JP2023040873A - N2O treatment system - Google Patents

Abstract

To efficiently treat N2O released from the soil of a cultivation facility.SOLUTION: An N2O treatment system 100 has: a cultivation facility 1 that forms a cultivation space 1a for cultivating crops in a fertilized soil 10 containing nitrogen; an intake pipe 12 that extends substantially parallel along a surface 10a of the fertilized soil 10 in the cultivation space 1a, is provided with an opening 12a facing the fertilized soil 10, and forms a channel 12b in which N2O released from the fertilized soil 10 passes through the opening 12a; and a treatment device 2 that is connected to the intake pipe 12 and sucks in the N2O guided through the channel 12b for treatment.SELECTED DRAWING: Figure 1

Description

The present invention relates to an N ₂ O treatment system for treating dinitrogen monoxide (N ₂ O) released from the soil of cultivation facilities.

2. Description of the Related Art Conventionally, there has been known an apparatus for treating various greenhouse gases (see Patent Document 1, for example). The device described in Patent Document 1 collects carbon dioxide discharged from a cogeneration device and supplies it to a plant cultivation facility.

JP 2016-52633 A

By the way, when crops are grown in soil to which nitrogen fertilizer is applied, N ₂ O is generated from the soil and released into the atmosphere. N ₂ O has an extremely high greenhouse effect, approximately 300 times that of carbon dioxide, a typical greenhouse gas, and is also a stratospheric ozone layer depleting substance. Efficient treatment of N ₂ O released from the soil is preferred. However, Patent Document 1 does not make any proposal regarding this point.

The N ₂ O treatment system, which is one aspect of the present invention, includes a cultivation facility that forms a cultivation space for cultivating crops with nitrogen-containing soil, and extends substantially parallel along the surface of the soil in the cultivation space, A flow path forming portion having an opening facing the soil and forming a flow path through which N ₂ O released from the soil passes; and a processing device for sucking and processing the N ₂ O guided through the air.

ADVANTAGE OF THE INVENTION According to this invention, _N2O emitted from the soil of a cultivation facility can be efficiently processed.

BRIEF DESCRIPTION OF THE DRAWINGS The conceptual diagram which shows roughly an example of the whole structure of the _N2O processing system which concerns on embodiment of this invention. FIG. 2 is a block diagram schematically showing an example of the peripheral configuration of a controller that controls the fuel supply section of FIG. 1;

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. An N ₂ O treatment system according to an embodiment of the present invention collects and treats N ₂ O released from soil within a cultivation facility. To cultivate crops, fertilization is performed by applying nitrogen fertilizer to the soil in order to promote the growth of crops. In such fertilized soil, nitrogen contained in the soil is decomposed by microorganisms to generate N ₂ O, which is released into the atmosphere from the surface of the soil. N ₂ O has an extremely high greenhouse effect, about 300 times that of carbon dioxide, a typical greenhouse gas, and is also _a stratospheric ozone layer depleting substance. Release into the atmosphere is not preferable from the viewpoint of global warming prevention.

N ₂ O is a combustion-supporting gas that decomposes into nitrogen and oxygen at high temperatures as shown in the following formula (i) to promote the combustion reaction. Therefore, in this embodiment, the N ₂ O released from the soil in the cultivation facility is collected and treated by using it for combustion reaction, and the N _{2 O} is as follows so that the environmental load can be minimized. Configure the O processing system.
_N2O → _N2 +O (i)

FIG. 1 is a conceptual diagram schematically showing an example of the overall configuration of an N ₂ O treatment system 100 according to an embodiment of the invention. As shown in FIG. 1, the N ₂ O treatment system 100 treats a cultivation facility 1 forming a cultivation space 1a for cultivating crops in fertilized soil 10 and N ₂ O contained in the inside air of the cultivation facility 1. A processing device 2 is mainly provided. Furthermore, it includes a generator 4 and a power conditioner 5 connected to the generator 4 and a commercial power system (not shown) via a power supply line.

The processing device 2 is configured by, for example, a reciprocating engine (reciprocating engine) such as a gas engine. Fuel is supplied to the processing device 2 from a fuel supply unit 3 including a fuel tank, a fuel pump, and the like. Thermal energy obtained by combustion in the processing device 2 is converted into rotational motion and output to the generator 4 connected via the output shaft 2a. As a result, the generator 4 rotates to generate power.

