Carbon dioxide permeation device and carbon dioxide permeation method

Abstract

To provide a carbon dioxide permeation device including a novel carbon dioxide permeation agent.SOLUTION: The carbon dioxide permeation device according to the present invention, includes a carbon dioxide permeation agent, a carbon dioxide supply unit, and a carbon dioxide permeation unit, the carbon dioxide permeation agent including a thin film made from a polymer including at least one species selected from the group consisting of rubber, polyethylene, cellulose and polyurethane, the carbon dioxide supply unit supplying the carbon dioxide permeation unit with a substance containing carbon dioxide i.e., mixed gas including carbon dioxide, hydrogen and methane, the carbon dioxide permeation unit including two sections connected with each other via the thin film, in which one section is supplied with the substance including carbon dioxide from the carbon dioxide supply unit, the other section is filled with a liquid so as to be in contact with the thin film, the carbon dioxide permeation unit being capable of separating carbon dioxide from the supplied substance containing carbon dioxide by the thin film selectively permeating carbon dioxide.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbon dioxide permeation agent, a carbon dioxide permeation device, and a carbon dioxide permeation method. [Background technology]

[0002] In recent years, as a measure against the problem of global warming, the development of technologies for separating and capturing carbon dioxide has been promoted. As a method for separating and capturing carbon dioxide, Patent Document 1 discloses a technology for obtaining carbon dioxide from oxygen and nitrogen by a membrane permeation method based on the principle of molecular sieves.

[0003] However, new methods capable of permeating and separating carbon dioxide are needed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-24776 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a new carbon dioxide permeation agent and a carbon dioxide permeation device containing the same. [Means for solving the problem]

[0006] In order to achieve the above object, the carbon dioxide permeation agent of the present invention includes a thin polymer film, The membrane is selectively permeable to carbon dioxide.

[0007] The carbon dioxide permeation device of the present invention includes a carbon dioxide supply unit and a carbon dioxide permeation unit, The carbon dioxide supply unit supplies a carbon dioxide-containing substance to the carbon dioxide permeation unit, The carbon dioxide-containing substance is at least one of a gas and a liquid, the carbon dioxide permeation section selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing material, The carbon dioxide permeable portion contains the carbon dioxide permeable agent of the present invention.

[0008] The carbon dioxide permeation method of the present invention includes a carbon dioxide supply step and a carbon dioxide permeation step, The carbon dioxide supply step supplies a carbon dioxide-containing substance to the carbon dioxide permeation step, The carbon dioxide-containing substance is at least one of a gas and a liquid, In the carbon dioxide permeation step, the carbon dioxide contained in the supplied carbon dioxide-containing substance is selectively permeated by the carbon dioxide permeation agent of the present invention. Effect of the Invention

[0009] The present invention can provide a new carbon dioxide permeation agent and a new carbon dioxide permeation device. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of a carbon dioxide permeation device according to the second embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing another example of the carbon dioxide permeation device of the second embodiment. [Diagram 3] FIG. 3 is a flow chart showing an example of the process in the carbon dioxide permeation method of the third embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of the carbon dioxide absorbing apparatus of the fifth embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing another example of the carbon dioxide absorbing apparatus of the fifth embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of the process in the carbon dioxide absorbing method of the sixth embodiment. [Figure 7] FIG. 7 is a graph showing the carbon dioxide concentration in Reference Example 3. [Figure 8]FIG. 8 is a graph showing the carbon dioxide concentration in Reference Example 3. [Figure 9] FIG. 9 is a graph showing the carbon dioxide concentration in Reference Example 4. [Figure 10] FIG. 10 is a graph showing the amount of reduction in the volume of the carbon dioxide absorbent in Reference Example 4. [Figure 11] FIG. 11 is a graph showing the carbon dioxide concentration in Reference Example 5. [Figure 12] FIG. 12 is a graph showing the carbon dioxide concentration in Example 1. [Figure 13] FIG. 13 is a graph showing the carbon dioxide concentration in Example 1. [Figure 14] FIG. 14 is a graph showing the volume of a rubber glove in Example 2. [Figure 15] FIG. 15 is a graph showing the volume of a rubber balloon in Example 2. [Figure 16] FIG. 16 is a graph showing the volume of a rubber balloon in Example 3. [Figure 17] FIG. 17 is a graph showing the carbon dioxide concentration in Example 4. [Figure 18] FIG. 18 is a graph showing the carbon dioxide concentration in Example 4. [Figure 19] FIG. 19 is a graph showing the volume of the Visking tube in Example 5. [Figure 20] FIG. 20 is a graph showing the carbon dioxide concentration in Example 5. [Figure 21] FIG. 21 is a graph showing the volume of the Visking tube in Example 5. [Figure 22] FIG. 4 is a graph showing the carbon dioxide concentration in Reference Example 1. [Diagram 23] FIG. 23 is a graph showing the carbon dioxide concentration in Example 5. [Figure 24] FIG. 24 is a graph showing the volume of the Visking tube in Example 5. [Diagram 25]FIG. 25 is a graph showing the volume of a rubber balloon in Example 3. [Figure 26] FIG. 26 is a graph showing the volume of a rubber balloon in Example 3. [Figure 27] FIG. 27 is a graph showing the volume of the Visking tube in Example 5. [Figure 28] FIG. 28 is a graph showing the volume of a rubber balloon in Example 3. [Figure 29] FIG. 29 is a graph showing the volume of the polyethylene bag in Example 4. [Diagram 30] FIG. 30 is a graph showing the volume of the polyethylene bag in Example 4. [Diagram 31] FIG. 31 is a graph showing the volume of the polyurethane bag in Example 6. [Diagram 32] FIG. 32 is a graph showing the volume of the polyurethane bag in Example 6. [Diagram 33] FIG. 33 is a graph showing the volume of a polyethylene bag in Example 6. [Diagram 34] FIG. 34 is a graph showing the volume of a polyethylene bag in Example 4. [Diagram 35] FIG. 35 is a graph showing the carbon dioxide concentration in Reference Example 1. [Diagram 36] FIG. 36 is a graph showing the carbon dioxide concentration in Reference Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The carbon dioxide permeation agent of the present invention may be in a form in which, for example, the polymer includes at least one selected from the group consisting of cellulose, polyethylene terephthalate, high density polyethylene, low density polyethylene, polypropylene, polytetrafluoroethylene, polycarbonate, rubber, polyurethane, and acrylic.

[0012] The carbon dioxide permeation agent of the present invention may be in a form in which the thin film is impermeable to oxygen and nitrogen, for example.

[0013] The carbon dioxide permeation agent of the present invention may be in a form such that the thin film is permeable to the carbon dioxide when heated, for example.

[0014] The carbon dioxide permeation agent of the present invention may be in a form in which, for example, the thin film selectively permeates carbon dioxide, thereby being capable of separating carbon dioxide from a mixed gas containing carbon dioxide and at least one of hydrogen and methane.

[0015] In the carbon dioxide permeation device of the present invention, for example, the carbon dioxide permeation section may be configured to permeate the carbon dioxide in a heated state.

[0016] In the carbon dioxide permeation device of the present invention, for example, the carbon dioxide permeation section may include two compartments, the two compartments are connected via the thin film of the carbon dioxide permeant, the carbon dioxide-containing substance is supplied from the carbon dioxide supply section to one of the compartments, and the other compartment is filled with a liquid so as to be in contact with the thin film. Also, the carbon dioxide-containing substance may be a mixed gas containing carbon dioxide and at least one of hydrogen and methane, and the thin film may selectively permeate carbon dioxide, thereby separating carbon dioxide from the mixed gas supplied to the one compartment into the liquid filled in the other compartment.

[0017] In the carbon dioxide permeation method of the present invention, for example, the carbon dioxide permeation step may be performed in a form in which the carbon dioxide is permeated in a heated state.

[0018] In the carbon dioxide permeation method of the present invention, for example, the carbon dioxide permeation step may be such that the carbon dioxide is permeated by a carbon dioxide permeation section, the carbon dioxide permeation section includes the carbon dioxide permeating agent and two compartments, the two compartments are connected via the thin film of the carbon dioxide permeating agent, the carbon dioxide-containing material is supplied from the carbon dioxide supply section to one of the compartments, and the other compartment is filled with a liquid so as to be in contact with the thin film. Also, the carbon dioxide-containing material may be a mixed gas containing carbon dioxide and at least one of hydrogen and methane, and the thin film may selectively permeate carbon dioxide in the carbon dioxide permeation step to separate carbon dioxide from the mixed gas supplied to the one compartment into the liquid filled in the other compartment.

[0019] An embodiment of the present invention will be described. Note that the present invention is not limited to the following embodiment. Note that in each of the following drawings, the same parts are given the same reference numerals. In addition, the explanations of each embodiment can be mutually incorporated unless otherwise specified. Furthermore, the configurations of each embodiment can be combined unless otherwise specified. The terms used in this specification can be used in the sense commonly used in the technical field unless otherwise specified.

[0020] [Embodiment 1] (Carbon dioxide permeation agent) The carbon dioxide permeable agent of the present embodiment includes a thin polymer film that selectively allows carbon dioxide (CO2) to pass through. Other than this, there is no particular limitation.

[0021] Examples of the polymer include cellulose, polyethylene terephthalate, high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), polycarbonate, rubber, polyurethane, and acrylic. Examples of the rubber include latex. In the present specification, the term "polyethylene" refers to low density polyethylene. The carbon dioxide permeation agent may contain one type of the polymer, or may contain multiple types of the polymer.

[0022] In the carbon dioxide permeation agent of the present embodiment, the content of the polymer is not particularly limited and can be set appropriately.

[0023] The carbon dioxide permeation agent may contain, for example, a component other than the polymer. The component other than the polymer is not particularly limited.

[0024] The thickness of the thin film is not particularly limited as long as it is selectively permeable to carbon dioxide, and is, for example, 0.005 to 0.1 mm, and specifically, for example, 0.005 mm, 0.03 mm, 0.04 mm, and 0.08 mm. For example, a rubber balloon and a glove have a thickness in the range of 0.005 to 0.1 mm when inflated.

[0025] The carbon dioxide permeable agent, for example, allows the carbon dioxide contained in the carbon dioxide-containing material to pass through. The carbon dioxide-containing material may be a gas, i.e., a carbon dioxide-containing gas, or a liquid, i.e., a carbon dioxide-containing solution. The carbon dioxide-containing gas is not particularly limited, and examples thereof include combustion exhaust gas, indoor air, and atmospheric air. The carbon dioxide concentration in the carbon dioxide-containing gas is not particularly limited, and is greater than 0 and 100% or less. The carbon dioxide-containing solution is not particularly limited, and examples thereof include carbonated water, carbon dioxide water, and the like. In the carbonated water, carbon dioxide exists mainly as carbonate ions and bicarbonate ions. On the other hand, in the carbon dioxide water, carbon dioxide exists in an unionized state. In addition, the carbon dioxide-containing gas may be passed through a liquid such as water. The carbon dioxide concentration in the carbon dioxide-containing solution is not particularly limited, and is greater than 0 and 0.14 g / dl or less.

[0026] The thin film selectively transmits carbon dioxide. Specifically, "selectively transmits carbon dioxide" means, for example, that carbon dioxide transmits and substances other than carbon dioxide do not transmit. The "does not transmit" includes, for example, "almost no transmission". Examples of substances that the thin film does not transmit include oxygen and nitrogen. In addition, "selectively transmits carbon dioxide" means, for example, that the transmission rate of substances other than carbon dioxide is slower than the transmission rate of carbon dioxide. Examples of substances that transmit slower than the transmission rate of carbon dioxide include hydrogen and methane. Note that, as described later, when one surface of the thin film is in contact with a gas phase and the other surface is in contact with a liquid phase, hydrogen and methane do not transmit from the gas phase to the liquid phase. In addition, when both surfaces of the thin film are in contact with liquid phases, for example, hydrogen and methane do not transmit from one liquid phase to the other liquid phase. In this case, for example, liquids having different solubilities of substances other than carbon dioxide contained in the carbon dioxide-containing substance (substances to be separated; oxygen, nitrogen, hydrogen, methane, etc.) can be used for each liquid phase.

