Co2 recovery / isolation device

Abstract

This CO2 recovery / isolation device (1) comprises: a reaction vessel (10) in which a CO2-containing gas is brought into contact with an aqueous solution of an alkali metal hydroxide or an aqueous solution of an alkali earth metal hydroxide; a CO2-containing-gas supply unit (41) that supplies the CO2-containing gas into the reaction vessel; a CO2-removed-gas discharge unit (42) that discharges a CO2-removed gas, from which CO2 has been removed, from the reaction vessel; an acid supply unit (44) that supplies an acid into the reaction vessel; and a CO2 gas discharge unit (45) that discharges the CO2 gas generated within the reaction vessel.

Description

CO2 capture and separation equipment

[0001] The present disclosure provides ２ Regarding recovery and separation equipment.

[0002] In recent years, CO as a greenhouse gas ２ There is a need to reduce CO emissions from exhaust gases in various facilities. ２ For example, Patent Document 1 discloses a device for recovering CO in exhaust gas by bringing the exhaust gas into contact with a carbon dioxide absorbent. ２ is absorbed in a carbon dioxide absorbent, and then CO ２ By contacting the carbon dioxide absorbent with citric acid, the CO absorbed in the carbon dioxide absorbent can be reduced. ２ Separating CO ２ A gas recovery arrangement is disclosed.

[0003] JP 2019-55394 A

[0004] However, in the configuration disclosed in Patent Document 1, ２ The absorption of CO into the carbon dioxide absorbent is carried out in an absorption tower, and the CO ２ The separation of CO is carried out in a regeneration tower. ２ Therefore, the overall size of the device increases and the configuration becomes complicated, which increases the manufacturing cost of the device. ２ When separating the carbon dioxide after absorption, it is necessary to move the carbon dioxide absorbent from the absorption tower to the regeneration tower, which makes the work complicated and reduces the work efficiency.

[0005] The present disclosure provides a CO ２ The present invention aims to provide a recovery and separation device.

[0006] One aspect of the present disclosure is to add CO to an aqueous alkali metal hydroxide solution or an aqueous alkaline earth metal hydroxide solution. ２ a reaction vessel in which the CO-containing gas is contacted; ２ CO containing gas supply ２ a CO -containing gas supply unit; and ２CO removed ２ CO to exhaust removal gas ２ a removal gas discharge section; an acid supply section for supplying acid into the reaction vessel; and CO generated in the reaction vessel. ２ CO emissions ２ a gas exhaust section; ２ Located in the recovery and separation device.

[0007] The above CO ２ In the recovery and separation device, CO is added to an alkali metal hydroxide aqueous solution or an alkaline earth metal hydroxide aqueous solution. ２ A reaction vessel in which the CO-containing gas is contacted ２ By supplying a gas containing CO ２ and CO ２ The removal gas can be vented. ２ By supplying acid into the reaction vessel in which CO is immobilized, the immobilized CO ２ High concentration of CO ２ This allows the CO ２ Since the fixation and separation of CO can be carried out in one reaction vessel, the configuration of the device can be simplified, and the device can be made smaller and the cost of the device can be reduced. ２ This improves workability compared to when the fixing and separation are performed using different devices.

[0008] As described above, according to the above-mentioned aspect, it is possible to achieve a CO 2 refrigeration system that is compact, inexpensive, and has improved work efficiency. ２ A recovery and separation device can be provided.

[0009] Note that the symbols in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described below, and do not limit the technical scope of the present disclosure.

[0010] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. ２ FIG. 2 is a schematic vertical cross-sectional view showing the configuration of a recovery and separation device in the first embodiment. ２3 is a perspective view showing the configuration of a recovery and separation device, FIG. 3 is a conceptual diagram showing a state before a cover member is connected in the first embodiment, FIG. 4 is a conceptual diagram showing a state after a cover member is connected in the first embodiment, and FIG. 5 is a conceptual diagram showing a state after a cover member is connected in the first embodiment, ２ FIG. 6 is a diagram illustrating the control flow of the recovery and separation device. ２ FIG. 2 is a schematic vertical cross-sectional view showing the configuration of a recovery and separation device.

[0011] (Embodiment 1) CO ２ An embodiment of the recovery and separation device will be described with reference to Figs. 1 to 5. As shown in Fig. 1, the CO ２ The recovery and separation device 1 mainly comprises a reaction vessel 10, a main body 40, a CO ２ Containing gas supply unit 41, CO ２ Removal gas exhaust unit 42, sensor 43, acid supply unit 44, CO ２ It is equipped with a gas exhaust section 45 and a control device 50.

[0012] 1 and 2, the main body 40 has a side portion 40c standing in the vertical direction Z, an upper portion 40a located above the side portion 40c, and a lower portion 40b located below the side portion 40c, and is configured to form a roughly U-shape. ２ Containing gas supply unit 41, CO ２ Removal gas exhaust unit 42, sensor 43, acid supply unit 44, CO ２ A gas exhaust unit 45 is attached to the lower portion 40b. The reaction vessel 10 is placed on the lower portion 40b. A weighing scale 401 for detecting the weight of the reaction vessel 10 is provided on the lower portion 40b. In Figures 1 and 2, the width direction is designated as X, the front-rear direction is designated as Y, and the vertical direction is designated as Z.

