Methanol adsorbent, method for producing high-concentration methanol, and methanol recovery device

Abstract

A methanol adsorbing material which adsorbs methanol contained in a liquid or gas containing water and methanol, and which contains, as an active ingredient, a Prussian blue analogue represented by general formula (1): AxM [M '(CN) 6] y.zH2O (1) wherein x, y and z are 0 < = x < = 3, 0.1 < = y < = 1.5, and 0 < = z < = 6, and A is at least one of a hydrogen ion, an ammonium cation, an alkali metal ion, and an alkaline earth metal ion. M and M'are mutually independent cations (but do not include hydrogen ions, ammonium cations, alkali metal ions and alkaline earth metal ions).

Description

Technical Field

[0001] The present invention relates to a methanol adsorbing material for adsorbing methanol in water or gas, a method for producing high-concentration methanol using the methanol adsorbing material, and a methanol recovery device. Background Art

[0002] Methanol is harmful to the human body, but it is also used as a resource. Methanol is used in a variety of ways, such as as a synthetic raw material and solvent in the chemical industry, as a direct combustion fuel, and as a fuel for fuel cells. 2 The demand for methanol is increasing. If the methanol contained in exhaust gas or wastewater can be recovered at a high concentration, it can be used as a resource. For example, methanol with a concentration of 54% by mass or more can be used in commercial direct methanol fuel cells.

[0003] When methanol is used as a resource, a high methanol concentration is desired. Wastewater, of course, contains water as water vapor, so separation from water is important in order to recover methanol at a high concentration. Prussian blue analogs used as adsorbents for ammonia and cesium ions are known to adsorb a large amount of methanol in an environment without coexisting substances (Non-Patent Document 1).

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-patent literature 1: M. Asai, et.al, J. Phys. Chem. C 2018, 122, 22, 11918-11925. Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, the Prussian blue analogues and the like in Non-Patent Document 1 have high affinity for water molecules in addition to methanol. Therefore, it is unclear whether the Prussian blue analogues and the like in Non-Patent Document 1 can adsorb methanol in water or a gas containing water vapor. In addition, even if the Prussian blue analogues in Non-Patent Document 1 can adsorb methanol, there is a problem that it is not easy to selectively desorb methanol when water is also adsorbed.

[0009] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a methanol adsorbent that adsorbs methanol contained in a liquid or gas containing water and methanol, a method for producing high-concentration methanol using the methanol adsorbent, and a methanol recovery device.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the following methanol adsorbent, method for producing high-concentration methanol, and methanol recovery device are provided.

[0012] [1] A methanol adsorbent that adsorbs methanol contained in a liquid or gas containing water and methanol, wherein the adsorbent contains a Prussian blue analogue represented by the following general formula (1) as an effective ingredient.

[0013] A x M[M'(CN) 6 ] y ·zH 2 O(1)

[0014] In the general formula, x, y and z are 0≤x≤3, 0.1≤y≤1.5, 0≤z≤6, A is one or more of hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion, and M and M' are independent cations (but excluding hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion).

[0015] [2] The methanol adsorbent material as described in [1] above, wherein M is Mn 2+ 、Co 2+ , Ga 2+ 、Ni 2+ 、Zn 2+ Any of the following, M' is Co 3+ or Fe 3+ .

[0016] [3] The methanol adsorbent material as described in [1] above, wherein M is Mn 2+ ,M' is Co 3+ or Fe 3+ .

[0017] [4] A method for producing high-concentration methanol, comprising: an adsorption step, in which the methanol adsorbent of any one of [1] to [3] is brought into contact with a liquid or gas containing water and methanol, so that water and methanol are adsorbed on the methanol adsorbent; a water desorption step, in which the methanol adsorbent that has undergone the adsorption step is maintained at a first temperature, so that water is desorbed from the methanol adsorbent; and a methanol desorption step, in which the methanol adsorbent that has undergone the water desorption step is maintained at a second temperature higher than the first temperature, so that high-concentration methanol is desorbed from the methanol adsorbent and recovered.

[0018] [5] The method for producing high-concentration methanol according to [4], wherein the first temperature is 70°C or higher and lower than 120°C, and the second temperature is 120°C or higher and 250°C or lower.

[0019] [6] A method for producing high-concentration methanol, comprising: a methanol adsorption step, in which the methanol adsorption material of any one of [1] to [3] is brought into contact with a liquid or gas containing water and methanol at a third temperature, thereby selectively adsorbing methanol onto the methanol adsorption material relative to water; and a methanol recovery step, in which the methanol adsorption material that has passed the methanol adsorption step is maintained at a fourth temperature higher than the third temperature, thereby desorbing and recovering high-concentration methanol from the methanol adsorption material.

[0020] [7] The method for producing high-concentration methanol according to [6] above, wherein the third temperature is 35°C or higher and lower than 120°C, and the fourth temperature is 120°C or higher and 250°C or lower.

[0021] [8] A methanol recovery device, comprising: a methanol adsorbent material as described in any one of [1] to [3] above; a retaining portion for retaining the methanol adsorbent material inside; a heating portion capable of heating the methanol adsorbent material in the retaining portion to a temperature between 35°C and 250°C; a first supply portion for supplying a liquid or gas containing water and methanol to the methanol adsorbent material in the retaining portion; and a recovery portion for recovering high-concentration methanol desorbed from the methanol adsorbent material in the retaining portion.

[0022] Effects of the Invention

[0023] The methanol adsorbent of the present invention has a predetermined Prussian blue analogue that adsorbs water and methanol as an effective component. The Prussian blue analogue mainly desorbs water at a first temperature and mainly desorbs methanol at a second temperature higher than the first temperature. Therefore, the methanol adsorbent of the present invention that adsorbs water and methanol is set to the first temperature to desorb water, and then methanol is recovered at the second temperature, thereby obtaining high-concentration methanol.

[0024] In addition, the methanol adsorbent of the present invention selectively adsorbs methanol relative to water in a predetermined temperature range. Therefore, by using the methanol adsorbent of the present invention and the method for producing high-concentration methanol, the methanol adsorbent of the present invention is brought into contact with water and methanol in a predetermined temperature range to adsorb methanol, and then the methanol adsorbed on the methanol adsorbent is recovered at a higher temperature, thereby obtaining high-concentration methanol. Furthermore, by using a methanol recovery device using the methanol adsorbent of the present invention, high-concentration methanol can be recovered. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a diagram showing a flow chart of an example of the method for producing high-concentration methanol according to the first embodiment.