[0027] The carbon dioxide permeable agent can separate carbon dioxide from a mixed gas containing carbon dioxide and at least one of hydrogen and methane, for example, by selectively allowing carbon dioxide to permeate through the thin film. In this case, for example, as described below, the thin film can separate carbon dioxide from the mixed gas supplied to one compartment into a liquid (e.g., water, an aqueous solution, etc.) filled in the other compartment. Also, for example, the thin film can separate carbon dioxide from the liquid supplied to one compartment into the liquid filled in the other compartment.

[0028] In this embodiment, "permeable to carbon dioxide", "not permeable to carbon dioxide", and "almost not permeable to carbon dioxide" can be determined by known methods, for example, the carbon dioxide permeability measured in accordance with JIS K7126-1 (2006) can be used. For example, as shown in the examples described later, the thin film can be made into a bag, carbon dioxide can be placed in the bag, and the presence or absence and speed of carbon dioxide permeation can be examined based on the change in the volume of the bag over time. For example, the permeation of substances other than carbon dioxide can also be determined in a similar manner.

[0029] The contact conditions between the carbon dioxide permeation agent and the carbon dioxide-containing substance are not particularly limited. For example, the carbon dioxide-containing substance can be placed in a container containing the carbon dioxide permeation agent and allowed to stand at room temperature (e.g., 24°C) for 30 minutes, 1 hour, 1.5 hours, 2 hours, 5 hours, or 6 hours to allow the contact.

[0030] The carbon dioxide permeable agent may be heated so that the thin film allows the carbon dioxide to permeate. The heating conditions are not particularly limited and may be, for example, 5 to 80°C, and specifically, for example, 50°C. In this case, the carbon dioxide permeable agent may be heated, or the carbon dioxide may be heated. By the heating, for example, the amount of the carbon dioxide that permeates can be increased.

[0031] According to the carbon dioxide permeation agent of the present embodiment, the thin film selectively allows carbon dioxide to permeate, so that, for example, carbon dioxide can be separated from the carbon dioxide-containing substance. Furthermore, for example, by using the carbon dioxide permeation agent in a state where one surface of the thin film is in contact with a gas phase and the other surface is in contact with a liquid phase, carbon dioxide can be more suitably separated from a mixed gas containing carbon dioxide into the liquid phase.

[0032] (Carbon dioxide absorbent) The carbon dioxide absorbent of this embodiment (first carbon dioxide absorbent) includes a carbon dioxide absorbing section, which includes the carbon dioxide permeation agent of the present invention. The inside of the carbon dioxide absorbing section is sealed, and carbon dioxide is absorbed from the outside to the inside of the carbon dioxide absorbing section by selectively permeating carbon dioxide through the thin film of the carbon dioxide permeation agent.

[0033] The sealed inside of the carbon dioxide absorbing unit is filled with, for example, a gas or liquid having a lower carbon dioxide concentration than the outside, which allows carbon dioxide to permeate from the outside to the inside of the carbon dioxide absorbing unit through the thin film, and the carbon dioxide is absorbed inside the carbon dioxide absorbing unit.

[0034] The shape of the carbon dioxide absorbent of the present embodiment is not particularly limited, and examples thereof include a bubble wrap shape, a bag shape, a tube shape, and the like.

[0035] The carbon dioxide absorbing section increases and decreases in volume due to, for example, the absorption and release of carbon dioxide. In the carbon dioxide absorbing section, for example, the thin film is formed from a material having elasticity. As a result, the thin film expands and contracts due to the absorption and release of carbon dioxide, and the volume of the carbon dioxide absorbing section changes.

[0036] [Embodiment 2] (Carbon dioxide permeation device) Fig. 1 is a schematic diagram showing an example of a carbon dioxide permeation device 1 of this embodiment. As shown in Fig. 1, the carbon dioxide permeation device 1 includes a carbon dioxide supply section 11 and a carbon dioxide permeation section 12. The size and forming material of each component included in the carbon dioxide permeation device 1 are not particularly limited and can be set appropriately. The carbon dioxide permeation device of this embodiment can also be called, for example, a carbon dioxide separation device.

[0037] The carbon dioxide supply section 11 supplies a carbon dioxide-containing substance to the carbon dioxide permeation section 12. The carbon dioxide-containing substance is the same as the carbon dioxide-containing substance in the first embodiment.

[0038] The carbon dioxide supplying section 11 is not particularly limited as long as it can supply the carbon dioxide-containing material to the carbon dioxide permeation section 12. The carbon dioxide supplying section 11 may, for example, supply the carbon dioxide-containing gas into the carbon dioxide permeation section 12, or may supply the carbon dioxide-containing solution, or may supply the carbon dioxide-containing gas into the liquid in the carbon dioxide permeation section 12. Specifically, the carbon dioxide supplying section 11 may be, for example, a pipe, a hose, or the like, a vent, or a bubble-shaped gas supplying device such as a bubble former.

[0039] The carbon dioxide permeation section 12 selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing substance. The carbon dioxide permeation section 12 includes a carbon dioxide permeation agent 121. The carbon dioxide permeation agent 121 is the carbon dioxide permeation agent of the first embodiment.

[0040] 1, the carbon dioxide permeation section 12 includes a first chamber 12A and a second chamber 12B, and the first chamber 12A and the second chamber 12B may be connected via a carbon dioxide permeation agent 121. The carbon dioxide supply section 11 supplies carbon dioxide to the first chamber 12A, and the carbon dioxide permeation agent 121 selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing substance, thereby transmitting carbon dioxide from the first chamber 12A to the second chamber 12B.

[0041] In the carbon dioxide permeation device 1 of this embodiment, the second chamber 12B may contain a gas (e.g., air, etc.), a liquid phase or a liquid layer, or both. The liquid layer is, for example, a structure that covers the surface of a thin film, and specifically, for example, the liquid may be flowed on the surface of the membrane, or may be a stationary thin structure that covers the surface. The liquid phase is, for example, a structure that is thicker than the liquid layer, and specifically, for example, the partition (second chamber 12B) may be filled with the liquid. The liquid is not particularly limited, and is, for example, water, an aqueous solution, etc. The liquid can be, for example, a liquid in which the solubility of substances other than carbon dioxide contained in the carbon dioxide-containing substance (substances to be separated; oxygen, nitrogen, hydrogen, methane, etc.) is lower than the solubility of carbon dioxide. Even when the second chamber 12B contains a liquid, for example, the carbon dioxide can be sufficiently permeated without impeding the permeation of the carbon dioxide.

[0042] In this manner, the carbon dioxide permeation device 1 of this embodiment includes two compartments (first chamber 12A and second chamber 12B), and the two compartments are connected via the thin film of the carbon dioxide permeation agent (carbon dioxide permeation agent 121). One of the compartments (first chamber 12A) is supplied with the carbon dioxide-containing substance from the carbon dioxide supply unit (carbon dioxide supply unit 11), and the other compartment (second chamber 12B) may be filled with the liquid so as to be in contact with the thin film (forming the liquid phase), or the liquid may be layered (forming the liquid layer).

[0043] By containing the liquid in the second chamber 12B, for example, when the carbon dioxide-containing material contains carbon dioxide and hydrogen, it is possible to easily separate the carbon dioxide. Specifically, for example, when the carbon dioxide supply unit 11 supplies the carbon dioxide-containing material containing carbon dioxide and at least one of hydrogen and methane to the first chamber 12A, the carbon dioxide permeation agent 121 permeates the carbon dioxide contained in the carbon dioxide-containing material, while the presence of the liquid inhibits the permeation of hydrogen and methane gas. This makes it possible to send carbon dioxide from which hydrogen and methane gas have been separated and removed from the first chamber 12A to the second chamber 12B. Note that, as shown in Example 5 described later, by using a cellulose membrane and water, it is possible to separate each gas from a mixed gas of carbon dioxide and hydrogen or methane gas.

[0044] In this manner, in the carbon dioxide permeation device 1 of this embodiment, when the carbon dioxide-containing substance is a mixed gas containing carbon dioxide and at least one of hydrogen and methane, the thin film selectively permeates carbon dioxide, thereby enabling separation of carbon dioxide from the mixed gas supplied to one of the compartments into the liquid filled in the other compartment.

[0045] The carbon dioxide permeation device 1 of this embodiment may further include, for example, a carbon dioxide release section, which releases the carbon dioxide permeated by the carbon dioxide permeation section 12. The carbon dioxide release section may be, for example, a pipe, a hose, or a vent. The carbon dioxide release section is provided in, for example, the second chamber 12B.

[0046] The carbon dioxide permeation section 12 may, for example, be heated to allow the carbon dioxide to permeate. In this case, as shown in FIG. 2, the carbon dioxide permeation section 12 may be heated by a heating section 2. The heating section 2 may or may not be included in the carbon dioxide permeation device 1. The heating section 2 is not particularly limited as long as it can heat the carbon dioxide permeation section 12, and a general heating device may be used. The heating section 2 may, for example, be a heating device that uses reflux of hot water. It is not limited to this, and for example, the carbon dioxide-containing material supplied from the carbon dioxide supply section 11 may be in a heated state. The conditions for the heating and the release of the carbon dioxide may be referred to the description of the first embodiment.

[0047] [Embodiment 3] (Carbon dioxide permeation method) The carbon dioxide permeation method of the present embodiment includes a carbon dioxide supplying step and a carbon dioxide permeation step. The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide permeation step. The carbon dioxide permeation step selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing substance by the carbon dioxide permeation agent. Other configurations and conditions of the carbon dioxide permeation method of the present embodiment are not particularly limited. The carbon dioxide permeation method of the present embodiment can also be referred to as, for example, a carbon dioxide separation method.

[0048] The carbon dioxide permeation method of this embodiment will be described with reference to Fig. 3. Fig. 3 is a flow chart showing an example of the carbon dioxide permeation method. The carbon dioxide permeation method of this embodiment can be carried out as follows, for example, using the carbon dioxide permeation device 1 of Fig. 1. Note that the carbon dioxide permeation method of this embodiment is not limited to the use of the carbon dioxide permeation device 1 of Fig. 1. The flow chart of Fig. 3 is an example of the order of processing of each step, and the present invention is not limited to this order, and each step may be carried out simultaneously or in a different order within a range in which the carbon dioxide permeation reaction can be carried out.

[0049] In the carbon dioxide supply step (S101), a carbon dioxide-containing substance is supplied to the carbon dioxide permeation step (S102) by the carbon dioxide supply unit 11. The carbon dioxide-containing substance is the same as the carbon dioxide-containing substance in the first embodiment.

[0050] Next, the carbon dioxide permeation step (S102) is terminated by selectively permeating the carbon dioxide contained in the supplied carbon dioxide-containing material by the carbon dioxide permeation agent 121 of the carbon dioxide permeation section 12 (END). In the carbon dioxide permeation step (S102), for example, the carbon dioxide may be permeated in a heated state.

[0051] (Carbon dioxide absorption method) The carbon dioxide absorption method of this embodiment (first carbon dioxide absorption method) includes a carbon dioxide supplying step and a carbon dioxide absorbing step. The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide absorbing step. The carbon dioxide absorbing step selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing substance by the carbon dioxide absorbent (first carbon dioxide absorbent), thereby absorbing carbon dioxide in the carbon dioxide absorbing section. Other configurations and conditions of the carbon dioxide absorbing method of this embodiment are not particularly limited.

