JP2008237115A - Carbon dioxide generator and cultivation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon dioxide generator capable of easily controlling an emission amount of carbon dioxide from a carbon dioxide-emitting substance which is produced by making an absorption material absorb carbon dioxide, and rapidly increasing and reducing an emission amount of carbon dioxide. <P>SOLUTION: This carbon dioxide generator has a reactor which has a gas introducing pipe for introducing gas and carrier gas containing carbon dioxide in a switchable manner, and a gas discharging pipe, and which is filled with a carbon dioxide-absorbing material containing lithium complex oxide in the inside, and a heater for heating a carbon dioxide-emitting substance which is produced by making carbon dioxide react on the carbon dioxide-absorbing material in the reactor. Furthermore, the generator has a water vapor feeding means for supplying water vapor to the carbon dioxide-absorbing material in the reactor, and a control means for performing adjustment of a supply amount of water vapor from the water vapor feeding means to the reactor and intermittent supply. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a carbon dioxide generator and a cultivation system.

As a method for separating carbon dioxide (CO ₂ ) gas in high-temperature exhaust gas from energy plants and chemical plants that use hydrocarbon-based fuels, carbon dioxide absorbers containing lithium composite oxides such as lithium silicate are known. (Patent Document 1). Patent Document 1 describes that when releasing carbon dioxide absorbed by the absorbent, the absorbent is heated at a temperature higher than the temperature at the time of carbon dioxide absorption. However, in the method of releasing carbon dioxide by adjusting the temperature from the absorbent material that has absorbed carbon dioxide, it is difficult to increase or decrease the release rate of carbon dioxide in response to temperature rise and heating stop, and followability Inferior to this, causing a time delay. In addition, since the carbon dioxide release rate cannot be increased rapidly, it is substantially difficult to release a large amount of carbon dioxide.

  On the other hand, in facilities that require carbon dioxide, for example, cultivation facilities, carbon dioxide, which is one of the raw materials for photosynthesis, is supplied into the greenhouse to increase the productivity of agricultural products. For example, Patent Document 2 discloses a waste heat recovery combined carbon dioxide supply system that uses carbon dioxide and waste heat in combustion exhaust gas discharged from a greenhouse heater.

  In the invention of Patent Document 2, since the supply of carbon dioxide into the greenhouse is only during the operation of the heater, the heater is not operated, for example, in the daytime when the greenhouse is heated by sunlight, Can not be supplied to.

For this reason, a combustion apparatus such as a boiler dedicated to carbon dioxide generation is placed in the cultivation facility only for the purpose of supplying carbon dioxide, and carbon dioxide is constantly supplied into the greenhouse. However, the installation of such a dedicated boiler for generating carbon dioxide consumes wasteful fuel and is not economical.
JP 2000-262890 A JP 2004-344154

  The present invention is easy to control the amount of carbon dioxide released from a carbon dioxide-releasing substance produced by absorbing carbon dioxide in an absorbent material, and can quickly increase and decrease the amount of carbon dioxide released. An object is to provide a generator.

  The present invention is easy to control the amount of carbon dioxide released from a carbon dioxide-releasing substance produced by absorbing carbon dioxide in an absorbent material, and can quickly increase and decrease the amount of carbon dioxide released. Necessary for photosynthesis of agricultural products in the greenhouse when it is necessary to heat the interior of the greenhouse with a generator, for example, by operating the combustion device at night, and absorbing the carbon dioxide in the combustion exhaust gas with the carbon dioxide generator An object of the present invention is to provide a cultivation system capable of supplying carbon dioxide from the generator to a greenhouse at a desired amount and speed during a daytime.

According to the first aspect of the present invention, there is provided a carbon dioxide absorbent having a gas introduction pipe and a gas discharge pipe into which a gas containing carbon dioxide and a carrier gas are introduced in a switchable manner, and containing a lithium composite oxide therein. A filled reactor;
A heater for heating a carbon dioxide-releasing substance generated by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
Water vapor supply means for supplying water vapor to the carbon dioxide-releasing substance in the reactor;
There is provided a carbon dioxide generator comprising a control means for adjusting the supply amount of water vapor from the water vapor supply means into the reactor and performing intermittent supply.