[0026] Figure 2It is a figure which shows the schematic diagram of the methanol recovery apparatus which concerns on embodiment ((a) is when methanol is adsorbed, (b) is when methanol is desorbed).

[0027] Figure 3 The figures show the powder X-ray diffraction patterns of the Prussian blue analogs obtained in Production Examples 1 to 6, respectively.

[0028] Figure 4 This is a diagram showing a graph indicating the amount of methanol adsorption of each sample (Example 1).

[0029] Figure 5 This is a diagram showing the isosteric differential heat of adsorption of methanol on activated carbon (Example 2).

[0030] Figure 6 This is a graph showing the isosteric differential heat of adsorption of methanol of a Mn-Co analog (Example 2).

[0031] Figure 7 This is a graph showing the isosteric differential heat of adsorption of water of a Mn-Co analog (Example 2).

[0032] Figure 8 It is a diagram showing a TG-MS (thermogravimetric mass spectrometry) curve of activated carbon (Example 3).

[0033] Fig. 9 It is a diagram showing the TG-MS curve of the Mn-Co analog (Example 3).

[0034] Fig.10 It is a diagram showing the TG-MS curve of Co-Co analogue (Example 3).

[0035] Fig.11 It is a diagram showing the TG-MS curve of Ga—Fe analogue (Example 3).

[0036] Fig.12 It is a diagram showing the TG-MS curve of Ni-Fe analogue (Example 3).

[0037] Fig.13 is a diagram showing a graph indicating the amount of methanol desorption from a Mn—Co analog (Example 6).

[0038] Fig.14 This is a graph showing the equilibrium methanol concentration and the amount of methanol adsorbed at equilibrium (Example 9).

[0039] Fig.15 This is a graph showing a comparison of the methanol adsorption amount at 1000 mg-methanol / L equilibrium (Example 10).

[0040] Fig.16This is a graph showing the relationship between the methanol-water flow rate per unit adsorbent and the methanol concentration after the water passes through the column. DETAILED DESCRIPTION

[0041] Hereinafter, one embodiment of the methanol adsorbent of the present invention will be described.

[0042] <Methanol adsorbent (Prussian blue analogue)>

[0043] The methanol adsorbent is an adsorbent that can adsorb methanol contained in a liquid or gas containing water and methanol. A typical methanol adsorbent is an adsorbent that can adsorb methanol contained in water or methanol contained in a gas containing water vapor. It should be noted that the methanol adsorbent of this embodiment can adsorb water together with methanol.

[0044] The methanol adsorbent of the present embodiment contains a Prussian blue analog represented by the following general formula (1) (hereinafter, sometimes referred to as "the Prussian blue analog of the embodiment") as an active ingredient.

[0045] A x M[M'(CN) 6 ] y ·zH 2 O(1)

[0046] It should be noted that in the following embodiments, A x M[M'(CN) 6 ] y ·zH 2 The compound represented by O is referred to as "M-M' analog".

[0047] Wherein, x, y and z are 0≤x≤3, 0.1≤y≤1.5, 0≤z≤6 (the same below). In addition, A is one or more of hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion (the same below). Furthermore, M and M' are mutually independent cations (the same below). However, M and M' are not hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion (the same below). Examples of M include Mn 2+ 、Co 2+ , Ga 2+ 、Ni 2+ 、Zn 2+ 、In 2+ , Fe 2+ Cu 2+ Among them, M is preferably Mn, because of its strong cubic structure and ability to adsorb a large amount of adsorbate (such as methanol). 2+ 、Co 2+ , Ga 2+ 、Ni 2+ and Zn2+ .

[0048] The methanol adsorbent of the present embodiment may include the above-mentioned Prussian blue analogue and a carrier that supports the Prussian blue analogue. Examples of the carrier include zeolite, bentonite, and activated carbon. The methanol adsorbent may be in the form of a powder of the Prussian blue analogue of the present embodiment, or may be in the form of a granulate obtained by kneading the Prussian blue analogue of the embodiment with a cross-linking agent. In addition, the methanol adsorbent may also be in the form of a column in which the Prussian blue analogue of the above-mentioned embodiment is supported.

[0049] The present inventors have found that the methanol adsorption characteristics of the Prussian blue analogue are not only affected by the type of the coordination unsaturated M, but also by the valence of M'. The Prussian blue analogue of this embodiment has an adsorption site with a higher adsorption energy with methanol than with water. The valence of M' is preferably +3 or more. Examples of such M' include Co 3+ , Fe 3+ , Mn 3+ and Cr 3+ Among them, M' is preferably Co 3+ and Fe 3+ In addition, from the viewpoints of the amount of methanol adsorption and the clear distinction between the desorption temperatures of water and methanol, M is preferably Mn. 2+ .

[0050] Compared to water, methanol binds more strongly to the Prussian blue analog of the embodiment. Therefore, the temperature at which methanol is desorbed from the Prussian blue analog of the embodiment is higher than the temperature at which water is desorbed from the Prussian blue analog of the embodiment. Therefore, by separating the desorption of water and methanol from the Prussian blue analog through the water desorption process under relatively low temperature conditions and the methanol desorption process under relatively high temperature conditions, it is possible to recover high-concentration methanol that has passed through the methanol desorption process. As the Prussian blue analog of the embodiment, specifically, Mn[Fe(CN) 6 ] y ·zH 2 O、Co[Cr(CN) 6 ] y ·zH 2 O、Mn[Cr(CN) 6 ] y ·zH 2 O and Cr[Co(CN) 6 ] y ·zH 2 O.

[0051] Next, one embodiment (first embodiment and second embodiment) of the method for producing high-concentration methanol of the present invention will be described.

[0052] <First Embodiment of the Method for Producing High-Concentration Methanol>

[0053] The high-concentration methanol production method of the first embodiment has an adsorption step, a water desorption step, and a methanol desorption step. In the present invention, for high-concentration methanol, "the mass of methanol / (the mass of methanol+the mass of water)×100" is preferably 40% or more, more preferably 60% or more, further preferably 80% or more, and particularly preferably 90% or more.

[0054] Hereinafter, each step of the method for producing high-concentration methanol according to the first embodiment will be described.

