JP2013063951A - Method and apparatus for separating unsaturated hydrocarbon and saturated hydrocarbon, and metal complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrocarbon separation method for highly efficiently separating unsaturated hydrocarbons and saturated hydrocarbons even if the hydrocarbons are ones having three or more carbon atoms and having the same number of carbon atoms, such as propylene and propane.SOLUTION: The hydrocarbon separation method includes bringing a mixture into contact with a metal complex containing a metal ion, a counter ion, and a ligand represented by the following formula (I): Q-(R)-Q, wherein Qand Qare each independently a heterocycle group containing a nitrogen atom; n is an integer of 3 to 20; R is one selected from the group consisting of the following formulae (II-1) to (II-4): -C(R)(R)-, -C(=O)-, -O-, and -N(R)-, respectively, wherein Rand Rare each a hydrogen atom, a halogen atom or a hydrocarbon group which may have a substituent; and Ris a hydrogen atom, or a hydrocarbon group which may have a substituent.

Description

  The present invention relates to a method for separating unsaturated hydrocarbons and saturated hydrocarbons having 3 or more carbon atoms, a separation apparatus used therefor, and a metal complex useful therefor.

  Separation of unsaturated hydrocarbons and saturated hydrocarbons is generally carried out by distillation, but unsaturated hydrocarbons and saturated hydrocarbons with the same carbon number such as propylene and propane have similar boiling points, so such hydrocarbons are separated. In order to do this, a very high number of rectifying columns was indispensable. In addition, separation methods using the difference in adsorption characteristics with respect to the adsorbent are also known, but activated carbon and zeolite generally known as adsorbents have almost no difference in the adsorption characteristics of such hydrocarbons. In order to separate them, there is a problem that a large facility and a large amount of energy are required.

  Under such circumstances, in recent years, porous metal complexes have been studied as new adsorbents. In the following Non-Patent Document 1 and Non-Patent Document 2, regarding the adsorption characteristics for propylene and propane, 1, 3, Adsorption characteristics of porous metal complexes having 5-benzenetricarboxylic acid as a ligand have been reported. However, even when such a porous metal complex is used as an adsorbent, a large difference in the adsorption characteristics of propylene and propane is in the pressure region of less than 1 kPa that requires an excessively low pressure in practice. Propylene and propane could not be separated with high efficiency in a pressure region of 1 kPa or more.

N. Lamia et al. , Chem. Eng. Sci. 64 (2009) p. 3246-3259 J. et al. W. Yoon et al. , Angew. Chem. Int. Ed. 49 (2010) p. 5949-5952

  The present invention has been made in view of the problems of the prior art, and has a carbon number of 3 or more such as propylene and propane in a pressure region of 1 kPa or more that can be used without requiring excessive pressure reduction in practice. And a hydrocarbon separation method and separation apparatus capable of separating unsaturated hydrocarbons and saturated hydrocarbons with high efficiency even with hydrocarbons having the same carbon number, and a metal complex useful therefor Objective.

  As a result of intensive studies to achieve the above object, the present inventors have made the present invention.

That is, the hydrocarbon separation method of the present invention comprises the following formula (I):
Q ^1- (R) _n -Q ² (I)
{In the formula, Q ¹ and Q ² may be the same or different and each is a heterocyclic group containing a nitrogen atom; n is an integer of 3 to 20; -1) to (II-4):
-C (R ¹ ) (R ² )-(II-1)
-C (= O)-(II-2)
-O- (II-3)
-N (R ³ )-(II-4)
(In the formula, R ¹ and R ² may be the same or different, and each is a hydrogen atom, a halogen atom, or a hydrocarbon group that may have a substituent, and R ³ is hydrogen. (A hydrocarbon group which may have an atom or a substituent.)
Or a group represented by the formula (II-3) or the formula (II-4) is not adjacent, and R is R ¹ to R. ^When it has two or more hydrocarbon groups which may have a substituent as ³ , they may be bonded to form a ring, and a plurality of R may be the same or different. }
The mixture of a unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms is brought into contact with a metal complex containing a ligand represented by the formula (I), a counter ion, and a metal ion. It is a method having a step of separating saturated hydrocarbons from the saturated hydrocarbons.

  The metal complex used in such a hydrocarbon separation method of the present invention preferably contains two or more types of counter ions, such as fluoride ions, chloride ions, bromide ions, iodide ions, oxide ions, sulfides. Ion, hydroxide ion, hydride ion, sulfite ion, phosphate ion, cyanide ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, More preferably, it contains two or more counter ions selected from the group consisting of tetrafluoroborate ion, hexafluorophosphate ion, acetylacetonate, carboxylate ion, and alkoxide ion.

  In such a hydrocarbon separation method of the present invention, an adsorption step of bringing the mixture into contact with the metal complex under a first predetermined pressure and selectively adsorbing one of the hydrocarbons to the metal complex is performed. It is preferable to include. In that case, it is more preferable that the method further includes a desorption step of desorbing hydrocarbons adsorbed on the metal complex by changing the pressure to a second predetermined pressure after the adsorption step.

Further, the hydrocarbon separation apparatus of the present invention is a separation means comprising a metal complex containing a ligand represented by the formula (I), a counter ion, and a metal ion,
Introducing means for introducing a mixture of an unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms into the separating means;
And the apparatus separates the unsaturated hydrocarbon and the saturated hydrocarbon by bringing the mixture into contact with the metal complex.

  In such a hydrocarbon separation apparatus of the present invention, it is preferable that the separation means further includes a pressure control means for controlling the pressure of the space in which the metal complex is arranged. It is preferable that the mixture is brought into contact with the metal complex under a predetermined pressure, and one hydrocarbon is selectively adsorbed on the metal complex. Further, in this case, after selectively adsorbing one of the hydrocarbons to the metal complex, the pressure is changed to the second predetermined pressure by the pressure control means, and the hydrocarbon adsorbed to the metal complex is removed. More preferably, they are separated.

  Further, the metal complex of the present invention comprises a ligand represented by the formula (I), fluoride ion, chloride ion, bromide ion, iodide ion, oxide ion, sulfide ion, hydroxide ion. , Hydride ion, sulfite ion, phosphate ion, cyanide ion, carbonate ion, sulfate ion, nitrate ion, hydrogen carbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, It is a metal complex containing two or more counter ions selected from the group consisting of hexafluorophosphate ion, acetylacetonate, carboxylate ion, and alkoxide ion, and a metal ion.

In addition, the ligand of the metal complex used in the hydrocarbon separation method and hydrocarbon separation apparatus of the present invention, and the ligand in the metal complex of the present invention are the following (i) to (iii):
(I) In the formula (I), Q ¹ and Q ² may be the same or different and each is an aromatic heteromonocyclic group containing a nitrogen atom.
(Ii) In the formula (I), R is a group represented by the formula (II-1).
(Iii) In said formula (I), n is an integer of 3-6.
It is preferable to satisfy at least one of the conditions.

  Further, in the metal complex of the present invention, the adsorption property is preferably controlled by adjusting the ratio of the two or more types of counter ions, and the metal complex of the present invention is preferably an unsaturated hydrocarbon (particularly preferably Propylene) is preferably used for separating saturated hydrocarbons (particularly preferably propane).

