JP7633145B2 - Carbon Dioxide Treatment System - Google Patents

Description

The present invention relates to a carbon dioxide treatment system.

The exhaust gases from the incinerators at waste incineration facilities and the boilers at thermal power plants contain large amounts of carbon dioxide. Carbon dioxide is known to be a greenhouse gas. Therefore, it is necessary to properly treat the carbon dioxide in the exhaust gases without releasing it into the atmosphere.

The following Patent Document 1 describes an exhaust gas treatment facility that treats exhaust gas (containing carbon dioxide) from a gas turbine power generation system. The facility includes a pressurized cylinder, an impregnation tank, and an accumulation tank. In the pressurized cylinder, exhaust gas is pressurized to dissolve carbon dioxide in water. This produces carbonated water. Concrete materials (scrap materials) are piled up in the impregnation tank. The carbonated water is sprayed toward the impregnation tank from above. When the carbonated water passes through the impregnation tank, carbonates such as calcium carbonate are produced by contact between the carbonated water and the concrete materials. The carbonates flow downward in the impregnation tank together with the carbonated water. The water that passes through the impregnation tank is stored in the accumulation tank. In the water in the accumulation tank, carbonates are precipitated by a specified process. In this way, carbon dioxide in the exhaust gas from the gas turbine power generation system is fixed.

On the other hand, the following Patent Document 2 describes a waste stabilization treatment system for a final disposal site. The system includes a carbon dioxide addition device, a sprinkler pipe, a leachate collection pipe, and a water treatment facility at the disposal site. A leachate collection pipe is laid at the bottom of the disposal site. Waste is buried in the disposal site. A sprinkler pipe is installed above the disposal site. In this system, a carbon dioxide addition device adds carbon dioxide nanobubbles to water to prepare carbon dioxide nanobubble water. The carbon dioxide nanobubble water is sprayed toward the disposal site from above the disposal site by the sprinkler pipe. When the carbon dioxide nanobubble water passes through the disposal site, calcium carbonate is generated by contact between the carbon dioxide nanobubbles and the calcium components in the waste. As a result, carbon dioxide is fixed in the disposal site as calcium carbonate. Therefore, the elution of calcium components from the waste into rainwater that infiltrates the disposal site is suppressed (stabilization of the disposal site). In addition, at the disposal site, after contacting the waste, the rainwater and carbon dioxide nanobubble water reach the bottom of the disposal site as leachate. This leachate is collected through a leachate collection pipe and transported to a water treatment facility where it is purified.

Japanese Patent Application Publication No. 7-213861 JP 2020-99878 A

However, to continue operating the exhaust gas treatment equipment of Patent Document 1, it is necessary to replace the concrete material in the permeation tank and to collect the sediment from the accumulation tank. Such equipment is not suitable for fixing large amounts of carbon dioxide. Furthermore, with the waste stabilization treatment system of Patent Document 2, the amount of leachate at the waste disposal site becomes larger than before. Treating the leachate takes time and costs money. Therefore, the waste stabilization treatment system of Patent Document 2 is not efficient as a carbon dioxide treatment system.

The present invention provides a carbon dioxide processing system suitable for efficiently fixing large amounts of carbon dioxide.

The present invention [1] includes a carbon dioxide treatment system comprising a gas pipe having a gas release section buried in a landfill layer containing waste, a gas supply means for supplying a gas containing carbon dioxide to the gas pipe, a carbon dioxide concentration detection means for detecting the carbon dioxide concentration inside and/or on the surface of the landfill layer, and a control means for controlling the gas supply means based on the carbon dioxide concentration detected by the carbon dioxide concentration detection means, and adjusting the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe.

According to this carbon dioxide treatment system, gas containing carbon dioxide (carbon dioxide-containing gas) can be discharged into the landfill layer from the gas discharge section of the gas pipe buried in the landfill layer containing waste. The carbon dioxide-containing gas passes upward through the landfill layer. A part or all of the carbon dioxide in the gas is immobilized with the alkaline components of the waste by contacting the waste in the landfill layer. Since the system can fix carbon dioxide in the landfill layer of waste, it is suitable for immobilizing and treating a large amount of carbon dioxide. Furthermore, since the system treats carbon dioxide in a gaseous state, the amount of leachate in the landfill layer of waste is not increased from the conventional amount (the time and cost required for treating the leachate are not increased). In addition, as described above, the system can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe based on the carbon dioxide concentration inside and/or on the surface of the landfill layer. The carbon dioxide concentration in the landfill layer is useful for understanding the remaining capacity of carbon dioxide immobilization in the landfill layer. Therefore, the system can adjust the amount of carbon dioxide supplied to the landfill layer according to changes in the remaining carbon dioxide fixation capacity in the landfill layer. The carbon dioxide treatment system described above is suitable for efficiently fixing large amounts of carbon dioxide.

The present invention [2] includes the carbon dioxide treatment system described in [1] above, in which the carbon dioxide concentration detection means detects the carbon dioxide concentration in a plurality of vertically separated portions of the landfill layer.

Such a carbon dioxide treatment system is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer. This helps to efficiently fix carbon dioxide.

The present invention [3] includes the carbon dioxide treatment system described in [1] or [2] above, in which the carbon dioxide concentration detection means detects the carbon dioxide concentration in a plurality of parts that are horizontally separated in the landfill layer.

Such a carbon dioxide treatment system is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer. This helps to efficiently fix carbon dioxide.

The present invention [4] includes the carbon dioxide treatment system according to any one of [1] to [3] above, further comprising an oxygen concentration detection means for detecting the oxygen concentration on the surface of the landfill layer, and the control means controls the gas supply means based on the oxygen concentration detected by the oxygen concentration detection means to adjust the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe.

The oxygen concentration at the landfill surface is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill. Therefore, in such a carbon dioxide treatment system, the amount of carbon dioxide supplied to the landfill can be adjusted according to changes in the remaining capacity of carbon dioxide fixation in the landfill, also from the perspective of the oxygen concentration at the landfill surface.