[0055] (Adsorption process)

[0056] In the adsorption step, the methanol adsorbent of the present invention is brought into contact with a liquid or gas containing water and methanol, and water and methanol are adsorbed on the methanol adsorbent. Examples of the contact method include a batch method in which the methanol adsorbent and the liquid or gas containing water and methanol are mixed in a container, and a column method in which a substance containing water and methanol is passed through the methanol adsorbent, but the method is not particularly limited. It is believed that water is adsorbed in the space within the crystal lattice of the Prussian blue analogue of the embodiment contained in the methanol adsorbent, and methanol is adsorbed at the M' metal defect site.

[0057] As a liquid containing water and methanol, for example, a methanol aqueous solution can be exemplified. As a gas containing water and methanol, for example, a gas containing water vapor and methanol vapor can be exemplified. As long as it does not hinder the adsorption of water and methanol on the methanol adsorbent and the desorption of water and methanol from the methanol adsorbent at different temperatures, other substances may be included in the liquid or gas containing water and methanol. Specifically, in the liquid containing water and methanol, for example, NaCl, KCl, CaCl 2 Examples of liquids containing water and methanol include wastewater from pulp mills, 2 A methanol aqueous solution produced when synthesizing methanol, etc. In addition, the gas containing water and methanol may contain, for example, helium, argon, nitrogen, oxygen, or carbon dioxide, etc. Examples of the gas containing water and methanol include volatile gas from black liquor of a paper mill or exhaust gas from a chemical plant, etc.

[0058] From the viewpoint of increasing the amount of methanol adsorbed by the methanol adsorbent, the temperature at which the methanol adsorbent is brought into contact with the methanol aqueous solution (in other words, the temperature at which water and methanol are adsorbed on the Prussian blue analog of the embodiment) is preferably 60° C. or less. The lower limit of this temperature is the temperature at which the methanol aqueous solution does not solidify. The solidification temperature of the methanol aqueous solution depends on the methanol concentration of the methanol aqueous solution, but is generally 0° C. or more.

[0059] In addition, from the viewpoint of increasing the amount of methanol adsorbed by the methanol adsorbent, the temperature at which the methanol adsorbent is brought into contact with the gas containing water vapor and methanol (in other words, the temperature at which water and methanol in the gas are adsorbed on the Prussian blue analog of the embodiment) is also preferably 60° C. or lower. The lower limit of this temperature is a temperature at which problems such as ice generation in the gas do not occur. Although it depends on the concentration of salts or molecules dissolved in water, the temperature at which water and methanol in the gas are adsorbed is preferably, for example, -30° C. or higher.

[0060] (Water desorption process)

[0061] In the water desorption process, the methanol adsorbent of the embodiment that has undergone the adsorption process is maintained at a first temperature to desorb water from the methanol adsorbent. The first temperature is a temperature at which water is desorbed in large quantities from the methanol adsorbent of the embodiment that adsorbs water and methanol. In the water desorption process, water is desorbed in large quantities and a portion of methanol may also be desorbed. From the viewpoint of desorbing water in large quantities from the methanol adsorbent of the embodiment and desorbing methanol in small quantities from the methanol adsorbent of the embodiment, the first temperature is preferably above 70°C and below 120°C. It should be noted that maintaining the first temperature does not require a fixed temperature, and the temperature may be varied within the temperature range at which a large amount of water is desorbed from the methanol adsorbent of the embodiment.

[0062] (Methanol desorption process)

[0063] In the methanol desorption process, the methanol adsorbent of the embodiment that has undergone the water desorption process is maintained at a second temperature higher than the first temperature, so that high-concentration methanol is desorbed and recovered from the methanol adsorbent. The second temperature is a temperature at which methanol is desorbed in large quantities from the methanol adsorbent of the embodiment that has adsorbed methanol and a small amount of water that has not been desorbed even after the water desorption process. In the methanol desorption process, methanol is desorbed in large quantities from the methanol adsorbent of the embodiment, and a small amount of water that has been adsorbed even after the water desorption process can also be desorbed. From the viewpoint of desorbing methanol in large quantities from the methanol adsorbent of the embodiment, the second temperature is preferably above 120°C and below 250°C. It should be noted that maintaining the second temperature does not require a fixed temperature, and the temperature can be changed within the temperature range at which a large amount of methanol is desorbed from the methanol adsorbent of the embodiment.

[0064] In the method for producing high-concentration methanol of this embodiment, water is mainly desorbed from the Prussian blue analogue contained in the methanol adsorbent of the above embodiment at a first temperature, and methanol is mainly desorbed from the Prussian blue analogue contained in the methanol adsorbent of the above embodiment at a second temperature higher than the first temperature. Therefore, the methanol adsorbent having adsorbed water and methanol is set to the first temperature to desorb water, and then methanol is desorbed at the second temperature, thereby recovering high-concentration methanol.

[0065] It should be noted that in the method for producing high-concentration methanol in the present embodiment, recovering high-concentration methanol also includes: cooling the gas containing water vapor and methanol vapor to obtain a methanol aqueous solution with a high methanol content, and sending the gas containing water vapor and methanol vapor greater than water vapor to the next process of the methanol desorption process, etc.

[0066] The high-concentration methanol production method of the first embodiment is performed by, for example, Figure 1 The process shown is typically implemented. First, after the adsorption process, a Prussian blue analogue adsorbed with methanol and water is obtained. Then, the Prussian blue analogue is heated to 90°C as a first temperature for dehydration (water desorption process). Through the dehydration based on the heating at 90°C, water vapor is desorbed from the Prussian blue analogue. The desorbed water vapor is exhausted.

[0067] On the other hand, in the dehydrated Prussian blue analogue, methanol remains in an adsorbed state. Then, the Prussian blue analogue is heated to 150°C as a second temperature to desorb methanol (methanol desorption process). By heating at 150°C, a Prussian blue analogue after desorption of water and methanol and a high-concentration methanol sometimes containing a small amount of water are obtained. The Prussian blue analogue can be reused. That is, it can be used again in the adsorption process. On the other hand, the high-concentration methanol desorbed from the Prussian blue analogue can be recovered by an appropriate method.

[0068] <Second Embodiment of the Method for Producing High-Concentration Methanol>

[0069] The high-concentration methanol production method of the second embodiment of the present application has a methanol adsorption process and a methanol recovery process. It should be noted that in the high-concentration methanol production method of the second embodiment, a portion of the description of the contents common to the high-concentration methanol production method of the first embodiment (for example, the contact method, high-concentration methanol, and the recovery of high-concentration methanol, etc.) is omitted. The inventors of the present invention have discovered new knowledge, that is, by contacting water and methanol with the methanol adsorption material of the embodiment at a predetermined temperature (third temperature), water is difficult to be adsorbed on the methanol adsorption material, while methanol is easily adsorbed on the methanol adsorption material, and the second embodiment utilizes this knowledge.