The power conditioner 5 includes an inverter and the like, converts the power generated by the generator 4 into alternating current of an appropriate frequency, and supplies the alternating current to each part of the N ₂ O processing system 100 . When the power generated by the generator 4 is surplus, the power conditioner 5 supplies (sells) the generated power to the commercial power system, and when the power is insufficient, the power from the commercial power system is supplied. Supplied to each part of the N ₂ O treatment system 100 (power purchase).

The cultivation facility 1 is configured as, for example, a greenhouse in which fertilized soil 10 for cultivating crops is covered with a framework such as a pipe material and a vinyl sheet to form a cultivation space 1a. The cultivation facility 1 may be configured as an indoor facility in which the fertilized soil 10 is laid on the floor surface, or may be configured as a facility in which planters containing the fertilized soil 10 are arranged.

The cultivation facility 1 is connected with a pipe 11 that communicates the cultivation space 1a and the outside space, and outside air is taken into the cultivation space 1a through the pipe 11 . A heat exchanger 6 and an intake fan 7 are provided in the pipe 11 . The outside air taken from the outside space by the intake fan 7 and heated by the heat exchanger 6 is taken into the cultivation space 1a through the pipe 11, thereby maintaining the cultivation space 1a within a temperature range suitable for growing crops. drool. The power generated by the generator 4 is supplied to the intake fan 7 .

In the cultivation space 1a of the cultivation facility 1, an intake pipe 12 connected to the intake side of the processing device 2 extends along the surface 10a of the fertilized soil 10 so as to be substantially parallel. More specifically, the intake pipe 12 avoids the crops, for example, in a mesh shape so as to cover the entire floor surface on which the fertilized soil 10 is laid, or branched into a plurality of pipes, and extends over the entire cultivation space 1a. stretched horizontally.

The intake pipe 12 is provided with a plurality of openings 12a facing the fertilized soil 10, and through the openings 12a, flow paths 12b are formed through which N ₂ O released from the fertilized soil 10 passes. The intake pipe 12 is arranged near the surface 10a of the fertilized soil 10, at a distance (for example, about several centimeters) from the surface 10a of the fertilized soil 10 to the extent that foreign matter such as soil does not block the opening 12a.

The inside air of the cultivation space 1 a is sucked into the processing device 2 through the suction pipe 12 as the processing device 2 operates. In particular, since N ₂ O released from the fertilized soil 10 is heavier than air (nitrogen, oxygen, etc.), it efficiently enters the flow path 12b of the intake pipe 12 through the opening 12a near the surface 10a of the fertilized soil 10. It is taken in and sucked into the processing device 2 via the flow path 12b. The intake pipe 12 is provided with an intake concentration sensor 20 that detects the N ₂ O concentration Cin of the inside air of the cultivation facility 1 that is sucked into the processing device 2 .

The processing device 2 mixes the inside air of the cultivation facility 1 sucked through the intake pipe 12 with the fuel supplied by the fuel supply unit 3, and combusts the air-fuel mixture (combustion treatment). In the combustion treatment in the treatment device 2 , N ₂ O is treated by decomposing into nitrogen and oxygen at a high temperature due to the combustion reaction, and the oxygen generated by the decomposition reaction promotes the combustion reaction in the treatment device 2 . Exhaust from the processing device 2 is discharged through an exhaust pipe 21 .

The exhaust pipe 21 has a pipe 21a whose one end is connected to the exhaust side of the processing apparatus 2, a pipe 21b whose one end is open to the water of the water storage tank 8, and a pipe 21c whose one end is connected to the pipe 21b. , and the other ends of the pipes 21a to 21c are connected to the three-way valves 22, respectively. A heat exchanger 6 is provided in the pipe 21c.

When the three-way valve 22 is switched to connect the pipes 21a and 21b, the exhaust gas from the processing device 2 does not pass through the heat exchanger 6 and flows to the pipe 21b. On the other hand, when the three-way valve 22 is switched to connect the pipes 21a and 21c, the exhaust gas from the processing device 2 passes through the heat exchanger 6 and flows to the pipe 21b. In this case, in the heat exchanger 6 , the outside air taken into the pipe 11 by the intake fan 7 is heated by the high-temperature exhaust air from the processing device 2 . For example, by switching the three-way valve 22 according to the outside temperature and switching between heating and non-heating of the outside air taken into the cultivation space 1a of the cultivation facility 1 through the pipe 11, the cultivation space 1a is made suitable for growing crops. It can be kept within the temperature range.