The present invention [5] includes a carbon dioxide treatment system comprising a gas pipe having a gas release section buried in a landfill layer containing waste, a gas supply means for supplying a gas containing carbon dioxide to the gas pipe, an oxygen concentration detection means for detecting the oxygen concentration on the surface of the landfill layer, and a control means for controlling the gas supply means based on the oxygen concentration detected by the oxygen concentration detection means, and adjusting the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe.

Since this carbon dioxide processing system can fix carbon dioxide in the waste landfill layer, it is suitable for immobilizing and processing large amounts of carbon dioxide. Furthermore, since this system processes carbon dioxide in a gaseous state, it does not increase the amount of leachate in the waste landfill layer from the conventional amount. In addition, as described above, this system can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe based on the oxygen concentration at the surface of the landfill layer. The oxygen concentration at the landfill layer surface is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill layer. Therefore, this system can adjust the amount of carbon dioxide supplied to the landfill layer in response to changes in the remaining capacity of carbon dioxide fixation in the landfill layer. Such a carbon dioxide processing system is suitable for efficiently immobilizing and processing large amounts of carbon dioxide.

The present invention [6] includes the carbon dioxide treatment system described in [4] or [5] above, in which the oxygen concentration detection means detects the oxygen concentration at multiple horizontally separated portions on the surface of the landfill layer.

Such a carbon dioxide treatment system is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer. This helps to efficiently fix carbon dioxide.

The present invention [7] includes the carbon dioxide treatment system according to any one of the above [1] to [6], further comprising a temperature detection means for detecting the temperature inside and/or on the surface of the landfill layer, and the control means controls the gas supply means based on the temperature detected by the temperature detection means to adjust the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe.

In such a carbon dioxide treatment system, the heat generated by contact between the waste in the landfill and carbon dioxide can be detected by a temperature detection means. In addition, the temperature inside and/or on the surface of the landfill is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill. Therefore, in such a carbon dioxide treatment system, the amount of carbon dioxide supplied to the landfill can be adjusted in accordance with changes in the remaining capacity of carbon dioxide fixation in the landfill, also from the perspective of the temperature in the landfill.

The present invention [8] includes a carbon dioxide treatment system comprising a gas pipe having a gas release section buried in a landfill layer containing waste, a gas supply means for supplying a gas containing carbon dioxide to the gas pipe, a temperature detection means for detecting the temperature inside and/or on the surface of the landfill layer, and a control means for controlling the gas supply means based on the temperature detected by the temperature detection means, and adjusting the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe.

Since this carbon dioxide processing system can fix carbon dioxide in the waste landfill layer, it is suitable for immobilizing and processing large amounts of carbon dioxide. Furthermore, since this system processes carbon dioxide in a gaseous state, it does not increase the amount of leachate in the waste landfill layer compared to the conventional amount. In addition, as described above, this system can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe based on the temperature inside and/or on the surface of the landfill layer. The temperature in the landfill layer is useful for understanding the remaining carbon dioxide fixation capacity of the landfill layer. Therefore, this system can adjust the amount of carbon dioxide supplied to the landfill layer according to changes in the remaining carbon dioxide fixation capacity in the landfill layer. Such a carbon dioxide processing system is suitable for efficiently immobilizing and processing large amounts of carbon dioxide.

The present invention [9] includes the carbon dioxide treatment system described in [7] or [8] above, in which the temperature detection means detects the temperatures of multiple parts of the landfill layer that are separated in the vertical direction.

Such a carbon dioxide treatment system is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer. This helps to efficiently fix carbon dioxide.

The present invention [10] includes a carbon dioxide treatment system according to any one of [7] to [9] above, in which the temperature detection means detects the temperatures of a plurality of parts in the landfill layer that are separated in the horizontal direction.

Such a carbon dioxide treatment system is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer. This helps to efficiently fix carbon dioxide.

The present invention [11] includes a carbon dioxide treatment system according to any one of [1] to [10] above, which includes a plurality of the gas pipes, and the gas release sections in the plurality of gas pipes are separated from each other in the horizontal direction.

Such a carbon dioxide treatment system is suitable for supplying carbon dioxide-containing gas to a wide area in the landfill. Supplying carbon dioxide-containing gas to a wide area helps to efficiently fix and treat a large amount of carbon dioxide.

The present invention [12] includes a carbon dioxide treatment system according to any one of [1] to [11] above, in which the gas release section is disposed at the bottom of the landfill layer.

In this type of carbon dioxide treatment system, the entire vertical dimension of the landfill layer can be effectively utilized for carbon dioxide fixation treatment. This is useful for efficiently fixing large amounts of carbon dioxide.

1 is an overall configuration diagram of one embodiment of a carbon dioxide treatment system of the present invention. FIG. 4 is a partial perspective view showing the arrangement of gas pipes. 3A shows an example of the arrangement of a carbon dioxide concentration meter in a first direction (extension direction of a gas releasing portion), and FIG 3B shows the arrangement in a second direction (direction perpendicular to the first direction). 4A and 4B show examples of oximeter placements, with Fig. 4A showing the placement in a first orientation and Fig. 4B showing the placement in a second orientation. 5A and 5B show examples of thermometer placements, where Fig. 5A shows the placement in a first orientation and Fig. 5B shows the placement in a second orientation. 6A shows a modified example of a gas pipe, with Fig. 6A showing the arrangement of the gas discharge parts in a first direction, and Fig. 6B showing the arrangement of the gas discharge parts in a second direction.

As shown in FIG. 1, a treatment system X (carbon dioxide treatment system) as one embodiment of the carbon dioxide treatment system of the present invention includes a gas pipe 10, a gas supply unit 20 (gas supply means), a first tank 30, a second tank 40, a carbon dioxide concentration detection means 50, an oxygen concentration detection means 60, a temperature detection means 70, and a control unit 80 (control means). The treatment system X is a system that performs fixation treatment of carbon dioxide. In this embodiment, the treatment system X is used in a waste disposal site 100. An example of the waste disposal site 100 is a final disposal site for waste.

A storage space 110 is formed in the waste disposal site 100. The storage space 110 is a space surrounded by a wall surface 111 and a bottom surface 112. Waste is put into the storage space 110. Such a storage space 110 is formed, for example, by excavating land. A waterproofing work (not shown) may be formed on the wall surface 111 and the bottom surface 112. Examples of materials for the waterproofing work include concrete, waterproof sheets, and combinations of these. The depth of the storage space 110 is, for example, several meters or more. The area of the storage space 110 is, for example, 1000 ^m2 or more.

