adjusted by the flow rate adjustment means with oxygen and supplies the mixture to the waste incinerator,
The power supplied to the water electrolyzer is controlled by the amount of oxygen required in the waste incinerator.
Waste treatment equipment. burning the waste in a garbage incinerator using an oxidizing agent;
generating steam by recovering heat contained in the combustion exhaust gas generated in the garbage incinerator;
a step of rotating a steam turbine with the steam generated in the step of generating steam;
driving a generator in conjunction with driving the steam turbine;
operating a water electrolyzer using the electric power generated by the generator to electrolyze water;
supplying oxygen generated when water is electrolyzed as an oxidizing agent to the garbage incinerator;
separating carbon dioxide from the flue gas generated in the waste incinerator;
a step of synthesizing hydrogen generated when water is electrolyzed and carbon dioxide separated from combustion exhaust gas to generate methane gas;
recirculating a portion of the flue gas purified by the bag filter supplied with an alkaline agent to the waste incinerator ;
comprising the step of adjusting the flow rate of the recirculated combustion exhaust gas,
In the step of supplying oxygen, the combustion exhaust gas whose flow rate has been adjusted is mixed with oxygen and supplied to the garbage incinerator,
The power supplied to the water electrolyzer is controlled by the amount of oxygen required in the waste incinerator.
Waste disposal methods.