  In the hydrocarbon separation method and separation apparatus of the present invention, unsaturated hydrocarbons and saturated hydrocarbons are separated with high efficiency even in the pressure region of 1 kPa or more even if the number of carbons is 3 or more and the same number of carbons. The reason why it is possible to do this is not necessarily clear, but the present inventors speculate as follows. In the present invention, since a ligand in which a heterocyclic group containing a nitrogen atom is bonded with a predetermined group is used together with a counter ion and a metal ion, the heterocyclic group containing the nitrogen atom is coordinated to the metal ion. In the metal complex formed in this manner, a regular skeleton of metal ions and organic groups having a predetermined length is formed, and these metal complexes have a regular structure. In addition, the metal complex of the present invention has a flexible structure whose structure is changed by an external stimulus such as adsorption of a guest molecule. When this novel flexible structure metal complex is used as an adsorbent, a unique phenomenon has been observed in which gas adsorption does not occur up to a certain pressure, but gas adsorption begins when a certain pressure is exceeded. In addition, a phenomenon has been observed in which the adsorption start pressure varies depending on the type of gas. As described above, since the metal complex of the present invention has a regular structure and a flexible structure, a selective interaction works even for an unsaturated hydrocarbon and a saturated hydrocarbon having 3 or more carbon atoms and the same carbon number. The present inventors infer that it will act as an adsorbent or molecular sieve that can selectively (preferentially) recognize one of such hydrocarbons.

  According to the present invention, even in the pressure region of 1 kPa or more that can be used without requiring excessively low pressure in practice, even if the hydrocarbon has 3 or more carbon atoms such as propylene and propane and has the same carbon number. It is possible to provide a hydrocarbon separation method and separation apparatus capable of separating saturated hydrocarbons and saturated hydrocarbons with high efficiency, and a metal complex useful therefor.

It is a schematic diagram which shows suitable one Embodiment of the separation apparatus of the hydrocarbon of this invention. 4 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 1. 5 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 2. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 3. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 4. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 5. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 6. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 7. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 8. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 9. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 10. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 1. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 2. It is a graph which shows the adsorption / desorption isotherm measured at 273K among the adsorption / desorption isotherms of propane and propylene measured in Example 1 using the metal complex obtained in Synthesis Example 1. It is a graph which shows the adsorption / desorption isotherm of propane and propylene measured in Example 1 using the metal complex obtained in Synthesis Example 1. It is a graph which shows the adsorption / desorption isotherm measured at 273K among the adsorption / desorption isotherms of propane and propylene measured in Example 2 using the metal complex obtained in Synthesis Example 2. It is a graph which shows the adsorption / desorption isotherm of propane and propylene measured in Example 2 using the metal complex obtained in Synthesis Example 2. It is a graph which shows the adsorption / desorption isotherm of the propane and propylene which were measured in Example 3 using the metal complex obtained in the synthesis example 3. It is a graph which shows the adsorption / desorption isotherm of propane and propylene which were measured in Example 4 using the metal complex obtained in the synthesis example 4. It is a graph which shows the adsorption / desorption isotherm of the propane and propylene measured in Example 5 using the metal complex obtained in the synthesis example 5. 6 is a graph showing adsorption and desorption isotherms of propane and propylene measured in Example 6 using the metal complex obtained in Synthesis Example 6. 6 is a graph showing adsorption / desorption isotherms of propane and propylene measured in Example 7 using the metal complex obtained in Synthesis Example 7. FIG. It is a graph which shows the adsorption / desorption isotherm of propane and propylene measured in Example 8 using the metal complex obtained in Synthesis Example 8. It is a graph which shows the adsorption-and-desorption isotherm of the propane and propylene measured in Example 9 using the metal complex obtained in the synthesis example 9. It is a graph which shows the adsorption-and-desorption isotherm of the propane and propylene which were measured in Example 10 using the metal complex obtained in the synthesis example 10. It is a graph which shows the adsorption / desorption isotherm of propane and propylene measured in Comparative Example 1 using the metal complex obtained in Comparative Synthesis Example 1. It is a graph which shows the adsorption / desorption isotherm of propane and propylene which were measured in Comparative Example 2 using the metal complex obtained in Comparative Synthesis Example 2.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof. First, the hydrocarbon separation method of the present invention will be described.

  In the method for separating hydrocarbons of the present invention, a metal complex containing a ligand, a counter ion, and a metal ion in which a heterocyclic group containing a nitrogen atom described in detail below is bonded with a predetermined group, This is a method comprising a step of separating the unsaturated hydrocarbon and the saturated hydrocarbon by bringing the mixture of the unsaturated hydrocarbon and the saturated hydrocarbon having 3 or more carbon atoms into contact with each other.

That is, the metal complex used in the present invention is represented by the following formula (I):
Q ^1- (R) _n -Q ² (I)
The ligand represented by these is included.

Q ¹ and Q ² in the above formula (I) are each a heterocyclic group containing a nitrogen atom and may be the same or different. Such a heterocyclic group may be an aliphatic heterocyclic group or an aromatic heterocyclic group, but is preferably an aromatic heterocyclic group because the structure around the metal can be further strengthened. In addition, such a heterocyclic group may be a monocyclic group or a condensed ring group, but a monocyclic group is preferable because synthesis of a ligand is easier.

Accordingly, Q ¹ and Q ² are preferably aromatic heteromonocyclic groups. As such an aromatic heteromonocyclic group, a pyridyl group, a pyrimidine group, a pyrazine group, a triazine group, an imidazolyl group, an oxazolyl group, and a thiazolyl group are preferable, and a 4-pyridyl group and a 1-imidazolyl group are more preferable. A pyridyl group is particularly preferred.

R in the above formula (I) represents the following formulas (II-1) to (II-4):
-C (R ¹ ) (R ² )-(II-1)
-C (= O)-(II-2)
-O- (II-3)
-N (R ³ )-(II-4)
(In the formula, R ¹ and R ² may be the same or different, and each is a hydrogen atom, a halogen atom, or a hydrocarbon group that may have a substituent, and R ³ is hydrogen. (A hydrocarbon group which may have an atom or a substituent.)
Any one selected from the group consisting of groups represented by: A plurality of R may be the same or different. Therefore, although all R may be the same, the group represented by Formula (II-3) or Formula (II-4) is not adjacent. Moreover, when R has two or more hydrocarbon groups which may have a substituent as R ^{1 to} R ³ , they may be bonded to form a ring (for example, a cyclohexane ring).

  As such R, since separation performance becomes better and synthesis becomes easier, all R are groups represented by the formula (II-1), or one or two R are It is preferable that any of the groups represented by formula (II-2), formula (II-3) and formula (II-4) and the remaining R is a group represented by formula (II-1). All R's are groups represented by formula (II-1), or one R is a group represented by formula (II-2), formula (II-3), or formula (II-4). It is more preferable that any one of the remaining Rs is a group represented by the formula (II-1), and it is particularly preferable that all Rs are groups represented by the formula (II-1).

Examples of the halogen atom in R ¹ and R ² in the formula (II-1) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A fluorine atom, a chlorine atom, and a bromine atom are preferable, and a fluorine atom, A chlorine atom is more preferred, and a fluorine atom is particularly preferred. Moreover, as a hydrocarbon group in R < ¹ > -R < ³ > in Formula (II-1) and Formula (II-4), a C6 or less hydrocarbon group is preferable, and a methyl group, an ethyl group, a propyl group, butyl A group is more preferable, and a methyl group is particularly preferable. Furthermore, examples of the substituent that such a hydrocarbon group may have include a heterocyclic group containing a halogen atom and a nitrogen atom, and preferred examples thereof are the same as described above.