[0013] In this embodiment, the upper part 40a of the main body 40 is slidable in the vertical direction Z, and the lower part 40b of the main body 40 is slidable in the front-to-back direction Y, making it possible to easily attach and detach the reaction tank 10 described below to the main body 40.

[0014] 2. Reaction Tank 10 The reaction tank 10 has a hollow cylindrical shape. An aqueous solution L, such as an aqueous solution of an alkali metal hydroxide or an aqueous solution of an alkaline earth metal hydroxide, is introduced into the reaction tank 10. The aqueous solution L may be, for example, an aqueous solution of NaOH, an aqueous solution of KOH, or an aqueous solution of Ca(OH). ２ Aqueous solution, Mg(OH) ２ An example of the solution is an aqueous solution, and in this embodiment, an aqueous NaOH solution is used.

[0015] The material of the reaction tank 10 is not particularly limited as long as it is alkali-resistant, but it can be made of, for example, stainless steel, or metal with a surface treatment such as a resin lining. It can also be made of resin such as polyethylene resin. If the reaction tank 10 is made of resin, it is preferable to prevent the internal pressure of the reaction tank 10 from becoming excessively high.

[0016] In the first embodiment, as shown in Fig. 1, a first opening 11, a second opening 12, a third opening 13, a fourth opening 14, and a fifth opening 15 are formed on the top surface of a reaction vessel 10. The first opening 11 is provided with a CO ２ The containing gas supply unit 41 is attached, and the second opening 12 is supplied with CO ２ A removal gas exhaust unit 42 is attached, a sensor 43 (described later) is attached to the third opening 13, an acid supply unit 44 (described later) is attached to the fourth opening 14, and a CO ２ A gas exhaust unit 45 is attached. Threaded portions 11a to 15a having thread grooves are provided on the outer circumferential surfaces of the cylindrical portions forming the first opening 11 to the fifth opening 15. A pressure sensor 402 for detecting the pressure inside the reaction tank 10 is also provided in the reaction tank 10.

[0017] 3. CO ２ Containing gas supply unit 41 CO ２ The containing gas supply unit 41 supplies CO ２ In the first embodiment, as shown in FIG. ２ The containing gas supply unit 41 is CO ２ The containing gas supply unit main body 411 and CO ２The CO gas supply portion 41 ２ and a CO containing gas supply nozzle portion 412. ２ The containing gas supply nozzle 412 is fixed to the upper part of the reaction vessel 10 in a state where it is inserted into the first opening 11. ２ The lower end of the containing gas supply nozzle 412 is positioned in the aqueous solution L.

[0018] 1, the first opening 11 is covered with a first cover member 21, and the inner circumferential surface of the first cover member 21 is formed with a threaded portion 21a having a thread groove that conforms to the shape of the threaded portion 11a of the first opening 11. When the first cover member 21 is placed over the first opening 11 and turned, the threaded portions 11a and 21a of both members are screwed together, and the first cover member 21 is detachably attached to the reaction tank 10, as shown in FIG.

[0019] As shown in FIG. 3, the first cover member 21 has a through-hole 211 formed therein. ２ The containing gas supply unit main body 411 is loosely inserted into the through-hole 211 and extends outward from the reaction vessel 10. ２ The main body 411 of the gas-containing supply unit 411 is formed at its tip with an expanded diameter portion 411a. ２ The containing gas supply unit main body 411 is prevented from coming off.

[0020] As a result, when attaching the first cover member 21 to the first opening 11, the upper part 40a of the main body 40, which has been moved vertically upward Z1, is moved vertically downward Z2 as shown by the arrow P, and the first cover member 21 is then rotated to cover the first opening 11, thereby ２ The containing gas supply unit main body 411 does not rotate, and the expanded diameter portion 411a ２ The gas is pressed against the gas-containing supply nozzle 412, ２ The containing gas supply unit main body 411 and CO ２ The containing gas supply nozzle 412 is in communication with the containing gas supply nozzle 412 .

[0021] CO ２ The containing gas supply unit 41 contains CO ２ A first valve 413 is provided to open and close the containing gas supply unit 41. By opening the first valve 413, CO２ The CO -containing gas supply unit 41 is connected to the reaction vessel 10 and supplies the CO -containing gas to the reaction vessel 10. ２ On the other hand, by closing the first valve 413, the CO ２ The CO 2 -containing gas supply unit 41 is shut off from the reaction vessel 10. ２ The CO2 gas cannot be supplied from the reaction vessel 10. ２ It also prevents backflow to the containing gas supply unit 41. The opening and closing state of the first valve 413 is controlled by the control device 50, which will be described later.

[0022] CO ２ In the containing gas supply unit 41, although not shown, CO ２ The end opposite to the containing gas supply nozzle portion 412 is ２ Connected to a source of CO ２ The source of the containing gas is not limited to, for example, CO ２ CO contained in the gas is discharged as exhaust gas ２ It can be used as a CO gas exhaust facility. ２ Examples of the contained gas discharge equipment include equipment with a boiler, a fuel cell, an incinerator, and a heat treatment equipment.