According to the second aspect of the present invention, there is provided a carbon dioxide absorbent having a gas introduction pipe and a gas discharge pipe into which a gas containing carbon dioxide and a carrier gas are introduced in a switchable manner, and containing a lithium composite oxide therein. A filled reactor;
A heater for heating a carbon dioxide-releasing substance generated by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
Water injection means for injecting water into the carbon dioxide-releasing substance in the reactor;
There is provided a carbon dioxide generator comprising a control means for adjusting the amount of water injected into the reactor from the water injection means and intermittent injection.

According to a third aspect of the present invention, a greenhouse for growing agricultural products;
A combustion apparatus for heating the greenhouse; and (a) a gas introduction pipe into which the exhaust gas and carrier gas of the combustion apparatus are introduced in a switchable manner and a gas discharge pipe connected to the house; A reactor filled with a carbon dioxide absorbent containing a composite oxide;
(B) a heater for heating the carbon dioxide-releasing substance produced by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
(C) water vapor supply means for supplying water vapor to the carbon dioxide-releasing material in the reactor;
(D) a carbon dioxide generator having a control means for adjusting and intermittently supplying the amount of steam supplied from the steam supply means into the reactor;
A cultivation system characterized by comprising: is provided.

According to a fourth aspect of the present invention, a greenhouse for growing agricultural products;
A combustion apparatus for heating the greenhouse; and (a) a gas introduction pipe into which the exhaust gas and carrier gas of the combustion apparatus are introduced in a switchable manner and a gas discharge pipe connected to the house; A reactor filled with a carbon dioxide absorbent containing a composite oxide;
(B) a heater for heating the carbon dioxide-releasing substance produced by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
(C) water injection means for injecting water into the carbon dioxide-releasing substance in the reactor;
(D) a carbon dioxide generator having control means for adjusting and intermittently injecting water into the reactor from the water injection means;
A cultivation system characterized by comprising: is provided.

  According to the present invention, it is easy to control the amount of carbon dioxide released from a carbon dioxide-releasing substance generated by absorbing carbon dioxide in an absorbent material, and it is possible to quickly increase and decrease the amount of carbon dioxide released. A carbon dioxide generator can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the cultivation system which can perform the photosynthesis of the agricultural product in a greenhouse appropriately, and can increase the growth, without consuming fuel wastefully can be provided.

  Hereinafter, a carbon dioxide generator and a cultivation system concerning an embodiment of the present invention are explained in detail with reference to drawings.

(First embodiment)
FIG. 1 is a schematic view showing a carbon dioxide generator according to the first embodiment.

  The carbon dioxide generator 1 includes a reactor 3 in which a carbon dioxide absorbent 2 containing a lithium composite oxide is filled. The heater 4 is disposed on the outer periphery of the reactor 3 and heats the reactor 3 to a target temperature. A gas containing carbon dioxide, for example, a combustion exhaust gas introduction line L1 and a carrier gas introduction line L2 are connected to a main introduction line L3 through a three-way electromagnetic valve SV, and the main introduction line L3 is connected to an upper portion of the reactor 3. That is, the combustion exhaust gas and the carrier gas introduced into the introduction lines L1 and L2 are introduced into the reactor 3 through the main introduction line L3 so as to be switched by the three-way electromagnetic valve SV. As the carrier gas, for example, air, nitrogen gas or the like can be used. The first opening / closing valve V1 is interposed in the introduction line L1. The second opening / closing valve V1 and the first mass flow controller MF1 are interposed in this order from the carrier gas introduction source (not shown) side in the introduction line L2.

  The steam generator 5 is connected to the main introduction line L3 through the steam supply line L4. The third on-off valve V3 and the second mass flow controller MF2 are interposed in this order from the steam generator 5 side in the steam supply line L4. The third on-off valve V3 intermittently supplies (supplies and stops) the steam from the steam generator 5 to the reactor 3, and the second mass flow controller MF2 adjusts the amount of steam supplied from the steam generator 5 to the reactor 3. It is used as a control means for The discharge line L5 is connected to the lower part of the reactor 3.

Examples of the lithium composite oxide include lithium silicate and lithium zirconate. These lithium composite oxides can be used alone or in the form of a mixture. For example, in lithium silicate (Li ₄ SiO ₄ ), as shown in the following formula (1), it reacts with carbon dioxide to produce a mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ which are carbon dioxide releasing substances.