[0052] [Embodiment 4] (Carbon dioxide absorbent) In recent years, as a measure against the problem of global warming, the development of a technique for separating and capturing carbon dioxide has been promoted. As a method for separating and capturing carbon dioxide, Patent Document 2 discloses a technique for absorbing carbon dioxide into an amine solution containing an amine. Patent Document 2: JP 2021-095357 A

[0053] However, new methods are needed that can separate and capture carbon dioxide.

[0054] In order to achieve the above object, the carbon dioxide absorbent of the present invention (second carbon dioxide absorbent) contains a polymer, The polymer absorbs carbon dioxide.

[0055] The present invention can provide a new carbon dioxide absorbent.

[0056] The carbon dioxide absorbent of the present invention may be in a form in which the polymer contains at least one selected from the group consisting of cellulose, polyethylene terephthalate, high density polyethylene, low density polyethylene, polypropylene, polytetrafluoroethylene, polycarbonate, rubber, polyurethane, and acrylic, for example.

[0057] The carbon dioxide absorbent of the present invention may be in a form in which the polymer releases the absorbed carbon dioxide when heated, for example. The carbon dioxide absorbent of the present invention may be in a form in which the heated state is a state heated to 50° C. or higher, for example.

[0058] The carbon dioxide absorbent of the present embodiment includes a polymer, and the polymer absorbs carbon dioxide (CO2). Other than this point, there is no particular limitation.

[0059] Examples of the polymer include cellulose, polyethylene terephthalate, high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), polycarbonate, rubber, polyurethane, and acrylic. Examples of the rubber include latex. The carbon dioxide absorbent may include one type of the polymer, or may include multiple types of the polymer.

[0060] In the carbon dioxide absorbent of the present embodiment, the content of the polymer is not particularly limited and can be set appropriately.

[0061] The carbon dioxide absorbent may contain, for example, a component other than the polymer. The component other than the polymer is not particularly limited.

[0062] The shape of the carbon dioxide absorbent is not particularly limited, and may be, for example, a container shape, a sheet shape, a mesh shape, a bubble wrap shape, a bead shape, etc. The size of the carbon dioxide absorbent is not particularly limited as long as it can absorb carbon dioxide.

[0063] The carbon dioxide absorbent absorbs carbon dioxide contained in a carbon dioxide-containing substance, for example. The carbon dioxide-containing substance may be a gas, i.e., a carbon dioxide-containing gas, or a liquid, i.e., a carbon dioxide-containing solution. The carbon dioxide-containing gas is not particularly limited, and examples thereof include combustion exhaust gas, indoor air, and atmospheric air. The carbon dioxide concentration in the carbon dioxide-containing gas is not particularly limited, and is greater than 0 and 100% or less. The carbon dioxide-containing solution is not particularly limited, and examples thereof include carbonated water, carbon dioxide water, and the like. In the carbonated water, carbon dioxide exists mainly as carbonate ions and bicarbonate ions. On the other hand, in the carbon dioxide water, carbon dioxide exists in an unionized state. In addition, for example, the carbon dioxide-containing gas may be passed through a liquid such as water. The carbon dioxide concentration in the carbon dioxide-containing solution is not particularly limited, and is greater than 0 and 0.14 g / dl% or less.

[0064] The contact conditions between the carbon dioxide absorbent and the carbon dioxide-containing substance are not particularly limited. For example, the carbon dioxide-containing substance can be placed in a container containing the carbon dioxide absorbent and allowed to stand at room temperature (e.g., 20°C) for 5 hours to allow the contact to occur.

[0065] The temperature at which the carbon dioxide absorbent is brought into contact with the carbon dioxide-containing substance may be, for example, room temperature, or the carbon dioxide absorbent may be cooled.

[0066] The carbon dioxide absorbent increases in volume, for example, by absorbing the carbon dioxide.

[0067] The carbon dioxide absorbent of the present embodiment may also release the absorbed carbon dioxide.

[0068] Specifically, for example, the carbon dioxide absorbent that has absorbed the carbon dioxide can be brought into contact with a gas or liquid containing carbon dioxide at a lower concentration, thereby allowing the absorbed carbon dioxide to be released.

[0069] The release can be carried out, for example, with the polymer in a heated state. The temperature in the heated state is, for example, 5 to 80° C., and specifically, for example, 20° C. or higher, 50° C. or higher. The temperature in the heated state may be, for example, a higher temperature than the temperature at which the carbon dioxide is absorbed.

[0070] For example, the container containing the carbon dioxide absorbent that has absorbed the carbon dioxide can be left standing at 50° C. for 5 hours, thereby allowing the absorbed carbon dioxide to be released.

[0071] [Embodiment 5] (Carbon dioxide absorber) The carbon dioxide absorption device of the present invention includes a carbon dioxide supply unit and a carbon dioxide absorption unit, The carbon dioxide supply unit supplies a carbon dioxide-containing substance to the carbon dioxide absorption unit, The carbon dioxide-containing substance is at least one of a gas and a liquid, The carbon dioxide absorption unit absorbs the carbon dioxide contained in the supplied carbon dioxide-containing material, The carbon dioxide absorbing portion contains the carbon dioxide absorbent of the present invention.

[0072] The carbon dioxide absorbing device of the present invention may have a configuration in which, for example, the carbon dioxide absorbing section is heatable, and the carbon dioxide absorbing section further releases the absorbed carbon dioxide in a heated state.

[0073] Fig. 4 is a schematic diagram showing an example of the carbon dioxide absorbing apparatus 3 of this embodiment. As shown in Fig. 4(A) and (B), the carbon dioxide absorbing apparatus 3 includes a carbon dioxide supply unit 31 and a carbon dioxide absorbing unit 32. The size, forming material, etc. of each component included in the carbon dioxide absorbing apparatus 3 are not particularly limited and can be set appropriately.

[0074] The carbon dioxide supplying section 31 supplies the carbon dioxide-containing substance to the carbon dioxide absorbing section 32. The carbon dioxide-containing substance is the same as the carbon dioxide-containing substance in the fourth embodiment.

[0075] The carbon dioxide supplying unit 31 is not particularly limited as long as it can supply the carbon dioxide-containing substance to the carbon dioxide absorbing unit 32. For example, the carbon dioxide supplying unit 31 may supply the carbon dioxide-containing gas into the carbon dioxide absorbing unit 32, may supply the carbon dioxide-containing solution, or may supply the carbon dioxide-containing gas into the liquid in the carbon dioxide absorbing unit 32. Specifically, the carbon dioxide supplying unit 31 may be, for example, a pipe, a hose, or the like, a vent, or a bubble-shaped gas supplying device such as a bubble former.

[0076] The carbon dioxide absorbing section 32 absorbs the carbon dioxide contained in the supplied carbon dioxide-containing substance. The carbon dioxide absorbing section 32 includes a carbon dioxide absorbent 321. The carbon dioxide absorbent 321 is the carbon dioxide absorbent of the fourth embodiment.

[0077] The carbon dioxide absorbing section 32 may be, for example, a carbon dioxide absorbent 321 itself having a container shape as shown in FIG. 4(A), or may be a container containing a carbon dioxide absorbent 321 having a sheet-like shape or the like as shown in FIG. 4(B).

[0078] 4(A) and (B), the carbon dioxide absorbing device 3 of this embodiment further includes a carbon dioxide releasing section 33. The carbon dioxide releasing section 33 can release, for example, the carbon dioxide absorbed by the carbon dioxide absorbing section 32. Specifically, the carbon dioxide releasing section 33 may be, for example, a pipe, a hose, or the like, or may be an air vent. The carbon dioxide releasing section 33 may have a common structure with the carbon dioxide supplying section 31, for example.

[0079] The carbon dioxide absorbing section 32 may be, for example, heatable. In this case, as shown in Figs. 5(A) and (B), the carbon dioxide absorbing section 32 is heated by the heating section 4. The heating section 4 may or may not be included in the carbon dioxide absorbing device 3. The heating section 4 is not particularly limited as long as it can heat the carbon dioxide absorbing section 32, and a general heating device can be used. The heating section 4 may be, for example, a heating device that uses reflux of hot water. The conditions of the heating and the release of the carbon dioxide can be referred to the description of the fourth embodiment. Then, the carbon dioxide absorbing section 32 can release the absorbed carbon dioxide in a heated state.

[0080] [Embodiment 6] (Carbon dioxide absorption method) The carbon dioxide absorption method of the present invention (second carbon dioxide absorption method) includes a carbon dioxide supply step and a carbon dioxide absorption step, The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide absorbing step, The carbon dioxide-containing substance is at least one of a gas and a liquid, In the carbon dioxide absorbing step, the carbon dioxide contained in the supplied carbon dioxide-containing substance is absorbed by the carbon dioxide absorbent of the present invention.

[0081] The carbon dioxide absorption method of the present invention may further include, for example, a carbon dioxide releasing step, and the carbon dioxide releasing step may be in a form in which the absorbed carbon dioxide is released in a state in which the carbon dioxide absorbent is heated.

[0082] The carbon dioxide absorption method of the present embodiment includes a carbon dioxide supplying step and a carbon dioxide absorbing step. The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide absorbing step. The carbon dioxide absorbing step absorbs the carbon dioxide contained in the supplied carbon dioxide-containing substance by the carbon dioxide absorbent. Other configurations and conditions of the carbon dioxide absorbing method of the present embodiment are not particularly limited.

[0083] The carbon dioxide absorption method of this embodiment will be described with reference to Fig. 6(A). Fig. 6(A) is a flow chart showing an example of the carbon dioxide absorption method. The carbon dioxide absorption method of this embodiment can be carried out as follows, for example, using the carbon dioxide absorption apparatus 3 of Fig. 4. Note that the carbon dioxide absorption method of this embodiment is not limited to the use of the carbon dioxide absorption apparatus 3 of Fig. 4. The flow chart of Fig. 6(A) is an example of the order of processing of each step, and the present invention is not limited to this order, and each step may be carried out simultaneously or in a different order within a range in which the carbon dioxide absorption reaction can be carried out.

[0084] In the carbon dioxide supplying step (S201), a carbon dioxide-containing substance is supplied to the carbon dioxide absorbing step (S202) by the carbon dioxide supply unit 31. The carbon dioxide-containing substance is the same as the carbon dioxide-containing substance in the fourth embodiment.

[0085] Next, in the carbon dioxide absorption step (S202), the carbon dioxide contained in the supplied carbon dioxide-containing substance is absorbed by the carbon dioxide absorbent 321 of the carbon dioxide absorption section 32, and the process ends (END).

[0086] As shown in FIG. 6(B), the carbon dioxide absorption method of the present embodiment may further include a carbon dioxide releasing step (S203).

[0087] The carbon dioxide releasing step (S203) is terminated by releasing the absorbed carbon dioxide with the carbon dioxide absorbent 321 heated by the carbon dioxide releasing section 33 (END). In the carbon dioxide releasing step (S203), for example, the carbon dioxide absorbing section 12 may be heated by the heating section 2.

[0088] Next, examples of the present invention will be described. However, the present invention is not limited to the following examples. Commercially available reagents were used according to their protocols unless otherwise indicated.

[0089] [Example 1] It was confirmed that the polymer was permeable to carbon dioxide.

[0090] Approximately 150 ml of 100% carbon dioxide was placed in a polyethylene (low density polyethylene) bag (0.03 mm and 0.08 mm thick, commercially available). The bag was inserted into a 450 ml wide-mouth glass bottle, and the bottle was sealed with a lid. The bottle was left to stand at room temperature (24° C.) for 30 minutes, 1 hour, 1.5 hours, 2 hours, and 5 hours. After the standing, the carbon dioxide concentration of the gas in the portion between the wall of the glass bottle and the bag was measured using a carbon dioxide detector (XP-3140, COSMO) (for low concentration) and (CX-6000, RIKEN KEIKI) (for high concentration).