When the exhaust gas from the processing device 2 is introduced into the water of the water storage tank 8 through the exhaust pipe 21 (pipe 21b), the carbon dioxide in the exhaust gas is dissolved in the water, and the exhaust gas with a reduced carbon dioxide concentration flows into the water storage tank 8. gather in the upper space 8a of the . The water storage tank 8 is connected to a pipe 23 that communicates the upper space 8a with the external space, and exhaust air from the upper space 8a is guided to the external space via the pipe 23 and released into the atmosphere. The pipe 23 is provided with an exhaust concentration sensor 24 that detects the N ₂ O concentration Cex of the exhaust discharged into the atmosphere.

The cultivation space 1 a of the cultivation facility 1 is further provided with a water sprinkler 13 to which power generated by the generator 4 is supplied and a lighting 14 . The watering device 13 waters the cultivation space 1a with water stored in the water storage tank 8, in which carbon dioxide contained in the exhaust gas from the processing device 2 is dissolved. As a result, the crops in the cultivation space 1a are watered, and the carbon dioxide concentration in the cultivation space 1a is increased. The crops in the cultivation space 1a undergo photosynthesis by being irradiated with sunlight or light from the lighting 14, thereby absorbing carbon dioxide in the cultivation space 1a and utilizing it for growing the crops.

FIG. 2 is a block diagram schematically showing an example of the peripheral configuration of the controller 50 that controls the fuel supply section 3. As shown in FIG. As shown in FIG. 2, the controller 50 includes a computer having an arithmetic section 51 such as a CPU, a storage section 52 such as ROM and RAM, and other peripheral circuits. The controller 50 is connected to the intake concentration sensor 20 , the exhaust concentration sensor 24 and the fuel supply section 3 .

The controller 50 controls the fuel supply section 3 based on the N ₂ O concentration Cin detected by the intake air concentration sensor 20 and the N ₂ O concentration Cex detected by the exhaust concentration sensor 24 . More specifically, the amount of fuel to be supplied to the processing device 2 is calculated according to, for example, a predetermined characteristic so that N ₂ O is completely decomposed by the combustion processing in the processing device 2, and according to the calculation result, It controls the fuel supply unit 3 . That is, based on the difference between the N ₂ O concentration Cin detected by the intake concentration sensor 20 and the N ₂ O concentration Cex detected by the exhaust concentration sensor 24, the amount of oxygen produced by decomposition of N ₂ O is calculated. Taking into account the amount of oxygen, the amount of fuel supply is calculated according to predetermined characteristics.

According to this embodiment, the following effects can be obtained.
(1) The N ₂ O treatment system 100 is substantially parallel along the surface 10a of the fertilized soil 10 in the cultivation space 1a and the cultivation facility 1 forming the cultivation space 1a for cultivating crops with the fertilized soil 10 containing nitrogen. an intake pipe 12 extending to the fertilized soil 10 and provided with an opening 12a facing the fertilized soil 10 and forming a flow path 12b through which the N ₂ O released from the fertilized soil 10 passes through; A treatment device 2 connected to the pipe 12 and sucking and treating the N ₂ O guided through the flow path 12b is provided (FIG. 1). By providing the opening 12a facing the fertilized soil 10 of the cultivation facility 1, N ₂ O released from the fertilized soil 10, which is heavier than air, can be efficiently collected and treated. In addition, by recovering in the cultivation space 1a of the cultivation facility 1 such as a greenhouse, diffusion of N 2 O to the outside space can be suppressed and the N ₂ O can be efficiently recovered.

(2) The N ₂ O treatment system 100 includes a water storage tank 8 , an exhaust pipe 21 having one end connected to the exhaust side of the treatment device 2 and the other end open to the water of the water storage tank 8 , and the water stored in the water storage tank 8 . and a sprinkler device 13 for sprinkling water in the cultivation space 1a (FIG. 1). As a result, the carbon dioxide generated with the treatment of N ₂ O can be efficiently recovered and used for growing crops.

(3) The N ₂ O treatment system 100 includes a pipe 11 that communicates between the cultivation space 1a and the external space, an intake fan 7 that is provided in the pipe 11 and takes in the outside air from the external space into the cultivation space 1a, and the pipe 11. A heat exchanger 6 heats the outside air taken in by the intake fan 7 with the exhaust air from the processing device 2 (FIG. 1). Thereby, the cultivation space 1a can be maintained in a temperature range suitable for growing agricultural products.