R ¹ and R ² in the formula (II-1) are preferably a hydrogen atom, a fluorine atom, a methyl group, or a 4-pyridylmethyl group because the separation performance becomes better and the synthesis becomes easier. A hydrogen atom, a fluorine atom, and a methyl group are more preferable, and a hydrogen atom is particularly preferable. In addition, R ³ in the formula (II-4) is preferably a hydrogen atom, a methyl group, or a 4-pyridylmethyl group because the separation performance becomes better and the synthesis becomes easier. A group is more preferable, and a hydrogen atom is particularly preferable.

  N in the above formula (I) is an integer of 3 to 20. When n is 2 or less, the selective interaction does not work for unsaturated hydrocarbons and saturated hydrocarbons having 3 or more carbon atoms and the same carbon number, and one of them is selective to such hydrocarbons. It becomes impossible to recognize (priority). On the other hand, when n exceeds 20, a regular skeleton cannot be formed from the ligand and the metal ion. In addition, n in the above formula (I) is preferably an integer of 3 to 6, more preferably 3 or 4, and particularly preferably 3, because the separation performance becomes better and the synthesis becomes easier.

  Specific examples of the ligand represented by the above formula (I) include the following 1 to 24, and the separation performance becomes better and the synthesis becomes easier. Yes, more preferably 1-8, particularly preferably 1-4, and most preferably 1.

  In the present invention, a metal complex containing a metal ion and a counter ion together with the aforementioned ligand is used.

  Examples of such metal ions include group 2 to group 13 metal ions of the periodic table. Among them, since skeleton formation is easy and separation performance is better, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium , Holmium, erbium, thulium, ytterbium, lutetium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum , Copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, tin, lead, bismuth ions are preferred, magnesium , Titanium, vanadium, chromium, manganese, iron, cobalt, nickel, palladium, platinum, copper, silver, gold, zinc, more preferably aluminum ions, iron, copper, silver ion is particularly preferred. Such metal ions may be one kind or two or more kinds. Moreover, as a valence of such a metal ion, 1-6 are preferable, 1-4 are more preferable, and 2-3 are especially preferable.

  Since the metal ion is usually a cation, the counter ion is usually an anion in order to electrically neutralize the entire metal complex obtained. Examples of such counter ions include fluoride ions, chloride ions, bromide ions, iodide ions, oxide ions, sulfide ions, hydroxide ions, hydride ions, sulfite ions, phosphate ions, cyanide ions. Fluoride ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, acetylacetonate; formate ion, Examples thereof include carboxylate ions such as acetate ion, propionate ion and trifluoroacetate ion; alkoxide ions such as methoxide ion, ethoxide ion and isopropoxide ion. Among them, since the separation performance becomes better, fluoride ion, chloride ion, bromide ion, iodide ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, Formate ion, acetate ion, and trifluoroacetate ion are preferable, and methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, and trifluoroacetate ion are more preferable. Such counter ions may be one kind or two or more kinds.

  If the metal complex used in the hydrocarbon separation method of the present invention contains two or more types of counter ions, the ratio of the two or more types of counter ions can be changed to allow stepwise control of the adsorption separation characteristics. Since it becomes easy to optimize in accordance with the separation system, the metal complex used in the hydrocarbon separation method of the present invention preferably contains two or more kinds of counter ions, such as fluoride ions, chloride ions, Bromide ion, iodide ion, oxide ion, sulfide ion, hydroxide ion, hydride ion, sulfite ion, phosphate ion, cyanide ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate Ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluoro Acid ion, acetylacetonate, carboxylate ion (preferably formate ion, acetate ion, propionate ion, trifluoroacetate ion, etc.), and alkoxide ion (preferably methoxide ion, ethoxide ion, isopropoxide ion, etc.) It is more preferable that two or more types of counter ions selected from the group consisting of:

  The metal complex used in the hydrocarbon separation method of the present invention includes fluoride ion, chloride ion, bromide ion, iodide ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate. It is more preferable that two or more kinds of counter ions selected from the group consisting of ions, formate ions, acetate ions and trifluoroacetate ions are included, methanesulfonate ions, trifluoromethanesulfonate ions, tetrafluoroborate ions, hexafluoro It is even more preferable that two or more types of counter ions selected from the group consisting of phosphate ions and trifluoroacetate ions are included.

  When the metal complex of the present invention includes two or more types of counter ions, it is preferable that at least two types of counter ions are included in an amount of 0.01 mol% or more based on the total amount of counter ions. More preferably, at least two of the counter ions are contained in an amount of 0.1 mol% or more with respect to the total amount of the counter ions, and at least two of the counter ions are contained in an amount of 1 mol% or more with respect to the total amount of the counter ions. More preferably.

  The composition ratio (molar ratio) of the metal ion, counter ion, and ligand represented by the formula (I) constituting the metal complex used in the present invention is electrically neutral as a whole metal complex. Although there are no restrictions other than the above, since skeleton formation is easy and separation performance is better, metal ion: counter ion: ligand represented by formula (I) = 1: 0.2 to 6: 1-6 are preferable, and 1: 0.3-3: 1-3 are more preferable.

  In this invention, in order to form the above-mentioned metal complex, you may have an auxiliary ligand other than the ligand represented by the said formula (I). Examples of such auxiliary ligands include ethylenediamine, trimethylenediamine, piperazine, triethylenediamine, pyridazine, pyrimidine, pyrazine, 2,2′-bipyridyl, 3,3′-bipyridyl, 4,4′-bipyridyl, and the like. And compounds having two carboxyl groups such as oxalic acid, malonic acid, succinic acid, phthalic acid, isophthalic acid and terephthalic acid. Preferred are ethylenediamine, trimethylenediamine, piperazine, triethylenediamine, pyrazine, 4,4'-bipyridyl, oxalic acid, oxalic acid, malonic acid, and terephthalic acid. Such auxiliary ligands may be one kind or two or more kinds.

  Moreover, the metal complex used in the present invention may have a solvent as a ligand in addition to the auxiliary ligand described above. Examples of such a solvent include water, methanol, ethanol, isopropyl alcohol, ethylene glycol, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, Examples include dimethyl sulfoxide, acetone, chloroform, acetonitrile, benzonitrile, triethylamine, pyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, methyl ethyl ether, 1,4-dioxane, and preferably water, methanol, ethanol, isopropyl alcohol, ethylene Glycol, N, N-dimethylformamide, N, N-diethylformamide. Such a solvent may be one kind or two or more kinds.

The metal complex used in the present invention preferably has a regular structure and a flexible structure because the separation efficiency between unsaturated hydrocarbons and saturated hydrocarbons can be further increased. The regular structure here is characterized in that a peak derived from a unit cell is observed at 15 ^o (2θ) or less, preferably 12 ^o or less, more preferably 10 ^o or less by measurement of powder X-ray diffraction. It is a regular structure, and the peak is preferably 3 ^o (2θ) or more, and more preferably 4 ^o or more. Further, the flexible structure here is characterized in that the structure is changed by an external stimulus (for example, adsorption of guest molecules). In the present invention, the powder X-ray diffraction pattern of the metal complex having a flexible structure changes with the adsorption of small molecules. In addition, the metal complex having a flexible structure changes its structure again when the adsorbed small molecules are desorbed, and usually recovers the structure before adsorbing the small molecules.

  The method for producing the metal complex used in the present invention is not particularly limited, but the ligand represented by the above formula (I) is reacted in a solvent with the metal salt comprising the metal ion and the counter ion. It is preferable to manufacture by caulking. As the solvent used here, the above-mentioned solvents can be used, and the auxiliary ligand may be further added to the solvent.