Li ₄ SiO ₄ + CO ₂ → Li ₂ SiO ₃ + Li ₂ CO ₃ (1)
The carbon dioxide absorbent permits to contain an alkali carbonate such as potassium carbonate or sodium carbonate in addition to the lithium composite oxide.

  The carbon dioxide absorbent is filled in the reactor in various forms such as powder, granules, and pellets.

  Hereinafter, the operation of the carbon dioxide generator according to the first embodiment will be described with reference to FIG.

If necessary, the reactor 3 is heated to a temperature of, for example, about 200 to 300 ° C. by the heater 4, and the first on-off valve V1 is opened to convert the combustion exhaust gas containing carbon dioxide into the combustion exhaust gas introduction line L1 and the main introduction line. It introduce | transduces in the reactor 3 through L3. At this time, the carbon dioxide in the combustion exhaust gas reacts with the carbon dioxide absorbent 2 made of, for example, lithium silicate filled in the reactor 3 according to the above formula (1) to absorb the carbon dioxide and release carbon dioxide. A mixture of the materials Li ₂ SiO ₃ and Li ₂ CO ₃ is produced. In the process of flowing through the reactor 3, the combustion exhaust gas is sufficiently reduced in carbon dioxide concentration therein, and is then discharged out of the system through the discharge line L <b> 5.

When the carbon dioxide absorption reaction of the formula (1) sufficiently proceeds, the introduction line L1 is switched to the carrier gas introduction line L2 by the three-way electromagnetic valve SV. The second on-off valve V2 interposed in the introduction line L2 is opened, and a carrier gas (for example, air) is introduced into the reactor 3 through the introduction line L2 and the main introduction line L3, and the air flow rate is changed by the first mass flow controller MF1. Adjust. At this time, by heating the reactor 3 to a temperature higher than the carbon dioxide absorption reaction temperature, for example, 600 to 700 ° C., by the heater 4, the mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ , which are carbon dioxide-releasing substances. A part of the reaction proceeds from the right side to the left side of the formula (1) to generate carbon dioxide, and lithium silicate (absorbent) is generated and regenerated. The air containing carbon dioxide is supplied to the carbon dioxide demand facility through the discharge line L5.

In the heating of the reactor 3 and the introduction of the carrier gas, the third on-off valve V3 interposed in the water vapor supply line L4 is opened, and the main introduction line L3 through which air flows through the water vapor of the water vapor generator 5 through the supply line L4. , And by adjusting the water vapor flow rate with the second mass flow controller MF2, air containing a desired amount of water vapor is introduced into the reactor 3 from the main introduction line L3. By introducing such water vapor into the reactor ₃ , the mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ which are carbon dioxide releasing materials in the reactor 3 reacts from the right side to the left side in the formula (1). Is quickly generated, and a large amount of carbon dioxide is generated, and air containing extremely high concentration of carbon dioxide is supplied to the carbon dioxide demand facility through the discharge line L5. By increasing the supply amount of water vapor to the main introduction line L3 through which air flows by adjusting the second mass flow controller MF2, the CO ₂ emission amount from the carbon dioxide-releasing substance further increases. Further, by closing the third on-off valve V3 and stopping the supply of the steam to the main introduction line L3, that is, the supply of the steam to the reactor 3 is stopped, the reaction from the right side to the left side of the formula (1). As a result, the amount of carbon dioxide released is rapidly reduced.

In fact, according to the following experimental example and comparative experimental example, the carbon dioxide generating apparatus according to the first embodiment is carbon dioxide from a mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ , which are carbon dioxide releasing substances by conventional temperature control. Compared with the generation of CO2, it was confirmed that the generation of a large amount of carbon dioxide and the rapid decrease of carbon dioxide can be achieved.

(Experimental example 1)
A silicon oxide powder having an average particle diameter of 1 μm and a lithium carbonate powder having an average particle diameter of 1 μm were mixed at a molar ratio of 1: 2, and a molded body having a thickness of 2 mm and a diameter of 5 mm was obtained by extrusion molding. This molded body was fired at 800 ° C. in the atmosphere to produce a pellet-like carbon dioxide absorbent material made of lithium silicate having a thickness of about 2 mm and a diameter of about 5 mm.