[0091] The results are shown in Figure 12. Figure 12 is a graph showing the carbon dioxide concentration. In Figure 12, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, 30 minutes, 1 hour, 1.5 hours, 2 hours, and 5 hours. The open graph shows the results when the bag thickness was 0.08 mm, and the closed graph shows the results when the bag thickness was 0.03 mm. The carbon dioxide concentration value was the average value of the measured values ​​for a total of four samples.

[0092] As shown in Figure 12, when the thickness of the bag was 0.03 mm, the carbon dioxide concentration reached 6.8% after 30 minutes and 11.3% after 5 hours. When the thickness of the bag was 0.08 mm, the carbon dioxide concentration was low at 0.75% after 30 minutes, but increased with increasing standing time, reaching 11.3% after 5 hours.

[0093] The results show that carbon dioxide permeates the polyethylene bag, and that the permeation is related to the thickness of the polyethylene bag.

[0094] Next, an experiment was conducted in the same manner except that the experimental conditions were 50° C., the standing time was 30 minutes, and the thickness of the polyethylene bag was 0.08 mm.

[0095] The results are shown in Figure 13. Figure 13 is a graph showing the carbon dioxide concentration. In Figure 13, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, 24°C and 50°C. The carbon dioxide concentration value was the average value of the measured values ​​of a total of five samples.

[0096] As shown in Fig. 13, when the temperature was 50°C, the carbon dioxide concentration reached 6.5% after 30 minutes, which was a large increase compared to the result when the temperature was 24°C. The result when the temperature was 50°C was similar to the result when the 0.03 mm polyethylene bag was used at 24°C.

[0097] From this result, it was found that the permeation of carbon dioxide through the polyethylene bag is temperature dependent.

[0098] As described above, it was confirmed that the polymer allows carbon dioxide to permeate.

[0099] [Example 2] It was confirmed that the rubber was permeable to carbon dioxide.

[0100] 150 ml of 100% carbon dioxide was injected under pressure into a rubber (latex) glove (commercially available). The glove was sealed and left to stand at room temperature for 2 hours and 6 hours. The volume of the glove was measured immediately after sealing and after leaving it to stand. The volume was measured by filling a container with water, submerging the glove in the water, measuring the amount of water displaced, and recording it as the volume of the glove. The volume immediately after sealing was set to 1, and the ratio of the volume of the glove after leaving it to stand was calculated as a relative value.

[0101] The results are shown in Figure 14. Figure 14 is a graph showing the volume of the glove. In Figure 14, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the values ​​immediately after sealing, 2 hours, and 6 hours later. The volume value was the average value of the measured values ​​of a total of 4 samples.

[0102] As shown in Figure 14, the volume of the glove expanded with carbon dioxide decreased over time. The volume of the glove immediately after sealing was 600 to 700 ml. This result shows that carbon dioxide permeates the rubber (latex) glove over time.

[0103] Next, an experiment was conducted in the same manner, except that a rubber balloon (commercially available) was used.

[0104] The results are shown in Figure 15. Figure 15 is a graph showing the volume of the balloon. In Figure 15, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, immediately after sealing, 1 hour, 2 hours, and 5 hours later. The volume value was the average value of the measured values ​​for a total of three samples.

[0105] As shown in Figure 15, the volume of the balloon inflated with carbon dioxide decreased over time. This result indicates that carbon dioxide permeates the rubber balloon over time.

[0106] As described above, it was confirmed that rubber allows carbon dioxide to pass through.

[0107] [Example 3] It was confirmed that rubber selectively allows carbon dioxide to permeate. It was also confirmed that a rubber membrane and water can be used to separate a mixture of carbon dioxide, hydrogen, and methane into individual gases.

[0108] A rubber balloon (commercially available) was inflated to a moderate level by human breath. The balloon was sealed and placed in a 4-liter glass bottle filled with 80% carbon dioxide and allowed to stand for 5 hours. The balloon was then removed from the glass bottle and allowed to stand in a room for 4 hours. The volume of the balloon was calculated immediately after the inflation, after the standing under carbon dioxide, and after the standing in the room in the same manner as in Example 2.

[0109] The results are shown in Figure 16. Figure 16 is a graph showing the volume of the balloon. In Figure 16, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, immediately after the expansion, after standing still under the carbon dioxide, and after standing still in the room. The volume value was the average value of the measured values ​​of a total of five samples.

[0110] As shown in FIG. 16, the balloon, which had been inflated to a moderate level, was left standing under the high concentration of carbon dioxide, and after 5 hours, the balloon expanded to about 1.8 times its volume. After 4 hours of standing in the room, the volume of the balloon decreased to about the same volume as immediately after the expansion. Even if the balloon was left in the room after standing in the room, there was no further decrease in volume. This result showed that the rubber balloon selectively allows carbon dioxide to pass through, but does not allow substances other than carbon dioxide (e.g., oxygen and nitrogen) to pass through.

[0111] Next, the rubber balloon was used to confirm the permeation of carbon dioxide into liquid.

[0112] 200 to 450 ml of 100% carbon dioxide was poured into a rubber balloon in the same manner as in Example 2. The balloon was placed in a 450 ml wide-mouth glass bottle, and the space between the balloon and the wall of the glass bottle was filled with water until the volume was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 4 hours, 8 hours, and 21 hours. The volume of the balloon was calculated immediately after sealing and after leaving the bottle to stand in the same manner as in Example 2.

[0113] The results are shown in Figure 25. Figure 25 is a graph showing the volume of the balloon. In Figure 25, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, 4 hours, 8 hours, and 21 hours. The volume value was the average value of the measured values ​​of a total of 4 samples.

[0114] As shown in Figure 25, 60% of the carbon dioxide was released after 4 hours of standing, and 75% of the carbon dioxide was released after 8 hours. After 21 hours, the carbon dioxide in the balloon was almost completely released. Thus, the permeation of carbon dioxide into liquid was confirmed using the rubber balloon.

[0115] Next, using the rubber balloon, it was confirmed that the balloon was permeable to hydrogen and that the permeation rate of hydrogen was slower than the permeation rate of carbon dioxide.

[0116] 100% hydrogen was similarly injected into a rubber balloon. The balloon was sealed and left at room temperature for 5 hours and 10 hours. The volume of the balloon was measured immediately after sealing and after leaving the balloon.

[0117] The results are shown in Figure 26. Figure 26 is a graph showing the volume of the balloon. In Figure 26, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour and 10 hour times. The volume value shows the measured value of one sample.

[0118] As shown in FIG. 26, after standing for 5 hours, the volume of the balloon was significantly reduced compared to that immediately after sealing, and the relative value of the volume was 0.71. After standing for 10 hours, the volume was further reduced, and the relative value of the volume was 0.44. This shows that the rubber balloon is permeable to hydrogen. As mentioned above, when carbon dioxide was used, the relative value of the volume was 0.42 after standing for 4 hours. This shows that the permeation rate of carbon dioxide is faster than that of hydrogen. This shows that carbon dioxide can selectively permeate the balloon.

[0119] Next, using the rubber balloon, it was confirmed that the balloon was permeable to methane and that the permeation rate of methane was slower than the permeation rate of carbon dioxide.

[0120] 100% methane (manufactured by AS ONE Corporation) was poured into a rubber balloon in the same manner. The balloon was sealed and left to stand at room temperature for 5, 10, and 15 hours. The volume of the balloon was measured immediately after sealing and after leaving it to stand.

[0121] The results are shown in Figure 28. Figure 28 is a graph showing the volume of the balloon. In Figure 28, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour, 10 hour, and 15 hour times. The volume value was the average value of the measured values ​​of a total of 4 samples.

[0122] As a result, after 5 hours of standing, the volume of the balloon was slightly decreased compared to that immediately after sealing, and the relative value of the volume was 0.91. After 10 hours of standing, the volume was further slightly decreased, and the relative value of the volume was 0.79. After 15 hours of standing, the volume was further slightly decreased, and the relative value of the volume was 0.66. This shows that the rubber balloon is permeable to methane. As mentioned above, when carbon dioxide was used, the relative value of the volume was 0.42 after 4 hours of standing. This shows that the permeation rate of carbon dioxide is faster than that of methane. The above shows that carbon dioxide can selectively permeate the balloon.

[0123] Next, using the rubber balloon, it was confirmed that hydrogen does not permeate from the gas phase to the liquid phase.

[0124] 100% hydrogen was poured into a rubber balloon in the same manner. After placing the balloon in a 450 ml wide-mouth glass bottle, the space between the balloon and the wall of the glass bottle was filled with water until the volume was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the balloon was calculated in the same manner immediately after sealing and after leaving it to stand.

[0125] As a result, even after leaving it still for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that hydrogen does not permeate from the gas phase to the liquid phase in the rubber balloon.

[0126] Next, using the rubber balloon, it was confirmed that methane does not permeate from the gas phase to the liquid phase.

[0127] 100% methane (manufactured by AS ONE) was poured into a rubber balloon in the same manner. After placing the balloon in a 450 ml wide-mouth glass bottle, the space between the balloon and the wall of the glass bottle was filled with water until the volume was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the balloon was calculated in the same manner immediately after sealing and after leaving it to stand.

[0128] As a result, even after leaving it still for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that methane does not permeate from the gas phase to the liquid phase in the rubber balloon.

[0129] As described above, it was confirmed that rubber selectively allows carbon dioxide to permeate. It was also confirmed that a mixed gas of carbon dioxide, hydrogen, and methane can be separated into each gas by using a rubber membrane and water.

[0130] [Example 4] It was confirmed that polyethylene allows carbon dioxide in liquid to pass through. It was also confirmed that a polyethylene membrane and water can be used to separate each gas from a mixed gas of carbon dioxide, hydrogen, and methane.

[0131] First, the permeation of carbon dioxide through the polyethylene bag was confirmed by measuring the volume of the polyethylene bag.

[0132] A polyethylene bag (0.04 mm thick, commercially available) was inflated to a moderate level by human breath. The bag was sealed, placed in a 4-liter glass bottle filled with 80% carbon dioxide, and left to stand for 5 hours. The bag was then removed from the glass bottle and left to stand in a room for 4 and 9 hours. The volume of the bag was calculated immediately after the inflation, after the standing under carbon dioxide, and after the standing in the room, in the same manner as in Example 2.

[0133] The results are shown in Figure 34. Figure 34 is a graph showing the volume of the bag. In Figure 34, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, immediately after the expansion, after standing under the carbon dioxide, and after standing in the room for 4 and 9 hours. The volume value was the average value of the measured values ​​of a total of 4 samples.

[0134] As shown in Fig. 34, the bag, which had been moderately expanded, was left standing under the high concentration of carbon dioxide, and after 5 hours, the bag expanded to about 1.5 times its volume. After 4 hours of standing in the room, the volume of the bag decreased, and after 2 hours of standing in the room, it became about 1.2 times the volume immediately after the expansion. After 9 hours of standing in the room, it became about the same volume as immediately after the expansion. This result shows that the polyurethane bag selectively allows carbon dioxide to pass through, but does not allow substances other than carbon dioxide (for example, oxygen and nitrogen) to pass through.

[0135] Next, it was confirmed that polyethylene allows carbon dioxide in liquid to permeate.

[0136] 150 ml of carbon dioxide water (commercially available) was placed in a polyethylene bag (0.04 mm thick, commercially available; hereinafter, polyethylene bags are also referred to as "poly bags"). The bag was inserted into a 450 ml wide-mouth glass bottle, and the bottle was sealed with a lid. This was left to stand at room temperature for 10 minutes, 30 minutes, 1 hour, 2 hours, and 3 hours. After the standing, the carbon dioxide concentration of the gas in the portion between the wall of the glass bottle and the bag was measured.

[0137] The results are shown in Figure 17. Figure 17 is a graph showing the carbon dioxide concentration. In Figure 17, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, 10 minutes, 30 minutes, 1 hour, 2 hours, and 3 hours. The carbon dioxide concentration value was the average value of the measured values ​​of a total of four samples.