  The molar ratio of the ligand represented by the formula (I) and the metal salt is preferably 0.1 to 10.0: 1, more preferably 0.2 to 5: 1. The concentration of the ligand represented by the formula (I) and the metal salt is preferably 1 to 1000 mmol / L, more preferably 10 to 500 mmol / L.

  The reaction temperature at the time of reacting the ligand with the metal salt is preferably room temperature or higher, more preferably 100 ° C. or higher, and the upper limit is generally 200 ° C. Such a reaction can be carried out under normal pressure, preferably under a pressure of 0.01 to 100 MPa, more preferably under a pressure of 0.01 to 10 MPa, and under a pressure of 0.1 to 10 MPa. More preferably it is performed. The reaction time is usually 1 minute to 1 week, preferably 5 minutes to 120 hours.

  The reaction vessel used for such a reaction may be an open vessel, but is preferably a closed vessel such as an autoclave. The reaction vessel can be heated by using an oil bath or an oven, or by irradiating microwaves or ultrasonic waves.

  In addition, when an appropriate solvent is selected in the reaction, the generated metal complex is precipitated in the reaction solution as a precipitate. After collecting the precipitated metal complex by filtration or the like, the precipitated metal complex can be washed with the same type of solvent used for the reaction or a solvent that is more volatile than the solvent used for the reaction. preferable. Furthermore, when the obtained metal complex is porous, since the raw material compound and the solvent may be adsorbed in the pores, it is preferable to dry the metal complex in order to remove them. . As such drying, vacuum drying under room temperature or heating conditions is preferable.

  In the present invention, the unsaturated hydrocarbon and the saturated hydrocarbon are separated by bringing the aforementioned metal complex into contact with a mixture of an unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms. In this case, the metal complex can be suitably used as an adsorbent or a molecular sieve. Such metal complexes may be one kind or may contain two or more kinds.

  The saturated hydrocarbon here is alkane or cycloalkane, and alkane is preferable. The unsaturated hydrocarbon includes alkene, alkyne, alkadiene, alkatriene, and aromatic hydrocarbon, preferably alkene, alkyne, and alkadiene, and more preferably alkene and alkyne. The unsaturated hydrocarbon and saturated hydrocarbon to be separated in the present invention are those having 3 or more carbon atoms, preferably unsaturated hydrocarbons and saturated hydrocarbons having 3 to 6 carbon atoms, Is more preferably 3 or 4 unsaturated hydrocarbons and saturated hydrocarbons, particularly preferably propylene and propane. Although the mechanism of action when the metal complex is used as an adsorbent is not clear, the adsorption amount of unsaturated hydrocarbons is usually much larger than the adsorption amount of saturated hydrocarbons, and unsaturated hydrocarbons and saturated hydrocarbons. Can be separated.

  In the separation method of the present invention, the metal complex can be used as it is or in a powder form by appropriate pulverization, but it may be molded by an appropriate molding means and used as a molded body. In the case of using a molding agent in this molding, the type of molding agent and the type of the molding agent are selected so that the hydrocarbon gas adsorption characteristics and the hydrocarbon gas desorption characteristics after adsorption are not significantly impaired. It is preferable to determine the amount used. An example of such a molding means is press molding. The shape of the molded body when used as an adsorbent is desirably a shape that can maintain the strength required for the adsorbent. Moreover, it is preferable that the surface area of a molded article is large from a viewpoint of improving the hydrocarbon gas adsorption rate.

  In the present invention, specific processes for separating the unsaturated hydrocarbon and the saturated hydrocarbon using the metal complex described above include, for example, a pressure swing adsorption method (pressure swing adsorption method) and a temperature swing adsorption. Method (Temperature Swing Adsorption) and permeation separation (membrane separation), and pressure swing adsorption is preferred.

  In the pressure swing adsorption method, the metal complex is brought into contact with a mixture of the unsaturated hydrocarbon and the saturated hydrocarbon under a first predetermined pressure (adsorption pressure), and one hydrocarbon is selected as the metal complex. It is preferable to include an adsorption process for adsorption. In such an adsorption step, the pressure in the space where the metal complex is arranged (for example, in the adsorption tank) is raised or reduced to a desired adsorption pressure in advance, and then the mixture is subjected to the adsorption pressure under the adsorption pressure. Introducing into the space, one hydrocarbon (for example, unsaturated hydrocarbon) is selectively (preferentially) adsorbed and concentrated on the metal complex, and the hydrocarbon depletion and the other hydrocarbon (for example, saturated) Hydrocarbons) are discharged from the space.

  In such a pressure swing adsorption method, after the adsorption step, the pressure is changed to a second predetermined pressure (desorption pressure) to desorb hydrocarbons adsorbed on the metal complex. More preferably, the method further includes a step. In such a desorption process (regeneration process), the pressure in the space where the metal complex that selectively adsorbs one of the hydrocarbons is reduced to a desired desorption pressure, and is adsorbed by the metal complex. The concentrated hydrocarbon (eg, unsaturated hydrocarbon) is discharged from the space by desorbing it from the metal complex.

  In addition, when such a pressure swing adsorption method is insufficient in one step, it can be made two or more steps, in which case the adsorption step and the desorption step are repeated twice or more. .

  The adsorption conditions in the pressure swing adsorption method are determined depending on the separation target, but the temperature is preferably 200 to 523 K, more preferably 250 to 427 K, and the pressure is preferably 1 to 3000 kPa, more preferably 5 to 300 kPa. The adsorption pressure is a pressure at which the difference between the adsorption amount of one hydrocarbon and the adsorption amount of the other hydrocarbon is large (preferably maximum), while the desorption pressure is The pressure at which both the hydrocarbon adsorption amount and the other hydrocarbon adsorption amount become small is employed.

Next, the hydrocarbon separation apparatus of the present invention will be described. The hydrocarbon separation apparatus of the present invention comprises a separation means comprising the metal complex described above,
Introducing means for introducing a mixture of an unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms into the separating means;
An apparatus for separating the unsaturated hydrocarbon and the saturated hydrocarbon by bringing the mixture into contact with the metal complex, and capable of carrying out the hydrocarbon separation method of the present invention described above. It is.

  The hydrocarbon separation apparatus of the present invention preferably further comprises pressure control means for controlling the pressure of the space in which the metal complex is arranged in the separation means. It is preferable that the above-described adsorption step can be performed by bringing the mixture into contact with the metal complex under a predetermined pressure and selectively adsorbing one of the hydrocarbons to the metal complex.

  Further, in this case, after selectively adsorbing one of the hydrocarbons to the metal complex, the pressure is changed to the second predetermined pressure by the pressure control means, and the hydrocarbon adsorbed to the metal complex is removed. It is preferable that the above-described desorption step can be performed by separating them.

  FIG. 1 shows a preferred embodiment of the hydrocarbon separation apparatus of the present invention.

  In the separation apparatus (an example of a pressure swing adsorption apparatus) shown in FIG. 1, an adsorption tank (separation means) 1 filled with the above-described metal complex is disposed, and an inlet pipe P1 having a valve V1 at one end thereof is disposed. The compressor 2 (introducing means) is connected, and the compressor 2 is connected to a feed gas P2 having a valve V2 (the mixture) and a purge gas introducing pipe P3 having a valve V3. Further, a decompressor 3 (pressure control means) is connected to the other end of the adsorption tank 1 via a discharge pipe P4 having a valve V4. Further, a product gas having a valve V5 (separated carbonization) is connected to the decompressor 3. Hydrogen) discharge pipe P5 and purge gas discharge pipe P6 having valve V6 are connected. Furthermore, a control means 4 (for example, PLC) is electrically connected to the compressor 2, the decompressor 3, and the valves V1 to V6, and is configured to be able to control their operations.