[0070] (Methanol adsorption process)

[0071] In the methanol adsorption step, a liquid or gas containing water and methanol is brought into contact with the methanol adsorbent of the above embodiment at a third temperature, and methanol is selectively adsorbed on the methanol adsorbent relative to water. As in the first embodiment, the liquid or gas containing water and methanol may be, for example, a methanol aqueous solution or a gas containing water vapor and methanol vapor.

[0072] The liquid or gas containing water and methanol may contain other substances as long as they do not hinder the adsorption of methanol on the methanol adsorbent of the embodiment and the desorption of methanol from the methanol adsorbent.

[0073] Moreover, in the methanol adsorption step, "selectively adsorbing methanol on the methanol adsorbent relative to water" means that "the mass of methanol adsorbed on the methanol adsorbent / the mass of water adsorbed on the methanol adsorbent (hereinafter sometimes referred to as "selectivity")" is 2 or more.

[0074] It should be noted that the case where water is not adsorbed on the methanol adsorbent is also included in the case where methanol is selectively adsorbed on the methanol adsorbent relative to water. The mass of methanol adsorbed on the methanol adsorbent / the mass of water adsorbed on the methanol adsorbent (selectivity) is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more.

[0075] The third temperature is a temperature at which methanol is adsorbed to the methanol adsorbent of the embodiment with a high selectivity. From the viewpoint of allowing methanol to be adsorbed to the methanol adsorbent with a high selectivity, the third temperature is preferably 35°C or higher and lower than 120°C. However, this lower limit temperature is a temperature for producing a methanol aqueous solution with a concentration of 54% by mass used as a fuel for a direct methanol fuel cell. In the case where a methanol aqueous solution with a lower methanol concentration can be used, the third temperature may be lower than 35°C.

[0076] (Methanol recovery process)

[0077] In the methanol recovery step, the methanol adsorbent material of the embodiment that has undergone the adsorption step is maintained at a fourth temperature higher than the third temperature, so that high-concentration methanol is desorbed and recovered from the methanol adsorbent material. Through this methanol recovery step, high-concentration methanol can be recovered from the methanol adsorbent material that has adsorbed methanol with a high selectivity. From the viewpoint of efficiently desorbing methanol from the methanol adsorbent material, the fourth temperature is preferably 120° C. or higher and 250° C. or lower.

[0078] Next, one embodiment of the methanol recovery device of the present invention will be described.

[0079] <Methanol Recovery Unit>

[0080] Figure 2 One embodiment of the methanol recovery device 10 according to the embodiment of the present application is schematically illustrated. Figure 2 (a) shows the methanol recovery device 10 when methanol is adsorbed, Figure 2 (b) shows the methanol recovery device 10 during methanol desorption. It should be noted that the methanol recovery device 10 is an example, and the form can be appropriately changed as long as the functions of the components of the methanol recovery device 10 are exerted.

[0081] The methanol recovery device 10 includes a methanol adsorbent (Prussian blue analogue), a housing 12 and a heating unit 14. The housing 12 includes a holding unit 16, a first supply unit 18, a second supply unit 20, a recovery unit 22 and a discharge unit 24.

[0082] The holding part 16 has a gap inside, and a methanol adsorbent (Prussian blue analogue) is held inside. The gas and liquid supplied to the holding part are designed to pass through the methanol adsorbent (Prussian blue analogue). The holding part 16 is configured so that the methanol adsorbent, and the gas and liquid passing through will not leak to the outside. The material of the holding part 16 is corrosion-resistant to methanol, and is not particularly limited as long as it does not decompose or deform under the temperature conditions of various processes for manufacturing high-concentration methanol and is stable. Examples of the material of the holding part 16 include stainless steel and heat-resistant fluororesins such as polytetrafluoroethylene (PTFE).

[0083] In the methanol recovery device 10 of the present embodiment, the methanol adsorbent is the Prussian blue analog of the embodiment, and the granular Prussian blue analog is sandwiched by glass filters from top to bottom and is arranged in the holding portion 16. It should be noted that as long as ventilation and liquid can be performed, deformation, combustion or decomposition will not occur in various processes for producing high-concentration methanol, and the adsorption and desorption function of methanol is exhibited, there is no particular limitation on the form of the Prussian blue analog. The Prussian blue analog can also be composited with other substances.

[0084] For example, a granular methanol adsorbent containing other materials such as a Prussian blue analogue and a binder can play a role in adsorbing methanol. In addition, a Prussian blue analogue can also be loaded on other base materials. As such base materials, fibers, nonwoven fabrics, glass filters, and honeycomb structures can be cited. As long as there are no problems in the various processes for manufacturing high-concentration methanol, the methanol adsorbent can also be in a powder or slurry form.

[0085] The heating unit 14 is provided around the holding unit 16 so as to be able to heat the methanol adsorbent (Prussian blue analogue) in the holding unit 16 to a temperature of 35° C. to 250° C. In addition, the frame 12, the methanol adsorbent, and the gas or liquid supplied to the frame 12 are heated by the heating unit 14. As long as the inside of the frame 12 can be heated and maintained at a predetermined temperature, the shape of the heating unit 14 or the heating mechanism of the heating unit 14 are not particularly limited.

[0086] In the methanol recovery device 10, the heating part 14 is arranged around the holding part 16, but the heating part 14 can also be arranged inside the frame 12. In addition, the heating part 14 can also have a linear heating member wound around the frame 12. As long as the material of the heating member does not decompose, dissolve, or deform, there is no particular limitation. For example, in the case where the heating part 14 is an electric heating mechanism, a nickel-chromium alloy wire coated with rubber can be used as the heating member. For example, in the case where the heating part 14 is a temperature control mechanism based on liquid flow, stainless steel and heat-resistant rubber can be used as a liquid flow tube. The liquid flow tube is made of a material that will not be dissolved by the liquid flowing inside.

[0087] The temperature control mechanism of the heating unit 14 can adopt the mechanism of utilizing electric heating wire, heating the circulation of gas such as water vapor, or the circulation of liquid, etc., and is not particularly limited. In addition, the heating unit 14 can be equipped with a cooling mechanism as required. For example, the heating unit 14 can be equipped with a device capable of controlling the temperature of the liquid such as a heat exchanger, so that the liquid of the specified temperature is circulated near the frame 12, the temperature of the frame 12 is controlled, and the method of heating and cooling the frame 12, etc. can be cited.