[0138] As shown in Figure 17, the carbon dioxide concentration increased almost over time. No water (liquid) was released from the bag. This shows that carbon dioxide was released from the carbon dioxide water, which was liquid, through the bag and into the space inside the glass bottle.

[0139] Next, an experiment was conducted in the same manner, except that the portion between the wall of the glass bottle and the bag was liquid instead of gas. 150 ml of the carbon dioxide water was placed in the polyethylene bag (thickness 0.04 mm). The bag was inserted into a 450 ml wide-mouth glass bottle, and water was placed between the wall of the glass bottle and the bag to the full capacity, and the bottle was sealed with a lid. This was left to stand at room temperature for 14 hours. After the standing, the carbon dioxide concentration was calculated for the strong carbonated water in the bag (internal liquid) and the liquid in the portion between the wall of the glass bottle and the bag (external liquid). The carbon dioxide concentration was calculated indirectly by placing 1.8 ml of each liquid in a test tube, adding a mixed liquid containing 0.2 ml of a 1N NaOH aqueous solution and 2 ml of a 0.1 mol / l CaCl2 aqueous solution to the test tube, and weighing the precipitate formed by the addition.

[0140] The results are shown in Figure 18. Figure 18 is a graph showing the carbon dioxide concentration. In Figure 18, the vertical axis shows the weight of the precipitate (g / tube), and the horizontal axis shows, from the left, the external liquid and the internal liquid. The carbon dioxide concentration value was the average value of the measured values ​​of a total of five samples.

[0141] As shown in Figure 18, high carbon dioxide concentrations were detected not only in the carbon dioxide water (internal liquid) in the bag, but also in the liquid (external liquid) between the wall of the glass bottle and the bag. This result indicates that carbon dioxide moved between the liquids via the bag.

[0142] Next, the polyethylene bag was used to confirm that the bag was permeable to hydrogen.

[0143] 100% hydrogen was poured into the polyethylene bag in the same manner. The bag was sealed and left to stand at room temperature for 5 hours and 10 hours. The volume of the bag was measured immediately after sealing and after leaving the bag.

[0144] The results are shown in Figure 29. Figure 29 is a graph showing the volume of the bag. In Figure 29, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour and 10 hour times. The carbon dioxide concentration value was the average value of the measured values ​​of a total of 4 samples.

[0145] As shown in FIG. 29, after standing for 5 hours, the volume of the bag significantly decreased compared to immediately after sealing, and the relative value of the volume was 0.7. After standing for 10 hours, the volume further decreased, and the relative value of the volume was 0.36. This shows that the polyethylene bag is permeable to hydrogen. As described above, when carbon dioxide is absorbed from the outside of the polyethylene bag, the relative value of the volume becomes 1.5 times after standing for 5 hours, and it was confirmed that the permeation rate is fast. This suggests that the permeation rate of carbon dioxide is faster than that of hydrogen. The above shows that carbon dioxide can selectively permeate the membrane.

[0146] Next, using the polyethylene bag, it was confirmed that the bag was slightly permeable to methane.

[0147] 100% methane (manufactured by AS ONE Corporation) was poured into the polyethylene bag in the same manner. The bag was sealed and left to stand at room temperature for 5 hours, 10 hours, and 15 hours. The volume of the bag was measured immediately after sealing and after leaving it to stand.

[0148] The results are shown in Figure 30. Figure 30 is a graph showing the volume of the bag. In Figure 30, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour, 10 hour, and 15 hour times. The carbon dioxide concentration value was the average value of the measured values ​​of a total of 4 samples.

[0149] As a result, after 5 hours of standing, the volume of the bag did not change compared to immediately after sealing, and the relative value of the volume was 1.0. After 10 hours of standing, the relative value of the volume was 0.99. After 15 hours of standing, the volume slightly decreased, and the relative value of the volume was 0.83. This shows that the polyethylene bag is slightly permeable to methane. As mentioned above, when carbon dioxide is absorbed from the outside of the polyethylene bag, the relative value of the volume becomes 1.5 times after 5 hours of standing, and it was confirmed that the permeation rate is fast. From this, it is considered that the permeation rate of carbon dioxide is faster than that of methane. From the above, it was shown that carbon dioxide can selectively permeate the membrane.

[0150] Next, using the polyethylene bag, it was confirmed that hydrogen does not permeate from the gas phase to the liquid phase.

[0151] 100% hydrogen was poured into the polyethylene bag in the same manner. After placing the bag in a 450 ml wide-mouthed glass bottle, water was poured into the space between the bag and the wall of the glass bottle until the bottle was full, and the bottle was sealed with a lid. After pouring water in the same manner, the bag was left submerged in water without the lid on. Each of these was left standing at room temperature for 24 hours. The volume of the bag was calculated in the same manner immediately after sealing and after leaving the bag standing.

[0152] As a result, in both the case where the lid was placed and the case where the lid was not placed, even after the 24-hour standing, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that hydrogen does not permeate from the gas phase to the liquid phase in the polyethylene bag.

[0153] Next, using the polyethylene bag, it was confirmed that methane does not permeate from the gas phase to the liquid phase.

[0154] 100% methane (manufactured by AS ONE Corporation) was poured into the polyethylene bag in the same manner. After placing the bag in a 450 ml wide-mouth glass bottle, the space between the wall of the glass bottle and the bag was filled with water until the bottle was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the bag was calculated in the same manner immediately after sealing and after leaving the bag.

[0155] As a result, even after leaving the bag to stand for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that methane does not permeate from the gas phase to the liquid phase in the polyethylene bag.

[0156] As described above, it was confirmed that polyethylene allows carbon dioxide in liquid to permeate. It was also confirmed that a mixed gas of carbon dioxide, hydrogen, and methane can be separated into each gas by using a polyethylene membrane and water.

[0157] [Example 5] It was confirmed that the cellulose membrane selectively allows the permeation of carbon dioxide. It was also confirmed that the cellulose membrane allows the permeation of hydrogen and methane, and that the cellulose membrane and water can be used to separate each gas from a mixed gas of carbon dioxide, hydrogen, and methane.

[0158] A Visking tube (cellulose dialysis membrane) (manufactured by Sanko Junyaku Co., Ltd.) with both ends closed was filled with 60 ml of 100% carbon dioxide. The Visking tube was sealed and allowed to stand at room temperature for 10, 20, and 30 minutes. The volume of the Visking tube was calculated immediately after sealing and after leaving it standing in the same manner as in Example 2.

[0159] The results are shown in Figure 19. Figure 19 is a graph showing the volume of the Visking tube. In Figure 19, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, immediately after sealing (0), 30 minutes, and 60 minutes. The volume value was the average value of the measured values ​​for a total of four samples.

[0160] As shown in Figure 19, after 30 minutes of standing, the volume was reduced to about 25%, and after 60 minutes of standing, the volume was reduced to a few percent, indicating that the release of carbon dioxide from the Visking tube was extremely fast.

[0161] Next, the concentration of carbon dioxide released from the Visking tube was measured. 60 ml of 100% carbon dioxide was filled into the Visking tube with both ends closed. The Visking tube was sealed, placed in a 450 ml glass bottle, and left to stand at room temperature for 10 minutes and 20 minutes. After the standing, the carbon dioxide concentration was measured for the gas in the portion between the wall of the glass bottle and the Visking tube.

[0162] The results are shown in Figure 20. Figure 20 is a graph showing the carbon dioxide concentration. In Figure 20, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, immediately after sealing (0), 10 minutes, and 20 minutes. The carbon dioxide concentration value was the average value of the measured values ​​of a total of four samples.

[0163] As shown in FIG. 20, after 10 minutes of standing, the carbon dioxide concentration in the glass bottle increased, and increased further after 20 minutes.

[0164] Next, it was confirmed that the Visking tube also allows carbon dioxide to permeate from the outside to the inside. 30 ml of air was put into the Visking tube and sealed, and the Visking tube was placed in a glass bottle with a volume of 4 L, and then the space between the wall of the glass bottle and the Visking tube was filled with 80% carbon dioxide. This was left to stand at room temperature for 1 hour (1-hour absorption). Then, it was left to stand in a room for 1 hour and 2 hours (1-hour release and 2-hour release). After the standing, the volume of the Visking tube was measured.

[0165] The results are shown in Figure 21. Figure 21 is a graph showing the volume of the sealed Visking tube. In Figure 21, the vertical axis shows the relative value of the volume to that immediately after sealing, and the horizontal axis shows, from the left, after standing for 1 hour (1-hour absorption), and after standing for 1 hour and 2 hours in a room (1-hour release, and 2-hour release). The volume value was the average value of the measured values ​​for a total of 4 samples.

[0166] As shown in Figure 21, the volume of the Visking tube after standing for 1 hour (1-h absorption) was approximately 2.3 times that of the volume immediately after sealing. When the Visking tube was left standing in a room, the volume rapidly decreased, and returned to the original volume after 1 hour (1-h release). Furthermore, even when left for a further period (2-h release), no further decrease in volume was observed. This demonstrated that the Visking tube selectively allows carbon dioxide to pass through (absorb and release).

[0167] Next, it was confirmed that carbon dioxide between the liquids permeated the Visking tube. 60 ml of the carbon dioxide water was placed in the Visking tube. The Visking tube was inserted into a wide-mouthed glass bottle with a volume of 450 ml, and water was added to the space between the wall of the glass bottle and the Visking tube up to the full capacity, and the bottle was sealed with a lid. This was left to stand at room temperature for 5 hours. After the standing, the carbon dioxide concentration was calculated for the strong carbonated water (internal liquid) in the Visking tube and the liquid (external liquid) in the portion between the wall of the glass bottle and the Visking tube. The carbon dioxide concentration was calculated indirectly by placing 1.8 ml of each of the liquids in a test tube, adding a mixed liquid containing 0.2 ml of a 1N NaOH aqueous solution and 2 ml of a 0.1 mol / l CaCl2 aqueous solution to the test tube, and weighing the precipitate formed by the addition.

[0168] The results are shown in Figure 23. Figure 23 is a graph showing the carbon dioxide concentration. In Figure 23, the vertical axis shows the weight of the precipitate (g / tube), and the horizontal axis shows, from the left, the external liquid (Outside) and the internal liquid (Inside). The carbon dioxide concentration value was the average value of the measured values ​​of a total of four samples.

[0169] As shown in Figure 23, high carbon dioxide concentrations were detected not only in the strongly carbonated water (internal liquid) in the Visking tube, but also in the liquid (external liquid) between the wall of the glass bottle and the Visking tube. This result indicates that carbon dioxide was transferred between the liquids via the Visking tube.

[0170] Next, using the Visking tube, it was confirmed that the permeation rate of hydrogen was slower than the permeation rate of carbon dioxide.

[0171] 34 to 50 ml of 100% hydrogen was placed in the Visking tube and sealed. The Visking tube was inserted into a wide-mouth glass bottle with a volume of 450 ml, and the bottle was then capped and sealed. This was left to stand at room temperature for 4, 8, and 12 hours. Similarly, the bottle was left to stand at room temperature for 5 and 10 hours. The volume of the Visking tube was calculated immediately after sealing and after leaving the bottle to stand in the same manner as in Example 2.

[0172] The results are shown in Figures 24(A) and (B). Figures 24 and (B) are graphs showing the volume of the Visking tube. In Figure 24(A), the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, 4, 8, and 12 hours. The volume value is the average value of the measured values ​​of a total of four samples. In Figure 24(B), the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, 5 and 10 hours. The volume value is the average value of the measured values ​​of a total of four samples.

[0173] As shown in Figure 24(A), after 4 hours of standing, the volume was reduced to about 60%. After 8 hours and 12 hours of standing, the volume was reduced to 40% and 32%, respectively. The results in Figure 24(B) were similar. As mentioned above, when a similar experiment was performed using carbon dioxide, the volume was reduced to about 25% after 30 minutes of standing. This shows that the release of hydrogen from the Visking tube is slower than the release of carbon dioxide.

