Carbon dioxide recovery apparatus

Abstract

To provide a carbon dioxide recovery apparatus that can be introduced at low cost.SOLUTION: A carbon dioxide recovery apparatus according to one aspect of the present embodiment has a cooling tower, and comprises a carbon dioxide absorbent in a flow path through which water in contact with outside air circulates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to carbon dioxide capture devices. [Background technology]

[0002] Separating carbon dioxide contained in a gas by passing the gas through an ion exchange resin has been studied. For example, Patent Document 1 discloses a method for improving or purifying a gas by separating carbon dioxide from the gas, the method comprising the steps of: i) introducing the gas flow into a bed of a weakly basic ion exchange resin having amine groups under temperature and pressure conditions at which the carbon dioxide is adsorbed by the resin; and ii) desorbing the adsorbed carbon dioxide from the resin by increasing the temperature and / or decreasing the pressure in the bed, wherein the water content in the ion exchange resin bed during step i) exceeds 35% of the total weight of the ion exchange resin and water. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2015-507527 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional methods for capturing carbon dioxide require the construction of new facilities, which is expensive.

[0005] The present disclosure aims to provide a carbon dioxide capture device that can be introduced at low cost. [Means for solving the problem]

[0006] The present inventors conducted extensive research to solve the above problems and discovered that carbon dioxide can be recovered without incurring high costs by placing a carbon dioxide absorbent in a flow path through which water that has come into contact with outside air flows, leading to the present disclosure.

[0007] An example aspect of this embodiment is described as follows.

[0008] (1) A carbon dioxide capture device that has a cooling tower and is equipped with a carbon dioxide absorbent in a flow path through which water that has come into contact with outside air flows. (2) The carbon dioxide recovery device according to (1), wherein the carbon dioxide absorbent is an ion exchange resin. (3) The carbon dioxide recovery device according to (1) or (2), wherein the carbon dioxide absorbent is housed in a replaceable cartridge. (4) The carbon dioxide capture device has a regeneration unit capable of regenerating the carbon dioxide absorbent, The carbon dioxide absorbent is movably disposed, The carbon dioxide recovery device according to (1) or (2), wherein a part of the carbon dioxide absorbent is disposed in the flow path and a part of the carbon dioxide absorbent is disposed in the regeneration section. [Effects of the Invention]

[0009] The present disclosure makes it possible to provide a carbon dioxide capture device that can be introduced at low cost. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of a carbon dioxide capture device. [Figure 2] FIG. 1 is a schematic diagram of one embodiment of a carbon dioxide capture device. [Figure 3] FIG. 1 is a graph showing the change in carbonate ion concentration over time in Experimental Example 1. [Figure 4] 10 is a graph showing the amount of CO2 and the amount of desorption before and after liquid passage in Experimental Example 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The carbon dioxide capture device of this embodiment will be described in detail below. (Carbon dioxide capture device) One aspect of this embodiment is a carbon dioxide capture device having a cooling tower and a carbon dioxide absorbent in a flow path through which water that has come into contact with outside air flows. The cooling tower constituting the carbon dioxide capture device of this embodiment is not particularly limited, and is, for example, a device for cooling cooling water used in plants, factory equipment, buildings, etc., and is a machine that dissipates heat by utilizing the evaporation of water. In one preferred aspect, the carbon dioxide absorbent is housed in a replaceable cartridge. By housing the carbon dioxide absorbent in a cartridge, it can be easily replaced when the carbon dioxide absorption capacity of the carbon dioxide absorbent decreases. In another preferred aspect, the carbon dioxide capture device has a regeneration unit that can regenerate the carbon dioxide absorbent, and the carbon dioxide absorbent is movably arranged, with a portion of the carbon dioxide absorbent being arranged in the flow path and a portion being arranged in the regeneration unit. In this aspect, the carbon dioxide absorbent is, for example, rotated so that a portion is arranged in the flow path and a portion is arranged in the regeneration unit. When the carbon dioxide absorption capacity of the carbon dioxide absorbent arranged in the flow path decreases, the carbon dioxide absorbent that was arranged in the regeneration unit is moved to the regeneration unit, and the carbon dioxide absorbent that was arranged in the regeneration unit is moved to the flow path, thereby enabling long-term operation and significantly delaying the timing for replacing the carbon dioxide absorbent.

[0012] The cooling tower may be an open cooling tower or a closed cooling tower, and is not particularly limited. The cooling tower may be a counterflow type or a crossflow type. The carbon dioxide capture device of this embodiment can be introduced at low cost because an existing cooling tower can be used.