[0023] 4. CO ２ Removed gas exhaust section 42 CO ２ The removal gas discharge section 42 is a gas supply section for discharging CO generated in the reaction vessel 10. ２ The removed gas is discharged to the outside of the reaction vessel 10. ２ The "removal gas" refers to CO ２ The fixation reaction ２ CO from contained gas ２ As shown in Figure 1, CO ２ The removal gas exhaust section 42 is CO ２ The removed gas discharge unit main body 421 and CO ２ The CO forming the tip of the removal gas discharge part 42 ２ The CO ２ The removal gas discharge nozzle part 422 is fixed to the upper part of the reaction vessel 10 in a state where it is inserted into the second opening 12. ２The tip of the removal gas discharge nozzle 422 is located in the upper gas phase within the reaction vessel 10 and is not in contact with the aqueous solution L.

[0024] And CO ２ The removed gas discharge unit main body 421 and CO ２ The removal gas discharge nozzle portion 422 is ２ The containing gas supply unit main body 411 and CO ２ As with the containing gas supply nozzle part 412 , they are connected to each other when the second cover member 22 is attached to the top of the reaction vessel 10 so as to cover the second opening 12 .

[0025] CO ２ The removal gas discharge section 42 contains CO ２ A second valve 423 is provided to open and close the removal gas discharge part 42. By opening the second valve 423, CO ２ The removal gas discharge part 42 is connected to the reaction vessel 10 and discharges CO generated in the reaction vessel 10. ２ On the other hand, by closing the second valve 423, the CO ２ The removal gas discharge part 42 is closed to the reaction vessel 10, and CO ２ The removal gas cannot be discharged and CO ２ It also prevents backflow from the removed gas discharge part 42 to the reaction vessel 10. The open / close state of the second valve 423 is controlled by the control device 50, which will be described later.

[0026] CO ２ In the removal gas exhaust section 42, although not shown, CO ２ The end opposite to the removal gas discharge nozzle portion 422 can be connected to an impurity removal filter. ２ Water-soluble substances in the removal gas (for example, CO 2 that has been formed into droplets by bubbling in the reaction vessel 10) ２ The NaOH aqueous solution that has reached the removal gas discharge nozzle portion 422 and nitrogen oxides NO contained in the exhaust gas ｘ etc.) can be removed.

[0027] 5. Sensor 43 The sensor 43 can detect various conditions of the aqueous solution L, such as the pH, temperature, and product concentration of the aqueous solution L. In the first embodiment, the sensor 43 detects the pH and temperature of the aqueous solution L. As shown in FIG. 1 , the sensor 43 has a sensor body 431 and a sensor tip 432 that forms the tip of the sensor 43. The sensor tip 432 is fixed to the top of the reaction tank 10 while being inserted into the third opening 13. The tip of the sensor tip 432 is located in the aqueous solution L.

[0028] The sensor body 431 and the sensor tip 432 are ２ The containing gas supply unit main body 411 and CO ２ As with the containing gas supply nozzle part 412 , they are brought into communication with each other when the third cover member 23 is attached to the top of the reaction vessel 10 so as to cover the third opening 13 .

[0029] 6. Acid Supply Unit 44 The acid supply unit 44 supplies acid into the reaction tank 10. As shown in FIG. 1 , the acid supply unit 44 has an acid supply unit main body 441 and an acid supply nozzle unit 442 that forms the tip of the acid supply unit main body 441. The acid supply nozzle unit 442 is fixed to the top of the reaction tank 10 while being inserted through the fourth opening 14. The tip of the acid supply nozzle unit 442 is located in the upper gas phase within the reaction tank 10 and is not in contact with the aqueous solution L.

[0030] The acid supply unit main body 441 and the acid supply nozzle unit 442 are ２ The containing gas supply unit main body 411 and CO ２ As with the containing gas supply nozzle part 412, the fourth cover member 24 is attached to the top of the reaction vessel 10 so as to cover the fourth opening 14, and the fourth cover member 24 and the fourth opening 14 are thereby brought into communication with each other.

[0031] The acid supply unit 44 is provided with a third valve 443 that opens and closes the acid supply unit 44. By opening the third valve 443, the acid supply unit 44 communicates with the reaction tank 10 and is able to supply acid into the reaction tank 10. On the other hand, by closing the third valve 443, the acid supply unit 44 is cut off from the reaction tank 10 and is unable to supply acid to the reaction tank 10, and backflow from the acid supply unit 44 to the reaction tank 10 is also prevented. The open / closed state of the third valve 443 is controlled by a control device 50, which will be described later.

[0032] Although not shown, the end of the acid supply unit 44 opposite the acid supply nozzle 442 is connected to an acid supply source. The type of acid supplied by the acid supply unit 44 can be an inorganic acid or an organic acid. For example, inorganic acids can be sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, or hydroiodic acid. Organic acids can be carboxylic acids or sulfonic acids, such as citric acid, formic acid, acetic acid, gluconic acid, lactic acid, oxalic acid, or tartaric acid. The acid can be at least one of the above acids, or can include a combination of the above acids. The acid supplied by the acid supply unit 44 can be a solid or an aqueous solution. In this embodiment, solid citric acid is used as the acid supplied by the acid supply unit 44.