  30 mg of the obtained pellet-shaped carbon dioxide absorbent was placed on a platinum dish, and this platinum dish was supported on a balance member of a thermogravimetric measuring apparatus (trade name: TG-DTA2000S, manufactured by Bruker AXS Co., Ltd.). Inserted into. The inside of the heating furnace was made a 100% carbon dioxide atmosphere, heated to 600 ° C., and the temperature was maintained for 1 hour. The weight (W1) of the carbon dioxide releasing substance produced | generated when the absorber (lithium silicate) absorbed the carbon dioxide was measured with the balance member.

  Next, carbon dioxide was switched to 100% nitrogen gas while maintaining the temperature in the heating furnace at 600 ° C., and carbon dioxide was released from the carbon dioxide-releasing substance. On the way, the supply and stop of water vapor into the heating furnace were performed three times in total. The first and third supply of water vapor was performed so that the water vapor concentration in the heating furnace was 25% by volume, and the second supply of water vapor was 50% by volume in the heating furnace. The supply of water vapor was performed for about 2 minutes. The weight (W2) of the carbon dioxide-releasing substance in the process of releasing carbon dioxide was measured with a balance member.

  The amount of carbon dioxide released was calculated based on the weight (W1) of the carbon dioxide-releasing substance immediately after absorption of carbon dioxide and the weight (W2) in the process of releasing carbon dioxide from the carbon dioxide-releasing substance. The result is shown in FIG.

(Comparative Experimental Example 1)
30 mg of a pellet-like carbon dioxide absorbent similar to that in Experimental Example 1 was placed on a platinum dish, and this platinum dish was supported by a balance member of a thermogravimetric measuring apparatus similar to that in Experimental Example 1 and inserted into a heating furnace. The inside of the heating furnace was made a 100% carbon dioxide atmosphere, heated to 600 ° C., and the temperature was maintained for 1 hour. The weight (W1) of the carbon dioxide releasing substance produced | generated when the absorber (lithium silicate) absorbed the carbon dioxide was measured with the balance member.

  Next, carbon dioxide was switched to 100% nitrogen gas while maintaining the temperature in the heating furnace at 600 ° C., and carbon dioxide was released from the carbon dioxide-releasing substance. A temperature control is performed in which the temperature in the heating furnace is raised and raised to 620 ° C. in about 3 minutes, then lowered to 600 ° C., and the temperature in the heating furnace is raised again to about 650 ° C. in about 3 minutes. went. The weight (W2) of the carbon dioxide-releasing substance in the process of releasing carbon dioxide was measured with a balance member.

  The amount of carbon dioxide released was calculated based on the weight (W1) of the carbon dioxide-releasing substance immediately after absorption of carbon dioxide and the weight (W2) of the carbon dioxide-releasing substance in the process of releasing carbon dioxide. The result is shown in FIG.

  As is apparent from FIG. 2, in Experimental Example 1, it can be seen that the amount of carbon dioxide released increases rapidly in response to the supply of water vapor, and the amount of carbon dioxide released decreases rapidly by stopping the supply of water vapor. It can also be seen that the amount of carbon dioxide released is further increased by increasing the supply of water vapor (for example, from 25 vol% to 50 vol%). Therefore, it can be seen that a large amount of carbon dioxide and rapid carbon dioxide can be released by adjusting the supply amount of water vapor.

  On the other hand, in the comparative experimental example 1 in which the temperature control is performed, as is apparent from FIG. 3, the carbon dioxide emission amount increases as the temperature is increased, but the carbon dioxide emission amount is larger than that in the experimental example 1 in which water vapor is supplied. It can be seen that the increase in carbon dioxide is low and the increase in carbon dioxide emission is slow. In addition, it can be seen that the decrease in carbon dioxide emission when the temperature is lowered is slow and slow. Therefore, it can be seen that a large amount of carbon dioxide release and rapid carbon dioxide release cannot be expected by temperature control.

  As described above, according to the carbon dioxide generator 1 according to the first embodiment, when air containing carbon dioxide is supplied to the carbon dioxide demand facility through the discharge line L5, the carbon dioxide from the carbon dioxide releasing substance in the reactor 3 is supplied. Emissions can be easily controlled, and carbon dioxide emissions can be increased and decreased quickly, enabling smooth supply of air containing carbon dioxide at a concentration that meets the demands of carbon dioxide demand facilities. become.