  When hydrocarbons are separated using the separation apparatus shown in FIG. 1, the following control is performed, for example. That is, first, purge gas is introduced into the adsorption tank 1 by the compressor 2, and then the pressure in the adsorption tank 1 is reduced by the decompressor 3 so as to become the first predetermined pressure (adsorption pressure). Next, the raw material gas is introduced into the adsorption tank 1 by the compressor 2 under the pressure, and one hydrocarbon (for example, unsaturated hydrocarbon) is selectively adsorbed and concentrated on the metal complex, and the carbonization is performed. Hydrogen depletion and the other hydrocarbon (for example, saturated hydrocarbon) are discharged as the first product gas.

  Next, the pressure in the adsorption tank 1 is reduced to the second predetermined pressure (desorption pressure) by the decompressor 3, whereby hydrocarbons (for example, unsaturated hydrocarbons) adsorbed on the metal complex are reduced. The concentrate is desorbed from the metal complex and discharged as a second product gas.

  The preferred embodiment of the hydrocarbon separation apparatus of the present invention has been described above. However, the separation apparatus of the present invention is not limited to the above-described embodiment. For example, one of the compressor and the decompressor is an introduction means. When both serve as pressure control means, only one of them may be used. Moreover, as an adsorption tank filled with the metal complex, a plurality of adsorption tanks (adsorption towers) may be connected in parallel or in series.

  Next, the metal complex of the present invention will be described. The metal complex of the present invention includes a ligand represented by the above formula (I), fluoride ion, chloride ion, bromide ion, iodide ion, oxide ion, sulfide ion, hydroxide ion, hydrogen Fluoride ion, sulfite ion, phosphate ion, cyanide ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluoro Phosphate ion, acetylacetonate, carboxylate ion (preferably formate ion, acetate ion, propionate ion, trifluoroacetate ion, etc.), and alkoxide ion (preferably methoxide ion, ethoxide ion, isopropoxide ion, etc.) ) Two or more cows selected from the group consisting of And Taion, a metal complex containing a metal ion.

  The preferred form of the ligand represented by the formula (I) in the metal complex of the present invention is the same as the preferred form of the ligand represented by the formula (I) in the hydrocarbon separation method of the present invention described above. It is.

  The preferred form of the metal ion in the metal complex of the present invention is the same as the preferred form of the metal ion in the hydrocarbon separation method of the present invention described above.

  The metal complex of the present invention comprises fluoride ion, chloride ion, bromide ion, iodide ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, formate ion, acetate ion. And two or more counter ions selected from the group consisting of trifluoroacetate ions, methanesulfonate ions, trifluoromethanesulfonate ions, tetrafluoroborate ions, hexafluorophosphate ions and trifluoroacetate ions More preferably, two or more types of counter ions selected from the group consisting of:

  The metal complex of the present invention contains the two or more types of counter ions, but it is preferable that at least two types of the counter ions contained are each contained in an amount of 0.01 mol% or more based on the total amount of the counter ions. More preferably, at least two of the counter ions are contained in an amount of 0.1 mol% or more with respect to the total amount of the counter ions, and at least two of the counter ions are contained in an amount of 1 mol% or more with respect to the total amount of the counter ions. More preferably.

  The composition ratio (molar ratio) of the metal ion, counter ion, and ligand represented by the formula (I) constituting the metal complex of the present invention is electrically neutral as a whole metal complex. There is no restriction other than the above, and a preferred embodiment is a composition ratio of the metal ion, the counter ion and the ligand represented by the formula (I) constituting the metal complex in the hydrocarbon separation method of the present invention described above. It is the same as the preferable form of (molar ratio).

  The metal complex of the present invention may have an auxiliary ligand in addition to the ligand represented by the above formula (I). The preferred form of the auxiliary ligand of the metal complex is the same as the preferred form of the auxiliary ligand in the hydrocarbon separation method of the present invention described above.

  In addition to the above-mentioned auxiliary ligand, the metal complex of the present invention may have a solvent as a ligand or a substance adsorbed in a gap, for example, water, methanol , Ethanol, isopropyl alcohol, ethylene glycol, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, acetone, chloroform, acetonitrile, benzonitrile, Examples include triethylamine, pyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, methyl ethyl ether, 1,4-dioxane, and preferably water, methanol, ethanol, isopropyl alcohol, ethylene glycol, N, N-dimethylformamide, N, - diethyl formamide. Such a solvent may be one kind or two or more kinds.

Since the metal complex in the present invention can further increase the separation efficiency between unsaturated hydrocarbons and saturated hydrocarbons, it preferably has a regular structure and a flexible structure. The regular structure here is characterized in that a peak derived from a unit cell is observed at 15 ^o (2θ) or less, preferably 12 ^o or less, more preferably 10 ^o or less by measurement of powder X-ray diffraction. It is a regular structure, and the peak is preferably 3 ^o (2θ) or more, and more preferably 4 ^o or more. Further, the flexible structure here is characterized in that the structure is changed by an external stimulus (for example, adsorption of guest molecules). In the present invention, the powder X-ray diffraction pattern of the metal complex having a flexible structure changes with the adsorption of small molecules. In addition, the metal complex having a flexible structure changes its structure again when the adsorbed small molecules are desorbed, and usually recovers the structure before adsorbing the small molecules.

  Further, in the metal complex of the present invention, the adsorption property is preferably controlled by adjusting the ratio of the two or more types of counter ions, and the metal complex of the present invention is preferably an unsaturated hydrocarbon (particularly preferably Propylene) is preferably used for separating saturated hydrocarbons (particularly preferably propane).

  The ratio of counter ions contained in the metal complex of the present invention can be adjusted by controlling the ratio of ions contained in the metal complex raw material. In this case, the control of the ratio of ions contained in the raw material of the metal complex can be achieved by using a metal salt containing different counter ions as a raw material at an arbitrary ratio, or reacting an organic salt or an inorganic salt for partial ion exchange. By adding it to the system, a metal complex containing two or more types of counter ions can be obtained at an arbitrary ratio.

  The ratio of counter ions contained in the metal complex of the present invention can also be adjusted by performing partial ion exchange on the metal complex described in the hydrocarbon separation method of the present invention. In this case, the ratio of ions contained in the raw material of the metal complex is controlled by the kind and amount of counter ions contained in the metal complex before ion exchange and the organic salt or inorganic added to perform partial ion exchange. By controlling the type and amount of the salt, a metal complex containing two or more types of counter ions can be obtained at an arbitrary ratio.

  The adsorption characteristics of metal complexes containing two or more types of counter ions are different from those exhibited by a mixture of metal complexes with only one type of counter ions, and the adsorption characteristics are gradually controlled according to the ratio of counter ions. Is possible. Therefore, by controlling the adsorption characteristics by adjusting the ratio of two or more types of counter ions contained, more favorable adsorption characteristics can be achieved in accordance with the restrictions on the separation conditions of the mixture of unsaturated hydrocarbons and saturated hydrocarbons. It becomes easier to provide the metal complex shown.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Analysis and evaluation in the following examples and comparative examples were performed as follows.

