Separation method

Abstract

The present disclosure addresses the problem of providing a novel method for separating fluorocarbons.　Provided is a method for separating fluorocarbons that includes separating a second mixture from a first mixture containing a fluorocarbon A having one or more double bonds and having n carbon atoms and a fluorocarbon B which does not have a double bond but has m carbon atoms, the second mixture being different from the first mixture in terms of the compositional ratio of the fluorocarbon A and the fluorocarbon B. The separation is carried out by bringing the first mixture into contact with an adsorbent material containing a metal organic structure.

Description

Separation method

[0001] The present disclosure relates to a separation method.

[0002] A method of distilling a mixture of fluorocarbons is known as a method for separating fluorocarbons. Patent Document 1 describes a method of mixing a mixture containing 2,3,3,3-tetrafluoropropene and hexafluoropropene with an extraction solvent to obtain a mixture for extraction, and then distilling the mixture for extraction to obtain a distillate containing hexafluoropropene as a main component and a bottom product containing 2,3,3,3-tetrafluoropropene.

[0003] Japanese Patent Application Laid-Open No. 2018-002602

[0004] The inventors have found that the distillation method described in Patent Document 1 has difficulty in separating compounds with similar boiling points or compounds that form an azeotrope, and that when separating fluorocarbons, for example, fluorocarbons that differ in the presence or absence of a double bond, the method may be unable to sufficiently separate the compounds.

[0005] The problem in this disclosure is to provide a new method for separating fluorocarbons.

[0006] The present disclosure includes the following aspects. [1] A method for separating fluorocarbons, comprising separating a second mixture from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, the second mixture having a composition ratio of the fluorocarbon A to the fluorocarbon B different from that of the first mixture, the separation being carried out by contacting the first mixture with an adsorbent containing a metal-organic framework. [2] The separation method according to [1], wherein the contact of the first mixture with the adsorbent containing the metal-organic framework is carried out at a temperature of −10° C. or higher and 80° C. or lower. [3] The separation method according to [1] or [2], wherein n is 2 or higher and 3 or lower. [4] The separation method according to any one of [1] to [3], wherein m is 1 or higher and 3 or lower. [5] The separation method according to any one of [1] to [4], wherein the fluorocarbon A contains R1234yf. [6] The separation method according to any one of [1] to [5], wherein the fluorocarbon B comprises one or more selected from R134a, R143, R143a, R32, and R125. [7] The separation method according to any one of [1] to [6], wherein the metal-organic framework comprises a metal ion. [8] The separation method according to any one of [1] to [7], wherein the metal-organic framework comprises one or more organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to the metal ion per molecule. [9] The separation method according to any one of [1] to [8], wherein the metal-organic framework comprises a metal ion and one or more organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to the metal ion per molecule.

[10] The separation method according to any one of [1] to [9], wherein the metal-organic framework has an open metal site composed of a coordinatively unsaturated metal ion.

[11] The separation method according to any one of [1] to

[10] , wherein the adsorbent comprising the metal organic framework further comprises a resin.

[12] The separation method according to any one of [1] to

[11] , wherein the adsorbent comprising the metal organic framework is in the form of a powder, granules, flakes, or pellets.

[13] The separation method according to any one of [1] to

[12] , wherein the first mixture is an azeotropic or pseudo-azeotropic mixture of fluorocarbons.

[14] The separation method according to any one of [1] to

[13] , further comprising contacting the separated second mixture with an adsorbent comprising the metal-organic framework.

[15] The separation method according to any one of [1] to

[14] , further comprising purifying the separated second mixture.

[16] The separation method according to any one of [1] to

[15] , further comprising, after contacting the first mixture with the adsorbent comprising the metal-organic framework, desorbing the fluorocarbon A adsorbed on the adsorbent comprising the metal-organic framework from the adsorbent comprising the metal-organic framework.

[17] A fluorocarbon purification system performing the separation method according to any one of [1] to

[16] .

[18] A method for separating fluorocarbons, comprising separating a third mixture from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, wherein the third mixture has a lower concentration of fluorocarbon A than that of the first mixture, and the separation is carried out by contacting the first mixture with an adsorbent.

[19] The separation method according to

[18] , wherein the contact of the first mixture with the adsorbent is carried out at a temperature of −10° C. or higher and 80° C. or lower.

[20] The separation method according to

[18] or

[19] , wherein n is 2 or higher and 3 or lower.

[21] The separation method according to any one of

[18] to

[20] , wherein m is 1 or higher and 3 or lower.

[22] The separation method according to any one of

[18] to

[21] , wherein the fluorocarbon A includes R1234yf.

[23] The separation method according to any one of

[18] to

[22] , wherein the fluorocarbon B comprises one or more selected from R134a, R143, R143a, R32, and R125.

[24] The separation method according to any one of

[18] to

[23] , wherein the adsorbent comprises a porous material.

[25] The separation method according to any one of

[18] to

[24] , wherein the adsorbent comprises a metal-organic framework.

[26] The separation method according to

[25] , wherein the metal-organic framework comprises a metal ion.

[27] The separation method according to

[25] , wherein the metal-organic framework comprises one or more organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to a metal ion per molecule.

[28] The separation method according to

[25] , wherein the metal-organic framework comprises a metal ion and one or more organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to the metal ion per molecule.

[29] The separation method according to

[25] , wherein the metal-organic framework has open metal sites composed of coordinatively unsaturated metal ions.

[30] The separation method according to any one of

[18] to

[29] , wherein the adsorbent further comprises a resin.

[31] The separation method according to any one of

[18] to

[30] , wherein the adsorbent is in the form of a powder, granules, flakes, or pellets.

[32] The separation method according to any one of

[18] to

[31] , wherein the first mixture is an azeotropic or pseudo-azeotropic mixture of fluorocarbons.

[33] The separation method according to any one of

[18] to

[32] , further comprising contacting the separated third mixture with an adsorbent.

[34] The separation method according to any one of

[18] to

[33] , further comprising purifying the separated third mixture.

[35] The separation method according to any one of

[18] to

[34] , further comprising, after contacting the first mixture with the adsorbent, desorbing the fluorocarbon A adsorbed to the adsorbent from the adsorbent.

[36] A fluorocarbon purification system that performs the separation method according to any one of

[18] to

[35] .

[37] A composite material comprising a metal-organic framework and a fluorocarbon A having one or more double bonds and n carbon atoms, wherein the metal-organic framework has open metal sites composed of coordinatively unsaturated metal ions.

[0007] The present disclosure may provide a new method for separating fluorocarbons.

[0008] Figure 1 is a schematic diagram showing a fluorocarbon purification system according to one embodiment of the present disclosure. Figure 2 is a schematic diagram showing a fluorocarbon purification system according to another embodiment of the present disclosure. Figure 3 shows the adsorption breakthrough curves of Example 1 and Comparative Example 1.

[0009] (First embodiment: First separation method) A first separation method of the present disclosure comprises separating, from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, a second mixture having a composition ratio of the fluorocarbon A to the fluorocarbon B different from that of the first mixture, and the separation is carried out by contacting the first mixture with an adsorbent containing a metal organic framework.

[0010] According to the first separation method of the present disclosure, by contacting an adsorbent containing a metal-organic framework with a first mixture containing two or more fluorocarbon gases, it is possible to separate a second mixture in which the proportion of either the fluorocarbon gas having a double bond or the fluorocarbon gas having no double bond is reduced. Although the present disclosure should not be interpreted as being limited to a particular theory, it is believed that the pore structure of the metal-organic framework can control the adsorption behavior between the fluorocarbon A having a double bond or the fluorocarbon B having no double bond and the metal-organic framework, thereby obtaining a mixture with a different composition ratio. Note that the second mixture may also include a case in which either the fluorocarbon A or the fluorocarbon B is not contained.

[0011] In one aspect, a first separation method includes separating, from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, a second mixture in which the concentration of fluorocarbon A is reduced compared to that of the first mixture, and the separation is carried out by contacting the first mixture with an adsorbent containing a metal organic framework.

[0012] In another aspect, a first separation method includes separating, from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, a second mixture in which the concentration of fluorocarbon B is reduced compared to that of the first mixture, and the separation is carried out by contacting the first mixture with an adsorbent containing a metal organic framework.

[0013] (First mixture) The first mixture contains fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds. In this embodiment, fluorocarbon A or fluorocarbon B is also referred to as an adsorbate.

[0014] The number of double bonds in the fluorocarbon A may be 1 or more, preferably 1 or more and 5 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or more and 2 or less.