[0174] Here, hydrogen has a small molecular size, so from the viewpoint of molecular sieving, it can be said that it easily permeates the membrane. Despite this, the results show that the permeation rate of carbon dioxide is faster than that of hydrogen. From the above, it was shown that carbon dioxide can selectively permeate the membrane.

[0175] Next, using the Visking tube, it was confirmed that the permeation rate of methane was slower than the permeation rate of carbon dioxide.

[0176] 34 to 50 ml of 100% methane (manufactured by AS ONE Corporation) was placed in the Visking tube and sealed. The Visking tube was inserted into a wide-mouth glass bottle with a volume of 450 ml, and the bottle was then capped and sealed. This was allowed to stand at room temperature for 5, 10, and 15 hours. The volume of the Visking tube was calculated in the same manner immediately after sealing and after leaving the bottle standing.

[0177] The results are shown in Figure 27. Figure 27 is a graph showing the volume of the Visking tube. In Figure 27, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, 5, 10, and 15 hours. The volume value was the average value of the measured values ​​of a total of four samples.

[0178] As shown in Fig. 27, after the 5-hour standing, the volume hardly decreased, and the relative value of the volume was 0.97. After the 10-hour and 15-hour standing, the relative values ​​were 0.86 and 0.77, respectively. As mentioned above, when a similar experiment was performed using carbon dioxide, the volume decreased to about 25% after the 30-minute standing. This indicates that the release of methane from the Visking tube is slower than the release of carbon dioxide.

[0179] Here, methane also has a smaller molecular size than carbon dioxide, so from the viewpoint of molecular sieving, it can be said to be easy to permeate the membrane. Despite this, the results show that the permeation rate of carbon dioxide is faster than that of methane. From the above, it was shown that carbon dioxide can selectively permeate the membrane.

[0180] Next, using the Visking tube, it was confirmed that hydrogen does not permeate from the gas phase to the liquid phase.

[0181] 100% hydrogen was similarly placed in the Visking tube and sealed. After placing the Visking tube in a 450 ml wide-mouth glass bottle, water was added to the space between the wall of the glass bottle and the Visking tube until the volume was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the Visking tube was calculated in the same manner as in Example 2 immediately after sealing and after leaving the bottle to stand.

[0182] As a result, even after leaving it still for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that hydrogen does not permeate from the gas phase to the liquid phase in the cellulose bag.

[0183] Next, using the Visking tube, it was confirmed that methane does not permeate from the gas phase to the liquid phase.

[0184] 100% methane (manufactured by AS ONE) was similarly placed in the Visking tube and sealed. After placing the Visking tube in a 450 ml wide-mouth glass bottle, water was added to the space between the wall of the glass bottle and the Visking tube until the volume was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the Visking tube was calculated in the same manner as in Example 2 immediately after sealing and after leaving the bottle to stand.

[0185] As a result, even after leaving the bag for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that methane does not permeate from the gas phase to the liquid phase in the cellulose bag.

[0186] As described above, it was confirmed that the cellulose membrane allows selective permeation of carbon dioxide. It was also confirmed that the cellulose membrane allows permeation of hydrogen and methane, and that the cellulose membrane and water can be used to separate each gas from a mixed gas of carbon dioxide, hydrogen, and methane.

[0187] [Example 6] It was confirmed that polyurethane selectively allows carbon dioxide to pass through. It was also confirmed that a mixture of carbon dioxide, hydrogen, and methane can be separated into individual gases by using a polyurethane bag and water.

[0188] A polyurethane bag (0.02 mm thick, commercially available) was inflated to a moderate level by human breath. The bag was sealed, placed in a 4-liter glass bottle filled with 80% carbon dioxide, and left to stand for 2 hours. Thereafter, the bag was removed from the glass bottle and left to stand in a room for 1, 2, and 4 hours. The volume of the bag was calculated immediately after the inflation, after the standing under carbon dioxide, and after the standing in the room, in the same manner as in Example 2.

[0189] The results are shown in Figure 31. Figure 31 is a graph showing the volume of the bag. In Figure 31, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, immediately after the expansion, after standing under the carbon dioxide, and after standing in the room for 1, 2, and 4 hours. The volume value was the average value of the measured values ​​for a total of three samples.

[0190] As shown in Fig. 31, the bag, which had been moderately expanded, was left standing under the high concentration of carbon dioxide, and after standing for two hours, the bag expanded to about 2.3 times its volume. After standing for one hour in the room, the volume of the bag decreased, and after standing for two hours in the room, it became about the same volume (1.05) as immediately after the expansion. In addition, after standing for four hours in the room, it was still about the same volume as immediately after the expansion. This result showed that the polyurethane bag selectively allows carbon dioxide to pass through, but does not allow substances other than carbon dioxide (for example, oxygen and nitrogen) to pass through.

[0191] Next, using the polyurethane bag, it was confirmed that the bag was permeable to hydrogen and that the permeation rate of hydrogen was slower than the permeation rate of carbon dioxide.

[0192] 100% hydrogen was poured into the polyurethane bag in the same manner. The bag was sealed and left to stand at room temperature for 5 hours and 10 hours. The volume of the bag was measured immediately after sealing and after standing.

[0193] The results are shown in Figure 32. Figure 32 is a graph showing the volume of the bag. In Figure 32, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour and 10 hour times. The carbon dioxide concentration value was the average value of the measured values ​​of a total of 4 samples.

[0194] As shown in FIG. 32, after standing for 5 hours, the volume of the bag significantly decreased compared to immediately after sealing, and the relative value of the volume was 0.47. After standing for 10 hours, the volume further decreased, and the relative value of the volume was 0.26. This shows that the polyurethane bag is permeable to hydrogen. As described above, the bag expanded to about 2.3 times by the high concentration of carbon dioxide, and when it was left standing for 2 hours indoors, the volume became approximately the same as the volume before expansion by the high concentration of carbon dioxide (1.05). That is, the relative value of the volume became 1.05÷2.3=0.46. This shows that the permeation rate of carbon dioxide is faster than the permeation rate of hydrogen. The above shows that carbon dioxide can selectively permeate the bag.

[0195] Next, using the polyurethane bag, it was confirmed that the bag was permeable to methane and that the permeation rate of methane was slower than the permeation rate of carbon dioxide.

[0196] 100% methane (manufactured by AS ONE Corporation) was poured into the polyurethane bag in the same manner. The bag was sealed and left to stand at room temperature for 5 hours, 10 hours, and 15 hours. The volume of the bag was measured immediately after sealing and after leaving it to stand.

[0197] The results are shown in Figure 33. Figure 33 is a graph showing the volume of the bag. In Figure 33, the vertical axis shows the relative value of the volume, and the horizontal axis shows, from the left, the 5 hour, 10 hour, and 15 hour times. The carbon dioxide concentration value was the average value of the measured values ​​of a total of four samples.

[0198] As a result, after 5 hours of standing, the volume of the bag decreased compared to that immediately after sealing, and the relative value of the volume was 0.76. After 10 hours of standing, the volume further decreased, and the relative value of the volume was 0.6. After 15 hours of standing, the volume further decreased, and the relative value of the volume was 0.39. This shows that the polyethylene bag is permeable to methane. As described above, the bag expanded to about 2.3 times by the high concentration of carbon dioxide, and when the bag was left standing for 2 hours indoors, the volume became approximately the same as that before the expansion by the high concentration of carbon dioxide (1.05). That is, the relative value of the volume became 1.05÷2.3=0.46. This shows that the permeation rate of carbon dioxide is faster than that of methane. The above shows that carbon dioxide can selectively permeate the bag.

[0199] Next, it was confirmed that hydrogen does not permeate from the gas phase to the liquid phase using the polyurethane bag.

[0200] 100% hydrogen was poured into the polyurethane bag in the same manner. After placing the bag in a 450 ml wide-mouth glass bottle, water was poured into the space between the glass bottle wall and the bag until the bottle was full, and the bottle was sealed with a lid. The bag was left to stand at room temperature for 24 hours. The volume of the bag was calculated in the same manner immediately after sealing and after leaving the bag.

[0201] As a result, even after leaving it still for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that hydrogen does not permeate from the gas phase to the liquid phase in the polyurethane bag.

[0202] Next, it was confirmed that methane does not permeate from the gas phase to the liquid phase using the polyurethane bag.

[0203] 100% methane (manufactured by AS ONE Corporation) was poured into the polyurethane bag in the same manner. After placing the bag in a 450 ml wide-mouth glass bottle, the space between the wall of the glass bottle and the bag was filled with water until the bottle was full, and the bottle was sealed with a lid. This was left to stand at room temperature for 24 hours. The volume of the bag was calculated in the same manner immediately after sealing and after leaving the bag.

[0204] As a result, even after leaving the bag to stand for 24 hours, the relative volume compared to the volume immediately after sealing was 1, and the standard deviation was about 0. This confirmed that methane does not permeate from the gas phase to the liquid phase in the polyurethane bag.

[0205] As described above, it was confirmed that polyurethane selectively allows carbon dioxide to permeate. It was also confirmed that by using a polyurethane bag and water, it is possible to separate each gas from a mixed gas of carbon dioxide, hydrogen, and methane. [Example 7] It was confirmed that the volume of the carbon dioxide permeable agent having a bubble structure was changed by passing carbon dioxide into the bubble structure.

[0206] As a carbon dioxide absorbent, a foam packaging material (bubble wrap) (made of polyethylene, size: 10x60cm, commercially available) was used. Two types of foam packaging materials were used: a double-structured one with a cover covering the bubble structure (Babble Wrap II) and one without a cover covering the bubble structure (Babble Wrap I). The foam packaging materials were washed with tap water, and then rolled up and placed in a 300ml wide-mouthed glass bottle with a lid (commercially available). The glass bottle was filled with strong carbonated water (commercially available) to the fullest capacity, sealed, and left at room temperature for 5 hours. Thereafter, the glass bottle was filled with tap water to the fullest capacity with the foam packaging material inside, and then immediately removed, thereby washing the bottle a total of three times. Furthermore, after the three washings, the container was sealed and left at rest for 5 hours in a thermostatic device heated to 50°C, and then left at room temperature. When the temperature inside the container reached room temperature, the carbon dioxide concentration was measured.

[0207] In addition, an experiment was conducted in the same manner, except that 100% carbon dioxide was thoroughly pumped into the glass bottle to fill it with carbon dioxide instead of the strongly carbonated water.

[0208] These results are shown in Figure 9. Figure 9 is a graph showing the carbon dioxide concentration. In Figure 9, the vertical axis shows carbon dioxide concentration (%), and on the horizontal axis, the left side shows the foam packaging material without the cover (Babble Wrap I), and the right side shows the foam packaging material with the double structure (Babble Wrap II). The open graph shows the results for strong carbonated water, and the closed graph shows the results for 100% carbon dioxide. The carbon dioxide concentration value was the average value of the measured values ​​for a total of four samples.

[0209] As shown in FIG. 9, when strong carbonated water was used and when 100% carbon dioxide was used, a significant amount of carbon dioxide was released from the two foam packaging materials.

[0210] Next, the change in the volume of the carbon dioxide absorbent due to the above experiment was measured. First, in the same manner as in the above experiment, the above foam packaging material (Babble Wrap II) was used as the carbon dioxide absorbent, and after treatment with strong carbonated water was performed at room temperature for 5 hours, washing was performed three times. After the washing, the glass bottle containing the foam packaging material was filled with water to its full capacity. The volume of the water was measured by transferring the entire amount of the water to a graduated cylinder. In addition, the glass bottle not containing the foam packaging material was filled with water to its full capacity, and the volume of the water was measured in the same manner. Then, the volume of the foam packaging material after carbon dioxide absorption was calculated by subtracting the volume of the water in the glass bottle containing the foam packaging material after carbon dioxide absorption from the volume of the water in the glass bottle not containing the foam packaging material. Next, in the same manner as in the above experiment, the glass bottle containing the foam packaging material after carbon dioxide absorption was heated at 50°C for 5 hours and then allowed to cool. After the heat release, the glass bottle and the foam packaging material were washed three times with tap water in the same manner. After the cleaning, the glass bottle containing the foam packaging material was filled with water to the full capacity, and the volume of the water was measured in the same manner.The volume of the foam packaging material after the release of carbon dioxide was calculated by subtracting the volume of the water in the glass bottle containing the foam packaging material after the release of carbon dioxide from the volume of the water in the glass bottle without the foam packaging material.