(1) Measurement of Powder X-ray Diffraction Pattern Using a powder X-ray apparatus, a diffraction angle (2θ) = 3 to 40 ° was scanned at a scanning speed of 2 ° / min and measured by a symmetric reflection method. Details of the measurement conditions are shown below.
<Measurement conditions>
Apparatus: RINT-UltimaIII manufactured by Rigaku Corporation
X-ray source: CuKα (λ = 1.5418Å) 40 kV 40 mA
Goniometer: Horizontal goniometer Detector: Scintillation counter Step width: 0.02 °
Slit: Divergence slit = 1mm
Divergence length restriction slit = 10mm
Receiving slit = Open
Scattering slit = open.

(2) Elemental analysis About carbon, hydrogen, and nitrogen, it quantified using the carbon, hydrogen, and nitrogen simultaneous measuring apparatus. Halogen was quantified using an anion chromatography apparatus. Details of the measurement conditions are shown below.
<Measurement conditions>
≪Carbon, hydrogen, nitrogen≫
Apparatus: MICRO CORDER JM10 manufactured by J Science Lab Co., Ltd.
Combustion temperature: 950 ° C
Burning time: 4 minutes << Halogen >>
Apparatus: Nihon Dionex Co., Ltd. ion chromatograph DX-500
Column: AS12A
Column temperature: 30 ° C
Detector temperature: 35 ° C
Flow rate: 1.5 mL / min.

(3) Measurement of adsorption / desorption isotherm Measurement was performed by a volumetric method using an automatic specific surface area / pore distribution measuring device. At this time, the sample was dried at 373 K and 5 Pa for 16 hours prior to measurement to remove adsorbed water and the like. Details of the measurement conditions are shown below.
<Measurement conditions>
Apparatus: Nippon Bell Co., Ltd. BELSORP-miniII
Pressure program: 5 kPa or less → 120 kPa → 10 kPa or less Equilibrium waiting time: 300 seconds.

(Synthesis Example 1)
Under the atmosphere, 0.345 g (1.0 mmol) of copper tetrafluoroborate hexahydrate was dissolved in 20 mL of water and stirred at 298 K for 5 minutes. Subsequently, 20 mL of an acetone solution of 0.396 g (2.0 mmol) of 1,3-bis (4-pyridyl) propane was added dropwise to the resulting solution. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 3 hours to obtain 0.422 g (yield 67%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 2, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was copper ion: tetrafluoroborate ion: 1,3-bis (4-pyridyl) propane = 1: 2: 2.
Measured value C: 48.59, H: 4.41, N: 8.78, F: 22 (%)
Theoretical value C: 49.28, H: 4.45, N: 8.84, F: 23.98 (%).

(Synthesis Example 2)
In the atmosphere, 0.741 g (2.0 mmol) of copper perchlorate hexahydrate and 1.47 g (8.0 mmol) of potassium hexafluorophosphate were dissolved in 20 mL of methanol, and the mixture was stirred at 298 K for 30 minutes, followed by suction filtration. To remove impurities. Thereafter, 20 mL of water was added to the obtained solution to obtain a solution A. Subsequently, Solution A was added dropwise to 20 mL of an acetone solution of 0.792 g (4.0 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 5 hours to obtain 1.11 g (yield 74%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 3, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was copper ion: hexafluorophosphate ion: 1,3-bis (4-pyridyl) propane = 1: 2: 2.
Measured value C: 41.74, H: 3.90, N: 7.51, F: 28 (%)
Theoretical value C: 41.64, H: 3.76, N: 7.47, F: 30.40 (%).

(Synthesis Example 3)
Under air, 0.182 g (0.5 mmol) of copper trifluoromethanesulfonate was dissolved in 10 mL of water, and this was used as Solution A. Subsequently, the solution A was added dropwise to 10 mL of a 2-butanone solution of 0.198 g (1.0 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.268 g (yield 70%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 4, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was copper ion: trifluoromethanesulfonic acid ion: 1,3-bis (4-pyridyl) propane = 1: 2: 2.
Measured value C: 44.15, H: 3.63, N: 7.20, F: 14, S: 8.40 (%)
Theoretical value C: 44.35, H: 3.72, N: 7.39, F: 15.03, S: 8.46 (%).

(Synthesis Example 4)
In the atmosphere, 0.282 g (0.76 mmol) of copper perchlorate hexahydrate and 0.56 g (3.04 mmol) of potassium hexafluorophosphate were dissolved in 3.8 mL of methanol, and the mixture was stirred at 298 K for 30 minutes. Impurities were removed by suction filtration. Thereafter, 0.014 g (0.04 mmol) of copper trifluoromethanesulfonate and 5 mL of water were added to the resulting solution to prepare a solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.317 g (1.6 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The precipitated metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.540 g (yield 90%) of the target metal complex. FIG. 5 shows a powder X-ray diffraction pattern of the obtained metal complex. From the results shown in FIG. 5, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: hexafluorophosphate ion: trifluoromethanesulfonate ion: 1,3-bis (4-pyridyl) propane = 1.1.95. : 0.05: 2.
Measured value C: 41.71, H: 3.80, N: 7.48, F: 31, S: 0.27 (%)
Theoretical value C: 41.71, H: 3.76, N: 7.47, F: 30.01, S: 0.21 (%).

(Synthesis Example 5)
Under air, 0.069 g (0.2 mmol) of copper tetrafluoroborate hexahydrate and 0.072 g (0.2 mmol) of copper trifluoromethanesulfonate were dissolved in 10 mL of water, and this was used as Solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.159 g (0.8 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.126 g (yield 45%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 6, it was confirmed that the obtained metal complex had an ordered structure. Moreover, as a result of conducting the elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: tetrafluoroborate ion: trifluoromethanesulfonic acid ion: 1,3-bis (4-pyridyl) propane = 1: 1: 1. : 2.
Actual measurement C: 46.37, H: 4.02, N: 8.04, F: 19, S: 4.17 (%)
Theoretical value C: 46.60, H: 4.06, N: 8.05, F: 19.11, S: 4.61 (%).

(Synthesis Example 6)
Under air, 0.148 g (0.4 mmol) of copper perchlorate hexahydrate and 0.295 g (1.6 mmol) of potassium hexafluorophosphate were dissolved in 4 mL of methanol, and the mixture was stirred at 298 K for 30 minutes, followed by suction filtration. To remove impurities. Thereafter, 0.145 g (0.4 mmol) of copper trifluoromethanesulfonate and 5 mL of water were added to the resulting solution to prepare a solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.317 g (1.6 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The precipitated metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.523 g (yield 87%) of the desired metal complex. FIG. 7 shows a powder X-ray diffraction pattern of the obtained metal complex. From the results shown in FIG. 7, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: hexafluorophosphate ion: trifluoromethanesulfonate ion: 1,3-bis (4-pyridyl) propane = 1: 1.1 : 0.9: 2.
Measured value C: 42.79, H: 3.75, N: 7.17, F: 23, S: 3.96 (%)
Theoretical value C: 42.87, H: 3.74, N: 7.43, F: 23.44, S: 3.83 (%).

(Synthesis Example 7)
In the atmosphere, 0.333 g (0.9 mmol) of copper perchlorate hexahydrate and 0.663 g (3.6 mmol) of potassium hexafluorophosphate were dissolved in 4.5 mL of methanol, and the mixture was stirred at 298 K for 30 minutes. Impurities were removed by suction filtration. Thereafter, 0.036 g (0.1 mmol) of copper trifluoromethanesulfonate and 5 mL of water were added to the resulting solution to prepare a solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.397 g (2.0 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 8 hours to obtain 0.6131 g (yield 82%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 8, it was confirmed that the obtained metal complex had an ordered structure. Further, as a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: hexafluorophosphate ion: trifluoromethanesulfonate ion: 1,3-bis (4-pyridyl) propane = 1: 1.8 : 0.2: 2.
Measured value C: 41.72, H: 3.70, N: 7.34, F: 30, S: 0.82 (%)
Theoretical value C: 41.91, H: 3.76, N: 7.46, F: 28.85, S: 0.85 (%).