[0015] The carbon number n of the fluorocarbon A is preferably 2 or more and 10 or less, more preferably 2 or more and 5 or less, and even more preferably 2 or more and 3 or less.

[0016] The boiling point of the fluorocarbon A may be, for example, −80° C. or higher and −20° C. or lower, and may further be −60° C. or higher and −30° C. or lower. In one embodiment, the fluorocarbon having a carbon number n is present as a gas in the first mixture.

[0017] Examples of the fluorocarbon A include hydrochlorofluoroolefins and hydrofluoroolefins.

[0018] Examples of the hydrofluoroolefin include 1,1-difluoroethylene, 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, hexafluoropropene, 1,1,1,4,4,4-hexafluorobutene, etc. The fluorocarbon A is preferably a hydrofluorocarbon, and more preferably 2,3,3,3-tetrafluoropropene (R1234yf).

[0019] Examples of the hydrochlorofluoroolefin include 1-chloro-3,3,3-trifluoropropene, 1-chloro-2,3,3,3-tetrafluoropropene, etc. The fluorocarbon A may contain one or more compounds.

[0020] The concentration of fluorocarbon A in the first mixture may be, for example, 0.0001 mol % or more and 90 mol % or less, and may further be 0.0001 mol % or more and 20 mol % or less, based on the entire first mixture.

[0021] The carbon number m of the fluorocarbon B is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, and even more preferably 1 or more and 3 or less.

[0022] The difference between the carbon number of the fluorocarbon A and the carbon number of the fluorocarbon B may be, for example, from 0 to 5, further from 0 to 3, and particularly from 0 to 1. According to the separation method of the present disclosure, even when the carbon numbers of the fluorocarbon A and the fluorocarbon B are similar, a second mixture having a different composition ratio can be separated.

[0023] The boiling point of the fluorocarbon B may be, for example, −80° C. or higher and −20° C. or lower, and may further be −60° C. or higher and −30° C. or lower. In one embodiment, the fluorocarbon having a carbon number n is present as a gas in the first mixture.

[0024] The difference between the boiling point of the fluorocarbon A and the boiling point of the fluorocarbon B may be, for example, 0° C. or higher and 20° C. or lower, and may further be 0° C. or higher and 10° C. or lower. According to the separation method of the present disclosure, even when the boiling points of the fluorocarbon A and the fluorocarbon B are close to each other, a second mixture having a different composition ratio can be separated.

[0025] Examples of the fluorocarbon B include hydrochlorofluorocarbons and hydrofluorocarbons.

[0026] Examples of the hydrofluorocarbon include difluoromethane, 1,1-difluoroethane, 1,2-difluoroethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, and pentafluoroethane.

[0027] Examples of the hydrochlorofluorocarbon include chlorodifluoromethane and chlorotrifluoroethane.

[0028] The fluorocarbon B is preferably a hydrofluorocarbon, and more preferably one or more selected from 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), and 1,1,1,2,2-pentafluoroethane (R125). The fluorocarbon B may contain one or more compounds.

[0029] The concentration of fluorocarbon B in the first mixture may be, for example, 0.0001 mol % or more and 90 mol % or less, and may further be 0.0001 mol % or more and 20 mol % or less, based on the entire first mixture.

[0030] The composition ratio of fluorocarbon A to fluorocarbon B in the first composition (A / (A+B)×100) is C １ Then, C １ may be, for example, 0.0001 or more and 90 or less, more preferably 0.0001 or more and 50 or less, and even more preferably 0.0001 or more and 20 or less, on a molar basis.

[0031] The first mixture may be an azeotropic mixture or a pseudo-azeotropic mixture of fluorocarbons. According to the separation method of the present disclosure, even an azeotropic mixture or a pseudo-azeotropic mixture can separate fluorocarbons with a specific carbon number. Examples of such azeotropic mixtures or pseudo-azeotropic mixtures include mixtures in which the difference in boiling point between the fluorocarbon to be separated (in this embodiment, fluorocarbon A or fluorocarbon B) and the boiling point of the other fluorocarbon is 1°C or more and 20°C or less, or even 3°C or more and 18°C ​​or less, at 1 atmosphere (1,013 hPa).

[0032] In one embodiment, fluorocarbon A can be 2,3,3,3-tetrafluoropropene (R1234yf) and fluorocarbon B can be one or more selected from 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), and 1,1,1,2,2-pentafluoroethane (R125).

[0033] The first mixture may contain other compounds in addition to fluorocarbon A and fluorocarbon B. The boiling point of such other compounds may be, for example, −100° C. or lower, or −150° C. or lower. In one embodiment, such other compounds are contained in the first mixture as a gas.

[0034] The other compounds include nitrogen, oxygen, carbon dioxide, water, and the like.

[0035] (Adsorbent) The adsorbent includes a metal-organic framework (PCP: Porous Coordination Polymer, or MOF: Metal-Organic Framework). Hereinafter, in this embodiment, the adsorbent including the metal-organic framework will also be simply referred to as the adsorbent.

[0036] The metal-organic framework may typically be an organic-inorganic composite structure having a regularly continuous three-dimensional framework. The metal-organic framework preferably includes metal ions and one or more organic ligands. The organic ligand typically includes two or more groups capable of forming a coordinate bond to the metal ion per molecule. Coordination of the organic ligand to the metal ion forms a highly regular, three-dimensionally continuous structure (e.g., a network structure), and pores are formed between the metal ions and the organic ligands. In such a three-dimensional structure, the effective pore size and flexibility of the metal-organic framework, as well as the interaction between the metal-organic framework and the adsorbate, can be controlled by combining the type of metal ion and the organic ligand. Furthermore, the metal-organic framework exhibits high durability against repeated adsorption and desorption of the adsorbate, with no decrease in adsorption amount (maximum adsorption amount). Furthermore, the metal-organic framework is resistant to the effects of temperature (heat) and humidity, and exhibits high durability against high temperatures and humidity, with no decrease in adsorption amount even when stored for long periods under high temperatures and humidity.

[0037] It is believed that the pore structure of the metal-organic framework makes it possible to control the adsorption behavior between the metal-organic framework and fluorocarbon A having a double bond or fluorocarbon B having no double bond, and to change the composition ratio of fluorocarbon A and fluorocarbon B in the first mixture.

[0038] The metal ions are not particularly limited, but may be, for example, ions of metals selected from the group consisting of Group Ia, Group IIa, Group IIIa, Groups IVa to VIII, and Groups Ib to VIb. Such metals may be preferably one or more selected from the group consisting of Mg, Ca, Sr, Ba, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ro, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, TI, Si, Ge, Sn, Pb, As, Sb, Bi, La, Ce, Pr, Nd, Pm, Sm, En, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and more preferably one or more selected from the group consisting of Zn, Cu, Ti, Co, Mn, Ni, Al, Ca, Zr, and Mg.

[0039] Specifically, such metal ions include Mg ２＋ , Ca ２＋ , Sr ２＋ , Ba ２＋ , Sc ３＋ , Y ３＋ , Ln ３＋ , Ti ４＋ , Zr ４＋ , Hf ４＋ , V ４＋ , V ３＋ , V ２＋ , Nb ３＋ , Ta ３＋ , Cr ３＋ , Mo ３＋ , W ３＋ , Mn ３＋ , Mn ２＋ , Re ３＋ , Re ２＋ , Fe ３＋ , Fe ２＋ , Ru ３＋ , Ru ２＋ , Os３＋ , Os ２＋ , Co ３＋ , Co ２＋ , Rh ２＋ , Rh ＋ , Ir ２＋ , Ir ＋ , Ni ２＋ , Ni ＋ , Pd ２＋ , Pd ＋ , Pt ２＋ , Pt ＋ , Cu ２＋ , Cu ＋ , Ag ＋ , Au ＋ , Zn ２＋ , Cd ２＋ , Hg ２＋ , Al ３＋ , Ga ３＋ , ln ３＋ , T.I. ３＋ , Si ４＋ , Si ２＋ , Ge ４＋ , Ge ２＋ , Sn ４＋ , Sn ２＋ , Pb ４＋ , Pb ２＋ , As ５＋ , As ３＋ , As ＋ , Sb ５＋ , Sb ３＋ , Sb ＋ , Bi ５＋ , Bi ３＋ , Bi ＋ , La ３＋ , Ce ３＋ , Pr ３＋ , Nd ３＋ , Pm ３＋ , Sm ３＋ , En ３＋ , Gd ３＋ , Tb ３＋ , Dy ３＋ , Ho ３＋ , Er ３＋ , Tm ３＋ and Yb ３＋ and more preferably, Cr ３＋ , Zn ２＋ , Cu ２＋ , Cu+, Ti ４＋ , Ti３＋ , Co ３＋ , Co ２＋ , Mn ３＋ , Mn ２＋ , Fe ３＋ , Fe ２＋ , Ni ２＋ , Ni ＋ , Al ３＋ , Ca ２＋ , Zr ４＋ and Mg ２＋ The compound may be one or more selected from the group consisting of:

[0040] The metal ions may be of one type or two or more types, and preferably are of one type.

