WO2015012396A1 - Adsorption/separation method for hydrocarbon mixed gas having at least four carbon atoms, and separation device - Google Patents

Abstract

An adsorption/separation method for hydrocarbon mixed gas having at least four carbon atoms, characterized by causing hydrocarbons to be selectively adsorbed by a metal complex, by causing the mixed gas to come in contact with the metal complex, said metal complex including a ligand indicated by formula (1) and metal ions and said hydrocarbons having no more than a specified degree of unsaturation among mixed gases having at least four carbon atoms and including at least two types of hydrocarbons having the same number of carbon atoms and different degrees of unsaturation. (1) (in the formula, P indicates a saturated hydrocarbon group that can have a substituent other than R^a, R^a is a functional group having coordinating properties in relation to the metal ions, m is an integer between 1 and 4, and when m is an integer of 2 or higher, the plurality of R^a can be the same or different.)

Description

Method and apparatus for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms

The present invention relates to a method for adsorbing and separating a hydrocarbon mixed gas having 4 or more carbon atoms and a separation apparatus for carrying out the adsorbing and separating method.

1,3-Butadiene is a kind of raw material for synthetic rubber, and conventionally it has been produced mainly from naphtha. However, in the recent chemical industry, raw materials are shifting from naphtha to shale gas, and the supply of 1,3-butadiene derived from naphtha is decreasing. With the review of the chemical industry process, the production of hydrocarbon gas having 4 or more carbon atoms such as 1,3-butadiene using shale gas as a raw material is being studied. Here, when a hydrocarbon gas having 4 carbon atoms is produced from shale gas (methane) by FT reaction, for example, 1,3-butadiene (boiling point −4.41 ° C., critical diameter 4.31 angstrom) and 1-butene ( A mixed gas having a boiling point of −6.26 ° C. and a critical diameter of 4.46 Å is obtained. When high purity 1,3-butadiene is separated from this mixed gas, 1,3-butadiene and 1-butene are not easily separated because their boiling points and critical diameters are close to each other. Therefore, separation using an adsorbent is considered. In this case, since the mixed gas contains a large amount of 1,3-butadiene, in order to purify it, other components, that is, 1, It is desirable to purify 1,3-butadiene by adsorbing butene or butane having a lower degree of unsaturation than 3-butadiene to the adsorbent. It is also important for the chemical industry plant design to collect the butene and butane adsorbed and use them as industrial raw materials.

As a separation method using the difference in adsorption characteristics, a method using activated carbon or zeolite generally known as an adsorbent is known, but hydrocarbons having a low degree of unsaturation, particularly 1-butene and n- It is difficult to highly selectively adsorb hydrocarbons having 4 or more carbon atoms and low unsaturation such as butane, and such hydrocarbons having low unsaturation can be adsorbed with high selectivity. No practical adsorption method has been provided.

In recent years, porous metal complexes have been studied as new adsorbents. Gascon et al. , J. Am. Chem. Soc. 2010, 132, p. In 17704-17706 (Non-patent Document 1), in a specific porous metal complex, the affinity for a saturated hydrocarbon having a specific degree of unsaturation is higher than the affinity for a hydrocarbon having a higher degree of unsaturation. It has been found. In addition, J.H. Gascon et al. , Chem. Eur. J. , 2011, 17, p. In 8832-8840 (Non-patent Document 2), it is described that butene and butane are recovered by the porous metal complex. However, in this case, there is a problem that the temperature needs to be excessively increased.

The present invention has been made in view of the above-described problems of the prior art, and has a carbon number of 4 or more, such as a mixed gas of 1,3-butadiene and 1-butene, and is identical and unsaturated. By selectively adsorbing hydrocarbons having a specific degree of unsaturation or less from a mixed gas containing at least two types of hydrocarbons having different degrees, hydrocarbons having a higher degree of unsaturation can be purified. A method of adsorbing and separating a hydrocarbon mixed gas having 4 or more carbon atoms capable of recovering a gas adsorbed in a temperature range (for example, 25 to 200 ° C.) that is possible and does not require an excessive temperature rise in practice, and An object is to provide a separation device.