[0211] Then, the volume of the foamed packaging material after the carbon dioxide was released was subtracted from the volume of the foamed packaging material after the carbon dioxide was absorbed to calculate the reduction in the volume of the carbon dioxide absorbent due to the release of carbon dioxide.

[0212] These results are shown in Figure 10. Figure 10 is a graph showing the amount of volume reduction of the carbon dioxide absorbent due to the release of carbon dioxide. In Figure 10, the vertical axis shows the amount of volume reduction (ml) of the carbon dioxide absorbent. The value of the amount of volume reduction was taken as the average value of the measured values ​​of a total of eight samples.

[0213] As shown in Fig. 10, the volume of the foam packaging material, which is the carbon dioxide absorbent, decreased by 65 ml as carbon dioxide was released. From this, it is considered that the volume of the carbon dioxide absorbent increases as carbon dioxide is absorbed into the bubble structure, and the increased volume of the carbon dioxide absorbent decreases as carbon dioxide is released from the bubble structure.

[0214] As described above, it was confirmed that the volume of the carbon dioxide permeable agent having a bubble structure changes when carbon dioxide is permeated into the bubble structure.

[0215] [Reference example 1] It was confirmed that carbon dioxide (CO2) is absorbed into a resin container, and that carbon dioxide is released from the resin container that has absorbed carbon dioxide.

[0216] A polyethylene terephthalate container (PET bottle) containing 500 ml of strong carbonated water (product name: Strong Carbonated Water, manufactured by Kimura Beverage Co., Ltd.) was prepared. The container containing the strong carbonated water was a commercially available one that had been left to stand for one day or more before use.

[0217] The carbon dioxide concentration in the container was measured immediately after the strong carbonated water was removed from the container. The carbon dioxide concentration was measured by providing a gas outlet in the lid of the container and measuring the carbon dioxide concentration in the gas at the outlet using a carbon dioxide detector (XP-3140, manufactured by COSMO) (for low concentration) and (CX-6000, manufactured by RIKEN KEIKI) (for high concentration). As a result, the carbon dioxide concentration in the container immediately after the strong carbonated water was removed was a high value of 20.8% (average value of the measured values ​​of a total of six samples). The carbon dioxide concentration can be converted at 1% = 10,000 ppm.

[0218] Next, the container was washed by pouring tap water into the container until it reached the capacity and then immediately removing the tap water. This was counted as one wash, and washing was performed three times in total (1st Wash to 3rd Wash). Immediately after each wash, the carbon dioxide concentration was measured in the same manner.

[0219] Furthermore, after the three washings, the container was sealed and left to stand for 5 hours in a thermostatic device heated to 50°C, and then left to stand at room temperature. When the temperature inside the container reached room temperature, the carbon dioxide concentration was measured in the same manner.

[0220] These results are shown in Figure 22. Figure 22 is a graph showing the carbon dioxide concentration. In Figure 22, the vertical axis shows the carbon dioxide concentration (PPM), and the horizontal axis shows, from the left, after the 1st to 3rd washings (1st Wash to 3rd Wash) and after the heating. The carbon dioxide concentration value was the average value of the measured values ​​for a total of six samples.

[0221] As shown in Fig. 22, after the first cleaning, 4027 ppm of carbon dioxide remained. The remaining carbon dioxide was significantly reduced by the second and third cleanings. After the heating, 6800 ppm of carbon dioxide was measured. From this, it was confirmed that the carbon dioxide absorbed in the container was released by the heating.

[0222] Next, the heating conditions were changed and experiments were carried out. After the three washings, the container was left to stand in a thermostatic device at 50°C or 20°C for 1 hour, 2 hours, 6 hours, and 24 hours, and then left to stand at room temperature. When the temperature inside the container reached room temperature, the carbon dioxide concentration was measured in the same manner.

[0223] The results are shown in Figure 35. Figure 35 is a graph showing the carbon dioxide concentration. In Figure 35, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, the results after leaving for 1 hour, 2 hours, 6 hours, and 24 hours. The open graph shows the results at 50°C, and the closed graph shows the results at 20°C. The carbon dioxide concentration value was the average value of the measured values ​​for a total of four samples.

[0224] As shown in Fig. 35, the carbon dioxide concentration in the container increased over time in both the 50°C and 20°C treatments. This confirmed that the 20°C treatment also released the carbon dioxide absorbed in the container. Furthermore, the 50°C treatment released more carbon dioxide than the 20°C treatment. This confirmed that the heating released more carbon dioxide absorbed in the container.

[0225] As described above, it was confirmed that carbon dioxide is absorbed into the resin container, and that carbon dioxide is released from the resin container that has absorbed carbon dioxide.

[0226] [Reference example 2] Using resin containers made of different materials, it was confirmed that carbon dioxide was released from the resin containers that had absorbed carbon dioxide.

[0227] Containers of different resins with a capacity of 250 ml or 500 ml were prepared. The resins were high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), and polycarbonate (PC) (all manufactured by AS ONE Corporation), as well as polyethylene terephthalate (PET) (recycled plastic bottles of commercially available non-carbonated beverages).

[0228] Each of the containers was filled to capacity with strong carbonated water (commercially available), sealed, and left to stand at room temperature for 5 hours. Thereafter, washing was performed a total of three times in the same manner as in Reference Example 1. Furthermore, in the same manner as in Reference Example 1, the containers were heated at 50°C for 5 hours, then cooled, and the carbon dioxide concentration was measured.

[0229] In addition, each of the containers was filled with 100% carbon dioxide by sufficiently feeding it therein, and then sealed and left to stand at room temperature for 5 hours. Thereafter, washing was performed a total of three times in the same manner as in Reference Example 1. Furthermore, in the same manner as in Reference Example 1, the containers were heated at 50°C for 5 hours, then cooled, and the carbon dioxide concentration was measured.

[0230] These results are shown in Figure 36. Figure 36 is a graph showing the carbon dioxide concentration. In Figure 36, the vertical axis shows carbon dioxide concentration (PPM), and the horizontal axis shows, from the left, high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), polycarbonate (PC), and polyethylene terephthalate (PET). The open graph shows the results for 100% carbon dioxide, and the closed graph shows the results for strong carbonated water. The carbon dioxide concentration value was the average value of the measured values ​​for a total of three samples.

[0231] As shown in Figure 36, when strong carbonated water was used, carbon dioxide was released from all resins. High density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), and polycarbonate (PC) all released more carbon dioxide than polyethylene terephthalate (PET). In particular, polycarbonate (PC) showed a significant increase in carbon dioxide concentration.

[0232] Furthermore, as shown in Figure 36, when 100% carbon dioxide was used, carbon dioxide emission was observed for all resins. High density polyethylene (HDPE) was observed to emit the same amount of carbon dioxide as polyethylene terephthalate (PET). Low density polyethylene (LDPE), polypropylene (PP), polytetrafluoroethylene (PTFE), and polycarbonate (PC) were all observed to emit more carbon dioxide than polyethylene terephthalate (PET). In particular, polycarbonate (PC) showed a significant increase in carbon dioxide concentration.

[0233] As described above, it was confirmed that carbon dioxide was released from the resin containers that had absorbed carbon dioxide, using resin containers made of different materials.

[0234] [Reference example 3] Using carbon dioxide absorbents of different forms, it was confirmed that carbon dioxide was released from the carbon dioxide absorbents that had absorbed carbon dioxide.

[0235] A 10 ml polypropylene spitz tube (manufactured by Eiken Co., Ltd.) was used as the carbon dioxide absorbent. Eight of the spitz tubes were placed in a 300 ml wide-mouthed glass bottle (commercially available) with a lid. The glass bottle was filled to capacity with strong carbonated water (commercially available), sealed, and left to stand at room temperature for 5 hours. Thereafter, washing was performed a total of three times in the same manner as in Reference Example 1. Furthermore, after heating at 50°C for 5 hours, the bottle was allowed to cool, and the carbon dioxide concentration was measured in the same manner as in Reference Example 1.

[0236] In addition, the experiment was conducted in the same manner except that strong carbonated water made by another company was used instead of the strong carbonated water.In addition, the experiment was conducted in the same manner except that the bottle was left to stand at 4°C instead of at room temperature.In addition, the experiment was conducted in the same manner except that 100% carbon dioxide was sufficiently pumped into the glass bottle to fill it with the strong carbonated water instead of the strong carbonated water.

[0237] These results are shown in Figure 7. Figure 7 is a graph showing the carbon dioxide concentration. In Figure 7, the vertical axis shows carbon dioxide concentration (%), and the horizontal axis shows, from the left, 100% carbon dioxide (CO2), strong carbonated water (SBWater 20°C), strong carbonated water at 4°C (SBWater 4°C), and strong carbonated water made by another company (Gerolsteiner). The carbon dioxide concentration value was the average value of the measured values ​​for a total of 3 to 4 samples.

[0238] As shown in Figure 7, when strong carbonated water (SBWater 20°C), strong carbonated water at 4°C (SBWater 4°C), and strong carbonated water made by another company (Gerolsteiner) were used, the same amount of carbon dioxide was released. In addition, when 100% carbon dioxide (CO2) was used, carbon dioxide was released, although it was less than when the strong carbonated water was used.

[0239] Next, a rubber plate (with grooves, size: 3x100x100mm, manufactured by HIKARI Co., Ltd.) was used as a carbon dioxide absorbent (Rubber II). The rubber plate was placed in a 300ml wide-mouth glass bottle (commercially available) with a lid. The glass bottle was filled to capacity with strong carbonated water (commercially available), sealed, and left to stand at room temperature (24°C) for 5 hours. Thereafter, washing was performed a total of three times in the same manner as in Reference Example 1. Furthermore, after heating at 50°C for 5 hours, the bottle was allowed to cool and the carbon dioxide concentration was measured in the same manner as in Reference Example 1.

[0240] In addition, the experiment was conducted in the same manner, except that a rubber plate without a groove structure (size: 1x100x100mm, manufactured by HIKARI Co., Ltd.) (Rubber I), an acrylic rod (long diameter 6mm, length 170mm), a polyethylene mesh (size: 92-#18, manufactured by AS ONE Corporation), and a nylon mesh (size: 63μ, PA-2, manufactured by AS ONE Corporation) were used as carbon dioxide absorbents instead of the rubber plate.

[0241] Further, for each of the carbon dioxide absorbents, an experiment was carried out in the same manner, except that 100% carbon dioxide was sufficiently pumped into the glass bottle to fill it with carbon dioxide, instead of the strongly carbonated water.

[0242] These results are shown in Figure 8. Figure 8 is a graph showing the carbon dioxide concentration. In Figure 8, the vertical axis shows the carbon dioxide concentration (%), and the horizontal axis shows, from the left, a rubber plate (with streaks) (Rubber I), a rubber plate (without streaks) (Rubber II), an acrylic rod, a polyethylene mesh, and a nylon mesh. The open graph shows the results for 100% carbon dioxide, and the closed graph shows the results for strong carbonated water. The carbon dioxide concentration value was the average of the measured values ​​for a total of 3 to 4 samples.

[0243] As shown in Figure 8, when strong carbonated water was used and when 100% carbon dioxide was used, carbon dioxide release was observed for all carbon dioxide absorbents. In particular, when the carbon dioxide absorbent was a rubber plate (with grooves) and 100% carbon dioxide was used, the carbon dioxide concentration increased significantly.