A landfill layer 120 is formed in this storage space 110. The landfill layer 120 is where carbon dioxide is fixed in the treatment system X. The landfill layer 120 contains waste. Examples of waste include bottom ash and fly ash generated in waste incineration facilities, and coal ash generated in thermal power plants. The waste may also contain bulky waste and sludge. The landfill layer 120 can be formed, for example, by dumping the waste and soil (covering soil) into the storage space 110.

The gas pipe 10 is a passage for the carbon dioxide-containing gas described below. The gas pipe 10 has a portion extending along the wall surface 111 and a portion extending along the bottom surface 112 in the storage space 110. The gas pipe 10 has a gas release section 11. As shown in FIG. 2, the gas release section 11 is a portion of the gas pipe 10 having a gas hole 12 for releasing gas. The gas hole 12 penetrates the pipe wall of the gas pipe 10 in the pipe wall thickness direction. The carbon dioxide-containing gas in the gas release section 11 is released to the outside of the gas release section 11 through the gas hole 12. In this embodiment, a plurality of gas holes 12 are formed in the gas release section 11. Such a gas release section 11 is buried in the landfill layer 120 as shown in FIG. 1. From the viewpoint of suppressing clogging of the gas hole 12, it is preferable that the gas hole 12 opens downward from the horizontal level at which the gas release section 11 is arranged. The gas hole 12 may open upward (such a gas hole 12 is shown as an example in FIG. 2). A nozzle may also be attached to the gas hole 12. Such a gas pipe 10 is, for example, a hollow pipe made of polyvinyl chloride.

The gas release section 11 is preferably provided in a portion of the gas pipe 10 that extends along the bottom surface 112, as shown in FIG. 2. That is, the gas release section 11 is disposed at the bottom of the landfill layer 120. By disposing the gas release section 11 in this manner, the entire vertical direction of the landfill layer 120 can be effectively utilized for the fixation process of carbon dioxide. This helps to efficiently fix a large amount of carbon dioxide in the landfill layer 120. By laying the gas pipe 10 before forming the landfill layer 120 in the storage space 110, the gas release section 11 can be disposed at the bottom of the landfill layer 120.

In this embodiment, the processing system X includes a plurality of gas pipes 10. The plurality of gas release sections 11 in the plurality of gas pipes 10 are preferably spaced apart from each other in the horizontal direction. Such an arrangement of the gas release sections 11 is preferable for supplying carbon dioxide-containing gas to a wide range in the landfill layer 120. Supplying carbon dioxide-containing gas to such a wide range is useful for efficiently immobilizing a large amount of carbon dioxide. In addition, the plurality of gas release sections 11 extend, for example, parallel to each other. From the viewpoint of effectively utilizing the landfill layer 120 as a whole in the immobilization treatment of carbon dioxide, the distance between adjacent gas release sections 11 is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less. From the viewpoint of suppressing the installation cost of the processing system X, the distance between adjacent gas release sections 11 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more.

In this embodiment, the gas supply unit 20 includes a plurality of pumps 21. The pump 21 has a gas inlet 21a and an outlet 21b. The pump 21 has a function of sucking gas through the inlet 21a and discharging gas through the outlet 21b (gas flow function). The inlet 21a is connected to the first tank 30. Specifically, the inlet 21a and the first tank 30 are connected via a line 31 (shown by a thick line) as a pipe. On the other hand, the outlet 21b is connected to the gas pipe 10. In this embodiment, one pump 21 is connected to each gas pipe 10. That is, the gas pipe 10 (having a gas release section 11) and the pump 21 are in one-to-one correspondence. Such a gas supply unit 20 sends carbon dioxide-containing gas from the first tank 30 into the gas pipe 10. As a result, the gas supply unit 20 supplies carbon dioxide-containing gas to the gas pipe 10. The gas supply unit 20 can adjust the flow rate of the carbon dioxide-containing gas according to the control by the control unit 80.

Gas containing carbon dioxide (carbon dioxide-containing gas) is stored in the first tank 30. The carbon dioxide is the target of immobilization treatment by the treatment system X. The carbon dioxide is carbon dioxide recovered from exhaust gas (combustion exhaust gas) generated by combustion. Sources of exhaust gas include, for example, incinerators at waste incineration facilities and boilers at thermal power plants. The concentration of carbon dioxide in the first tank 30 is preferably 40% by volume or more, more preferably 60% by volume or more, even more preferably 80% by volume or more, and particularly preferably 90% by volume or more.

The second tank 40 stores a dilution gas. Examples of the dilution gas include air and nitrogen. From the viewpoint of suppressing the operating cost of the processing system X, air is preferable as the dilution gas. The second tank 40 is connected to the line 31 via the line 41. The second tank 40 is connected to the pump 21 via the line 41 and a part of the line 31. The line 41 is provided with an adjustment valve 42. The adjustment valve 42 can open and close the flow path in the line 41 according to the control by the control unit 80. In addition, the adjustment valve 42 can adjust the flow rate of the gas flowing through the line 41 according to the control by the control unit 80. When air is used as the dilution gas, a specified compressor may be used instead of the second tank 40 to supply the dilution gas to the line 31. In this case, the compressor is controlled instead of the adjustment valve 42 to adjust the supply amount of the dilution gas.

The carbon dioxide concentration detection means 50 detects the carbon dioxide concentration inside and/or on the surface of the landfill layer 120. The carbon dioxide concentration detection means 50 preferably includes a plurality of carbon dioxide concentration meters, and in this embodiment, a plurality of carbon dioxide concentration meters 51. The carbon dioxide concentration meters 51 are capable of measuring the concentration of gaseous carbon dioxide ( _CO2 concentration). That is, the carbon dioxide concentration detection means 50 detects the carbon _dioxide concentration (having a distribution) in the landfill layer 120 by measuring the CO2 concentration by the plurality of carbon dioxide concentration meters 51. The carbon dioxide concentration meters 51 output the measured _CO2 concentration (measured _CO2 concentration) as a signal to the control unit 80. Examples of the carbon dioxide concentration meters 51 include an aspiration type carbon dioxide concentration meter and a diffusion type carbon dioxide concentration meter.