(Synthesis Example 8)
Under air, 0.267 g (0.72 mmol) of copper perchlorate hexahydrate and 0.530 g (2.88 mmol) of potassium hexafluorophosphate were dissolved in 5 mL of methanol, and the mixture was stirred at 298 K for 30 minutes, and then filtered with suction. To remove impurities. Thereafter, 0.02 g (0.08 mmol) of copper methanesulfonate and 5 mL of water were added to the resulting solution to prepare a solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.317 g (1.6 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The precipitated metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.520 g (yield 88%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 9, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: hexafluorophosphate ion: methanesulfonic acid ion: 1,3-bis (4-pyridyl) propane = 1: 1.85: It was 0.15: 2.
Measured value C42.24 :, H3.81 :, N7.36 :, F: 29, S: 0.62 (%)
Theoretical value C: 42.30, H: 3.86, N: 7.55, F: 28.40, S: 0.65 (%).

(Synthesis Example 9)
In the atmosphere, 0.074 g (0.2 mmol) of copper perchlorate hexahydrate and 0.147 g (0.8 mmol) of potassium hexafluorophosphate were dissolved in 4 mL of methanol, and the mixture was stirred at 298 K for 30 minutes, followed by suction filtration. To remove impurities. Thereafter, 0.51 g (0.2 mmol) of copper methanesulfonate and 5 mL of water were added to the resulting solution to prepare a solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.159 g (0.8 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.203 g (yield 69%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 10, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: hexafluorophosphate ion: methane sulfonate ion: 1,3-bis (4-pyridyl) propane = 1: 1.6: 0.4: 2.
Actual measurement C: 43.16, H: 4.05, N: 7.43, F: 25, S: 1.68 (%)
Theoretical value C: 43.43, H: 4.03, N: 7.67, F: 24.98, S: 1.76 (%).

(Synthesis Example 10)
Under the atmosphere, 0.069 g (0.2 mmol) of copper tetrafluoroborate hexahydrate and 0.051 g (0.2 mmol) of copper methanesulfonate were dissolved in 10 mL of water, and this was used as Solution A. Subsequently, Solution A was added dropwise to 10 mL of an acetone solution of 0.159 g (0.8 mmol) of 1,3-bis (4-pyridyl) propane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 4 hours to obtain 0.203 g (yield 69%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From the results shown in FIG. 11, it was confirmed that the obtained metal complex had an ordered structure. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: tetrafluoroborate ion: methanesulfonic acid ion: 1,3-bis (4-pyridyl) propane = 1: 1.85: It was 0.15: 2.
Measured value C: 49.39, H: 4.30, N: 8.69, F: 21, S: 0.73 (%)
Theoretical value C: 49.47, H: 4.52, N: 8.82, F: 22.14, S: 0.76 (%).

(Comparative Synthesis Example 1)
Under the atmosphere, 0.345 g (1.0 mmol) of copper tetrafluoroborate hexahydrate was dissolved in 20 mL of water and stirred at 298 K for 5 minutes. Subsequently, 20 mL of an acetone solution of 0.368 g (2.0 mmol) of 1,3-bis (4-pyridyl) ethane was added dropwise to the obtained solution. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 3 hours to obtain 0.399 g (yield 66%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

(Comparative Synthesis Example 2)
In the atmosphere, 0.741 g (2.0 mmol) of copper perchlorate hexahydrate and 1.47 g (8.0 mmol) of potassium hexafluorophosphate were dissolved in 20 mL of methanol, and the mixture was stirred at 298 K for 30 minutes, followed by suction filtration. To remove impurities. Thereafter, 20 mL of water was added to the obtained solution to obtain a solution B. Subsequently, Solution B was added dropwise to 20 mL of an acetone solution of 0.736 g (4.0 mmol) of 1,3-bis (4-pyridyl) ethane. Thereafter, the mixture was stirred at 298K for 20 minutes. The deposited metal complex was collected by suction filtration, washed with water and then with acetone, and further dried at 373 K and 5 Pa for 5 hours to obtain 0.921 g (yield: 64%) of the desired metal complex. FIG. 13 shows a powder X-ray diffraction pattern of the obtained metal complex.

Example 1
With respect to the metal complex obtained in Synthesis Example 1, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 14. In the range of 6 to 10 kPa, the amount of propylene adsorbed exceeded the amount of propane adsorbed, and the value of propylene adsorbed amount / propane adsorbed amount was about 150 times at the maximum. It was confirmed that there is sex. FIG. 15 shows adsorption / desorption isotherms of propane and propylene at 263K, 273K, and 283K. The same tendency was confirmed at any temperature.

(Example 2)
For the metal complex obtained in Synthesis Example 2, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 16. In the range of 50 to 85 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 20 to 30 times. It was confirmed that there is sex. FIG. 17 shows adsorption / desorption isotherms of propane and propylene at 263K, 273K, and 283K. The same tendency was confirmed at any temperature.

(Example 3)
For the metal complex obtained in Synthesis Example 3, the adsorption and desorption isotherms of propane and propylene at 195 K were measured by the capacitance method. The results are shown in FIG. 18. In the range of 5 to 15 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 30 times at the maximum. It was confirmed that there is sex.

Example 4
For the metal complex obtained in Synthesis Example 4, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 19, but in the range of 45 to 75 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 20 times at the maximum. It was confirmed that there is sex.

(Example 5)
For the metal complex obtained in Synthesis Example 5, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 20, but in the range of 4 to 7 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 30 times at the maximum. It was confirmed that there is sex.

(Example 6)
For the metal complex obtained in Synthesis Example 6, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 21. In the range of 40 to 120 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 15 times at the maximum, so the adsorption characteristic was selected. It was confirmed that there is sex.

(Example 7)
For the metal complex obtained in Synthesis Example 7, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 22. In the range of 40 to 90 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 20 times at the maximum. It was confirmed that there is sex.

(Example 8)
For the metal complex obtained in Synthesis Example 8, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 23. In the range of 50 to 95 kPa, the amount of propylene adsorbed exceeded the amount of propane adsorbed, and the value of propylene adsorbed amount / propane adsorbed amount was about 30 times at the maximum. It was confirmed that there is sex.

Example 9
For the metal complex obtained in Synthesis Example 9, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 24. In the range of 60 to 120 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 20 times at the maximum. It was confirmed that there is sex.

(Example 10)
For the metal complex obtained in Synthesis Example 10, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the capacitance method. The results are shown in FIG. 25, but in the range of 8 to 20 kPa, the propylene adsorption amount exceeded the propane adsorption amount, and the value of propylene adsorption amount / propane adsorption amount was about 140 times at the maximum. It was confirmed that there is sex.

(Comparative Example 1)
For the metal complex obtained in Comparative Synthesis Example 1, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the volumetric method. The results are shown in FIG. 26, and both propylene and propane were hardly adsorbed, and adsorption selectivity was not obtained.