(Second Embodiment)
FIG. 4 is a schematic view showing a carbon dioxide generator according to the second embodiment. In FIG. 4, the same members as those in FIG.

  In the carbon dioxide generator 1 according to the second embodiment shown in FIG. 4, a water supply source 6 is connected to an injection nozzle 7 above the reactor 3 through a water supply line L6. The fourth on-off valve V4, the third mass flow controller MF3, and the pump P are interposed in this order from the water supply source 6 side in the water supply line L6.

  Hereinafter, the operation of the carbon dioxide generator according to the second embodiment will be described with reference to FIG.

In a state where the reactor 3 is heated to a temperature of, for example, about 200 to 300 ° C. by the heater 4, the first on-off valve V1 is opened and the combustion exhaust gas containing carbon dioxide is passed through the combustion exhaust gas introduction line L1 and the main introduction line L3. Introduce in. At this time, the carbon dioxide in the combustion exhaust gas reacts with the carbon dioxide absorbent 2 made of, for example, lithium silicate filled in the reactor 3 according to the above formula (1) to absorb the carbon dioxide and release carbon dioxide. A mixture of the materials Li ₂ SiO ₃ and Li ₂ CO ₃ is produced. In the process of flowing through the reactor 3, the combustion exhaust gas is sufficiently reduced in carbon dioxide concentration therein, and is then discharged out of the system through the discharge line L <b> 5.

When the absorption reaction of carbon dioxide of Formula (1) sufficiently proceeds, the introduction line L1 is switched to the carrier gas introduction line L2 by the three-way electromagnetic valve SV. The second on-off valve V2 interposed in the introduction line L2 is opened, and a carrier gas (for example, air) is introduced into the reactor 3 through the introduction line L2 and the main introduction line L3, and the air flow rate is changed by the first mass flow controller MF1. Adjust. At this time, by heating the reactor 3 to a temperature higher than the carbon dioxide absorption reaction temperature, for example, 600 to 700 ° C., by the heater 4, the mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ , which are carbon dioxide-releasing substances. A part of the reaction proceeds from the right side to the left side of the formula (1) to generate carbon dioxide, and lithium silicate (absorbent) is generated and regenerated. The air containing carbon dioxide is supplied to the carbon dioxide demand facility through the discharge line L5.

In the heating of the reactor 3 and the introduction of the carrier gas, the fourth open / close valve V4 interposed in the water supply line L6 is opened and the pump P is operated to inject water from the water supply source 6 through the water supply line L6. A desired amount of water is injected from the nozzle 7 onto the carbon dioxide-releasing substance in the reactor 3. The flow rate of the water flowing through the water supply line L6 is adjusted by the third mass flow controller MF3. By such injection of water onto the carbon dioxide-releasing substance in the reactor 3, substantially the same action as the water vapor supply of the first embodiment described above, that is, Li ₂ SiO ₃ and Li which are carbon dioxide-releasing substances. The reaction of the mixture of ₂ CO ₃ from the right side to the left side of the formula (1) is rapidly performed to generate a large amount of carbon dioxide, and is supplied to the carbon dioxide demand facility through the discharge line L5 together with air as the carrier gas. . The amount of carbon dioxide released is further increased by increasing the amount of water injected to the carbon dioxide-releasing substance in the reactor 3 by adjusting the third mass flow controller MF3. Further, by stopping the water injection into the reactor 3 by stopping the operation of the pump P and closing the fourth on-off valve V4, the reaction from the right side to the left side of the equation (1) can be suppressed. The amount released is rapidly reduced.

  Therefore, according to the carbon dioxide generator 1 according to the second embodiment, when air containing carbon dioxide is supplied to the carbon dioxide demand facility through the discharge line L5, the carbon dioxide from the carbon dioxide releasing substance in the reactor 3 is supplied. Emissions can be easily controlled, and carbon dioxide emissions can be increased and decreased quickly, enabling smooth supply of air containing carbon dioxide at a concentration that meets the demands of carbon dioxide demand facilities. become.

(Third embodiment)
FIG. 5 is a schematic diagram showing a cultivation system according to the third embodiment.