[0244] As described above, it was confirmed that, by using carbon dioxide absorbents of different forms, carbon dioxide was released from the carbon dioxide absorbents that had absorbed carbon dioxide.

[0245] [Reference example 4] It was confirmed that the gas released from the carbon dioxide absorbent after absorbing carbon dioxide was carbon dioxide.

[0246] A 300 ml resin (polyethylene terephthalate (PET)) container (a recycled PET bottle from a commercially available non-carbonated beverage) was prepared.

[0247] In the same manner as in Reference Example 2, strong carbonated water was placed in the container, carbon dioxide was absorbed, and then the container was heated (for 5 hours or 30 minutes) and cooled, and the carbon dioxide concentration in the container was measured. As a result, the carbon dioxide concentration was 27% (high concentration CO2) after 5 hours of heating, and 2.8% (low concentration CO2) after 30 minutes of heating.

[0248] Then, a mixture containing 10 ml of 0.1N NaOH aqueous solution and 10 ml of 0.1 mol / l CaCl2 aqueous solution was placed in each of the containers and vigorously shaken by hand for 30 seconds. It is known that a mixture containing 0.1N NaOH aqueous solution and 0.1 mol / l CaCl2 aqueous solution reacts with and absorbs carbon dioxide. Immediately after the shaking, the carbon dioxide concentration in the containers was measured.

[0249] The results are shown in Figure 11. Figure 11 is a graph showing the carbon dioxide concentration. In Figure 11, the vertical axis shows carbon dioxide concentration (%), and on the horizontal axis, the left side shows high concentration carbon dioxide (high concentration CO2), and the right side shows low concentration carbon dioxide (low concentration CO2). The open graph shows the results before the reaction with the mixed liquid, and the closed graph shows the results after the reaction with the mixed liquid. The carbon dioxide concentration value was the average value of the measured values ​​for a total of six samples.

[0250] 11, in both the high-concentration carbon dioxide and the low-concentration carbon dioxide, the carbon dioxide concentration after the reaction with the mixed liquid was significantly reduced compared to before the reaction with the mixed liquid. From this, it was chemically confirmed that the gas released from the carbon dioxide absorbent was capable of reacting as carbon dioxide.

[0251] As described above, it was confirmed that the gas released from the carbon dioxide absorbent after absorbing carbon dioxide was carbon dioxide.

[0252] Although the present invention has been described above with reference to the embodiment and examples, the present invention is not limited to the above embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0253] <Additional Notes> A part or all of the above-described embodiments can be described as follows, but is not limited to the following. (Appendix 1) It includes a thin polymer film, A carbon dioxide permeable agent, wherein the thin film is selectively permeable to carbon dioxide. (Appendix 2) The carbon dioxide permeation agent of claim 1, wherein the polymer comprises at least one selected from the group consisting of cellulose, polyethylene terephthalate, high density polyethylene, low density polyethylene, polypropylene, polytetrafluoroethylene, polycarbonate, rubber, polyurethane, and acrylic. (Appendix 3) 3. The carbon dioxide permeable agent according to claim 1 or 2, wherein the thin film is impermeable to oxygen and nitrogen. (Appendix 4) When heated, the membrane is permeable to the carbon dioxide. A carbon dioxide permeation agent according to any one of claims 1 to 3. (Appendix 5) The thin film is capable of separating carbon dioxide from a mixed gas containing carbon dioxide and at least one of hydrogen and methane by selectively allowing carbon dioxide to permeate through the thin film. 5. A carbon dioxide permeation agent according to any one of claims 1 to 4. (Appendix 6) A carbon dioxide supply section and a carbon dioxide permeation section are included, The carbon dioxide supply unit supplies a carbon dioxide-containing substance to the carbon dioxide permeation unit, The carbon dioxide-containing substance is at least one of a gas and a liquid, the carbon dioxide permeation section selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing material, The carbon dioxide permeation portion contains a carbon dioxide permeation agent according to any one of appendices 1 to 5. Carbon dioxide permeation apparatus. (Appendix 7) The carbon dioxide permeation portion permeates the carbon dioxide in a heated state. 7. The carbon dioxide absorption apparatus of claim 6. (Appendix 8) The carbon dioxide permeation section includes two compartments, the two compartments are connected via the thin film of the carbon dioxide permeable agent; The carbon dioxide-containing material is supplied to one of the compartments from the carbon dioxide supply unit, The other compartment is filled with a liquid so as to be in contact with the thin film. 8. The carbon dioxide permeation apparatus of claim 6 or 7. (Appendix 9) The carbon dioxide-containing substance is a mixed gas containing carbon dioxide and at least one of hydrogen and methane, The thin film is capable of separating carbon dioxide from the mixed gas supplied to the one compartment into the liquid filled in the other compartment by selectively allowing carbon dioxide to permeate through the thin film. 9. The carbon dioxide permeation apparatus of claim 8. (Appendix 10) The method includes a carbon dioxide supply step and a carbon dioxide permeation step, The carbon dioxide supply step supplies a carbon dioxide-containing substance to the carbon dioxide permeation step, The carbon dioxide-containing substance is at least one of a gas and a liquid, The carbon dioxide permeation step selectively permeates the carbon dioxide contained in the supplied carbon dioxide-containing material using the carbon dioxide permeation agent described in any one of Supplementary Notes 1 to 5. Carbon dioxide permeation method. (Appendix 11) The carbon dioxide permeation step is performed by permeating the carbon dioxide in a heated state. 11. The carbon dioxide absorption method according to claim 10. (Appendix 12) The carbon dioxide permeation step includes permeating the carbon dioxide through a carbon dioxide permeation section, The carbon dioxide permeable portion includes the carbon dioxide permeable agent and two compartments, the two compartments are connected via the thin film of the carbon dioxide permeable agent; The carbon dioxide-containing material is supplied to one of the compartments from the carbon dioxide supply unit, The other compartment is filled with a liquid so as to be in contact with the thin film. 12. The carbon dioxide permeation method according to claim 10 or 11. (Appendix 13) The carbon dioxide-containing substance is a mixed gas containing carbon dioxide and at least one of hydrogen and methane, In the carbon dioxide permeation step, the thin film selectively permeates carbon dioxide, thereby separating carbon dioxide from the mixed gas supplied to the one compartment into the liquid filled in the other compartment. 13. The carbon dioxide permeation method according to claim 12. (Appendix 14) A carbon dioxide absorption section is included, The carbon dioxide absorption section contains the carbon dioxide permeation agent according to any one of claims 1 to 5, The inside of the carbon dioxide absorption unit is sealed via the carbon dioxide permeable agent, The thin film of the carbon dioxide permeable agent selectively permeates carbon dioxide, so that carbon dioxide is absorbed from the outside to the inside of the carbon dioxide absorption section. Carbon dioxide absorber. (Appendix 15) The method includes a carbon dioxide supplying step and a carbon dioxide absorbing step, The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide absorbing step, The carbon dioxide absorption step includes absorbing carbon dioxide by a carbon dioxide absorption section, The carbon dioxide absorption part contains the carbon dioxide permeation agent described in any one of Supplementary Notes 1 to 5, The inside of the carbon dioxide absorption unit is sealed via the carbon dioxide permeable agent, The thin film of the carbon dioxide permeable agent selectively permeates carbon dioxide, so that carbon dioxide is absorbed from the outside to the inside of the carbon dioxide absorption section. Carbon dioxide absorption method. (Appendix 16) Contains polymers, A carbon dioxide absorbent, wherein the polymer absorbs carbon dioxide. (Appendix 17) The carbon dioxide absorbent according to claim 16, wherein the polymer comprises at least one selected from the group consisting of cellulose, polyethylene terephthalate, high density polyethylene, low density polyethylene, polypropylene, polytetrafluoroethylene, polycarbonate, rubber, polyurethane, and acrylic. (Appendix 18) The polymer releases the absorbed carbon dioxide when heated. Attachment 16 or 17. A carbon dioxide absorbent according to claim 16. (Appendix 19) The carbon dioxide absorbent according to claim 18, wherein the heated state is a state heated to 50°C or higher. (Appendix 20) A carbon dioxide supply unit and a carbon dioxide absorption unit are included, The carbon dioxide supply unit supplies a carbon dioxide-containing substance to the carbon dioxide absorption unit, The carbon dioxide-containing substance is at least one of a gas and a liquid, The carbon dioxide absorption unit absorbs the carbon dioxide contained in the supplied carbon dioxide-containing material, The carbon dioxide absorption unit includes a carbon dioxide absorbent according to any one of appendices 16 to 19. Carbon dioxide absorber. (Appendix 21) The carbon dioxide absorption unit is heatable, The carbon dioxide absorption unit further releases the absorbed carbon dioxide in a heated state. 21. The carbon dioxide absorption apparatus of claim 20. (Appendix 22) The method includes a carbon dioxide supplying step and a carbon dioxide absorbing step, The carbon dioxide supplying step supplies a carbon dioxide-containing substance to the carbon dioxide absorbing step, The carbon dioxide-containing substance is at least one of a gas and a liquid, The carbon dioxide absorption step includes absorbing carbon dioxide contained in the supplied carbon dioxide-containing material by a carbon dioxide absorbent according to any one of appendices 16 to 19. Carbon dioxide absorption method. (Appendix 23) Further, the method includes a carbon dioxide releasing step, The carbon dioxide releasing step releases the absorbed carbon dioxide while the carbon dioxide absorbent is heated. 23. The carbon dioxide absorption method according to claim 22. [Industrial Applicability]

[0254] As described above, according to the present invention, a new carbon dioxide permeation agent can be provided. [Explanation of symbols]

[0255] 1 Carbon dioxide permeation device 11 Carbon dioxide supply unit 12 Carbon dioxide permeation section 121 Carbon dioxide permeation agent 2 Heating section 3 Carbon Dioxide Absorber 31 Carbon dioxide supply unit 32 Carbon dioxide absorption section 321 Carbon dioxide absorbent 33 Carbon dioxide release section 4 Heating section

Claims

1. A carbon dioxide permeable agent, a carbon dioxide supply section, and a carbon dioxide permeable section are included, The carbon dioxide permeation agent includes a thin polymer film, the polymer comprises cellulose; the membrane is selectively permeable to carbon dioxide; The carbon dioxide supply unit supplies a carbon dioxide-containing substance to the carbon dioxide permeation unit, The carbon dioxide-containing substance is a mixed gas containing carbon dioxide, hydrogen, and methane, The carbon dioxide permeation section includes two compartments, the two compartments are connected via the thin film of the carbon dioxide permeable agent; The carbon dioxide-containing material is supplied to one of the compartments from the carbon dioxide supply unit, The other compartment is filled with a liquid so as to be in contact with the thin film, The liquid comprises water, The carbon dioxide permeation section is capable of separating carbon dioxide from the carbon dioxide-containing substance supplied to the one compartment into the liquid filled in the other compartment by selectively permeating carbon dioxide through the thin film. Carbon dioxide permeation apparatus.

2. The carbon dioxide permeation portion permeates the carbon dioxide in a heated state. The carbon dioxide permeation device of claim 1.

3. A carbon dioxide permeation method using the carbon dioxide permeation device according to claim 1 or 2, The carbon dioxide permeation method includes a carbon dioxide supply step and a carbon dioxide permeation step, The carbon dioxide supplying step includes supplying the carbon dioxide-containing material to the carbon dioxide permeation section by the carbon dioxide supplying section, The carbon dioxide permeable portion includes the carbon dioxide permeable agent and the two compartments, In the carbon dioxide permeation step, the thin film selectively permeates carbon dioxide, thereby separating carbon dioxide from the carbon dioxide-containing material supplied to the one compartment into the liquid filled in the other compartment. Carbon dioxide permeation method.

4. The carbon dioxide permeation step is performed by permeating the carbon dioxide in a heated state. The carbon dioxide permeation method according to claim 3.

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