3A and 3B show an example of the arrangement of the multiple carbon dioxide concentration meters 51. FIG. 3A shows the arrangement of the carbon dioxide concentration meters 51 in the first direction D1. The first direction D1 is the direction in which the gas release section 11 extends. FIG. 3B shows the arrangement of the carbon dioxide concentration meters 51 in the second direction D2. The first direction D1 and the second direction D2 are perpendicular to each other. As shown in FIGS. 3A and 3B, the multiple carbon dioxide concentration meters 51 (carbon dioxide detection means 50) include multiple carbon dioxide concentration meters 51 that are separated horizontally in the landfill layer 120. In the arrangement example shown in FIGS. 3A and 3B, the carbon dioxide concentration meters 51 are arranged in a matrix at each of three height positions (lowest position, middle position, and top position) in the vertical direction. That is, the multiple carbon dioxide concentration meters 51 include multiple carbon dioxide concentration meters 51 that are separated vertically in the landfill layer 120. As a result, the carbon dioxide concentration detection means 50 can detect the carbon dioxide concentration of multiple parts that are separated vertically in the landfill layer 120. The multiple carbon dioxide concentration meters 51 also include multiple carbon dioxide concentration meters 51 that are separated horizontally in the landfill layer 120. This allows the carbon dioxide concentration detection means 50 to detect the carbon dioxide concentration in multiple parts that are separated horizontally in the landfill layer 120. The carbon dioxide concentration meters 51 are specifically arranged as follows:

At the lowest position, a plurality of carbon dioxide concentration meters 51a are arranged in a matrix. The carbon dioxide concentration meters 51a are arranged above the gas release section 11. The carbon dioxide concentration meters 51a are arranged, for example, within 100 cm from the bottom surface 112 of the storage space 110. Also, as shown in FIG. 3A, a plurality of carbon dioxide concentration meters 51a are arranged in a line along the gas release section 11. In the line of carbon dioxide concentration meters 51a, the distance L ₁ between adjacent carbon dioxide concentration meters 51a is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of detection accuracy of the carbon dioxide concentration. The distance L ₁ is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more, from the viewpoint of suppressing the installation cost of the treatment system X. The preferable distance between adjacent carbon dioxide concentration meters 51a in the second direction D2 is the same as the distance L ₁ . Furthermore, as shown in FIG. 3B, the distance between adjacent carbon dioxide concentration meters 51a in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2.

A plurality of carbon dioxide concentration meters 51b are arranged in a matrix at the intermediate position. The carbon dioxide concentration meters 51b are arranged, for example, within 500 cm from the center position in the thickness direction of the landfill layer 120. Also, as shown in FIG. 3A, a plurality of carbon dioxide concentration meters 51b are arranged in a row along the gas release section 11. In the row of carbon dioxide concentration meters 51b, the distance _L2 between adjacent carbon dioxide concentration meters 51b is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of the detection accuracy of the carbon dioxide concentration. The distance _L2 between adjacent carbon dioxide concentration meters _51b is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more, from the viewpoint of suppressing the installation cost of the treatment system X. The distance L2 may be the same as or different from the above-mentioned distance _L1 . The preferred distance between adjacent carbon dioxide concentration meters 51b in the second direction D2 is the same as the distance _L2 . Furthermore, as shown in FIG. 3B, the distance between adjacent carbon dioxide concentration meters 51b in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2.

At the top position, a plurality of carbon dioxide concentration meters 51c are arranged in a matrix. The carbon dioxide concentration meters 51c are preferably arranged on the exposed surface (surface) of the landfill layer 120. Also, as shown in FIG. 3A, a plurality of carbon dioxide concentration meters 51c are arranged in a row along the gas release section 11. In the row of carbon dioxide concentration meters 51c, the distance _L3 between adjacent carbon dioxide concentration meters 51c is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of detection accuracy of the carbon dioxide concentration. From the viewpoint of suppressing the installation cost of the treatment system X, the distance _L3 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more. The distance _L3 may be the same as or different from the above-mentioned distances _L1 and _L2 . The preferred distance between adjacent carbon dioxide concentration meters 51c in the second direction D2 is the same as the distance _L3 . Furthermore, as shown in FIG. 3B, the distance between adjacent carbon dioxide concentration meters 51c in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2.

The distance between the carbon dioxide concentration meters 51a and 51b in the vertical direction (the difference between the lowest position and the middle position) is, for example, 100 m or less, preferably 30 m or less, and more preferably 10 m or less. The distance between the carbon dioxide concentration meters 51b and 51c in the vertical direction (the difference between the middle position and the top position) is, for example, 100 m or less, preferably 30 m or less, and more preferably 10 m or less.

The oxygen concentration detection means 60 detects the oxygen concentration on the surface of the landfill layer 120. The oxygen concentration detection means 60 preferably includes a plurality of oxygen concentration meters, and in this embodiment, a plurality of oxygen concentration meters 61. The oxygen concentration meters 61 can measure the concentration of gaseous oxygen ( _O2 concentration). That is, the oxygen concentration detection means 60 detects the oxygen concentration (having a distribution) of the landfill layer 120 by measuring the _O2 concentration by the plurality of oxygen concentration meters 61. The oxygen concentration meters 61 output a signal indicating the measured _O2 concentration (measured _O2 concentration) to the control unit 80. Examples of the oxygen concentration meters 61 include an aspiration type oxygen concentration meter and a diffusion type oxygen concentration meter.