[0041] In a preferred embodiment, the metal ions are one or more selected from Fe ions, Cu ions, Ni ions, Mg ions, Co ions, Cr ions, Zr ions and Zn ions, and preferably Fe ions. ２＋ , Fe ３＋ , Cu ２＋ , Ni ２＋ , Mg ２＋ , Co ２＋ , Cr ３＋ and Zn ２＋ One or more selected from the following:

[0042] The organic ligand is not particularly limited as long as it contains two or more groups capable of forming a coordinate bond with a metal ion in one molecule. The coordinate bond is formed, for example, by a functional group capable of forming a coordinate bond with a metal ion.

[0043] Examples of the functional group capable of forming a coordinate bond include —COOH and —CS ２ H, -NO ２ , -B(OH) ２ , -SO ３ H, —Si(OH) ３ , -Ge(OH) ３ , -Sn(OH) ３ , -Si(SH) ４ , -Ge(SH) ４ , -Sn(SH) ３ , -PO ３ H, -AsO ３ H, -AsO４ H, -P(SH) ３ , -As(SH) ３ , -CH(RSH) ２ , -C(RSH) ３ , —CH(RNH ２ ) ２ , -C(RNH ２ ) ３ , —CH(ROH) ２ , -C(ROH) ３ , -CH(RCN) ３ , and -C(RCN) ３ In the above formula, R represents a single bond, an alkylene group having 1 to 5 carbon atoms (e.g., methylene, ethylene, n-propylene, i-propylene, n-butylene, i-butylene, tert-butylene, or n-pentylene), a divalent aromatic group having 6 to 14 carbon atoms (e.g., phenylene), or a combination of the above alkylene group and an aromatic group (e.g., -phenylene-alkylene-phenylene-). In addition, the functional group capable of forming a coordinate bond may be a heteroatom (e.g., N, O, S, B, P, Si, or Al) contained in a heterocycle, and preferably a nitrogen atom contained in a heterocycle.

[0044] In a preferred embodiment, the functional group capable of forming a coordinate bond may be —COOH, a nitrogen atom contained in a heterocycle, or the like.

[0045] The organic ligand preferably has the functional groups so as to be bidentate or higher. In such an organic ligand, the portion other than the functional groups is not limited as long as the organic ligand can form a coordinate bond with a metal ion.

[0046] In one embodiment, the organic ligand is derived from a saturated or unsaturated aliphatic or aromatic compound. Alternatively, the ligand may be derived from a compound in which such an aliphatic compound is combined with an aromatic compound (hereinafter also referred to as an "aliphatic aromatic compound").

[0047] The aliphatic moiety of the aliphatic compound or aliphatic aromatic compound may be linear, branched, or cyclic. If the aliphatic moiety is cyclic, it may have multiple rings. The aliphatic moiety of the aliphatic compound or aliphatic aromatic compound preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In a preferred embodiment, the aliphatic moiety is derived from methane, adamantane, acetylene, ethylene, or butadiene.

[0048] The aromatic moiety of the aromatic compound or aromatic aliphatic compound may have one or more rings, for example, 2, 3, 4, or 5 rings. These rings may be fused or unfused. The aromatic moiety of the aromatic compound or aliphatic aromatic compound preferably has 1, 2, or 3 rings, more preferably 1 or 2 rings. Each ring of the compound may also have at least one heteroatom in the ring, such as N, O, S, B, P, Si, or Al, preferably N, O, or S. The aromatic moiety of the aromatic compound or aromatic aliphatic compound preferably contains one or two rings containing 6 carbon atoms. When the aromatic moiety has two rings, the two rings may be fused or unfused. In a preferred embodiment, the aromatic moiety is derived from benzene, naphthalene, biphenyl, bipyridyl, or pyridyl.

[0049] In one embodiment, the organic ligand is derived from a dicarboxylic acid, tricarboxylic acid, or tetracarboxylic acid.

[0050] Examples of the dicarboxylic acid include oxalic acid, succinic acid, tartaric acid, maleic acid, 1,4-butanedicarboxylic acid, 1,4-butenedicarboxylic acid, 4-oxopyran-2,6-dicarboxylic acid, 1,6-hexanedicarboxylic acid, decanedicarboxylic acid, 1,8-heptadecanedicarboxylic acid, 1,9-heptadecanedicarboxylic acid, heptadecanedicarboxylic acid, acetylenedicarboxylic acid, 1,2-benzenedicarboxylic acid, 1,3-benzenedicarboxylic acid, 2,3-pyridinedicarboxylic acid, pyridine-2,3-dicarboxylic acid, and 1,3-butadiene-1,4-dicarboxylic acid. carboxylic acid, 1,4-benzenedicarboxylic acid, p-benzenedicarboxylic acid, imidazole-2,4-dicarboxylic acid, 2-methylquinoline-3,4-dicarboxylic acid, quinoline-2,4-dicarboxylic acid, quinoxaline-2,3-dicarboxylic acid, 6-chloroquinoxaline-2,3-dicarboxylic acid, 4,4'-diaminophenylmethane-3,3'-dicarboxylic acid, quinoline-3,4-dicarboxylic acid, 7-chloro-4-hydroxyquinoline-2,8-dicarboxylic acid, diimidedicarboxylic acid, pyridine-2,6-dicarboxylic acid, 2-methylimidazole-4,5-dicarboxylic acid carboxylic acid, thiophene-3,4-dicarboxylic acid, 2-isopropylimidazole-4,5-dicarboxylic acid, tetrahydropyran-4,4-dicarboxylic acid, perylene-3,9-dicarboxylic acid, perylene dicarboxylic acid, Pluriol E200-dicarboxylic acid, 3,6-dioxaoctanedicarboxylic acid, 3,5-cyclohexadiene-1,2-dicarboxylic acid, octanedicarboxylic acid, pentane-3,3-dicarboxylic acid, 4,4'-diamino-1,1'-biphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, benzidine quinone-3,3'-dicarboxylic acid, 1,4-bis(phenylamino)benzene-2,5-dicarboxylic acid, 1,1'-binaphthyl dicarboxylic acid, 7-chloro-8-methylquinoline-2,3-dicarboxylic acid, 1-anilino-anthraquinone-2,4'-dicarboxylic acid, polytetrahydrofuran 250-dicarboxylic acid, 1,4-bis(carboxymethyl)piperazine-2,3-dicarboxylic acid, 7-chloroquinoline-3,8-dicarboxylic acid, 1-(4-carboxy)phenyl-3-(4-chloro)phenylpyrazoline-4,5-dicarboxylic acid, 1,4,5,6,7,7-Hexachloro-5-norbornene-2,3-dicarboxylic acid, phenylindanedicarboxylic acid, 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, naphthalene-1,8-dicarboxylic acid, 2-benzoylbenzene-1,3-dicarboxylic acid, 1,3-dibenzyl-2-oxoimidazolidine-4,5-cis-dicarboxylic acid, 2,2'-biquinoline-4,4'-dicarboxylic acid, pyridine-3,4-dicarboxylic acid, 3,6,9-trioxaundecanedicarboxylic acid, hydroxybenzophenone Pluriol E300-dicarboxylic acid, Pluriol E400-dicarboxylic acid, Pluriol E600-dicarboxylic acid, Pyrazole-3,4-dicarboxylic acid, 2,3-pyrazinedicarboxylic acid, 5,6-dimethyl-2,3-pyrazinedicarboxylic acid, 4,4'-diamino(diphenyl ether)diimidedicarboxylic acid, 4,4'-diaminodiphenylmethanediimidedicarboxylic acid, 4,4'-diamino(diphenyl sulfone)diimidedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-adamantine Benzenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 8-methoxy-2,3-naphthalenedicarboxylic acid, 8-nitro-2,3-naphthalenedicarboxylic acid, 8-sulfo-2,3-naphthalenedicarboxylic acid, anthracene-2,3-dicarboxylic acid, 2',3'-diphenyl-p-terphenyl-4,4"-dicarboxylic acid, (diphenyl ether)-4,4'-dicarboxylic acid, imidazole-4,5-dicarboxylic acid, 4(1H)-oxithiochromene-2,8-dicarboxylic acid, 5-tert-butyl-1,3-benzene dicarboxylic acid, 7,8-quinolinedicarboxylic acid, 4,5-imidazoledicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, hexatriacontanedicarboxylic acid, tetradecanedicarboxylic acid, 1,7-heptanedicarboxylic acid, 5-hydroxy-1,3-benzenedicarboxylic acid, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, pyrazine-2,3-dicarboxylic acid, furan-2,5-dicarboxylic acid, 1-nonene-6,9-dicarboxylic acid, eicosenedicarboxylic acid, 4,4'-dihydroxy-3,3'-biphenyldicarboxylic acid, 4,4'-Dihydroxydiphenylmethane-3,3'-dicarboxylic acid, 1-amino-4-methyl-9,10-dioxo-9,10-dihydroanthracene-2,3-dicarboxylic acid, 2,5-pyridinedicarboxylic acid, cyclohexene-2,3-dicarboxylic acid, 2,9-dichlorofluorubin-4,11-dicarboxylic acid, 7-chloro-3-methylquinoline-6,8-dicarboxylic acid, 2,4-dichlorobenzophenone-2',5'-dicarboxylic acid, 1,3-benzenedicarboxylic acid, 2,6-pyridinedicarboxylic acid , 1-methylpyrrole-3,4-dicarboxylic acid, 1-benzyl-1H-pyrrole-3,4-dicarboxylic acid, anthraquinone-1,5-dicarboxylic acid, 3,5-pyrazole dicarboxylic acid, 2-nitrobenzene-1,4-dicarboxylic acid, heptane-1,7-dicarboxylic acid, cyclobutane-1,1-dicarboxylic acid, 1,14-tetradecane dicarboxylic acid, 5,6-dehydronorbornane-2,3-dicarboxylic acid, 5-ethyl-2,3-pyridine dicarboxylic acid, and camphor dicarboxylic acid.