(4) The N ₂ O treatment system 100 includes an intake air concentration sensor 20 that detects the N ₂ O concentration of the intake air to the treatment device 2 and an exhaust concentration sensor 24 that detects the N ₂ O concentration of the exhaust air from the treatment device 2. , a fuel supply unit 3 for supplying fuel to the processing device 2, and a controller 50 for controlling the fuel supply unit 3 (FIG. 1). The processing device 2 mixes the N ₂ O sucked through the flow path 12b and the fuel supplied from the fuel supply unit 3, and burns them. The controller 50 controls the fuel supply section 3 based on the N ₂ O concentration detected by the intake air concentration sensor 20 and the N ₂ O concentration detected by the exhaust concentration sensor 24 . For example, the amount of fuel to be supplied to the processing device 2 is calculated accurately according to a predetermined characteristic, and the fuel supply unit 3 is configured so that N ₂ O is completely decomposed by the combustion processing in the processing device 2 according to the calculation result. can be properly controlled.

(5) The processing device 2 is a reciprocating engine. As a result, N ₂ O in the cultivation facility 1 can be treated, and the cultivation facility 1 can be ventilated and illuminated using electric power generated by thermal energy obtained by combustion.

In the above-described embodiment, a specific example of the cultivation facility 1 is shown in FIG. 1 and the like. Anything is fine. In the above-described embodiment, the tubular intake pipe 12 is illustrated in _FIG . do not have. For example, it may be a box-shaped one that entirely covers the fertilized soil, or a combination of these that entirely covers the fertilized soil. In the above embodiment, a specific example of the water sprinkler 13 is shown in FIG. 1 and the like. In addition to being provided on the wall, it may be provided on a wall surface or a floor surface.

The above description is merely an example, and the present invention is not limited by the above-described embodiments and modifications as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and it is also possible to combine modifications with each other.

1 cultivation facility, 1a cultivation space, 2 processing device, 3 fuel supply unit, 6 heat exchanger, 7 intake fan, 8 water storage tank, 10 fertilized soil, 11, 21a to 21c, 23 piping, 12 intake pipe, 12a opening, 12b flow path, 13 sprinkler device, 14 lighting, 20 intake air concentration sensor, 21 exhaust pipe, 22 three-way valve, 24 exhaust concentration sensor, 50 controller, 100 N ₂ O treatment system

Claims (5)

a cultivation facility forming a cultivation space for cultivating crops in nitrogen-containing soil;
A channel that extends substantially parallel along the surface of the soil in the cultivation space and has an opening facing the soil, through which the N ₂ O released from the soil passes. a flow path forming portion that forms a
an N ₂ O treatment system, comprising: a treatment device connected to the flow path forming portion and sucking and treating the N ₂ O guided through the flow path. In the N ₂ O treatment system of claim 1,
a water storage tank;
an exhaust pipe having one end connected to the exhaust side of the processing equipment and the other end open to the water of the water storage tank;
The N ₂ O treatment system, further comprising: a sprinkler for sprinkling the water stored in the water storage tank in the cultivation space. In the N ₂ O treatment system according to claim 1 or 2,
a pipe that communicates between the cultivation space and the external space;
an intake fan provided in the pipe and taking in outside air from the external space to the cultivation space;
The N ₂ O treatment system, further comprising: a heat exchanger that is provided in the pipe and heats the outside air taken in by the intake fan with exhaust air from the treatment device. In the N ₂ O treatment system according to any one of claims 1 to 3,
an intake air concentration sensor for detecting the N ₂ O concentration of the intake air to the processing device;
an exhaust gas concentration sensor that detects the N ₂ O concentration of the exhaust gas from the processing equipment;
a fuel supply unit that supplies fuel to the processing device;
A control unit that controls the fuel supply unit,
The processing device mixes and burns the N ₂ O sucked through the flow path and the fuel supplied from the fuel supply unit,
The control unit controls the _fuel supply unit based on the N ₂ O concentration detected by the intake air concentration sensor and the N ₂ O concentration detected by the exhaust gas concentration sensor. processing system. In the N ₂ O treatment system according to any one of claims 1 to 4,
The _N2O treatment system, wherein the treatment device is a reciprocating engine.

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