[0088] The first supply unit 18 supplies a methanol aqueous solution or a gas containing water vapor and methanol to the methanol adsorbent (Prussian blue analogue) in the holding unit 16. The second supply unit 20 supplies a gas containing no water vapor and methanol to the Prussian blue analogue in the holding unit 16.

[0089] The recovery unit 22 recovers the high-concentration methanol desorbed from the methanol adsorbent (Prussian blue analogue) in the holding unit 16. The discharge unit 24 discharges the liquid or gas after water and methanol are adsorbed to the methanol adsorbent (Prussian blue analogue).

[0090] The materials of the first supply unit 18, the second supply unit 20, the collection unit 22, and the discharge unit 24 are not particularly limited as long as they do not decompose, dissolve, or deform during use. Examples of these materials include stainless steel and heat-resistant plastics.

[0091] It should be noted that in other embodiments of the methanol recovery device 10, the first supply unit 18 and the second supply unit 20 may also be common. That is, the same supply unit (the first supply unit 18 or the second supply unit 20) may be used.

[0092] The first supply unit 18 or the second supply unit 20 may also function as a recovery unit.

[0093] For example, high-concentration methanol can be recovered using the methanol recovery device 10 by the following steps. It should be noted that, below, as an example, a method of recovering high-concentration methanol from a gas containing water vapor and methanol is described, but a method of recovering high-concentration methanol from a methanol aqueous solution can also be implemented by the same steps.

[0094] When the second supply unit 20 and the recovery unit 22 are closed and the first supply unit 18 and the discharge unit 24 are open, Figure 2 As shown in (a), a gas containing water vapor and methanol is supplied from the first supply unit 18 to the holding unit 16 in which the methanol adsorbent (Prussian blue analogue) is placed. At this time, the temperature of the Prussian blue analogue is adjusted by the heating unit 14 as needed.

[0095] When the gas supplied by the first supply unit 18 passes through the methanol adsorbent (Prussian blue analogue), methanol is adsorbed by the methanol adsorbent (Prussian blue analogue). In addition, at this time, depending on the temperature of the methanol adsorbent (Prussian blue analogue), water is also adsorbed by the methanol adsorbent (Prussian blue analogue). For example, when the methanol adsorbent (Prussian blue analogue) is 70°C, which is the third temperature, water is not much or almost not adsorbed by the methanol adsorbent (Prussian blue analogue), and methanol is mainly adsorbed by the methanol adsorbent (Prussian blue analogue). In addition, for example, when the methanol adsorbent (Prussian blue analogue) is 25°C, water and methanol are adsorbed by the methanol adsorbent (Prussian blue analogue). For the methanol adsorbent (downstream of the Prussian blue analogue), the gas after methanol is adsorbed and removed is discharged from the discharge unit 24.

[0096] When water and methanol are adsorbed on the Prussian blue analog, the Prussian blue analog is set to a first temperature (preferably 70° C. or higher and less than 120° C.) by the heating unit 14, the first supply unit 18 and the recovery unit 22 are set to a closed state, and the second supply unit 20 and the discharge unit 24 are set to an open state. Figure 2 As shown in (b), a purge gas (e.g., dry air, etc.) as a gas not containing water vapor and methanol is supplied from the second supply unit 20 to the holding unit 16 provided with a methanol adsorbent (Prussian blue analogue) adsorbing water and methanol. The purge gas containing water vapor is discharged from the discharge unit 24 downstream of the methanol adsorbent (Prussian blue analogue). Then, while the purge gas is supplied from the second supply unit 20, the methanol adsorbent (Prussian blue analogue) is heated by the heating unit 14. When the methanol adsorbent (Prussian blue analogue) reaches a second temperature (preferably 120° C. or higher and 250° C. or lower), the discharge unit 24 is closed, the recovery unit 22 is opened, and the high-concentration methanol desorbed from the Prussian blue analogue and discharged from the recovery unit 22 is recovered.

[0097] On the other hand, when water is not much or almost not adsorbed to the methanol adsorbent (Prussian blue analogue) and methanol is adsorbed to the methanol adsorbent (Prussian blue analogue), the methanol adsorbent (Prussian blue analogue) is heated by the heating unit 14 to a fourth temperature (preferably 120° C. or higher and 250° C. or lower), the first supply unit 18 and the discharge unit 24 are closed, and the second supply unit 20 and the recovery unit 22 are opened. Then, as Figure 2 As shown in (b), the second supply unit 20 supplies the cleaning gas to the holding unit 16 provided with the methanol adsorbing material (Prussian blue analogue) adsorbing methanol. The high-concentration methanol desorbed from the methanol adsorbing material (Prussian blue analogue) and discharged from the recovery unit 22 is recovered. When the recovery of the high-concentration methanol is completed, the methanol adsorbing material (Prussian blue analogue) can be reused. By increasing the frequency of this reuse, the methanol recovery device 10 can be made smaller than a distillation device that distills and recovers methanol from a methanol aqueous solution.

[0098] The methanol adsorbent, the method for producing high-concentration methanol, and the methanol recovery device of the present invention are not limited to the above embodiments.

[0099] Example

[0100] Hereinafter, the methanol adsorbent material and the method for producing high-concentration methanol of the present invention will be described with reference to examples, but the present invention is not limited to the following examples in any way.

[0101] The following Prussian blue analogs were produced (Production Examples 1 to 6).

[0102] Preparation Example 1: Mn-Co analogue

[0103] 20 mL of 0.6 mol / L manganese chloride aqueous solution was mixed with 20 mL of 0.3 mol / L potassium hexacyanocobaltate aqueous solution and shaken for 1 hour to obtain a precipitate. After the liquid containing the precipitate was subjected to solid-liquid separation at a centrifugal force of 16000G for 10 minutes, the supernatant was removed. After adding ultrapure water to the precipitate, the lid was closed, the container was shaken up and down, and the precipitate was stirred in ultrapure water. Further, the series of steps of centrifugal separation, removal of supernatant, and addition of ultrapure water for stirring were repeated 6 times. Then, the supernatant was removed and the precipitate was vacuum dried at room temperature for 4 hours to obtain a powder of Mn-Co analogue. Figure 3 The powder X-ray diffraction pattern of the Mn-Co analogue shown is the same as the diffraction pattern described in document A (X. Wu, wt. al, Cryst. Growth Des. 2006, 6, 26-28). Therefore, the Mn-Co analogue is K 0.06 Mn[Co(CN) 6 ] 0.66 4.6H2 O.