4A and 4B show an example of the arrangement of the oxygen concentration meters 61. FIG. 4A shows the arrangement of the oxygen concentration meters 61 in the first direction D1. FIG. 4B shows the arrangement of the oxygen concentration meters 61 in the second direction D2. The oxygen concentration meters 61 are arranged in a matrix on the exposed surface (surface) of the landfill layer 120 (i.e., the oxygen concentration detection means 60 includes a plurality of oxygen concentration meters 61 separated in the horizontal direction). This allows the oxygen concentration detection means 60 to detect the oxygen concentration of a plurality of parts separated in the horizontal direction on the surface of the landfill layer 120. Also, as shown in FIG. 4A, the plurality of oxygen concentration meters 61 are arranged in a row along the gas release section 11. In the oxygen concentration meters 61 in the row, the distance _L4 between adjacent oxygen concentration meters 61c is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of the detection accuracy of the oxygen concentration. From the viewpoint of suppressing the installation cost of the processing system X, the distance _L4 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more. The distance _L4 may be the same as or different from the above-mentioned distances _L1 , L2 _{, and L3} . The preferred distance between adjacent oxygen concentration meters 61 in the second direction D2 is the same as the distance _L4 . Also, as shown in FIG. 4B, the distance between adjacent oxygen concentration meters 61 in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2.

The temperature detection means 70 detects the temperature inside and/or on the surface of the landfill layer 120. The temperature detection means 70 preferably includes multiple thermometers, and in this embodiment, multiple thermometers 71. The thermometers 71 are capable of measuring temperature. That is, the temperature detection means 70 detects the temperature (having a distribution) of the landfill layer 120 by measuring the temperature with the multiple thermometers 71. The thermometers 71 output a signal indicating the measured temperature (measured temperature) to the control unit 80.

5A and 5B show an example of the arrangement of the thermometers 71. FIG. 5A shows the arrangement of the thermometers 71 in the first direction D1. FIG. 5B shows the arrangement of the thermometers 71 in the second direction D2. As shown in FIG. 5A and FIG. 5B, the thermometers 71 (temperature detection means 70) include a plurality of thermometers 71 spaced apart in the horizontal direction in the landfill layer 120. In addition, in the arrangement example shown in FIG. 5A and FIG. 5B, the thermometers 71 are arranged in a matrix at each of three height positions (lowest position, middle position, and highest position) in the vertical direction. That is, the plurality of thermometers 71 include a plurality of thermometers 71 spaced apart in the vertical direction in the landfill layer 120. This allows the temperature detection means 70 to detect the temperatures of a plurality of parts spaced apart in the vertical direction in the landfill layer 120. In addition, the plurality of thermometers 71 include a plurality of thermometers 71 spaced apart in the horizontal direction in the landfill layer 120. This allows the temperature detection means 70 to detect the temperatures of multiple parts of the landfill layer 120 that are separated horizontally. The thermometers 71 are specifically arranged as follows:

At the lowest position, a plurality of thermometers 71a are arranged in a matrix. The thermometers 71a are arranged above the gas discharge section 11. The thermometers 71a are arranged, for example, within 100 cm from the bottom surface 112 of the storage space 110. Also, as shown in FIG. 5A, a plurality of thermometers 71a are arranged in a row along the gas discharge section 11. In the row of thermometers 71a, the distance _L5 between adjacent thermometers 71a is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of temperature detection accuracy. The distance _L5 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more, from the viewpoint of suppressing the installation cost of the processing system X. The preferable distance between adjacent thermometers 71a in the second direction D2 is the same as the distance _L5 . 5B , the distance between adjacent thermometers 71a in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2. The thermometers 71a and the carbon dioxide concentration meter 51a may be disposed at substantially the same position.

A plurality of thermometers 71b are arranged in a matrix at the intermediate position. The thermometers 71b are arranged, for example, within 500 cm from the center position in the thickness direction of the buried layer 120. Also, as shown in FIG. 5A, a plurality of thermometers 71b are arranged in a row along the gas release section 11. In the row of thermometers 71b, the distance _L6 between adjacent thermometers 71b is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of temperature detection accuracy. The distance _L6 may be the same as the above-mentioned distance _L5 or may be different. From the viewpoint of suppressing the installation cost of the treatment system X, the distance _L6 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more. The distance _L6 may be the same as the above-mentioned distance _L5 or may be different. The preferred distance between adjacent thermometers 71b in the second direction D2 is the same as the distance _L6 . 5B, in this embodiment, the distance between adjacent thermometers 71b in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2. The thermometers 71b and the carbon dioxide concentration meter 51b may be disposed at substantially the same position.

At the top position, a plurality of thermometers 71c are arranged in a matrix. The thermometers 71c are preferably arranged on the exposed surface of the buried layer 120. Also, as shown in FIG. 5A, a plurality of thermometers 71c are arranged in a row along the gas release section 11. In the row of thermometers 71c, the distance L7 between adjacent thermometers 71c is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m _or less, and even more preferably 10 m or less, from the viewpoint of temperature detection accuracy. The distance _L7 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more, from the viewpoint of suppressing the installation cost of the treatment system X. The distance _L7 may be the same as or different from the above-mentioned distances _{L5 and L6} . The preferred distance between adjacent thermometers 71c in the second direction D2 is the same as the distance _L7 . 5B, in this embodiment, the distance between adjacent thermometers 71c in the second direction D2 may be substantially the same as the distance between adjacent gas emission sections 11 in the second direction D2. The thermometers 71c and the carbon dioxide concentration meter 51c may be disposed at substantially the same position.

The vertical distance between thermometers 71a and 71b (the difference between the lowest position and the middle position) is, for example, 100 m or less, preferably 30 m or less, and more preferably 10 m or less. The vertical distance between thermometers 71b and 71c (the difference between the middle position and the top position) is, for example, 100 m or less, preferably 30 m or less, and more preferably 10 m or less.

Instead of the uppermost multiple thermometers 71c, the temperature detection means 70 may be equipped with a thermograph capable of measuring the temperature of the entire surface of the landfill layer 120.

The control unit 80 includes, for example, a calculation unit, a memory unit, a comparison unit, and an operation control unit. The control unit 80 is configured by a computer. The computer is installed, for example, in a management building (not shown) of the waste disposal site 100. The pump 21, the control valve 42, the carbon dioxide concentration meter 51, the oxygen concentration meter 61, and the thermometer 71 are connected to the control unit 80 in a wired or wireless manner so as to be able to communicate with each other.