(Comparative Example 2)
For the metal complex obtained in Comparative Synthesis Example 2, the adsorption and desorption isotherms of propane and propylene at 273 K were measured by the volume method. The results are shown in FIG. 27, and both propylene and propane were hardly adsorbed, and adsorption selectivity was not obtained.

  As described above, according to the present invention, carbonization such as propylene and propane has 3 or more carbon atoms and the same carbon number in a pressure region of 1 kPa or more that can be used without requiring excessively low pressure in practice. It is possible to provide a hydrocarbon separation method and a separation apparatus capable of separating unsaturated hydrocarbons and saturated hydrocarbons with high efficiency even if they are hydrogen.

  In addition, according to the present invention, the adsorption characteristics can be controlled by adjusting the ratio of two or more types of counter ions, so that the separation conditions of the mixture of unsaturated hydrocarbons and saturated hydrocarbons can be matched. It becomes easy to provide a metal complex exhibiting preferable adsorption characteristics for the separation of a mixture of unsaturated hydrocarbon and saturated hydrocarbon.

  Therefore, the present invention is very useful as a technique for reducing the size of an apparatus for separating such hydrocarbons and saving energy for separation.

  DESCRIPTION OF SYMBOLS 1 ... Adsorption tank (separation means), 2 ... Compressor (introduction means), 3 ... Decompression machine (pressure control means), 4 ... Control means, V1-V6 ... Valve, P1-P6 ... Piping.

Claims (17)

The following formula (I):
Q ^1- (R) _n -Q ² (I)
{In the formula, Q ¹ and Q ² may be the same or different and each is a heterocyclic group containing a nitrogen atom; n is an integer of 3 to 20; -1) to (II-4):
-C (R ¹ ) (R ² )-(II-1)
-C (= O)-(II-2)
-O- (II-3)
-N (R ³ )-(II-4)
(In the formula, R ¹ and R ² may be the same or different, and each is a hydrogen atom, a halogen atom, or a hydrocarbon group that may have a substituent, and R ³ is hydrogen. (A hydrocarbon group which may have an atom or a substituent.)
Or a group represented by the formula (II-3) or the formula (II-4) is not adjacent, and R is R ¹ to R. ^When it has two or more hydrocarbon groups which may have a substituent as ³ , they may be bonded to form a ring, and a plurality of R may be the same or different. }
The mixture of a unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms is brought into contact with a metal complex containing a ligand represented by the formula (I), a counter ion, and a metal ion. A hydrocarbon separation method comprising a step of separating a saturated hydrocarbon and the saturated hydrocarbon. The method for separating hydrocarbons according to claim 1, wherein Q ¹ and Q ^{2 in} formula (I) may be the same or different and each is an aromatic heteromonocyclic group containing a nitrogen atom. .   The method for separating hydrocarbons according to claim 1 or 2, wherein R in the formula (I) is a group represented by the formula (II-1).   The hydrocarbon separation method according to any one of claims 1 to 3, wherein in the formula (I), n is an integer of 3 to 6.   The hydrocarbon separation method according to any one of claims 1 to 4, wherein the metal complex contains two or more kinds of counter ions.   The two or more types of counter ions are fluoride ion, chloride ion, bromide ion, iodide ion, oxide ion, sulfide ion, hydroxide ion, hydride ion, sulfite ion, phosphate ion, cyanide. Ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, acetylacetonate, carboxylate ion, And the hydrocarbon separation method according to claim 5, wherein the hydrocarbons are two or more types of counter ions selected from the group consisting of alkoxide ions.   7. The method according to claim 1, further comprising an adsorption step of bringing the mixture into contact with the metal complex under a first predetermined pressure and selectively adsorbing one of the hydrocarbons to the metal complex. 2. The hydrocarbon separation method described in 1.   The method for separating hydrocarbons according to claim 7, further comprising a desorption step of desorbing hydrocarbons adsorbed on the metal complex by changing the pressure to a second predetermined pressure after the adsorption step. The following formula (I):
Q ^1- (R) _n -Q ² (I)
{In the formula, Q ¹ and Q ² may be the same or different and each is a heterocyclic group containing a nitrogen atom; n is an integer of 3 to 20; -1) to (II-4):
-C (R ¹ ) (R ² )-(II-1)
-C (= O)-(II-2)
-O- (II-3)
-N (R ³ )-(II-4)
(In the formula, R ¹ and R ² may be the same or different, and each is a hydrogen atom, a halogen atom, or a hydrocarbon group that may have a substituent, and R ³ is hydrogen. (A hydrocarbon group which may have an atom or a substituent.)
Or a group represented by the formula (II-3) or the formula (II-4) is not adjacent, and R is R ¹ to R. ^When it has two or more hydrocarbon groups which may have a substituent as ³ , they may be bonded to form a ring, and a plurality of R may be the same or different. }
A separation means comprising a metal complex comprising a ligand represented by: a counter ion and a metal ion;
Introducing means for introducing a mixture of an unsaturated hydrocarbon having 3 or more carbon atoms and a saturated hydrocarbon having 3 or more carbon atoms into the separating means;
And separating the unsaturated hydrocarbon and the saturated hydrocarbon by bringing the mixture into contact with the metal complex. A pressure control means for controlling the pressure of the space in which the metal complex is arranged in the separation means;
The hydrocarbon separation apparatus according to claim 9, wherein the mixture is brought into contact with the metal complex under a first predetermined pressure by the pressure control means, and one hydrocarbon is selectively adsorbed on the metal complex. .   2. After selectively adsorbing one hydrocarbon on the metal complex, the pressure is changed to a second predetermined pressure by the pressure control means to desorb the hydrocarbon adsorbed on the metal complex. The hydrocarbon separator according to claim 10. The following formula (I):
Q ^1- (R) _n -Q ² (I)
{In the formula, Q ¹ and Q ² may be the same or different and each is a heterocyclic group containing a nitrogen atom; n is an integer of 3 to 20; -1) to (II-4):
-C (R ¹ ) (R ² )-(II-1)
-C (= O)-(II-2)
-O- (II-3)
-N (R ³ )-(II-4)
(In the formula, R ¹ and R ² may be the same or different, and each is a hydrogen atom, a halogen atom, or a hydrocarbon group that may have a substituent, and R ³ is hydrogen. (A hydrocarbon group which may have an atom or a substituent.)
Or a group represented by the formula (II-3) or the formula (II-4) is not adjacent, and R is R ¹ to R. ^When it has two or more hydrocarbon groups which may have a substituent as ³ , they may be bonded to form a ring, and a plurality of R may be the same or different. }
Fluoride ion, chloride ion, bromide ion, iodide ion, oxide ion, sulfide ion, hydroxide ion, hydride ion, sulfite ion, phosphate ion, cyanide Ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, thiocyanate ion, methanesulfonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, acetylacetonate, carboxylate ion, And a metal complex containing two or more types of counter ions selected from the group consisting of alkoxide ions and metal ions. The metal complex according to claim 12, wherein Q ¹ and Q ^{2 in the} formula (I) may be the same or different and each is an aromatic heteromonocyclic group containing a nitrogen atom.   The metal complex according to claim 12 or 13, wherein R is a group represented by the formula (II-1) in the formula (I).   In the said formula (I), n is an integer of 3-6, The metal complex as described in any one of Claims 12-14.   The adsorption characteristic is controlled by adjusting the ratio of the two or more types of counter ions, and is used to separate unsaturated hydrocarbons from saturated hydrocarbons. The metal complex according to item.   The metal complex according to claim 16, wherein the unsaturated hydrocarbon is propylene and the saturated hydrocarbon is propane.