[0033] 7. CO ２ Gas exhaust section 45 CO ２ The gas exhaust unit 45 is a CO ２ CO produced in the reaction vessel 10 by the separation reaction ２ The gas is released to the outside of the reaction vessel 10. As shown in FIG. ２ The gas exhaust unit 45 ２ Gas exhaust body 451 and CO ２ The CO gas forming the tip of the gas discharge body 451 ２ and a gas discharge nozzle portion 452. ２ The gas discharge nozzle part 452 is fixed to the upper part of the reaction vessel 10 in a state where it is inserted into the fifth opening 15. ２ The tip of the gas discharge nozzle 452 is located in the upper gas phase inside the reaction vessel 10 and is not in contact with the aqueous solution L.

[0034] And CO ２ Gas exhaust body 451 and CO ２ The gas discharge nozzle portion 452 is ２ The containing gas supply unit main body 411 and CO ２ As with the containing gas supply nozzle part 412, the fifth cover member 25 is attached to the top of the reaction vessel 10 so as to cover the fifth opening 15, and the fifth opening 15 and the fifth cover member 25 are thereby brought into communication with each other.

[0035] CO ２ The gas exhaust section 45 contains CO ２ A fourth valve 453 is provided to open and close the gas exhaust unit 45. By opening the fourth valve 453, CO ２ The gas exhaust section 45 is connected to the reaction vessel 10 to exhaust CO ２ On the other hand, by closing the fourth valve 453, the CO ２ The gas exhaust part 45 is closed to the reaction vessel 10, and CO ２ It becomes impossible to discharge gas and CO ２ It also prevents backflow from the gas exhaust part 45 to the reaction vessel 10. The open / close state of the fourth valve 453 is controlled by the control device 50, which will be described later.

[0036] CO ２ In the gas exhaust section 45, although not shown, CO ２ The end opposite to the gas discharge nozzle portion 452 is ２ It can be connected to gas facilities. ２ Gas usage equipment is CO ２ There is no limitation as long as it uses gas, but examples include agricultural vinyl greenhouses, carbonated beverage manufacturing facilities, CO ２ Examples include manufacturing facilities for products that use lactic acid bacteria as an additive.

[0037] 8. CO ２ Fixation reaction Next, CO in the reaction vessel 10 ２ The immobilization reaction will be described. In the present embodiment 1, a case where an aqueous solution of NaOH is used as the aqueous solution L will be described.

[0038] First, CO ２ The immobilization reaction is ２CO ２ It is initiated by contacting the CO containing gas with an aqueous solution of NaOH. ２ The immobilization reaction is carried out by carrying out the reaction of the following formula 1, followed by the reaction of formula 2: 2NaOH + CO ２ → Na ２ CO ３ +H ２ O (Formula 1) Na ２ CO ３ +CO ２ +H ２ O → 2NaHCO ３ (Formula 2)

[0039] In the reaction vessel 10 shown in FIG. 1, before the start of the reaction, NaHCO ３ and Na ２ CO ３ is not present, but depending on the progress of the above reaction, Na ２ CO ３ NaHCO is produced ３ There is no Na ２ CO ３ But more CO ２ reacts with NaHCO ３ is generated and both exist, and all Na ２ CO ３ NaHCO ３ Converted to Na ２ CO ３ No more NaHCO ３ The above reaction results in either a state where NaHCO ３ and Na ２ CO ３ Each of these is dissolved in the water in the reaction vessel 10 and is in the form of an aqueous solution. ３ , Na ２ CO ３ The mixture of both is collectively referred to as the "product", and the aqueous solution thereof is collectively referred to as the "aqueous product solution".

[0040] In the first embodiment, CO ２ CO supplied from the containing gas supply unit 41 ２The reaction can be initiated by bubbling the exhaust gas F1, which is a gas containing the NaOH aqueous solution, into the reaction vessel 10. In order to increase the frequency of contact between the exhaust gas F1 and the NaOH aqueous solution, it is preferable to discharge the exhaust gas F1 in the form of microbubbles. The formation of microbubbles is achieved by CO ２ This can be done by a microbubble generator (not shown) provided at the tip of the containing gas supply nozzle part 412 .

[0041] CO ２ The progress of the immobilization reaction can be grasped from the pH of the aqueous solution L obtained by the sensor 43 and the change in weight detected by the weight scale 401 .

[0042] CO ２ The immobilization reaction is ２ CO from the containing gas supply unit 41 to the reaction vessel 10 ２ It can be stopped by stopping the supply of the CO containing gas. ２ The supply of the CO containing gas can be stopped by closing the first valve 413. ２ The timing for terminating the immobilization reaction is not limited, and the state of the product may be in any state.

[0043] The above CO ２ The fixation reaction converts exhaust gas F1 into CO ２ CO removed ２ A removal gas is produced: CO ２ The removal gas is CO by opening the second valve 423. ２ The CO is discharged from the removal gas discharge section 42. ２ After the removal gas has been released, the second valve 423 is closed.

[0044] 9. CO ２ Next, the CO separation reaction in the reaction vessel 10 ２ The separation reaction will be described below. In the first embodiment, as described above, an NaOH aqueous solution is used as the aqueous solution L, and then citric acid is used as the acid.