  In a greenhouse 11 for cultivating agricultural products such as vegetables, fruits and flowers, a combustion device 21 for heating the greenhouse 11 and a carbon dioxide generator 1 having the same structure as that of the first embodiment are arranged adjacent to each other. ing.

  The combustion device 21 includes a housing 22 in which a combustion burner (not shown) is built. The fuel introduction line L11 is connected to the combustion burner in the housing 22. The heat exchange gas line L <b> 12 is arranged meandering above the combustion burner in the housing 22. One end of the heat exchange gas line L <b> 12 is connected to the air intake port 23 of the housing 22, and the other end extends from the housing 22 to the outside and is connected to the greenhouse 11. The blower 24 is interposed in the heat exchange gas line L12. The combustion exhaust gas generated in the housing 22 is connected to the three-way electromagnetic valve SV of the carbon dioxide generator 1 through the combustion exhaust gas introduction line L1.

  The discharge line (first discharge line) L5 of the carbon dioxide generator 1 is for discharging the gas in the reactor 3 to the outside, and an open / close valve V5 is interposed. The second discharge line L6 is branched at a position between the reactor 3 of the first discharge line L5 and the open / close valve V5, and the other end is connected to the greenhouse 11. An opening / closing valve V6 is interposed in the second discharge line L6. The carbon dioxide generator 1 is a reactor 3 filled with a sufficient amount of carbon dioxide absorbent 2 to absorb and remove carbon dioxide generated by combustion when the greenhouse 11 is heated by a combustion device 21 described later. Is provided.

  Hereinafter, the operation of the cultivation system according to the third embodiment will be described with reference to FIG.

  It is necessary to raise the temperature in the greenhouse 11, for example, from night to morning, fuel is supplied to the combustion burner (not shown) of the combustion device 21 through the fuel introduction line L11 and burned. At this time, by operating the blower 24 and taking air from the air intake port 23 of the housing 22 into the heat exchange gas line L12 meandering above the combustion burner in the housing 22, The air that is taken in and circulated into the gas line L12 is heated by the combustion flame of the combustion burner. The heated air is supplied into the greenhouse 11 through the heat exchange gas line L12 to heat the greenhouse.

In the combustion of the combustion device 21 for heating the inside of the greenhouse 11, the reactor 3 is heated to a temperature of, for example, about 200 to 300 ° C. by the heater 4 of the carbon dioxide generator 1, and the combustion exhaust gas introduction line L1 and The valves V1 and V5 of the first discharge line L5 are opened, and the combustion exhaust gas generated in the casing 22 of the combustion device 21 is introduced into the reactor 3 from the introduction line L1 through the three-way electromagnetic valve SV and the main introduction line L3. While combustion exhaust gas is generated in the housing 22, carbon dioxide in the combustion exhaust gas reacts with the carbon dioxide absorbent 2 made of, for example, lithium silicate filled in the reactor 3 according to the above formula (1), and carbon dioxide is While being absorbed, a mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ , which are carbon dioxide releasing substances, is produced. In the process of flowing through the reactor 3, the combustion exhaust gas is sufficiently reduced in carbon dioxide concentration therein, and then discharged to the outside through the first discharge line L <b> 5.

  When the heating of the greenhouse 11 becomes unnecessary, the combustion in the combustion device 21 is stopped, the valves V1 and V5 of the combustion exhaust gas introduction line L1 and the first exhaust line L5 are closed, and the reactor 3 is heated by the heater 4 Also stop.

On the other hand, the photosynthesis of agricultural products in the greenhouse 11 is thriving, for example, in a clear daytime, the three-way electromagnetic valve SV is used to switch from the introduction line L1 to the carrier gas introduction line L2. The second opening / closing valve V2 and the opening / closing valve V6 of the second discharge line L6 interposed in the introduction line L2 are opened, and the opening / closing valve V5 of the first discharge line L5 is closed. A carrier gas (for example, air) is introduced into the reactor 3 through the introduction line L2 and the main introduction line L3, and the air flow rate is adjusted by the first mass flow controller MF1. At this time, by heating the reactor 3 to a temperature higher than the carbon dioxide absorption reaction temperature, for example, 600 to 700 ° C., by the heater 4, the mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ , which are carbon dioxide-releasing substances. A part of the reaction proceeds from the right side to the left side of the formula (1) to generate carbon dioxide and to regenerate by generating lithium silicate (absorbent). The air containing carbon dioxide is supplied into the greenhouse 11 through the first discharge line L5 and the second discharge line L6 branched therefrom, and the carbon dioxide is consumed for photosynthesis of agricultural products.