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

That is, the adsorption separation method for hydrocarbon mixed gas having 4 or more carbon atoms of the present invention is represented by the following formula (1):

(In the formula (1), P is ^a saturated hydrocarbon group which may have a substituent other than R ^a ; R ^a is a functional group having a coordination property to ^a metal ion; And when m is an integer of 2 or more, a plurality of R ^a may be the same or different from each other.)
A metal complex containing a ligand represented by the formula (hereinafter sometimes referred to as “first ligand”) and a metal ion has 4 or more carbon atoms, the same carbon number, and unsaturated. Carbon having a specific degree of unsaturation or less is selectively adsorbed on the metal complex by bringing a mixed gas containing at least two kinds of hydrocarbons having different degrees into contact with each other. This is a method for adsorbing and separating hydrocarbon mixed gas of several formulas or more.

In the method for adsorbing and separating a hydrocarbon mixed gas having 4 or more carbon atoms according to the present invention, P in the first ligand may be substituted with a saturated hydrocarbon group having 1 to 8 carbon atoms. It is preferably a saturated hydrocarbon group having 3 to 12 carbon atoms having

In the method for adsorbing and separating a hydrocarbon mixture gas having 4 or more carbon atoms according to the present invention, R ^{a of} the first ligand is “—CO ₂ ⁻ ”, “—CS ₂ ⁻ ”, “—C ^A group represented by any one selected from the group consisting of (═O) S ⁻ ”and“ —C (═O) NR ^A— ”(wherein R ^A is a hydrogen atom or an alkyl group having 4 or less carbon atoms). It is preferable that

In the method for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms according to the present invention, the metal ion is at least one metal selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper and zinc. It is preferable that it is ion of these.

Further, in the method for adsorbing and separating a hydrocarbon mixture gas having 4 or more carbon atoms according to the present invention, the metal complex includes “a hetero atom having 2 to 4 atoms” and “a heterocyclic group having no double bond”. It is preferable to further include a second ligand that satisfies both the conditions of “compound”.

Moreover, in the adsorption separation method of the hydrocarbon mixed gas having 4 or more carbon atoms of the present invention, the metal complex is represented by the following formula (2):

(In the formula (2), Q is R have other substituents ^a be also substituted hydrocarbon group; and R ^a and m of R ^a and m the first in the ligand are each independently Synonymous.)
It is preferable that the 3rd ligand represented by these is further included. In the method for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms of the present invention, the metal complex has a molar ratio represented by [first ligand]: [third ligand]. The range is preferably 100: 0 to 20:80.

Furthermore, in the present invention, the metal complex is represented by the following formula (3):

(In Formula (3), P ¹ is a halogen atom or a saturated hydrocarbon group having 12 or less carbon atoms which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms, and m ¹ is 1 to 2) (It is an integer.)
A first ligand A represented by:
A second ligand B which is a heterocyclic compound containing 2 to 4 heteroatoms and no double bond;
Following formula (4):

(In Formula (4), Q ¹ is a halogen atom or an unsaturated hydrocarbon group having 12 or less carbon atoms which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms; m ¹ is 1 to 2; Is an integer.)
A third ligand C represented by:
Ions of at least one metal selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper and zinc;
It is preferable that it is a metal complex containing.

The separation apparatus of the present invention comprises a separation means comprising a metal complex containing a ligand represented by the above formula (1) and a metal ion,
An introduction means for introducing a mixed gas containing at least two kinds of hydrocarbons having 4 or more carbon atoms, the same carbon number, and different degrees of unsaturation into the separation means,
By bringing the mixed gas into contact with the metal complex, hydrocarbons having a specific degree of unsaturation or less in the mixed gas are selectively adsorbed on the metal complex, and hydrocarbons having a specific degree of unsaturation or less are not adsorbed. Separating hydrocarbons with higher saturation,
This is a separation apparatus for hydrocarbon mixed gas having 4 or more carbon atoms.