[0045] CO ２ The separation reaction is CO ２After the immobilization reaction, citric acid (C ６ H ８ O ７ It starts by adding CO ２ The separation reaction is carried out according to one of the following reactions, Formula 3, Formula 4, and Formula 5, depending on the product present in the reaction vessel 10. ６ H ８ O ７ + 3NaHCO ３ → Na ３ C ６ H5O ７ +3H ２ O + 3CO ２ (Formula 3) 2C ６ H ８ O ７ +3Na ２ CO ３ → 2Na ３ C ６ H5O ７ +3H ２ O + 3CO ２ (Formula 4) C ６ H ８ O ７ +Na ３ H(CO ３ ) ２ → Na ３ C ６ H5O ７ +3H ２ O + 3CO ２ (Formula 5) Note that Na ３ H(CO ３ ) ２ is NaHCO ３ and Na ２ CO ３ This shows a 1:1 mixture of sodium sesquicarbonate and sodium sesquicarbonate.

[0046] As shown in the above formulas 3 to 5, in either case, CO ２ The separation reaction produces sodium citrate (Na ３ C ６ H5O ７ , also known as trisodium citrate) and CO ２ Gas and water are generated. ２ Immediately after the start of the separation reaction, CO ２Since gas is generated, it is preferable to close the third valve 443 immediately after adding the citric acid. ２ CO generated by the separation reaction ２ The gas is CO by opening the fourth valve 453. ２ It is released through the gas exhaust 45 .

[0047] CO ２ The sodium citrate produced by the separation reaction can be removed from the reaction tank 10 via a drain cock (not shown) provided in the reaction tank 10. When sodium citrate precipitates in the reaction tank 10, it can be removed as solid sodium citrate, and when it is dissolved in the aqueous solution in the reaction tank 10, it can be removed as an aqueous sodium citrate solution. Solid sodium citrate and aqueous sodium citrate solutions can be used as pH adjusters in food additives, cosmetics, pharmaceuticals, etc., and are useful resources.

[0048] 10. Configuration of the control device 50 and control method by the control device 50 The control device 50 is configured with an arithmetic processing unit, a storage device, etc., and as shown in FIG. ２ Containing gas supply control unit 51, acid supply control unit 52, CO ２ It also functions as a gas discharge control unit 53. ２ A gas-containing gas supply control unit 51, an acid supply control unit 52, and a CO ２ The gas discharge control unit 53 controls the CO ２ The first valve 413 provided in the containing gas supply unit 41, ２ A second valve 423 provided in the removal gas exhaust unit 42, a third valve 443 provided in the acid supply unit 44, and a CO ２ The fourth valve 453 provided in the gas exhaust unit 45 is controlled to open and close.

[0049] CO ２ The containing gas supply control unit 51 controls, for example, CO ２ At the start of the immobilization reaction, the first valve 413 and the second valve 423 are opened, and the third valve 443 and the fourth valve 453 are closed. ２ CO is supplied to the reaction vessel 10 via the containing gas supply unit 41.２ The exhaust gas F1 can be supplied as a contained gas. ２ CO gas connected to the containing gas supply control unit 51 ２ An air pump (not shown) is provided between the exhaust unit and the CO ２ This can be done by suctioning the exhaust gas from the exhaust facility.

[0050] The acid supply control unit 52 controls, for example, CO ２ After the immobilization reaction, CO ２ The timing to start the separation reaction, i.e., CO ２ Fixation reaction and CO ２ At the timing of switching to the separation reaction, the first valve 413, the second valve 423, and the fourth valve 453 are closed, and the third valve 443 is opened. ２ The CO2 content gas supply unit 41 is blocked, and the CO2 content gas is not supplied to the reaction vessel 10. ２ The supply of the exhaust gas F1 as the contained gas is stopped, and the acid can be supplied to the reaction vessel 10 through the opened acid supply part 44. As a result, by stopping the supply of the exhaust gas F1 to the reaction vessel 10, the CO ２ The fixation reaction is completed, and CO is removed by supplying acid to the reaction vessel 10. ２ The separation reaction will then begin.

[0051] CO ２ Fixation reaction and CO ２ The timing of switching to the separation reaction can be controlled based on at least one of the weight of the reaction tank 10 obtained by the weighing scale 401, the pH of the aqueous solution in the reaction tank 10 obtained by the sensor 43, the product concentration in the aqueous solution in the reaction tank 10 obtained by the sensor 43, or the weight of the product in the reaction tank 10 obtained or calculated by the weighing scale 401.

[0052] For example, based on the weight of the reaction vessel 10 acquired by the weighing scale 401 or the pH of the aqueous solution in the reaction vessel 10 acquired by the sensor 43, ２ By understanding the progress of the fixation reaction, ２ When the amount or concentration of the immobilized product reaches a predetermined reference value, ２It can be determined that the time has come to switch to the separation reaction.

[0053] Furthermore, the acid supply control unit 52 can control the amount and / or concentration of acid supplied into the reaction tank 10 based on at least one of the pH of the aqueous solution L in the reaction tank 10, the product concentration in the aqueous solution L in the reaction tank 10, or the weight of the product in the reaction tank 10. For example, the acid supply control unit 52 can calculate the amount of acid to be supplied to the reaction tank 10 based on at least one of the pH of the aqueous solution L in the reaction tank 10, the product concentration in the aqueous solution L in the reaction tank 10, or the weight of the product in the reaction tank 10, and control the fourth valve to be opened to start supplying acid from the acid supply unit 44 to the reaction tank 10, and then close the fourth valve to stop supplying acid from the acid supply unit 44 when the calculated amount of acid has been supplied into the reaction tank 10.