The carbon dioxide fixation process in treatment system X is as follows:

The carbon dioxide-containing gas in the first tank 30 is sent to each pump 21 of the gas supply unit 20 via the line 31. If necessary, the diluted gas in the second tank 40 is also sent to each pump 21 via the line 41 and a part of the line 31. Then, the pump 21 (gas supply unit 20) supplies the carbon dioxide-containing gas with a predetermined _CO2 concentration to the gas pipe 10. The carbon dioxide-containing gas is released from the gas release section 11 into the landfill layer 120. When the carbon dioxide-containing gas passes upward through the landfill layer 120, the carbon dioxide in the gas comes into contact with the alkaline components in the waste, generating carbonates of the alkaline components. Examples of the alkaline components include sodium, potassium, calcium, and magnesium. As a result, the carbon dioxide is fixed in the landfill layer 120 as carbonates.

In addition, in the processing system X, the calculation unit of the control unit 80 calculates the CO ₂ concentration (supply CO ₂ concentration) of the carbon dioxide-containing gas supplied from the pump 21 to the gas pipe 10 based on, for example, the following first to third information. The first information is the CO ₂ concentration of the carbon dioxide-containing gas in the first tank 30. The second information is the CO ₂ concentration of the gas in the second tank 40. The third information is the opening degree of the control valve 42 of the line 41. The calculated supply CO ₂ concentration is stored in the memory unit. Then, in this embodiment, the control unit 80 controls the gas supply unit 20 for each pump 21 based on the above-mentioned measured CO ₂ concentration, measured O ₂ concentration, and measured temperature, and adjusts the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe 10. Specifically, it is as follows.

In the control unit 80, the memory unit prestores a threshold value of the carbon dioxide concentration ( _CO2 threshold concentration). For example, a value of 5% by volume or more is set as the _CO2 threshold concentration. The _CO2 threshold concentration may be set individually for each carbon dioxide concentration meter 51 associated with one gas release unit 11, or may be set as a common threshold concentration for the carbon dioxide concentration meter 51. For example, the set _CO2 threshold concentration is smaller in the order of the carbon dioxide concentration meter 51a, the carbon dioxide concentration meter 51b, and the carbon dioxide concentration meter 51c. On the other hand, the measured _CO2 concentration is input as a signal from each carbon dioxide concentration meter 51 to the control unit 80. The control unit 80 stores the input measured _CO2 concentration in the memory unit. The comparison unit compares the measured _CO2 concentration from each carbon dioxide concentration meter 51 with the _CO2 threshold concentration set in the carbon dioxide concentration meter 51. Then, when there is a measured _CO2 concentration that exceeds the _CO2 threshold concentration, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 associated with the carbon dioxide concentration meter ₅₁ whose measured concentration exceeds the _CO2 threshold concentration so as to decrease. The pump 21 associated with the carbon dioxide concentration meter 51 whose measured concentration exceeds the CO2 threshold concentration is a pump 21 that can be reasonably identified as the source of carbon dioxide detected by the carbon dioxide concentration meter 51, for example, a pump 21 that supplies carbon dioxide-containing gas to the gas pipe 10 having the gas release unit 11 closest to the carbon dioxide concentration meter 51. The flow rate is adjusted by controlling the discharge amount of the pump 21. The carbon dioxide concentration is adjusted by controlling the opening degree of the opening/closing valve 42. After these adjustments, the calculation unit calculates the supply _CO2 concentration. The new supply _CO2 concentration is stored in the memory unit (update of the supply _CO2 concentration). On the other hand, when the measured _CO2 concentration from the carbon dioxide concentration meter 51 falls below the _CO2 threshold concentration set in the carbon dioxide concentration meter 51, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 associated with the carbon dioxide concentration meter 51 so as to increase (for example, return to the value before the above-mentioned decrease). After this adjustment, the supply _CO2 concentration is updated. In the treatment system X, the above control based on the carbon dioxide concentration is performed periodically or constantly.

In the control unit 80, the memory unit also stores a threshold value of the oxygen concentration ( _O2 threshold concentration) in advance. The _O2 threshold concentration is, for example, 19% by volume (that is, the _O2 threshold concentration is set so that the _O2 concentration at the surface of the buried layer 120 does not fall below, for example, 19% by volume). The _O2 threshold concentration may be set individually for each oxygen concentration meter 61 associated with one gas release unit 11, or may be set as a common threshold concentration for the oxygen concentration meter 61. On the other hand, the measured _O2 concentration is input as a signal from each oxygen concentration meter 61 to the control unit 80. The control unit 80 stores the input measured _O2 concentration in the memory unit. The comparison unit compares the measured _O2 concentration from each oxygen concentration meter 61 with the _O2 threshold concentration set in the oxygen concentration meter 61. Then, when there is a measured _O2 concentration below the _O2 threshold concentration, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 associated with the oxygen concentration meter 61 whose measured concentration is below _{the O2} threshold concentration so as to decrease. The pump 21 associated with the oxygen concentration meter 61 whose measured concentration is below the O2 threshold concentration is a pump 21 that can be reasonably identified as the source of carbon dioxide contained in the gas detected by the oxygen concentration meter 61, for example, a pump 21 that supplies carbon dioxide-containing gas to the gas pipe 10 having the gas release unit 11 closest to the oxygen concentration meter 61. Then, after the adjustment, the above-mentioned update of the supply _CO2 concentration is performed. On the other hand, when the measured _O2 concentration from the oxygen concentration meter 61 exceeds the _O2 threshold concentration set in the oxygen concentration meter 61, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 associated with the oxygen concentration meter 61 so as to increase (e.g., return to the value before the above-mentioned decrease). After this adjustment, the supply _CO2 concentration is updated. In the treatment system X, the above control based on the oxygen concentration is performed periodically or constantly.