[0051] Examples of the tricarboxylic acid include 2-hydroxy-1,2,3-propanetricarboxylic acid, 7-chloro-2,3,8-quinolinetricarboxylic acid, 1,2,3-,1,2,4-benzenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 2-phosphono-1,2,4-butanetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 4,4',4"-(1,3,5-benzenetriyl)trisbenzoic acid, 1-hydroxy-1,2,3-propanetricarboxylic acid, 4,5-dihydro-4,5-dioxo-1H-pyrrolo[2,3-F]quinoline-2,7,9-tricarboxylic acid, 5-acetyl-3-amino-6-methylbenzene-1,2,4-tricarboxylic acid, 3-amino-5-benzoyl-6-methylbenzene-1,2,4-tricarboxylic acid, 1,2,3-propanetricarboxylic acid, and aurintricarboxylic acid.

[0052] Examples of the tetracarboxylic acid include perylene tetracarboxylic acids such as 1,1-dioxidoperillo[1,12-BCD]thiophene-3,4,9,10-tetracarboxylic acid, perylene-3,4,9,10-tetracarboxylic acid, and (perylene-1,12-sulfone)-3,4,9,10-tetracarboxylic acid; butane tetracarboxylic acids such as 1,2,3,4-butane tetracarboxylic acid and meso-1,2,3,4-butane tetracarboxylic acid; decane-2,4,6,8-tetracarboxylic acid; and 1,4,7,10,13,16-hexaoxacyclooctadecane-2,3,11 ,13-tetracarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, 1,2,11,12-dodecanetetracarboxylic acid, 1,2,5,6-hexanetetracarboxylic acid, 1,2,7,8-octanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,9,10-decanetetracarboxylic acid, benzophenonetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, tetrahydrofurantetracarboxylic acid, and cyclopentanetetracarboxylic acids such as cyclopentane-1,2,3,4-tetracarboxylic acid.

[0053] In one embodiment, the organic ligand is derived from a heterocycle capable of forming a coordinate bond through a ring heteroatom, such as the following heterocycle: The heterocycle may be unsubstituted or substituted:

[0054]

[0055] In one embodiment, the organic ligand is derived from an azole, such as a diazole or triazole, preferably a triazole.

[0056] In a preferred embodiment, the organic ligand includes an organic ligand derived from a polycarboxylic acid and an organic ligand derived from an azole, and preferably includes an organic ligand derived from an aromatic polycarboxylic acid.

[0057] In a preferred embodiment, the organic ligand is selected from 1,4-benzenedicarboxylic acid, 1,2-benzenedicarboxylic acid, maleic acid, 1,3,5-benzenetricarboxylic acid, 4,4',4"-(1,3,5-benzenetriyl)trisbenzoic acid, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, oxalic acid, 4,4'-dihydroxy-3,3'-biphenyldicarboxylic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid, 4,4'-bipyridine, triazole, imidazole, 3,3'-bipyrazole, benzimidazole, and 3,5-pyridinedicarboxylic acid. In a more preferred embodiment, the organic ligand is selected from 1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-3,3'-biphenyldicarboxylic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, and 2,5-dihydroxy-1,4-benzenedicarboxylic acid.

[0058] The organic ligand may be of one kind or two or more kinds.

[0059] In the present disclosure, "derived from a compound" includes not only the compound itself, but also a form in which the compound is partially protonated or a form in which the compound is completely protonated.

[0060] The metal organic framework preferably has an open metal site (OPEN METAL SITE) consisting of a coordinatively unsaturated metal ion. The open metal site refers to a site where the metal contained in the metal organic framework is in a coordinatively unsaturated state and any molecule can be coordinated. The presence or absence of the open metal site does not depend on the types of metal ion and organic ligand.

[0061] Metal organic frameworks having Open Metal Site include HKUST-1, MIL-100 (Fe), MIL-101 (Cr), MOF-74 (Ni), MOF-74 (Mg), MOF-74 (Co), MOF-74 (Cu), and Mg ２ (dobpdc) and UTSA-16(Zn).

[0062] The metal organic framework can be produced by contacting a metal ion with an organic ligand. The contacting of the metal ion with the organic ligand may be carried out in the presence of a solvent. The solvent may be water, ethanol, dimethylformamide, toluene, methanol, chlorobenzene, diethylformamide, dimethyl sulfoxide, water, hydrogen peroxide, methylamine, sodium hydroxide solution, N-methylpyrrolidone ether, acetonitrile, benzyl chloride, triethylamine, ethylene glycol, or a mixture thereof.

[0063] The contact of the metal ion with the organic ligand may be carried out under pressure or under normal pressure. The temperature during the contact may be, for example, 10 to 200° C. or 10 to 150° C. The mixture may be stirred during the contact.

[0064] The effective pore diameter is, for example, 0.30 nm or more and 5.00 nm or less, preferably 0.4 nm or more and 4.00 nm or less, and more preferably 1.00 nm or more and 2.50 nm or less. In one aspect, the effective pore diameter of the porous body is, for example, 0.30 nm or more, preferably 0.4 nm or more, and more preferably 1.00 nm or more, and for example, 5.00 nm or less, preferably 4.00 nm or less, and more preferably 2.00 nm or less.

[0065] The effective pore diameter is the pore diameter of a porous body, such as a metal-organic framework, that is determined from the degree of adsorption and the molecular diameter of the adsorbate when the porous body is brought into contact with the adsorbate. Specifically, the effective pore diameter can be determined by converting the relative pressure of the nitrogen adsorption isotherm into the effective pore diameter using the Horvath-Kawazoe method. The conversion formula may be the calculation formula described in J. Chem. Eng. Jpn., 1983, 16, 6, 470-475, and the parameter values ​​in the conversion formula may be values ​​based on a combination of carbon and nitrogen.

[0066] The specific surface area of ​​the metal organic framework is, for example, 40 m ２ / g or more, preferably 100m ２ / g or more, more preferably 300m ２ / g or more, for example, 3,000 m ２ / g or less, and ２ The specific surface area of ​​the metal organic framework is calculated from the nitrogen gas adsorption isotherm using the BET method.

[0067] The equilibrium adsorption amount of fluorocarbon A or fluorocarbon B in the metal organic framework may be, for example, 1 g / 10 g or more and 100 g / 10 g or less, when measured at a temperature of 298 K and a pressure in the range of 0.4 PaG to 1 MPaG (gauge pressure).

[0068] The content of the metal organic framework in the adsorbent is, for example, 50% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less.

[0069] The adsorbent may contain a resin in addition to the metal organic framework, such as an acrylic resin, a polyurethane resin, a polyolefin resin, a polyester resin, a polyamide resin, a vinyl chloride resin, a styrene resin, a vinyl ether resin, a polyvinyl alcohol resin, a polycarbonate resin, or a polysulfone resin.