[0054] CO ２ The gas discharge control unit 53 controls, for example, ２ After the separation reaction is completed or ２ At a predetermined timing during the progress of the separation reaction, the first valve 413, the second valve 423, and the third valve 443 are closed, and the fourth valve 453 is opened. ２ CO generated in the reaction vessel 10 through the gas exhaust part 45 ２ Gases can be vented from the reaction vessel 10. The vented CO ２ The gas is CO ２ CO gas discharge part 45 connected ２ It can be supplied to gas utilization facilities.

[0055] In addition, CO ２ CO to gas-using facilities ２ Gas discharge timing and CO ２ The gas discharge amount is determined based on, for example, at least one of the pressure in the reaction vessel 10 and the weight of the reaction vessel 10. ２ This can be controlled by controlling the opening and closing of the fourth valve 453 by the gas exhaust control unit 53. For example, ２ The gas discharge control unit 53 ２ CO is released into the reaction vessel 10 by the separation reaction. ２When a sufficient amount of gas has accumulated, the opening and closing state of the fourth valve 453 is controlled to ２ CO gas discharge part 45 connected ２ CO in the equipment used ２ CO according to gas demand ２ Gas F3 CO ２ The CO ２ It can be supplied to the utilization facility.

[0056] 11. Description of Control Mode Next, the control mode in the first embodiment will be described with reference to the flow chart shown in FIG. ２ After the immobilization reaction S1, ２ A separation reaction S2 is carried out.

[0057] First, CO ２ As shown in Fig. 5, in the immobilization reaction S1, in step S11, an aqueous solution of NaOH is introduced as an aqueous solution L into the reaction tank 10 as a preparation step. The concentration of the aqueous solution of NaOH is set to 5.0%, which is easy to handle since it is not a deleterious substance. ２ The containing gas supply control unit 51 opens the first valve 413 and the second valve 423 and closes the third valve 443 and the fourth valve 453 .

[0058] Next, in step S12, CO ２ The containing gas supply control unit 51 opens the first valve 413 to supply CO ２ The CO gas is supplied from the CO gas supply unit 41 to the reaction vessel 10. ２ The exhaust gas F1 is bubbled and supplied as the containing gas. ２ The fixation reaction S1 is initiated. As the reactions of the above formulas 1 and 2 proceed, CO ２ The removal gas is CO ２ The CO gas that has been released by the gas supply control unit 51 ２ The aqueous solution L is discharged from the removal gas discharge part 42. Thereafter, in step S13, the pH of the aqueous solution L is obtained by the sensor 43.

[0059] Then, in step S14, the acid supply control unit 52 determines whether the acquired pH has reached the target pH. ２ The amount of CO2 to be immobilized can be determined depending on the product produced in the immobilization reaction. ２ Large amount of NaHCO ３ The corresponding pH of the aqueous solution is taken as the target pH.

[0060] In step S14, if the acid supply control unit 52 determines that the acquired pH has not reached the target pH, the process proceeds to step S14 (No) and returns to step S13. On the other hand, in step S14, if the acid supply control unit 52 determines that the target pH has been reached, the process proceeds to step S15 (No). ２ It is determined that the timing for switching to the separation reaction S2 has arrived, and the process proceeds to step S14 (Yes). Then, in step S15, the acid supply control unit 52 closes the first valve 413 to stop the supply of the exhaust gas F1, and also closes the second valve 423. As a result, the CO ２ The immobilization reaction S1 is completed.

[0061] Next, in step S21, the acid supply control unit 52 opens the third valve 443 and supplies citric acid from the acid supply unit 44 to the reaction tank 10. In this flow, in step S21, the acid supply control unit 52 calculates the amount of citric acid to be supplied to the reaction tank 10 based on the pH of the aqueous solution L in the reaction tank 10. Then, after the calculated amount of citric acid has been supplied to the reaction tank 10, the acid supply control unit 52 immediately closes the third valve 443. As a result, CO ２ The separation reaction S2 is started.

[0062] Thereafter, in step S22, the internal pressure of the reaction vessel 10 is acquired by the pressure sensor 402. The internal pressure of the reaction vessel 10 is ２ As the separation reaction progresses, CO ２ The CO ２ The gas discharge control unit 53 determines whether the internal pressure of the reaction vessel 10 has reached a target value.２ The gas discharge control unit 53 controls the CO ２ CO fixed in fixation reaction S1 ２ The amount of CO that can be separated is calculated based on this. ２ Calculate the amount of gas and ２ The increase in the internal pressure corresponding to the amount of gas is set as the target value of the internal pressure.

[0063] In step S23, CO ２ If the gas discharge control unit 53 determines that the acquired internal pressure of the reaction vessel 10 has not reached the target value, the process proceeds to No in step S23 and returns to step S22 again. ２ If the gas discharge control unit 53 determines that the acquired internal pressure of the reaction vessel 10 has reached the target value, the process proceeds to Yes in step S23. Then, in step S24, ２ The gas discharge control unit 53 opens the fourth valve 453 to discharge CO ２ CO from the gas exhaust section 45 ２ Discharge the gas.