In the control unit 80, the memory unit stores a temperature threshold (threshold temperature) in advance. The threshold temperature may be set individually for each thermometer 71 associated with one gas release unit 11, or may be set as a common threshold temperature for the thermometer 71. Meanwhile, the measured temperature is input as a signal from each thermometer 71 to the control unit 80. The control unit 80 stores the input measured temperature in the memory unit. The comparison unit compares the measured temperature from each thermometer 71 with the threshold temperature set for the thermometer 71. Then, when there is a measured temperature exceeding the threshold temperature, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 (first pump 21) that supplies the carbon dioxide-containing gas to the gas pipe 10 having the gas release unit 11 closest to the thermometer 71 whose measured temperature exceeds the threshold temperature so as to decrease. In addition, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 (second pump 21) that supplies the carbon dioxide-containing gas to the gas pipe 10 having the gas release unit 11 second closest to the thermometer 71, as necessary, so as to decrease. Furthermore, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the pump 21 (third pump 21) that supplies the carbon dioxide-containing gas to the gas pipe 10 having the gas release unit 11 third closest to the thermometer 71, as necessary, so as to decrease. After such adjustment, the above-mentioned update of the supply CO ₂ concentration is performed. On the other hand, when the measured temperature from the thermometer 71 falls below the threshold temperature set for the thermometer 71, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the first pump 21 so as to increase (for example, return to the value before the above-mentioned decrease). Moreover, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the second pump 21 to increase as necessary. Furthermore, the operation control unit adjusts the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 by the third pump 21 to increase as necessary. After this adjustment, the supply _CO2 concentration is updated. In the treatment system X, the above control based on temperature is performed periodically or constantly.

In the treatment system X, the amount of carbon dioxide supplied to the gas pipe 10 is adjusted as described above, while the carbon dioxide is immobilized. With such a treatment system X, carbon dioxide can be immobilized in the waste landfill layer 120. Therefore, the treatment system X is suitable for immobilizing large amounts of carbon dioxide. Furthermore, the treatment system X can treat carbon dioxide in a gaseous state. Therefore, with the treatment system X, the amount of leachate in the landfill layer 120 does not increase from the conventional amount (the time and cost required to treat the leachate do not increase).

Furthermore, as described above, the treatment system X can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 based on the carbon dioxide concentration inside and/or on the surface of the landfill layer 120. The carbon dioxide concentration in the landfill layer 120 is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill layer 120. Therefore, the treatment system X can adjust the amount of carbon dioxide supplied to the landfill layer 120 in response to changes in the remaining capacity of carbon dioxide fixation in the landfill layer 120.

In addition, as described above, the treatment system X can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 based on the oxygen concentration at the surface of the landfill layer 120. The oxygen concentration at the surface of the landfill layer 120 is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill layer 120. Therefore, the treatment system X can adjust the amount of carbon dioxide supplied to the landfill layer in accordance with changes in the remaining capacity of carbon dioxide fixation in the landfill layer 120, also from the perspective of the oxygen concentration at the surface of the landfill layer 120.

In addition, as described above, the treatment system X can adjust the flow rate and/or carbon dioxide concentration of the carbon dioxide-containing gas supplied to the gas pipe 10 based on the temperature inside and/or on the surface of the landfill layer 120. The temperature inside and/or on the surface of the landfill layer 120 is useful for understanding the remaining capacity of carbon dioxide fixation in the landfill layer 120. Therefore, the treatment system X can adjust the amount of carbon dioxide supplied to the landfill layer 120 in accordance with changes in the remaining capacity of carbon dioxide fixation in the landfill layer 120, also from the perspective of the temperature in the landfill layer 120.

The above-described treatment system X is suitable for efficiently immobilizing large amounts of carbon dioxide.

In the treatment system X, as described above, the carbon dioxide concentration detection means 50 detects the carbon dioxide concentration in multiple vertically separated parts of the landfill layer 120. The carbon dioxide concentration detection means 50 also detects the carbon dioxide concentration in multiple horizontally separated parts of the landfill layer 120. Such a treatment system X is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer 120. This helps to efficiently fix carbon dioxide.

As described above, in the treatment system X, the oxygen concentration detection means 60 detects the oxygen concentration at multiple horizontally separated portions of the landfill layer 120. Such a treatment system X is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer 120. This helps to efficiently fix carbon dioxide.

In the treatment system X, as described above, the temperature detection means 70 detects the temperatures of multiple parts of the landfill layer 120 that are separated in the vertical direction. The temperature detection means 70 also detects the temperatures of multiple parts of the landfill layer 120 that are separated in the horizontal direction. Such a treatment system X is preferable for accurately tracking changes in the remaining carbon dioxide fixation capacity in the landfill layer 120. This helps to efficiently fix carbon dioxide.

In the treatment system X, the carbon dioxide concentration detection means 50 does not have to include multiple carbon dioxide concentration meters 51 spaced apart in the vertical direction, and does not have to include multiple carbon dioxide concentration meters 51 spaced apart in the horizontal direction. The oxygen concentration detection means 60 does not have to include multiple oxygen concentration meters 61 spaced apart in the horizontal direction. In addition, the temperature detection means 70 does not have to include multiple thermometers 71 spaced apart in the vertical direction, and does not have to include multiple thermometers 71 spaced apart in the horizontal direction.

In the treatment system X, the gas release section 11 of the gas pipe 10 does not have to be located at the bottom of the landfill layer 120. The gas release section 11 may be located in the vertical middle of the landfill layer 120.

The gas pipe 10 may have a gas release section 11 inserted into the landfill layer 120 from the upper surface of the landfill layer 120. With such a gas pipe 10, it is easy to arrange the gas release section 11 in the landfill layer 120 that has already been formed. Figures 6A and 6B show an example of a gas pipe 10 having such a gas release section 11. Each of the multiple gas pipes 10 shown in Figures 6A and 6B has a gas release section 11 extending vertically (the gas release section 11 has multiple gas holes 12). It is preferable that the gas pipe 10 is inserted into the landfill layer 120 until the gas release section 11 is arranged at the bottom of the landfill layer 120 (i.e., near the bottom surface 112 of the storage space 110). The gas pipe 10 and its gas release section 11 may be inserted into the landfill layer 120 at an angle to the vertical and horizontal directions. In the gas release section 11, the gas hole 12 is preferably provided so as to be located in the lower part of the landfill layer 120 (for example, the lower half of the landfill layer 120 in the vertical direction) or the bottom. In addition, the multiple gas release sections 11 in the multiple gas pipes 10 may be separated in the first direction D1 as shown in FIG. 6A, and may be separated in the second direction D2 as shown in FIG. 6B. In such a modified example, the distance between adjacent gas release sections 11 is preferably 100 m or less, more preferably 50 m or less, even more preferably 30 m or less, and even more preferably 10 m or less, from the viewpoint of effectively utilizing the landfill layer 120 as a whole in the fixation treatment of carbon dioxide. The distance between adjacent gas release sections 11 is preferably 2 m or more, more preferably 5 m or more, even more preferably 10 m or more, and even more preferably 30 m or more, from the viewpoint of suppressing the installation cost of the treatment system X.