[0013] The carbon dioxide capture device of this embodiment is capable of capturing carbon dioxide dissolved in water through contact with outside air in a cooling tower using a carbon dioxide absorbent. Because the operation of a cooling tower inevitably causes carbon dioxide to dissolve in water, no additional equipment or power is required to dissolve carbon dioxide from outside air into water. Since the carbon dioxide contained in the water is captured using the carbon dioxide absorbent, the carbon dioxide capture device can be obtained simply by adding equipment that brings the carbon dioxide absorbent into contact with water.

[0014] The carbon dioxide capture device of this embodiment is provided with a carbon dioxide absorbent in a flow path through which water that has come into contact with outside air flows. For example, if the cooling tower is an open-type cooling tower, cooling water is sprayed by a sprinkler system, and the sprayed water corresponds to water that has come into contact with outside air. Normally, cooling water that has come into contact with outside air is supplied to a chiller or the like, and one example of this embodiment is a mode in which a carbon dioxide absorbent is provided in the flow path between them. Furthermore, for example, if the cooling tower is a closed-type cooling tower, the cooling water does not come into contact with outside air, but the sprayed water comes into contact with outside air, and the recovered sprayed water corresponds to water that has come into contact with outside air. In a closed-type cooling tower, the sprayed water is used repeatedly, and one example of this embodiment is a mode in which a carbon dioxide absorbent is provided in the flow path between the recovered sprayed water and the water that has come into contact with outside air until it is sprayed again.

[0015] The carbon dioxide absorbent is not particularly limited, but an ion exchange resin is one of the preferred embodiments. As the ion exchange resin, an anion exchange resin can usually be used. An anion exchange resin is an ion exchange resin that absorbs, for example, carbonate ions (CO3 2- ) and bicarbonate ions (HCO3 - ) can be absorbed by anion exchange resin and carbonate ions (CO3 2- ) and bicarbonate ion (HCO3 - An example of an ion exchange reaction with ) is shown in the following formula (1).

[0016] [ka]

[0017] A schematic diagram of one embodiment of a carbon dioxide recovery apparatus is shown in Figure 1. In the embodiment of Figure 1, an ion exchange resin is arranged in a flow path through which water that has come into contact with the atmosphere (outside air) in a cooling tower flows. In this embodiment, the ion exchange resin is preferably housed in a replaceable cartridge. Note that the ion exchange resin housed in the cartridge removed for replacement is preferably regenerated as appropriate and reused.

[0018] A schematic diagram of another embodiment of a carbon dioxide capture device is shown in FIG. 2. In the embodiment of FIG. 2, a portion of the ion exchange resin is arranged in a flow path through which water that has come into contact with the atmosphere (outside air) in a cooling tower flows. In addition, a portion of the ion exchange resin is arranged in a regeneration section that is composed of a regenerating liquid, a storage tank (and a flow path for the regenerating liquid). By rotatably arranging the ion exchange resin, it is possible to move ion exchange resin with reduced carbon dioxide absorption capacity to the regenerating section, and it is possible to move ion exchange resin that has been regenerated by the regenerating liquid to the flow path. The regenerating liquid is a liquid that converts carbon dioxide into carbonate ions (CO3 2- ) and bicarbonate ion (HCO3 - ) as long as the ion exchange resin that has adsorbed the ions can be regenerated. However, there are no particular limitations on the type of ion exchange resin that can be used. Examples of suitable ion exchange resins include hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide, chlorides such as sodium chloride, potassium chloride, magnesium chloride, and calcium chloride, nitrates, and sulfates. [Example]

[0019] The present embodiment will be described below with reference to examples, but the present disclosure is not limited to these examples.

[0020] Ambertec UP550 OH (manufactured by DuPont) was used as the ion exchange resin.

[0021] [Experimental Example 1] 1-1: 500 mL of pure water was prepared, and 100% CO2 gas (manufactured by Taiyo Nippon Sanso Corporation) was bubbled into the water while stirring with a stirrer. 1-2: Using a 25 mL measuring cylinder, 20 mL of ion exchange resin was dispensed. 1-3: 1-2 was transferred to a beaker, pure water was added, and the mixture was gently stirred. The supernatant was then discarded. (This procedure was repeated three times.) 1-4: The ion exchange resin of 1-3 was placed in a column (Organo Corporation, Amber column). 1-5: The water containing dissolved CO2 prepared in 1-1 was gently poured into the column packed with the ion exchange resin prepared in 1-4, taking care not to stir the ion exchange resin. 1-6: The flow rate was adjusted so that 200 mL of water was discharged over 1 hour. (SV=10h -1 ) 1-7: The water that came out of the solution was collected in a screw tube, changing the collection container every 10 minutes. 1-8: The water in 1-1 as the initial value (0 min) and the water recovered in 1-7 were subjected to ion chromatography (Ion Chromatograph (ICS-5000) manufactured by Nippon Dionex) to measure the carbonate ion concentration. The change in carbonate ion concentration over time is shown in Figure 3. Figure 3 suggests that carbon dioxide dissolved in water can be recovered by using an ion exchange resin.