When the required consumption of carbon dioxide in the greenhouse 11 increases, for example, in the increase in photosynthesis of agricultural products, the third open / close valve V3 interposed in the steam supply line L4 is opened, and the steam from the steam generator 5 is supplied to the supply line L4. Is supplied to the main introduction line L3 through which air flows, and the water flow rate is adjusted by the second mass flow controller MF2, thereby introducing air containing a desired amount of water vapor into the reactor 3 from the main introduction line L3. By introducing such steam into the reactor 3, the same action as the steam supply in Experimental Example 1 described above, that is, a mixture of Li ₂ SiO ₃ and Li ₂ CO ₃ which are carbon dioxide releasing substances in the reactor 3. The reaction from the right side to the left side of the formula (1) is rapidly performed to generate a large amount of carbon dioxide, and the air containing an extremely high concentration of carbon dioxide is branched into the first discharge line L5 and the second discharge line. It becomes possible to supply into the greenhouse 11 through L6. As a result, carbon dioxide commensurate with the required consumption can be quickly supplied into the greenhouse 11 from the first emission line L5 and the second emission line L6 branched therefrom. Further, when the required consumption of carbon dioxide further increases, the amount of water vapor supplied to the main introduction line L3 through which the air flows is adjusted by adjusting the second mass flow controller MF2, thereby increasing the amount of carbon dioxide from the carbon dioxide releasing substance. By further increasing the carbon dioxide emission amount, it becomes possible to supply air containing a higher concentration of carbon dioxide into the greenhouse 11 through the first exhaust line L5 and the second exhaust line L6 branched therefrom. For this reason, the photosynthesis of the agricultural products in the greenhouse 11 is appropriately performed, and the growth is increased.

  After the desired time has elapsed, the third on-off valve V3 of the water vapor supply line L4 is closed to stop the supply of water vapor to the main introduction line L3, that is, the supply of water vapor to the reactor 3 is stopped. The same action as the water vapor stop in FIG. 1, that is, the reaction from the right side to the left side of the formula (1) is suppressed, the amount of carbon dioxide released from the carbon dioxide-releasing substance is rapidly reduced, and unnecessary and wasteful carbon dioxide is generated. It is prevented from being supplied into the greenhouse 11 through the first discharge line L5 and the second discharge line L6 branched therefrom.

  Therefore, in the third embodiment, the inside of the greenhouse 11 is heated by the combustion device 21, for example, from night to morning, the carbon dioxide in the combustion exhaust gas generated by the combustion device 21 is charged in the reactor 3 of the carbon dioxide generator 1. It can be absorbed and stored by the carbon absorbent 2. On the other hand, when the required consumption of carbon dioxide in the greenhouse 11 increases, for example, when photosynthesis of agricultural products increases, the carbon dioxide generating device 1 quickly increases the amount of carbon dioxide released from the carbon dioxide-releasing substance in the reactor 3. Therefore, it is possible to further increase and decrease the emission amount, and therefore, the air containing carbon dioxide having a concentration corresponding to the required consumption amount of carbon dioxide in the greenhouse 11 is branched from the first exhaust line L5 and from this. It can be quickly supplied into the greenhouse 11 through the second discharge line L6. As a result, it is possible to optimize the photosynthesis of agricultural products in the greenhouse 11 and increase their growth. Further, as in the past, a combustion device such as a boiler dedicated to carbon dioxide generation is placed in the cultivation facility, and carbon dioxide is always kept in the greenhouse. It is possible to avoid wasteful fuel consumption supplied to the plant and to realize a highly economical cultivation system.

  In addition, in the supply of the carrier gas (air) containing carbon dioxide described in the third embodiment into the greenhouse, the control of the mass flow controller responsible for the opening and closing of the opening and closing valve responsible for the supply and stop of the water vapor and the adjustment of the amount of water vapor is performed. It may be performed by a predetermined timer function or intermittent supply of water vapor (supply, supply) using a carbon dioxide detector installed in a greenhouse and a controller such as a microcomputer to which this detection signal is input. The on-off valve responsible for stopping) and the mass flow controller responsible for adjusting the water vapor amount may be feedback-controlled.