[0064] The CO in step S24 ２ Gas emissions are CO ２ The gas discharge control unit 53 controls the CO ２ Gas supplied CO ２ CO in the equipment used ２ The amount of CO is controlled by controlling the opening state of the fourth valve 453 according to the gas demand. ２ When the gas discharge is complete, ２ The separation reaction S2 is completed, and CO ２ The gas discharge control unit 53 closes the fourth valve 453, and the flow ends.

[0065] In this flow, CO ２ When it is determined that the pH of the reaction vessel 10 has reached the target pH in the immobilization reaction S1, ２ It is determined that the timing for switching to the separation reaction S2 has arrived. However, instead of this, when it is determined that the weight of the reaction vessel 10, the product concentration in the reaction vessel 10, or the product weight has reached a predetermined target value, CO ２It may be determined that the timing for switching to the separation reaction S2 has arrived.

[0066] In this flow, the amount of citric acid to be supplied to the reaction tank 10 is calculated based on the pH of the aqueous solution L in the reaction tank 10. Alternatively, the amount of citric acid to be supplied to the reaction tank 10 may be calculated based on the product concentration in the aqueous solution L in the reaction tank 10 or the product weight in the reaction tank 10.

[0067] In addition, in this flow, CO ２ When it is determined that the internal pressure of the reaction vessel 10 has reached the target value in the separation reaction S2, ２ CO from the gas exhaust section 45 ２ Instead of releasing gas, CO ２ When it is determined that the weight change amount of the reaction vessel 10 reaches a predetermined target value in the separation reaction S2, CO ２ The gas may be controlled to be released.

[0068] In addition, in this flow, CO ２ At the start of the separation reaction S2, the second valve 423 was closed. ２ At the start of the separation reaction S2, the second valve 423 is kept open, and CO ２ After the start of the separation reaction S2, the gas phase in the reaction vessel 10 becomes CO ２ After the gas is filled, the second valve 423 may be closed. ２ CO remaining in the reaction vessel 10 at the start of the separation reaction S2 ２ Since the removal gas can be discharged from the reaction vessel 10, CO ２ Higher concentration CO from gas exhaust part 45 ２ The gas can be vented.

[0069] 12. Effects Next, the CO ２ The effects of the recovery and separation device 1 will be described in detail. ２ According to the recovery and separation device 1, CO ２ The reaction vessel 10 contacts the CO ２ By supplying a gas containing CO ２ and CO２ The removal gas can be vented. ２ By supplying acid into the reaction vessel 10 in which CO is immobilized, the immobilized CO ２ High concentration of CO ２ This allows the CO ２ Since the fixation and separation of CO can be performed in one reaction vessel 10, the configuration of the device can be simplified, and the device can be made smaller and the cost of the device can be reduced. ２ This improves workability compared to when the fixing and separation are performed using different devices.

[0070] In the first embodiment, the CO ２ Containing gas supply unit 41, CO ２ A removal gas exhaust unit 42, a sensor 43, an acid supply unit 44, and a CO ２ The gas exhaust units 45 can be separated with their respective tips fixed to the top of the reaction vessel 10. ２ It can be easily removed from the main body 40 of the recovery and separation device 1 and carried around, improving workability.

[0071] In the first embodiment, the acid supplied to the reaction vessel 10 may contain at least one of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, hydroiodic acid, citric acid, formic acid, acetic acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid. These acids are easily available and easy to handle, so they are suitable for CO ２ This can improve the workability of separation.

[0072] In the first embodiment, an aqueous solution of NaOH is stored in the reaction vessel 10 as the aqueous solution L, and citric acid is used as the acid. ２ The separation reaction produces sodium citrate, which is a highly useful resource, and CO ２ The products of the separation reaction can be effectively utilized.

[0073] Furthermore, in the first embodiment, a control device 50 is further provided, and the control device 50 controls the CO ２ CO in the containing gas supply unit 41 ２ The acid supply control unit 52 controls the timing to stop the supply of the containing gas and start the supply of the acid into the reaction vessel 10 in the acid supply unit 44. ２ CO from the fixation reaction ２ Switching to the separation reaction can be performed at an appropriate timing, improving workability.

[0074] In the first embodiment, CO ２ The acid supply control unit 52 further includes a first valve 413 for opening and closing the containing gas supply unit 41 and a third valve 433 for opening and closing the acid supply unit 44. ２ The open / close state of the first valve 413 that opens / closes the containing gas supply unit 41 and the open / close state of the third valve 433 that opens / closes the acid supply unit 44 are controlled. ２ CO from the fixation reaction ２ Since the switch to the separation reaction can be performed at an appropriate timing, the workability is improved, and since the configuration is not complicated, an increase in the cost of the device can be suppressed.

[0075] In the first embodiment, the acid supply control unit 52 is configured to control the amount and / or concentration of acid supplied to the reaction vessel 10 based on at least one of the pH of the aqueous solution L in the reaction vessel 10, the product concentration in the aqueous solution L in the reaction vessel 10, and the product weight in the reaction vessel 10. This prevents unnecessary consumption of acid, reduces costs, and also reduces the amount of immobilized CO ２ can be reliably discharged from the reaction vessel 10 and utilized. ２ This will allow for greater utilization of the system.