The gas pipe 10 may also have a gas release section 11 (L-shaped gas release section) in the landfill layer 120, which has a section that extends vertically and a section that is connected to the gas release section and extends horizontally. The gas pipe 10 may also have a gas release section 11 in the landfill layer 120, which has a section (inclined section) that extends in a direction that intersects the vertical and horizontal directions, and a section that is connected to the gas release section and extends horizontally.

In the treatment system X, the suction port 21 a of the pump 21 may be connected to a plant that recovers carbon dioxide from combustion exhaust gas (CO ₂ recovery plant) instead of the first tank 30 .

Instead of the above-mentioned configuration in which one pump 21 is provided (i.e., connected) for each gas pipe 10, the processing system X may have a configuration in which one pump 21 is provided (i.e., connected) for each set of gas pipes 10 having adjacent gas release sections 11. Also, instead of the above-mentioned configuration in which one pump 21 is provided for each gas pipe 10, the processing system X may have a configuration in which one pump 21 is provided (i.e., connected) for all gas pipes 10.

In the treatment system X, the suction port 21 a of the pump 21 may be connected to a plant that recovers carbon dioxide from combustion exhaust gas (CO ₂ recovery plant) instead of the first tank 30 .

In addition, the processing system X may not include the oxygen concentration detection means 60 described above. That is, the processing system X may include the carbon dioxide concentration detection means 50 and the temperature detection means 70 described above, and execute the above-mentioned control based on the carbon dioxide concentration and the above-mentioned control based on the temperature. The processing system X may not include the temperature detection means 70. That is, the processing system X may include the carbon dioxide concentration detection means 50 and the oxygen concentration detection means 60, and execute the above-mentioned control based on the carbon dioxide concentration and the above-mentioned control based on the oxygen concentration. The processing system X may not include the oxygen concentration detection means 60 and the temperature detection means 70. That is, the processing system X may include the carbon dioxide concentration detection means 50, and execute the above-mentioned control based on the carbon dioxide concentration. The processing system X may not include the carbon dioxide concentration detection means 50. That is, the processing system X may include the oxygen concentration detection means 60 and the temperature detection means 70, and execute the above-mentioned control based on the oxygen concentration and the above-mentioned control based on the temperature ... and the temperature detection means 70. That is, the processing system X may be equipped with an oxygen concentration detection means 60 and perform the above-mentioned control based on the oxygen concentration.

X Treatment system (carbon dioxide treatment system)
10 Gas pipe 11 Gas discharge section 12 Gas hole 20 Gas supply unit (gas supply means)
30 First tank 40 Second tank 50 Carbon dioxide concentration detection means 51 Carbon dioxide concentration meter 60 Oxygen concentration detection means 61 Oxygen concentration meter 70 Temperature detection means 71 Thermometer 80 Control unit (control means)
100 Waste disposal site 110 Storage space 120 Landfill layer D1 First direction D2 Second direction

Claims (9)

a gas pipe having a gas discharge portion buried in a landfill layer containing waste;
A gas supply means for supplying a gas containing carbon dioxide to the gas pipe;
a carbon dioxide concentration detection means for detecting carbon dioxide concentrations at a plurality of vertically separated portions and a plurality of horizontally separated portions inside and/or on the surface of the landfill layer;
a control means for controlling the gas supply means based on the carbon dioxide concentration detected by the carbon dioxide concentration detection means, and adjusting a flow rate and/or a carbon dioxide concentration of the gas supplied to the gas pipe ;
the gas discharge portion is a portion of the gas pipe having a gas hole for discharging gas,
The gas hole is provided so as to be located in a lower layer or a bottom portion of the buried layer,
A carbon dioxide processing system , wherein the gas hole opens downwardly below a horizontal level at which the gas release portion is located . The method further includes an oxygen concentration detection means for detecting an oxygen concentration at the surface of the buried layer,
2. The carbon dioxide processing system according to claim 1, wherein the control means controls the gas supply means based on the oxygen concentration detected by the oxygen concentration detection means, and adjusts the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe. a gas pipe having a gas discharge portion buried in a landfill layer containing waste;
A gas supply means for supplying a gas containing carbon dioxide to the gas pipe;
an oxygen concentration detection means for detecting the oxygen concentration at a plurality of horizontally separated portions on the surface of the landfill layer;
a control means for controlling the gas supply means based on the oxygen concentration detected by the oxygen concentration detection means, and adjusting a flow rate and/or a carbon dioxide concentration of the gas supplied to the gas pipe ;
the gas discharge portion is a portion of the gas pipe having a gas hole for discharging gas,
The gas hole is provided so as to be located in a lower layer or a bottom portion of the buried layer,
A carbon dioxide processing system , wherein the gas hole opens downward below a horizontal level at which the gas release portion is located . 3. The carbon dioxide treatment system according to claim 2 , wherein the oxygen concentration detection means detects the oxygen concentration at a plurality of portions horizontally separated from each other on the surface of the landfill layer. Further comprising a temperature detection means for detecting the temperature inside and/or on the surface of the buried layer;
5. The carbon dioxide processing system according to claim 1, wherein the control means controls the gas supply means based on the temperature detected by the temperature detection means, and adjusts the flow rate and/or carbon dioxide concentration of the gas supplied to the gas pipe. 6. The carbon dioxide processing system according to claim 5 , wherein the temperature detection means detects the temperatures of a plurality of vertically separated portions of the landfill layer. 7. The carbon dioxide processing system according to claim 5 , wherein the temperature detection means detects temperatures at a plurality of horizontally separated portions of the landfill layer. The carbon dioxide processing system according to claim 1 , further comprising a plurality of the gas pipes, the plurality of gas discharge sections in the plurality of gas pipes being separated from each other in the horizontal direction. The carbon dioxide processing system according to claim 1 , wherein the gas release section is disposed at the bottom of the landfill layer.

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