[0022] [Experimental Example 2] (Absorption process) 2-1: 0.0687 g of sodium bicarbonate (Nacalai Tesque, Inc., special grade) was added to 360 mL of pure water and stirred. 2-2: 300 mL of the aqueous sodium hydrogen carbonate solution prepared in 2-1 was taken, and 20 mL of ion exchange resin was added thereto and stirred for 90 minutes. 2-3: The stirred solution of 2-2 was filtered to recover the ion exchange resin. The recovered ion exchange resin was washed twice with 50 mL of pure water. The absorption process releases carbonate ions (CO3 2- ) or bicarbonate ion (HCO3 - ) was absorbed onto an ion exchange resin.

[0023] (Desorption process) 2-4: 14.4 g of sodium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for volumetric analysis) was added to 360 mL of pure water and stirred to obtain an aqueous sodium hydroxide solution. 2-5: Using 20 mL of the ion exchange resin of 2-3, the procedures of 1-4 and 1-5 of Experimental Example 1 were carried out. However, in the procedure of 1-5, the CO2-dissolved water prepared in 1-1 was replaced with the sodium hydroxide aqueous solution prepared in 2-4. 2-6: The flow rate was adjusted so that 300 mL of sodium hydroxide solution was discharged over 90 min. (SV=10 h -1 ) 2-7: After the sodium hydroxide aqueous solution had been passed through the ion exchange resin, 50 mL of pure water was passed through the resin twice to wash the ion exchange resin. 2-8: 40 mL of the aqueous solution (after passing) through 2-6 and 2-7 was taken, and 2 M hydrochloric acid (Fujifilm Wako Pure Chemical Industries, Ltd., for volumetric analysis) was added to the solution until the pH was 4 or less (acid treatment). Similarly, 2 M hydrochloric acid (acid treatment) was added to 60 mL of the aqueous sodium hydroxide solution (before passing) prepared in 2-4 until the pH was 4 or less. 2-9: The CO2 concentrations of the two aqueous solutions in 2-8 were measured using a carbonate concentration meter (DKK-TOA Corporation, Portable Carbon Dioxide Concentration Meter CGP-31). The CO2 concentrations of the two aqueous solutions were determined, and the amount of CO2 was calculated using 300 mL of aqueous solution before and 380 mL after (the expected amount of aqueous solution was 400 mL, but the recovered amount was 380 mL). The CO2 concentration, CO2 amount, and desorption amount (the amount of CO2 desorbed from the ion exchange resin) are shown in Table 1. The CO2 amounts before and after the flow and the desorption amount (the amount of CO2 after the flow minus the amount of CO2 before the flow) are shown in Figure 4.

[0024] [Table 1]

[0025] Table 1 and Figure 4 suggest that the carbon dioxide absorbent (ion exchange resin) can be easily regenerated.

[0026] The upper and / or lower limit values ​​of the numerical ranges described herein can be arbitrarily combined to define a preferred range. For example, the upper and lower limit values ​​of the numerical ranges can be arbitrarily combined to define a preferred range, the upper limit values ​​of the numerical ranges can be arbitrarily combined to define a preferred range, and the lower limit values ​​of the numerical ranges can be arbitrarily combined to define a preferred range.

[0027] Although the present embodiment has been described in detail above, the specific configuration is not limited to this embodiment, and even if there are design changes within the scope that do not deviate from the gist of this disclosure, they are included in this disclosure.

Claims

1. A carbon dioxide recovery device having a cooling tower and a carbon dioxide absorbent in a flow path through which water that has come into contact with outside air flows.

2. The carbon dioxide recovery device according to claim 1 , wherein the carbon dioxide absorbent is an ion exchange resin.

3. The carbon dioxide capture device of claim 1 , wherein the carbon dioxide absorbent is contained in a replaceable cartridge.

4. the carbon dioxide capture device has a regeneration unit capable of regenerating the carbon dioxide absorbent, The carbon dioxide absorbent is movably disposed, The carbon dioxide recovery device according to claim 1 , wherein a portion of the carbon dioxide absorbent is disposed in the flow path, and a portion of the carbon dioxide absorbent is disposed in the regeneration section.

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