[0104] Preparation Example 2: Co-Co analogue

[0105] A Co—Co analogue was obtained by the same method as in Production Example 1 except that the manganese chloride aqueous solution was changed to a cobalt chloride aqueous solution. Figure 3 The powder X-ray diffraction pattern of the Co-Co analogue shown is the same as the diffraction pattern described in Document A. Therefore, the Co-Co analogue is K x Co[Co(CN) 6 ] y ·zH 2 O.

[0106] Preparation Example 3: Ga-Fe analogue

[0107] A Ga—Fe analogue was obtained by the same method as in Production Example 1 except that the manganese chloride aqueous solution was replaced by a gallium chloride aqueous solution and the potassium hexacyanocobaltate aqueous solution was replaced by a sodium hexacyanoferrate aqueous solution. Figure 3 The powder X-ray diffraction pattern of the Ga-Fe analogue shown is the same as the diffraction pattern described in Document A. Therefore, the Ga-Fe analogue is K x Ga[Fe(CN) 6 ] y ·zH 2 O.

[0108] Preparation Example 4: Ni-Fe analogue

[0109] A Ni—Fe analogue was obtained by the same method as in Production Example 1 except that the manganese chloride aqueous solution was replaced by a nickel nitrate aqueous solution and the potassium hexacyanocobaltate aqueous solution was replaced by a potassium hexacyanoferrate aqueous solution. Figure 3 The powder X-ray diffraction pattern of the Ni-Fe analogue shown is the same as the diffraction pattern described in Document A. Therefore, the Ni-Fe analogue is K 0.01 Ni[Fe(CN) 6 ] 0.69 5.0H 2 O.

[0110] Preparation Example 5: Zn-Fe analogue

[0111] A Zn—Fe analogue was obtained by the same method as in Preparation Example 1 except that the manganese chloride aqueous solution was replaced by a zinc sulfate aqueous solution and the potassium hexacyanocobaltate aqueous solution was replaced by a potassium hexacyanoferrate aqueous solution. Figure 3 The powder X-ray diffraction pattern of the Zn-Fe analogue shown is the same as the diffraction pattern described in Document A. Therefore, the Zn-Fe analogue is K xZn[Fe(CN) 6 ] y ·zH 2 O.

[0112] Preparation Example 6: Mn-Fe analogue

[0113] A Mn—Fe analogue was obtained by the same method as in Production Example 1 except that the potassium hexacyanocobaltate aqueous solution was changed to the sodium hexacyanoferrate aqueous solution. Figure 3 The powder X-ray diffraction pattern of the Mn-Fe analogue shown is the same as the diffraction pattern described in Document A. Therefore, the Mn-Fe analogue is K 0.06 Mn[Fe(CN) 6 ] 0.69 4.5H 2 O.

[0114] Example 1: Evaluation of methanol adsorption

[0115] The adsorption amount of methanol in the gas containing water and methanol was evaluated for each of the six samples of the Prussian blue analogs and activated carbon (Fujifilm Wako Pure Chemical Industries, Ltd., 037-02115 (hereinafter the same)) of Production Examples 1 to 5. Water and methanol were added to an aluminum gas bag filled with 30 L of nitrogen using a syringe so that the water concentration became 15000 ppmv and the methanol concentration became 5000 ppmv. The gas in the aluminum gas bag was passed through a column with an inner diameter of 6 mm filled with 50 mg of the sample at a temperature of 25° C. and a flow rate of 50 mL / min, and the gas discharged from the column was analyzed using a FTIR (Fourier transform infrared spectrometer) (JASCO Corporation, FT / IR-6600 (hereinafter the same)).

[0116] The amount of methanol adsorption was calculated by subtracting the cumulative amount of methanol detected by FTIR from the amount of methanol in the aluminum gas bag. Figure 4 .like Figure 4 As shown in FIG. 1 , all samples adsorbed methanol contained in the gas containing water. On the other hand, it was found that the amount of methanol adsorbed by the Prussian blue analogs of Production Examples 1 to 5 depended on the structure A of the Prussian blue analog. x M[M'(CN) 6 ] y ·zH 2 The type and valence of M' bound to the carbon side of O. The relationship between the methanol adsorption of Prussian blue analogs is as follows: Mn-Co analogs or Co-Co analogs (M' is Co 3+ )>Ni-Fe analogues or Zn-Fe analogues (M' is Fe 3+ )>Ga-Fe analogues (M' is Fe 2+ ).

[0117] Example 2: Evaluation of methanol adsorption energy

[0118] Using a specific surface area / pore distribution measuring device (Microtrac BEL Corp., Belsorp-MAXII), methanol adsorption isotherms of activated carbon and Mn-Co analogs at 25°C and 40°C, and water adsorption isotherms of Mn-Co analogs at 25°C and 40°C were prepared. The methanol adsorption energy was calculated from the methanol adsorption isotherms under two temperature conditions using Clausius-Clapeyron analysis software (Microtrac BEL Corp., Belmaster). The methanol isosteric differential heat of adsorption curve of activated carbon is shown in Figure 5 In addition, the methanol isotropic differential adsorption heat curve of Mn-Co analogue is shown in Figure 6 Similarly, the water adsorption energy is calculated from the water adsorption isotherms under two temperature conditions. The water isosteric differential adsorption heat curve of Mn-Co analogue is shown in Figure 7 .

[0119] like Figure 5 As shown in Figure 2, the maximum methanol adsorption energy of activated carbon is 52.5 kJ / mol. Figure 6 As shown in FIG. 1 , the maximum value of methanol adsorption energy of Mn-Co analogue is 71.4 kJ / mol, which is a very high value. This indicates that Mn-Co analogue easily adsorbs methanol but has difficulty in desorbing methanol compared to activated carbon. Figure 7 As shown in FIG. 1 , the maximum value of the water adsorption energy of the Mn-Co analogue is 60.3 kJ / mol. This indicates that the Mn-Co analogue easily adsorbs methanol compared to water, but has difficulty in desorbing methanol compared to water.