In the present invention, “selectively adsorbing hydrocarbons having a specific degree of unsaturation to a metal complex” means carbons having the same carbon number and different degrees of unsaturation under the same temperature and pressure conditions. When hydrogen is adsorbed on a metal complex, the adsorption amount of hydrocarbons having a specific degree of unsaturation or less is larger than the adsorption amount of hydrocarbons having a higher degree of unsaturation. The amount of adsorption can be measured by a volume method using, for example, an automatic specific surface area / pore distribution measuring device (BELSORP-miniII manufactured by Nippon Bell Co., Ltd.).

In the present invention, the degree of unsaturation means the proportion of carbon-carbon double bonds contained in hydrocarbons, and the degree of unsaturation is the number of double bonds in hydrocarbon molecules having the same carbon number and the same skeleton. It depends on the number of For example, in the case of a straight-chain hydrocarbon having 4 carbon atoms, the unsaturated is n-butane (double bond 0) <1-butene (double bond 1) <1,3-butadiene (double bond 2) in this order. The degree of unsaturation increases in the order of cyclohexane (double bond 0) <cyclohexene (double bond 1) in a cyclic hydrocarbon having 6 carbon atoms.

According to the present invention, a mixed gas containing at least two types of hydrocarbons having 4 or more carbon atoms, the same carbon number, and different degrees of unsaturation, such as a mixed gas of 1,3-butadiene and 1-butene The hydrocarbon gas having a carbon number of 4 or more can be purified by selectively adsorbing hydrocarbons having a specific degree of unsaturation or less in the mixed gas. An adsorption separation method and a separation apparatus can be provided. Further, according to the present invention, the adsorbed gas can be recovered in a temperature range (for example, 25 to 200 ° C.) that does not require an excessive temperature rise in practice.

It is a schematic diagram which shows suitable one Embodiment of the separation apparatus of the hydrocarbon useful for implementing 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. 6 is a schematic diagram showing a crystal structure of a metal complex obtained in Synthesis Example 7. FIG. 10 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 7. 6 is a graph showing a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 1. 2 is a graph showing the 273 K adsorption isotherm of 1-butene and 1,3-butadiene measured in Example 1 using the metal complex obtained in Synthesis Example 1. FIG. 4 is a graph showing the 273 K adsorption isotherm of n-butane, 1-butene and 1,3-butadiene measured in Example 2 using the metal complex obtained in Synthesis Example 2. 4 is a graph showing 273 K adsorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Example 3 using the metal complex obtained in Synthesis Example 3. 6 is a graph showing the 273 K adsorption isotherm of n-butane, 1-butene and 1,3-butadiene measured in Example 4 using the metal complex obtained in Synthesis Example 4. 6 is a graph showing the 273 K adsorption isotherm of n-butane, 1-butene and 1,3-butadiene measured in Example 5 using the metal complex obtained in Synthesis Example 5. 6 is a graph showing the 273K adsorption isotherm of 1-butene and 1,3-butadiene measured in Example 6 using the metal complex obtained in Synthesis Example 6. 3 is a graph showing 303 K desorption isotherms of 1-butene and 1,3-butadiene measured in Example 7 using the metal complex obtained in Synthesis Example 1. FIG. 6 is a graph showing 303 K desorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Example 8 using the metal complex obtained in Synthesis Example 2. FIG. 6 is a graph showing 303 K desorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Example 9 using the metal complex obtained in Synthesis Example 3. FIG. 6 is a graph showing 303 K desorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Example 10 using the metal complex obtained in Synthesis Example 4. FIG. 6 is a graph showing 303 K desorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Example 11 using the metal complex obtained in Synthesis Example 5. FIG. 10 is a graph showing the desorption isotherm of 303K of 1-butene and 1,3-butadiene measured in Example 12 using the metal complex obtained in Synthesis Example 6. FIG. 16 is a graph showing the 273 K adsorption isotherm of n-butane and 1,3-butadiene measured in Example 13 using the metal complex obtained in Synthesis Example 7. 4 is a graph showing the adsorption and desorption isotherms of n-butane, 1-butene and 1,3-butadiene measured in Comparative Example 1 using the metal complex obtained in Comparative Synthesis Example 1.