  In the third embodiment, the number of reactors of the carbon dioxide generator is not limited to one, and for example, two or more reactors may be provided in parallel according to the scale of the greenhouse, the amount of combustion exhaust gas from the combustion device, and the like.

  Further, in the third embodiment, the carbon dioxide generator having the same structure as that of the first embodiment is used. However, even if a structure similar to that of the second embodiment, that is, a water injection type carbon dioxide generator is used, The cultivation system which has an effect similar to 3rd Embodiment is realizable.

Schematic which shows the carbon dioxide generator which concerns on 1st Embodiment of this invention. The characteristic view which shows the carbon dioxide emission amount at the time of supply of the water vapor | steam to the carbon dioxide releasing substance in Experimental example 1 of this invention, and a stop. The characteristic view which shows the carbon dioxide emission amount at the time of the temperature control to the carbon dioxide releasing substance in the comparative experiment example 1. Schematic which shows the carbon dioxide generator which concerns on 2nd Embodiment of this invention. Schematic which shows the cultivation system which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Carbon dioxide generator, 2 ... Carbon dioxide absorber, 3 ... Reactor, 4 ... Heater, 5 ... Steam generator, 6 ... Water supply source, 7 ... Injection nozzle, 11 ... Greenhouse, 21 ... Combustion device, 22 ... Case, 24 ... Blower, L1, L2, L3, L4, L6, L11 ... Introduction line, L5, L6 ... Exhaust line, L12 ... Heat exchange gas line, V1, V2, V3, V4, V5, V6 ... Open / close valve, SV ... three-way solenoid valve, MF1, MF2, MF3 ... mass flow controller.

Claims (4)

A reactor having a gas introduction pipe and a gas discharge pipe into which a gas containing carbon dioxide and a carrier gas are introduced in a switchable manner, and filled with a carbon dioxide absorbent containing a lithium composite oxide inside;
A heater for heating a carbon dioxide-releasing substance generated by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
Water vapor supply means for supplying water vapor to the carbon dioxide-releasing substance in the reactor;
A carbon dioxide generator comprising: control means for adjusting supply amount and intermittent supply of water vapor from the water vapor supply means into the reactor. A reactor having a gas introduction pipe and a gas discharge pipe into which a gas containing carbon dioxide and a carrier gas are introduced in a switchable manner, and filled with a carbon dioxide absorbent containing a lithium composite oxide inside;
A heater for heating a carbon dioxide-releasing substance generated by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
Water injection means for injecting water into the carbon dioxide-releasing substance in the reactor;
A carbon dioxide generator comprising: control means for adjusting and intermittently injecting water into the reactor from the water injection means. Greenhouses where agricultural products are grown;
A combustion apparatus for heating the greenhouse; and (a) a gas introduction pipe into which the exhaust gas and carrier gas of the combustion apparatus are introduced in a switchable manner and a gas discharge pipe connected to the house; A reactor filled with a carbon dioxide absorbent containing a composite oxide;
(B) a heater for heating the carbon dioxide-releasing substance produced by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
(C) water vapor supply means for supplying water vapor to the carbon dioxide-releasing material in the reactor;
(D) a carbon dioxide generator having a control means for adjusting and intermittently supplying the amount of steam supplied from the steam supply means into the reactor;
A cultivation system comprising: Greenhouses where agricultural products are grown;
A combustion apparatus for heating the greenhouse; and (a) a gas introduction pipe into which the exhaust gas and carrier gas of the combustion apparatus are introduced in a switchable manner and a gas discharge pipe connected to the house; A reactor filled with a carbon dioxide absorbent containing a composite oxide;
(B) a heater for heating the carbon dioxide-releasing substance produced by reacting carbon dioxide with the carbon dioxide absorbent in the reactor;
(C) water injection means for injecting water into the carbon dioxide-releasing substance in the reactor;
(D) a carbon dioxide generator having control means for adjusting and intermittently injecting water into the reactor from the water injection means;
A cultivation system comprising:

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