[0120] Example 3: Evaluation of methanol desorption temperature

[0121] In five containers filled with air containing water at a concentration of 15000 ppmv and methanol at a concentration of 5000 ppmv, five samples of activated carbon and the Prussian blue analogs of Preparation Examples 1 to 4 were placed, respectively, and left to stand at about 20 to 30° C. for 3 days to adsorb water and methanol. The desorption of water and methanol from each of these samples adsorbed with water and methanol was measured by TG-MS (JEOL, JMS-Q1500GC) under the conditions of a helium flow rate of 211 mL / min and a heating rate of 5° C. / min. Figure 8 This is the TG-MS curve of activated carbon. Fig. 9 This is the TG-MS curve of Mn-Co analogue. Fig.10 This is the TG-MS curve of Co-Co analogue. Fig.11 This is the TG-MS curve of Ga-Fe analogue. Fig.12 TG-MS curve of Ni-Fe analogue.

[0122] It should be noted that in Figure 8 to Figure 10 When the weight change of the sample becomes less than 0.03wt% / ℃, the desorption is considered to be complete, and the mass of water and methanol adsorbed on the sample is consistent with the mass of water and methanol desorbed from the sample. The intensity of m / z=31 detected by MS is converted to methanol concentration, and the intensity of m / z=19 is converted to water concentration, which are expressed as a curve. Fig.11 and Fig.12 In the graph, it is assumed that the water and methanol adsorbed on the sample are completely desorbed at 300° C. (the desorption ratio is 100%), and the desorption ratios of water and methanol under each measurement temperature condition are represented by a curve.

[0123] like Figure 8 As shown in , for activated carbon, the desorption temperatures of water and methanol overlap, making it difficult to selectively desorb only methanol. Fig. 9 and Fig.10 As shown in the figure, for Co-Co analogs and Mn-Co analogs, although part of methanol is desorbed together with water under conditions below 100°C, almost only methanol is desorbed under conditions above 120°C. That is, high-concentration methanol is obtained by recovering and cooling the gas desorbed from Co-Co analogs or Mn-Co analogs adsorbing water and methanol under conditions above 120°C. It can be seen that the Prussian blue type complex is superior to activated carbon in terms of the ability to separate water and methanol.

[0124] In addition, if Fig.11 and Fig.12 As shown, in the case of Ga-Fe analogs and Ni-Fe analogs, similarly to Mn-Co analogs and Co-Co analogs, high-concentration methanol containing little water is desorbed under the condition of 120° C. or higher.

[0125] From the above, it is known that when the Prussian blue analogs (Production Examples 1 to 5) adsorbing water and methanol are heated to 120° C. or higher (second temperature), and the desorbed gas is recovered and cooled, high-concentration methanol can be obtained.

[0126] Example 4: Evaluation of methanol adsorption in methanol-water solution

[0127] 0.2 g of activated carbon or the Mn-Co analogue of Preparation Example 1 was added to 1 mL of 5 vol% methanol aqueous solution and shaken for 120 minutes. The supernatant after shaking was evaluated by FTIR-ATR (Fourier transform attenuated total reflection infrared spectroscopy). -1The methanol concentration in the aqueous solution was calculated by the absorption peak at . The methanol adsorption amount was calculated by subtracting the amount of methanol in the supernatant after shaking detected by FTIR from the amount of methanol in the aqueous solution before adding activated carbon or Mn-Co analog. The methanol adsorption amount of activated carbon was 32.6 mg / g, while the methanol adsorption amount of Mn-Co analog was 69.4 mg / g. This shows that Mn-Co analog is also effective in recovering methanol in water.

[0128] Example 5: Evaluation of methanol concentration

[0129] Nitrogen gas containing 15000 ppmv of water vapor and 5000 ppmv of methanol was passed through a column having an inner diameter of 10 mm filled with 400 mg of the Mn-Co analogue of Production Example 1 at a flow rate of 200 mL / min at 25° C. for 150 minutes to adsorb water and methanol to the Mn-Co analogue (adsorption step). Thereafter, nitrogen gas was passed through the column at a flow rate of 200 mL / min at 70° C. for 180 minutes (dehydration step), and further passed through the column at a flow rate of 100 mL / min at 150° C. for 180 minutes (methanol desorption step) to desorb water and methanol, and the concentrations of water and methanol in the gas at the outlet side were evaluated by FTIR.

[0130] The amount of water and methanol desorbed from the Mn-Co analog at 150°C was calculated by integrating the gas concentration detected by FTIR over time. Then, all of the water and methanol were recovered under liquid nitrogen temperature conditions, and the methanol concentration (mass of methanol / (mass of methanol+mass of water)×100 (the same below)) was 92%. From the above, it can be seen that by using the Mn-Co analog, methanol can be recovered from humid air containing methanol. In addition, it was confirmed that by pre-setting a water desorption step in which the Mn-Co analog adsorbed with water and methanol is maintained at less than 120°C (first temperature), a high concentration of methanol can be recovered by a subsequent methanol desorption step maintained at above 120°C (second temperature).

[0131] Example 6: Durability Evaluation

[0132] Under the same conditions as in Example 5, the process consisting of the adsorption step, the water desorption step, and the methanol desorption step was repeated 10 times, and the amount of methanol desorbed was evaluated by FTIR. The amount of methanol desorbed from the Mn-Co analog at 150°C is shown in FIG. Fig.13 .like Fig.13 As shown, it was confirmed that the Mn-Co analogue could adsorb methanol even after the adsorption and desorption processes were repeated 10 times, and a high concentration of methanol could be recovered from the Mn-Co analogue.

[0133] Example 7: Evaluation of methanol selective adsorption

[0134] A column with an inner diameter of 10 mm filled with 400 mg of the Mn-Co analogue of Production Example 1 was maintained at 70°C, and at the same time, nitrogen containing 15000 ppmv of water vapor and 5000 ppmv of methanol was passed at a flow rate of 200 mL / min for 150 minutes. The amounts of water and methanol adsorbed on the Mn-Co analogue were calculated in the same manner as in Example 3. As a result, methanol was adsorbed on the Mn-Co analogue at 24 mg / g, while water was not adsorbed. From the above, it can be seen that there is a temperature region in which the Mn-Co analogue hardly adsorbs water but adsorbs methanol.

[0135] That is, if the Prussian blue analogue of the present application is heated to a predetermined temperature range, for example, about 70°C, and a gas containing water and methanol is passed through, methanol can be selectively adsorbed. This temperature range can be grasped by the method of this embodiment without excessive trial and error. Then, if the Prussian blue analogue that selectively adsorbs methanol is heated to a higher temperature, for example, about 120°C, the desorbed gas is recovered and cooled, a high concentration of methanol is obtained.