[0070] The adsorbent may contain additives such as emulsifiers, antifoaming agents, surfactants, leveling agents, thickeners, viscoelasticity modifiers, defoamers, wetting agents, dispersants, preservatives, plasticizers, penetrants, fragrances, bactericides, miticides, mildewcides, ultraviolet absorbers, antioxidants, antistatic agents, flame retardants, dyes, pigments, etc. The adsorbent may be in the form of powder, granules, flakes, or pellets.

[0071] (Contact between First Mixture and Adsorbent) By contacting the first mixture with the adsorbent, fluorocarbon A or fluorocarbon B can be adsorbed onto the metal organic framework contained in the adsorbent, and a second mixture having a composition ratio of fluorocarbon A to fluorocarbon B different from that of the first mixture can be separated from the first mixture. In one aspect, when the first mixture is contacted with the adsorbent, the first mixture is preferably contacted as a gas.

[0072] The contact of the first mixture with the adsorbent may be carried out, for example, by a batch method or a column method. The batch method is a method in which the adsorbent and the first mixture are placed in a sealable container and allowed to stand for a certain period of time under conditions of a predetermined temperature and a predetermined pressure, thereby bringing the first mixture into contact with the adsorbent. The column method is a method in which the adsorbent is filled in a container (column), and the first mixture is allowed to flow through the container (column), thereby bringing the first mixture into contact with the adsorbent.

[0073] In one aspect, the temperature during the contact may be, for example, 0°C or higher and 100°C or lower, or even 0°C or higher and 50°C or lower. In another aspect, the temperature during the contact may be, for example, 10°C or higher and 50°C or lower, 15°C or higher and 50°C or lower, or 15°C or higher and 30°C or lower. Furthermore, the pressure (gauge pressure) during the contact may be 0 MPaG or higher and 2 MPaG or lower, or 0.2 MPaG or higher and 1.5 MPaG or lower. When the pressure during the contact is within the above range, the adsorbate is more easily adsorbed by the adsorbent, which can improve separation efficiency and maintain the pore structure of the adsorbent.

[0074] When the contacting is carried out by a column method, the linear velocity of the first mixture may be 0.01 cm / sec or more and 100 cm / sec or less, or 0.05 cm / sec or more and 10 cm / sec or less.

[0075] (Second mixture) The second mixture contains one or more selected from the fluorocarbon A and the fluorocarbon B, and is different from the first mixture in the composition ratio of the fluorocarbon A to the fluorocarbon B. The second mixture preferably contains the fluorocarbon A and the fluorocarbon B.

[0076] The composition ratio of fluorocarbon A to fluorocarbon B in the second mixture (A / (A+B)×100) is C ２ Then, C ２ may be, for example, 0.0001 or more and 10 or less, more preferably 0.0001 or more and 5 or less, and even more preferably 0.0001 or more and 1 or less, on a molar basis.

[0077] the molar concentration C of fluorocarbon A in the second mixture Ａ２ may be, for example, 0.0001 mol % or more and 1 mol % or less, and further may be 0.0001 mol % or more and 0.01 mol % or less, in the entire second mixture.

[0078] (Regeneration of Adsorbent) The separation method of the present disclosure may further include, after contacting the first mixture with the adsorbent, desorbing from the adsorbent the fluorocarbon A or fluorocarbon B adsorbed to the adsorbent. By desorbing the adsorbed fluorocarbon A or fluorocarbon B from the adsorbent, the adsorption capacity can be restored and the adsorbent can be regenerated. This also makes it possible to recover fluorocarbon A or fluorocarbon B.

[0079] In one embodiment, the fluorocarbon desorbed from the adsorbent can be fluorocarbon A. In another embodiment, the fluorocarbon desorbed from the adsorbent can be fluorocarbon B.

[0080] The desorption of fluorocarbon A or fluorocarbon B can be carried out by reducing pressure, increasing temperature, flowing air and nitrogen, or flowing heated air and heated nitrogen, or the like.

[0081] The pressure (gauge pressure) during the desorption may be preferably 0.1 MPaG or less, more preferably 0 MPaG or less, and even more preferably −0.10 MPaG or less. The temperature during the desorption may be preferably 15 to 200°C, more preferably 50 to 180°C, and even more preferably 100 to 150°C.

[0082] (Contacting the Second Mixture with an Adsorbent) The separation method of the present disclosure may further include contacting the separated second mixture with the adsorbent. Such an operation may produce a new mixture having a composition ratio of fluorocarbon A to fluorocarbon B different from that of the second mixture. In one aspect, when the concentration of fluorocarbon A in the second mixture is reduced compared to the concentration of fluorocarbon A in the first mixture, it is preferable that the concentration of fluorocarbon A in the new mixture is reduced compared to the concentration of fluorocarbon A in the second mixture. In another aspect, when the concentration of fluorocarbon B in the second mixture is reduced compared to the concentration of fluorocarbon B in the first mixture, it is preferable that the concentration of fluorocarbon B in the new mixture is reduced compared to the concentration of fluorocarbon B in the second mixture.

[0083] The number of times the adsorbent and the mixture are contacted is not particularly limited, and may be preferably 1 to 5 times, more preferably 1 to 3 times. In the present disclosure, the first contact corresponds to the contact of the first mixture with the adsorbent, and the mth contact of the adsorbent corresponds to the contact of the mixture obtained by the (m-1)th contact with the adsorbent with the adsorbent (where m is an integer of 2 or more). In this embodiment, the adsorbent used in the second or subsequent contacts is an adsorbent containing a metal organic framework, but is not limited thereto and may also be an adsorbent containing a porous body as described in the second embodiment. Furthermore, the adsorbents used in two or more contacts may be the same or different from each other.

[0084] The operation and conditions for contacting the mixture obtained in the (m-1)th contact with the adsorbent can be the same as those for contacting the first mixture with the adsorbent.

[0085] (Purification) The separation method of the present disclosure may further include purifying the separated second mixture. Such purification may include obtaining a new mixture having a composition ratio of fluorocarbon A to fluorocarbon B different from that of the second mixture. In one aspect, when the concentration of fluorocarbon A in the second mixture is reduced compared to the concentration of fluorocarbon A in the first mixture, it is preferable that the concentration of fluorocarbon A in the new mixture is reduced compared to the concentration of fluorocarbon A in the second mixture. In another aspect, when the concentration of fluorocarbon B in the second mixture is reduced compared to the concentration of fluorocarbon B in the first mixture, it is preferable that the concentration of fluorocarbon B in the new mixture is reduced compared to the concentration of fluorocarbon B in the second mixture.

[0086] The number of times of purification is not particularly limited, and may be preferably 1 to 5 times, more preferably 1 to 3 times. In the present disclosure, the nth purification refers to an operation of purifying the (n-1)th new mixture obtained by the (n-1)th purification (where n is an integer of 2 or more).

[0087] In one embodiment, the purification can be carried out by distillation or rectification. Such distillation may be carried out using a commonly used distillation column, for example, a packed column or a plate column. The purified product is distilled as a distillate from the top of the distillation column, and the remainder is distilled as a bottom product from the bottom of the distillation column. The number of theoretical plates of the distillation column may be, for example, 1 to 100. The pressure (gauge pressure) during distillation or rectification may be 0 MPaG or more and 5 MPaG or less. The temperature at the top of the distillation column may be, for example, -60°C or more and 100°C or less, and the temperature at the bottom of the distillation column may be, for example, 50°C or more and 200°C or less. An extraction solvent may be present during the distillation.

[0088] The distillate can be distilled again (two or more times) to carry out rectification.

[0089] In this embodiment, the second mixture is purified, but the present disclosure is not limited thereto. For example, the first mixture may be purified before contacting the first mixture with the adsorbent containing the metal-organic framework. That is, the mixture purified by the above operation may be contacted with the adsorbent containing the metal-organic framework.

[0090] (System) A fluorocarbon purification system (hereinafter simply referred to as "system") that implements the first separation method described above is also included within the technical scope of the present disclosure.

[0091] The system preferably includes an adsorbent containing a metal organic framework, and the adsorbent containing the metal organic framework can separate a second mixture from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds and fluorocarbon B having m carbon atoms and no double bonds, the second mixture having a composition ratio of the fluorocarbon A to the fluorocarbon B different from that of the first mixture.

[0092] FIG. 1 is a schematic diagram of a two-stage system as an example of a system according to this embodiment.

[0093] In the system of Fig. 1, the first mixture is stored in a gas tank 1. The first mixture is supplied to a first-stage separation module 4a via a pressure regulator 2a and a mass flow controller 3a. In one embodiment, the back pressure of the first mixture supplied to the separation module 4a can be pressurized and controlled by the pressure regulator 2a, but this is not a limitation. The pressure regulator 2a may be omitted.