[0076] In the first embodiment, the control device 50 controls the CO ２CO in the gas exhaust section 45 ２ CO gas emissions control ２ The gas discharge control unit 53 is provided. ２ CO gas discharge part 45 connected ２ CO for gas-using facilities ２ Reliably supply gas to fix CO ２ This will allow for greater utilization of the system.

[0077] In the first embodiment, CO ２ A fourth valve 453 for opening and closing the gas exhaust part 45 is further provided. ２ The gas discharge control unit 53 ２ The open / close state of the fourth valve 453 that opens and closes the gas exhaust unit 45 is controlled. ２ CO gas discharge part 45 connected ２ CO for gas-using facilities ２ Reliably supplying gas and fixing CO ２ This allows for greater utilization of the device, and also prevents the device from becoming complicated, thereby preventing an increase in device costs.

[0078] As described above, according to the first embodiment, a CO 2 refrigeration system that can achieve miniaturization, cost reduction, and improved work efficiency can be achieved. ２ A recovery and separation device 1 can be provided.

[0079] In the first embodiment, a stainless steel cylindrical container is used as the reaction vessel 10. However, instead of this, as in the first modified embodiment shown in FIG. 6, a polyethylene container, a so-called commercially available general-purpose polyethylene tank, may be used as the reaction vessel 10. In this case, ２ In order to prevent the internal pressure of the reaction vessel 10 from becoming excessively high during the separation reaction, ２ The gas discharge control unit 53 ２ It is preferable to control the open / close state of the gas exhaust part 45. The plastic container used as the reaction tank 10 may be one intended for use as a container for carrying and storing liquids such as drinking water, kerosene, and wastewater, and its capacity is not limited, and one with a capacity of 10 to 20 L can be used.

[0080] In the first modified embodiment shown in Figure 6, the reaction vessel 10 has a first opening 11 and a second opening 12. The reaction vessel 10 is placed on a cart 404 having tires 403 and is restrained to the cart 404 by restraining bands 405 so as to prevent displacement relative to the cart 404. The reaction vessel 10 is easily movable via the cart 404 even when aqueous solution L is stored therein. A handle 16 is provided on the top surface of the reaction vessel 10 between the first opening 11 and the second opening 12. The handle 16 is integrally molded in the reaction vessel 10.

[0081] In the first modified embodiment, as shown in FIG. ２ The containing gas supply unit 41 and the acid supply unit 44 are attached to the first cover member 21. ２ Removed gas exhaust section 42 and CO ２ The gas exhaust section 45 is attached to the second cover member 22. The other configurations in the first modified embodiment are the same as those in the first embodiment, and therefore the same reference numerals as those in the first embodiment are used and the description thereof will be omitted. The first modified embodiment also achieves the same effects as those in the first embodiment.

[0082] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. An aqueous solution of an alkali metal hydroxide or an aqueous solution of an alkaline earth metal hydroxide containing CO ２ A reaction vessel (10) for contacting the containing gas; The CO ２ CO containing gas supply ２ A gas-containing gas supply unit (41); From the reaction vessel ２ CO removed ２ CO to exhaust removal gas ２ A removal gas exhaust (42); an acid supply unit (44) for supplying acid into the reaction tank; CO generated in the reaction vessel ２ CO emissions ２ A gas exhaust section (45); The CO2 is calculated based on at least one of the weight of the reaction vessel, the pH of the aqueous solution in the reaction vessel, the product concentration in the aqueous solution in the reaction vessel, or the weight of the product in the reaction vessel. ２ The CO-containing gas supply unit ２ a control device (50) including an acid supply control unit (52) for controlling the timing of stopping the supply of the containing gas and starting the supply of the acid in the acid supply unit into the reaction tank; Equipped with CO ２ Recovery and separation device (1).

2. 2. The CO2 extracting method of claim 1, wherein the acid comprises at least one of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, hydroiodic acid, citric acid, formic acid, acetic acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid. ２ Recovery and separation device.

3. 2. The CO solution of claim 1, wherein the alkali metal hydroxide solution is an aqueous NaOH solution and the acid is citric acid. ２ Recovery and separation device.

4. The above CO ２ Further comprising a valve (413) for opening and closing the containing gas supply unit and a valve (433) for opening and closing the acid supply unit, The acid supply control unit is ２ The CO2 gas supply system according to any one of claims 1 to 3, further comprising a valve (413) for opening and closing the containing gas supply unit and a valve (433) for opening and closing the acid supply unit. ２ Recovery and separation device.

5. The CO method according to any one of claims 1 to 3, wherein the acid supply control unit controls the amount and / or concentration of the acid supplied to the reaction tank based on at least one of a pH of the aqueous solution in the reaction tank, a product concentration in the aqueous solution in the reaction tank, or a product weight in the reaction tank. ２ Recovery and separation device.

6. The control device controls the CO ２ The CO in the gas exhaust section ２ CO gas emissions control ２ The CO 2 gas purification device according to any one of claims 1 to 3, further comprising a gas emission control unit (53). ２ Recovery and separation device.

7. The above CO ２ Further comprising a valve (453) for opening and closing the gas exhaust part; The above CO ２ The gas discharge control unit is ２ The CO2 gas supply system according to claim 6, further comprising a valve (453) for opening and closing the gas exhaust section, the valve (453) being controlled to be open or closed. ２ Recovery and separation device.

8. (delete)