[0136] Example 8: Study of the third temperature

[0137] Methanol was concentrated by the same method as in Example 5 except that the water desorption step at 70°C was omitted. The methanol concentration in the gas at the outlet side of the column after concentration was 42%. This is equivalent to the case where the third temperature is 25°C and the fourth temperature is 150°C in the high-concentration methanol production method of the second embodiment. On the other hand, it can be considered that the result of Example 5 is equivalent to the case where the third temperature is 70°C and the fourth temperature is 150°C in the high-concentration methanol production method of the second embodiment, and the methanol concentration of the high-concentration methanol obtained at this time is 92%. Assuming that the methanol concentration after concentration is proportional to the adsorption temperature (absolute temperature) of water and methanol as the third temperature, it can be calculated that the methanol concentration of 54% that can be used in direct methanol fuel cells is when the third temperature is 35°C.

[0138] Example 9: Methanol adsorption test in liquid

[0139] As a comparison object of Mn-Fe analog (Production Example 6), activated carbon and zeolite powders were added to centrifuge tubes, and 24 tubes × 3 types of each sample were prepared. Eight methanol solutions (n=3) adjusted to 50000, 20000, 10000, 5000, 2000, 1000, 500, and 100 mg-methanol / L were added to each centrifuge tube.

[0140] The mixture was shaken at 25°C for more than 24 hours until the adsorbent material adsorbed methanol and the concentration in the liquid reached equilibrium. After the shaking was completed, the shaking liquid was recovered and measured by GC / MS (gas chromatography-mass spectrometry) to examine the equilibrium methanol concentration and the amount of methanol adsorbed at equilibrium. The results are shown in FIG. Fig.14 .like Fig.14 As shown, it can be seen that for the Mn-Fe analogue ( Fig.14 For MnHCF in the sample, methanol can be adsorbed even at a low equilibrium methanol concentration.

[0141] Example 10: Comparison of methanol adsorption at 1000 mg-methanol / L equilibrium

[0142] As a comparison object for the Mn-Fe analog (Production Example 6), the powder of the Mn-CO analog (Production Example 1) was filled in the column. A methanol water containing 1000 mg-methanol / L was flowed through the column at 25°C. The methanol adsorption amount of each sample was compared. The Mn-Fe analog was 0.36 mmol / g, and the Mn-CO analog was 0.11 mmol / g ( Fig.15 ). In addition, Fig.15 In FIG. 5 , the results are compared with the methanol adsorption amounts of activated carbon and zeolite at 1000 mg-methanol / L equilibrium according to the adsorption isotherms (for activated carbon and zeolite, the values ​​were calculated by interpolation from the adsorption isotherms).

[0143] The results of Example 10 are shown in Fig.16 .exist Fig.16 In the graph, the methanol concentration after passing through the column is represented graphically relative to the flow rate of 1000 mg-methanol / L of methanol water per 1 g of adsorbent filled in the column. The Mn-Co analogue can hardly be adsorbed from the initial stage, while the Mn-Fe analogue adsorbs methanol, so that methanol is hardly contained in the solution after passing through the column in the initial stage. As the amount of methanol water passing through the column increases, the Mn-Fe analogue can no longer adsorb methanol, and soon reaches equilibrium with the concentration before passing through the column.

[0144] Description of Reference Numerals

[0145] 10: Methanol recovery device. 12: Frame.

[0146] 14: Heating unit.

[0147] 16: Maintaining department.

[0148] 18: First supply unit.

[0149] 20: Second supply unit.

[0150] 22: Recycling department.

[0151] 24: Discharge section.

Claims

1. A methanol adsorbent material which adsorbs methanol contained in a liquid or gas containing water and methanol, wherein: The methanol adsorbent contains, as an effective ingredient, a Prussian blue analog represented by the following general formula (1): A x M[M’(CN)6] y ·zH2O(1) In the general formula, x, y and z are 0≤x≤3, 0.1≤y≤1.5, 0≤z≤6, A is one or more of hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion, M and M' are independent cations and do not include hydrogen ion, ammonium cation, alkali metal ion and alkaline earth metal ion.

2. The methanol adsorbent material according to claim 1, wherein M is Mn 2+ 、Co 2+ , Ga 2+ 、Ni 2+ 、Zn 2+ Any of the following, M' is Co 3+ or Fe 3+ .

3. The methanol adsorbent material according to claim 1, wherein M is Mn 2+ ,M' is Co 3+ or Fe 3+ .

4. A method for producing high-concentration methanol, wherein: The method for producing high-concentration methanol has the following characteristics: an adsorption step of contacting the methanol adsorbent according to any one of claims 1 to 3 with a liquid or gas containing water and methanol to adsorb the water and methanol onto the methanol adsorbent; a water desorption step, in which the methanol adsorbent material after the adsorption step is maintained at a first temperature to desorb water from the methanol adsorbent material; as well as A methanol desorption process is a process for maintaining the methanol adsorbent material after the water desorption process at a second temperature higher than the first temperature, so that high-concentration methanol is desorbed from the methanol adsorbent material and recovered.

5. The method for producing high-concentration methanol according to claim 4, wherein: The first temperature is 70° C. or higher and lower than 120° C., and the second temperature is 120° C. or higher and 250° C. or lower.

6. A method for producing high-concentration methanol, wherein: The method for producing high-concentration methanol has the following characteristics: a methanol adsorption step of bringing the methanol adsorbent according to any one of claims 1 to 3 into contact with a liquid or gas containing water and methanol at a third temperature to selectively adsorb methanol onto the methanol adsorbent relative to water; as well as A methanol recovery step is performed to maintain the methanol adsorption material after the methanol adsorption step at a fourth temperature higher than the third temperature, so that high-concentration methanol is desorbed from the methanol adsorption material and recovered.

7. The method for producing high-concentration methanol according to claim 6, wherein: The third temperature is greater than or equal to 35° C. and less than or equal to 120° C., and the fourth temperature is greater than or equal to 120° C. and less than or equal to 250° C.

8. A methanol recovery device, wherein: The methanol recovery device comprises: The methanol adsorption material according to any one of claims 1 to 3; a holding portion for holding the methanol adsorbent material inside; a heating unit capable of heating the methanol adsorbent in the holding unit to a temperature of 35° C. or higher and 250° C. or lower; a first supply unit for supplying a liquid or a gas containing water and methanol to the methanol adsorbent in the holding unit; and A recovery unit recovers the high-concentration methanol desorbed from the methanol adsorbent in the holding unit.

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