[0094] The separation module 4a includes an adsorbent 10a containing a metal-organic framework, and the first mixture is supplied to the adsorbent 10a containing such a metal-organic framework.

[0095] In the two-stage separation device, after contact with the adsorbent 10a containing the metal-organic framework, the flow rate of the second mixture is measured by a mass flow meter 5, and the second mixture is supplied to a second-stage separation module 4b via a pressure regulator 2b and a mass flow controller 3b. In one embodiment, the back pressure of the second mixture supplied to the second-stage separation module 4b can be pressurized and controlled by the pressure regulator 2b, but this embodiment is not limited to this. The pressure regulator 2b may also be omitted.

[0096] The second-stage separation module 4b includes an adsorbent 10b containing a metal-organic framework, and the second mixture is supplied to the adsorbent 10b containing the metal-organic framework.

[0097] A new mixture separated by contact between the second mixture and adsorbent 10b containing the metal-organic framework passes through pressure regulator 2c, has its gas composition analyzed by gas composition analyzer 8b, and is then recovered in recovery pipe 9. In one embodiment, a mass flow meter may be used to measure the flow rate of the new mixture separated by contact with adsorbent 10b containing the metal-organic framework. In another embodiment, gas composition analyzer 8a can be omitted.

[0098] In this embodiment, a two-stage separation device has been described, but the present invention is not limited to this and can be modified as appropriate. For example, the separation device may be a one-stage, three-stage, four-stage or more stage type.

[0099] In the case of a p-stage system (p is 3 or more), the p-1th mixture separated by contact with the adsorbent in the p-1th separation module may be supplied to a separation module via a pressure regulator and a mass flow controller, and brought into contact with the adsorbent contained in the separation module to separate a new pth mixture. The pth mixture can be recovered after gas composition analysis, which may be performed as necessary, to perform the pth separation.

[0100] (Composite Material) A composite material comprising a metal organic framework and the fluorocarbon A or the fluorocarbon B is also encompassed within the technical scope of the present disclosure. In such a composite material, the metal organic framework preferably has an Open Metal Site. In one aspect, the composite material preferably comprises the metal organic framework and the fluorocarbon A. In another aspect, the composite material preferably comprises the metal organic framework and the fluorocarbon B.

[0101] In the composite material, the content of fluorocarbon A or fluorocarbon B is, for example, 0.1 parts by mass or more and 100 parts by mass or less, and preferably 1 part by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the metal organic framework.

[0102] The composite material may contain a resin in addition to the fluorocarbon and porous organic salt, such as an acrylic resin, a polyurethane resin, a polyolefin resin, a polyester resin, a polyamide resin, a vinyl chloride resin, a styrene resin, a vinyl ether resin, a polyvinyl alcohol resin, a polycarbonate resin, or a polysulfone resin.

[0103] The composite material may contain additives such as emulsifiers, antifoaming agents, surfactants, leveling agents, thickeners, viscoelasticity modifiers, defoamers, wetting agents, dispersants, preservatives, plasticizers, penetrating agents, fragrances, bactericides, miticides, mildewcides, ultraviolet absorbers, antioxidants, antistatic agents, flame retardants, dyes, and pigments.

[0104] (Second embodiment: Second separation method) A second separation method of the present disclosure includes separating, from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, a third mixture in which the concentration of fluorocarbon A is reduced compared to that of the first mixture, and the separation is carried out by contacting the first mixture with an adsorbent.

[0105] According to the first separation method of the present disclosure, a third mixture in which the proportion of fluorocarbon gases having double bonds is reduced can be separated by contacting an adsorbent with a first mixture containing two or more fluorocarbon gases. Although the present disclosure should not be interpreted as being limited to a particular theory, it is believed that fluorocarbon A having double bonds can be adsorbed by the adsorbent, thereby obtaining a third mixture in which the proportion of fluorocarbon A having double bonds is reduced. Note that the third mixture may not contain fluorocarbon A.

[0106] The first mixture, fluorocarbon A, and fluorocarbon B have the same meanings as the first mixture, fluorocarbon A, and fluorocarbon B in the first embodiment.

[0107] The carbon number n of the fluorocarbon A is preferably 2 or more and 10 or less, more preferably 2 or more and 5 or less, and even more preferably 2 or more and 3 or less.

[0108] The fluorocarbon A is preferably a hydrofluoroolefin, more preferably 2,3,3,3-tetrafluoropropene (R1234yf). The fluorocarbon A may contain one or more compounds.

[0109] the concentration C of fluorocarbon A in the first mixture Ａ１ may be, for example, 0.0001 mol % or more and 90 mol % or less, and further may be 0.0001 mol % or more and 20 mol % or less, based on the entire first mixture.

[0110] The fluorocarbon B is preferably a hydrofluorocarbon, and more preferably one or more selected from 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), and 1,1,1,2,2-pentafluoroethane (R125). The fluorocarbon B may contain one or more compounds.

[0111] The concentration of fluorocarbon B in the first mixture may be, for example, 0.0001 mol % or more and 90 mol % or less, and may further be 0.0001 mol % or more and 20 mol % or less, based on the entire first mixture.

[0112] The first mixture may contain other compounds in addition to fluorocarbon A and fluorocarbon B. The boiling point of such other compounds may be, for example, −100° C. or lower, or −150° C. or lower. In one embodiment, such other compounds are contained in the first mixture as a gas.

[0113] The other compounds include nitrogen, oxygen, carbon dioxide, water, and the like.

[0114] (Adsorbent) The adsorbent (hereinafter also referred to as "second adsorbent" in this embodiment) can adsorb fluorocarbon A having a double bond and carbon number n. Typically, the second adsorbent adsorbs fluorocarbon A having a double bond, but does not adsorb fluorocarbon B having no double bond. Therefore, by contacting the first mixture with the second adsorbent, a third mixture in which fluorocarbon A has been reduced can be separated from the first mixture.

[0115] The second adsorbent preferably contains a porous body having pores as an adsorbent, and the fluorocarbon having a carbon number n can be separated from the first mixture by adsorbing the fluorocarbon into the pores.

[0116] The effective pore diameter of the porous body is, for example, 0.30 nm or more and 5.00 nm or less, preferably 0.4 nm or more and 4.00 nm or less, and more preferably 1.00 nm or more and 2.50 nm or less. In one aspect, the effective pore diameter of the porous body is, for example, 0.30 nm or more, preferably 0.40 nm or more, and more preferably 1.00 nm or more, and for example, 5.00 nm or less, preferably 4.00 nm or less, and more preferably 2.00 nm or less.

[0117] The specific surface area of ​​the porous body is, for example, 40 m ２ / g or more, preferably 100m ２ / g or more, more preferably 300m２ / g or more, for example, 3,000 m ２ / g or less, and ２ The specific surface area of ​​the porous body is calculated from the nitrogen gas adsorption isotherm using the BET method.

[0118] The equilibrium adsorption amount of the fluorocarbon having a carbon number n in the porous body may be, for example, 1 g / 10 g or more and 100 g / 10 g or less, when measured at a temperature of 298 K and a pressure in the range of 0.4 PaG to 1 MPaG (gauge pressure).

[0119] The porous body may be in the form of a powder (particle), a film, a granule, a molded body (pellet, etc.), etc., preferably a molded body, and more preferably a pellet. The pellet may be cylindrical or spherical. In the case of a cylindrical shape, the radius of the cylinder is preferably 1.6 mm or more and 6 mm or less, and the thickness of the cylinder is preferably 2 mm or more and 6 mm or less. In the case of a spherical shape, it may be a non-spherical one, and the radius of the sphere is preferably 4 mm or more and 12 mm or less.

[0120] The porous body preferably contains at least one selected from the group consisting of, for example, zeolite, activated carbon, silica gel, and a metal-organic framework (PCP: Porous Coordination Polymer, or MOF: Metal-Organic Framework), and typically contains a metal-organic framework.

[0121] The metal organic framework has the same meaning as the metal organic framework in the first embodiment.

[0122] The content of the porous body in the second adsorbent is, for example, 50% by mass to 100% by mass, preferably 70% by mass to 100% by mass, and more preferably 90% by mass to 100% by mass.

[0123] In addition to the porous body, the second adsorbent may contain a resin, such as an acrylic resin, a polyurethane resin, a polyolefin resin, a polyester resin, a polyamide resin, a vinyl chloride resin, a styrene resin, a vinyl ether resin, a polyvinyl alcohol resin, a polycarbonate resin, or a polysulfone resin.

[0124] The second adsorbent may contain additives such as emulsifiers, antifoaming agents, surfactants, leveling agents, thickeners, viscoelasticity modifiers, defoamers, wetting agents, dispersants, preservatives, plasticizers, penetrants, fragrances, bactericides, miticides, mildewcides, ultraviolet absorbers, antioxidants, antistatic agents, flame retardants, dyes, pigments, etc. The second adsorbent may be in the form of powder, granules, flakes, or pellets.

[0125] (Contact between First Mixture and Second Adsorbent) By contacting the first mixture with the second adsorbent, fluorocarbon A contained in the first mixture can be adsorbed onto the adsorbent, and a third mixture having a reduced concentration of fluorocarbon A can be separated from the first mixture. In one aspect, when the first mixture is contacted with the second adsorbent, the first mixture is preferably contacted as a gas.

[0126] The contact of the first mixture with the second adsorbent may be carried out, for example, by a batch method or a column method. The batch method is a method in which the second adsorbent and the first mixture are placed in a sealable container and allowed to stand for a certain period of time under conditions of a predetermined temperature and a predetermined pressure, thereby bringing the first mixture into contact with the second adsorbent. The column method is a method in which the second adsorbent is packed into a container (column), and the first mixture is allowed to flow through the container (column), thereby bringing the first mixture into contact with the second adsorbent.

[0127] In one aspect, the temperature during the contact may be, for example, 0°C or higher and 100°C or lower, or even 0°C or higher and 50°C or lower. In another aspect, the temperature during the contact may be, for example, 10°C or higher and 50°C or lower, 15°C or higher and 50°C or lower, or 15°C or higher and 30°C or lower. Furthermore, the pressure (gauge pressure) during the contact may be 0 MPaG or higher and 2 MPaG or lower, or 0.2 MPaG or higher and 1.5 MPaG or lower. When the pressure during the contact is within the above range, the adsorbate is more easily adsorbed by the adsorbent, which can improve separation efficiency and maintain the pore structure of the adsorbent.

[0128] When the contacting is carried out by a column method, the linear velocity of the first mixture may be 0.01 cm / sec or more and 100 cm / sec or less, or 0.05 cm / sec or more and 10 cm / sec or less.

[0129] (Third Mixture) The third mixture contains at least the fluorocarbon B, and the concentration of fluorocarbon A is reduced compared to the first mixture. The third mixture preferably contains fluorocarbon A and fluorocarbon B.

[0130] The composition ratio of fluorocarbon A to fluorocarbon B in the third mixture (A / (A+B)×100) is C ３ Then, C ３ may be, for example, 0.0001 or more and 10 or less, more preferably 0.0001 or more and 5 or less, and even more preferably 0.0001 or more and 1 or less, on a molar basis.

[0131] the molar concentration C of fluorocarbon A in the third mixture Ａ３ may be, for example, 0.0001 mol % or more and 1 mol % or less, and further may be 0.0001 mol % or more and 0.01 mol % or less, in the entire third mixture.

[0132] (Regeneration of Adsorbent) The separation method of the present disclosure may further include desorbing the fluorocarbon A adsorbed on the second adsorbent from the second adsorbent after contacting the first mixture with the second adsorbent. By desorbing the adsorbed fluorocarbon A from the second adsorbent, the adsorption capacity can be restored and the second adsorbent can be regenerated. This also makes it possible to recover the fluorocarbon A. The desorption of the fluorocarbon A can be carried out by reducing pressure, increasing temperature, flowing air and nitrogen, or flowing heated air and heated nitrogen, or the like.

[0133] The pressure (gauge pressure) during the desorption may be preferably 0.1 MPaG or less, more preferably 0 MPaG or less, and even more preferably −0.1 MPaG or less. The temperature during the desorption may be preferably 15 to 200°C, more preferably 50 to 180°C, and even more preferably 100 to 150°C.

[0134] (Contacting the Third Mixture with a Second Adsorbent) The separation method of the present disclosure may further include contacting the separated third mixture with the second adsorbent. Such an operation may produce a new mixture having a further reduced concentration of fluorocarbon A.

[0135] The number of times the second adsorbent is contacted with the mixture is not particularly limited, and may be preferably 1 to 5 times, more preferably 1 to 3 times. In two or more contacts, the second adsorbents used may be the same or different from each other.

[0136] The operation and conditions for contacting the mixture obtained in the (m-1)th contact with the adsorbent can be the same as those for contacting the first mixture with the adsorbent.

[0137] The separation method of the present disclosure may further include purifying the separated third mixture, which may include obtaining a new mixture having a further reduced concentration of fluorocarbon A compared to the second mixture.

[0138] The number of times of purification is not particularly limited, and may be preferably 1 to 5 times, more preferably 1 to 3 times. In the present disclosure, the nth purification refers to an operation of purifying the (n-1)th new mixture obtained by the (n-1)th purification (where n is an integer of 2 or more).

[0139] In one embodiment, the purification can be carried out by distillation or rectification. Such distillation may be carried out using a commonly used distillation column, for example, a packed column or a plate column. The purified product is distilled as a distillate from the top of the distillation column, and the remainder is distilled as a bottom product from the bottom of the distillation column. The number of theoretical plates of the distillation column may be, for example, 1 to 100. The pressure (gauge pressure) during distillation or rectification may be 0 MPaG or more and 5 MPaG or less. The temperature at the top of the distillation column may be, for example, -60°C or more and 100°C or less, and the temperature at the bottom of the distillation column may be, for example, 50°C or more and 200°C or less. An extraction solvent may be present during the distillation.

[0140] The distillate can be distilled again (two or more times) to carry out rectification.

[0141] In this embodiment, the third mixture is purified, but the present disclosure is not limited thereto. For example, the first mixture may be purified before contacting the first mixture with the adsorbent. That is, the mixture purified by the above-described procedure may be contacted with the adsorbent.

[0142] (System) A fluorocarbon purification system that implements the second separation method described above is also included within the technical scope of the present disclosure.

[0143] The system preferably includes an adsorbent, and the adsorbent is capable of separating a third mixture from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds and fluorocarbon B having m carbon atoms and no double bonds, the third mixture having a composition ratio of fluorocarbon A to fluorocarbon B different from that of the first mixture.

[0144] FIG. 2 is a schematic diagram illustrating a two-stage system as an example of a system according to this embodiment.

[0145] In the system of Fig. 2, the first mixture is stored in a gas tank 1. The first mixture is supplied to a first-stage separation module 4c via a pressure regulator 2a and a mass flow controller 3a. In one embodiment, the back pressure of the first mixture supplied to the separation module 4c can be controlled by the pressure regulator 2a, but is not limited to this embodiment. The pressure regulator 2a may be omitted.

[0146] The separation module 4c includes an adsorbent 11a, and the first mixture is supplied to the adsorbent 11a.

[0147] In the two-stage separation apparatus, after contact with the adsorbent 11a, the flow rate of the third mixture is measured by a mass flow meter 5, and the third mixture is supplied to a second-stage separation module 4b via a pressure regulator 2b and a mass flow controller 3b. In one embodiment, the back pressure of the third mixture supplied to the second-stage separation module 4b can be pressurized and controlled by the pressure regulator 2b, but this is not a limitation. The pressure regulator 2b may also be omitted.

[0148] The second-stage separation module 4d includes an adsorbent 11b, and the third mixture is supplied to the adsorbent 11b.

[0149] The third mixture and a new mixture separated by contact with the adsorbent 11b pass through a pressure regulator 2c, have their gas composition analyzed by a gas composition analyzer 8b, and are then recovered in a recovery pipe 9. In one embodiment, a mass flow meter may be used to measure the flow rate of the new mixture separated by contact with the adsorbent 11b. In another embodiment, the gas composition analyzer 8a can be omitted.

[0150] In this embodiment, a two-stage separation device has been described, but the present invention is not limited to this and can be modified as appropriate. For example, the separation device may be a one-stage, three-stage, four-stage or more stage type.

[0151] In the case of a p-stage system (p is 3 or more), the p-1th mixture separated by contact with the adsorbent in the p-1th separation module may be supplied to a separation module via a pressure regulator and a mass flow controller, and brought into contact with the adsorbent contained in the separation module to separate a new pth mixture. The pth mixture can be recovered after gas composition analysis, which may be performed as necessary, to perform the pth separation.

[0152] (Third Embodiment: Composite Material) A composite material including the metal organic framework and the above-mentioned fluorocarbon A is also included in the technical scope of the present disclosure. The metal organic framework and the fluorocarbon A have the same meanings as the metal organic framework and the fluorocarbon A in the first embodiment.

[0153] In such a composite material, the metal organic framework preferably contains metal ions and one or more organic ligands. The metal ions are one or more selected from Fe ions, Cu ions, Ni ions, Mg ions, Co ions, Cr ions, Zr ions, and Zn ions, and preferably Fe ions. ２＋ , Fe ３＋ , Cu ２＋ , Ni ２＋ , Mg ２＋ , Co ２＋ , Cr ３＋ and Zn ２＋More preferably, one or more selected from the following are used. The organic ligand is preferably selected from 1,4-benzenedicarboxylic acid, 1,2-benzenedicarboxylic acid, maleic acid, 1,3,5-benzenetricarboxylic acid, 4,4',4"-(1,3,5-benzenetriyl)trisbenzoic acid, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, oxalic acid, 4,4'-dihydroxy-3,3'-biphenyldicarboxylic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid, 4,4'-bipyridine, triazole, imidazole, 3,3'-bipyrazole, benzimidazole, and 3,5-pyridinedicarboxylic acid, and more preferably selected from 1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-3,3'-biphenyldicarboxylic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, and 2,5-dihydroxy-1,4-benzenedicarboxylic acid. The metal organic framework is manufactured by Open Metal It is preferable to have a Site.

[0154] In the composite material, the content of fluorocarbon A is, for example, 1 part by mass or more and 100 parts by mass or less, and preferably 10 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the metal organic framework.

[0155] The composite material may contain a resin in addition to the fluorocarbon and porous organic salt, such as an acrylic resin, a polyurethane resin, a polyolefin resin, a polyester resin, a polyamide resin, a vinyl chloride resin, a styrene resin, a vinyl ether resin, a polyvinyl alcohol resin, a polycarbonate resin, or a polysulfone resin.

[0156] The composite material may contain additives such as emulsifiers, antifoaming agents, surfactants, leveling agents, thickeners, viscoelasticity modifiers, defoamers, wetting agents, dispersants, preservatives, plasticizers, penetrating agents, fragrances, bactericides, miticides, mildewcides, ultraviolet absorbers, antioxidants, antistatic agents, flame retardants, dyes, and pigments.

[0157] The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0158] Example 1 and Comparative Example 1 The adsorbents used were HKUST-1 (manufactured by Atomis) and CALF-20 (manufactured by Atomis) shown in Table 1. As a pretreatment of the adsorbents used, a vacuum treatment was carried out at 130°C for 2 hours.

[0159] (Adsorption Breakthrough Measurement of Mixed Gas) A mixed gas of R1234yf / R134a = 10 mol% / 90 mol% was passed through an adsorption tower packed with the adsorbent shown in Table 1 at a total pressure of 0.4 MPaG, a temperature of 298 K, and a linear velocity of 0.4 cm / sec, and the R1234yf concentration at the outlet of the adsorption tower was measured. An adsorption breakthrough curve showing the change in R1234yf concentration is shown in Figure 3. The R1234yf adsorption amount (amount per gram of adsorbent) obtained from the adsorption breakthrough curve is shown in Table 1 as the gas A adsorption amount.

[0160] REFERENCE SIGNS LIST 1 Gas tank 2a, 2b, 2c Pressure regulator 3a, 3b Mass flow controller 4a, 4b, 4c, 4d Separation module 5 Mass flow meter 7 Pressure reducing booster 8a, 8b Gas composition analyzer 9 Recovery pipe 10a, 10b Adsorbent containing metal organic framework 11a, 11b Adsorbent

Claims

1. A method for separating fluorocarbons, comprising separating a second mixture from a first mixture containing fluorocarbon A having one or more double bonds and a carbon number n, and fluorocarbon B having no double bond and a carbon number m, the second mixture having a composition ratio of fluorocarbon A and fluorocarbon B different from that of the first mixture, the separation being carried out by contacting the first mixture with an adsorbent containing a metal organic framework.

2. The separation method according to claim 1, wherein the contact of the first mixture with the adsorbent containing the metal-organic framework is carried out at a temperature of -10°C or higher and 80°C or lower.

3. The separation method according to claim 1 or 2, wherein n is 2 or more and 3 or less.

4. The separation method according to any one of claims 1 to 3, wherein m is 1 or more and 3 or less.

5. The separation method according to any one of claims 1 to 4, wherein the fluorocarbon A comprises R1234yf.

6. The separation method according to any one of claims 1 to 5, wherein the fluorocarbon B comprises one or more selected from the group consisting of R134a, R143, R143a, R32 and R125.

7. The separation method according to any one of claims 1 to 6, wherein the metal-organic framework comprises a metal ion.

8. The separation method according to any one of claims 1 to 7, wherein the metal-organic framework comprises one or more types of organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to a metal ion in one molecule.

9. The separation method according to any one of claims 1 to 8, wherein the metal-organic framework comprises a metal ion and one or more types of organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond with the metal ion in one molecule.

10. The separation method according to any one of claims 1 to 9, wherein the metal-organic framework has open metal sites consisting of coordinatively unsaturated metal ions.

11. The separation method according to any one of claims 1 to 10, wherein the adsorbent comprising the metal-organic framework further comprises a resin.

12. The separation method according to any one of claims 1 to 11, wherein the adsorbent containing the metal-organic framework is in the form of a powder, granules, flakes or pellets.

13. The method of any one of claims 1 to 12, wherein the first mixture is an azeotrope or near-azeotrope of fluorocarbons.

14. The method of any one of claims 1 to 13, further comprising contacting the separated second mixture with an adsorbent comprising the metal-organic framework.

15. The method of any one of claims 1 to 14, further comprising purifying the separated second mixture.

16. The separation method according to any one of claims 1 to 15, further comprising, after contacting the first mixture with the adsorbent comprising the metal-organic framework, desorbing the fluorocarbon A adsorbed to the adsorbent comprising the metal-organic framework from the adsorbent comprising the metal-organic framework.

17. A fluorocarbon purification system implementing the separation method according to any one of claims 1 to 16.

18. A method for separating fluorocarbons, comprising separating from a first mixture containing fluorocarbon A having n carbon atoms and one or more double bonds, and fluorocarbon B having m carbon atoms and no double bonds, a third mixture in which the concentration of fluorocarbon A is reduced compared to that of the first mixture, the separation being carried out by contacting the first mixture with an adsorbent.

19. The method of claim 18, wherein the contacting of the first mixture with the adsorbent is carried out at a temperature of at least -10°C and at most 80°C.

20. The separation method according to claim 18 or 19, wherein n is 2 or more and 3 or less.

21. The separation method according to any one of claims 18 to 20, wherein m is 1 or more and 3 or less.

22. The separation method according to any one of claims 18 to 21, wherein the fluorocarbon A comprises R1234yf.

23. The separation method according to any one of claims 18 to 22, wherein the fluorocarbon B comprises one or more selected from the group consisting of R134a, R143, R143a, R32 and R125.

24. The separation method according to any one of claims 18 to 23, wherein the adsorbent comprises a porous material.

25. The method of any one of claims 18 to 24, wherein the adsorbent comprises a metal-organic framework.

26. The method of claim 25, wherein the metal-organic framework comprises a metal ion.

27. The separation method according to claim 25 or 26, wherein the metal-organic framework comprises one or more types of organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond to a metal ion in one molecule.

28. The separation method according to any one of claims 25 to 27, wherein the metal-organic framework comprises a metal ion and one or more types of organic ligands, and the organic ligand comprises two or more groups capable of forming a coordinate bond with the metal ion in one molecule.

29. The separation method according to any one of claims 25 to 28, wherein the metal-organic framework has open metal sites consisting of coordinatively unsaturated metal ions.

30. The separation method according to any one of claims 18 to 29, wherein the adsorbent further comprises a resin.

31. The separation method according to any one of claims 18 to 30, wherein the adsorbent is in the form of a powder, granules, flakes or pellets.

32. The method of any one of claims 18 to 31, wherein the first mixture is an azeotrope or near-azeotrope of fluorocarbons.

33. The method of any one of claims 18 to 32, further comprising contacting the separated third mixture with an adsorbent.

34. The method of any one of claims 18 to 33, further comprising purifying the separated third mixture.

35. The method for separation according to any one of claims 18 to 34, further comprising, after contacting the first mixture with the adsorbent, desorbing from the adsorbent the fluorocarbon A adsorbed on the adsorbent.

36. A fluorocarbon purification system implementing the separation method of any one of claims 18 to 35.

37. A composite material comprising a metal organic framework and a fluorocarbon A having one or more double bonds and a carbon number n, wherein the metal organic framework has open metal sites composed of coordinatively unsaturated metal ions.

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