Hereinafter, the present invention will be described in detail on the basis of preferred embodiments thereof. First, the method for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms according to the present invention will be described.

The hydrocarbon mixed gas having 4 or more carbon atoms, which is an object of the adsorption separation of the present invention, is a mixed gas containing at least two hydrocarbons having 4 or more carbon atoms, the same carbon number, and different degrees of unsaturation. It is. The hydrocarbon has preferably 6 or less carbon atoms. The hydrocarbon mixture gas having 4 or more carbon atoms includes at least two kinds of saturated hydrocarbons and unsaturated hydrocarbons having different degrees of unsaturation, for example, a mixture containing hydrocarbons having 4 carbon atoms. Examples of the gas include a mixed gas containing at least two or more of n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene, isobutene, 1,3-butadiene, cyclobutane, and cyclobutene. As the mixed gas containing a hydrocarbon having 5 carbon atoms, n-pentane, 1-pentene, cis-2-pentene, trans-2-pentene, 1,3-pentadiene, 1,4-pentadiene, cyclopentane, Examples include a mixed gas containing at least two of cyclopentene and cyclopentadiene, and a mixture containing a hydrocarbon having 6 carbon atoms. The scan, hexane, 1-hexene, cyclohexane, a mixed gas containing at least two or more of cyclohexene and benzene. The mixed gas to be subjected to the adsorption separation of the present invention may be a mixed gas containing at least two kinds of hydrocarbons having the same carbon number and different degree of unsaturation, but has the same carbon number and the same skeleton. A mixed gas containing at least two kinds of hydrocarbons having different degrees of unsaturation is preferable.

Examples of such a mixed gas include a mixed gas produced from shale gas (methane) by an FT reaction. Specifically, a mixed gas of 1-butene and 1,3-butadiene, a mixed gas of n-butane and 1,3-butadiene, a mixed gas of cis-2-butene and 1,3-butadiene, trans-2- Mixed gas of butene and 1,3-butadiene, mixed gas of n-butane and 1-butene, mixed gas of n-butane and cis-2-butene, mixed gas of n-butane and trans-2-butene, isobutane and A mixed gas of isobutene, a mixed gas of cyclobutane and cyclobutene, a mixed gas of n-pentane and 1-pentene, a mixed gas of n-pentane and cis-2-pentene, a mixed gas of n-pentane and trans-2-pentene, n A mixed gas of pentane and 1,3-pentadiene, a mixed gas of n-pentane and 1,4-pentadiene, cyclopentane and A mixed gas of clopentadiene, a mixed gas of cyclopentene and cyclopentadiene, a mixed gas of cyclopentane and cyclopentene, a mixed gas of hexane and 1-hexene, a mixed gas of cyclohexane and cyclohexene, a mixed gas of cyclohexane and benzene, etc. A mixed gas of 1-butene and 1,3-butadiene, and a mixed gas of n-butane and 1,3-butadiene are more preferable.

The adsorption separation method for hydrocarbon mixed gas having 4 or more carbon atoms of the present invention is represented by the following formula (1):

(In the formula (1), P is ^a saturated hydrocarbon group which may have a substituent other than R ^a ; R ^a is a functional group having a coordination property to ^a metal ion; And when m is an integer of 2 or more, a plurality of R ^a may be the same or different from each other.)
By bringing the hydrocarbon mixed gas having 4 or more carbon atoms into contact with a metal complex containing a ligand represented by the formula (hereinafter also referred to as “first ligand”) and a metal ion. In the mixed gas, hydrocarbons having a specific degree of unsaturation or less are selectively adsorbed on the metal complex to separate hydrocarbons having a specific degree of unsaturation or less from hydrocarbons having a higher degree of unsaturation. This is an adsorption separation method for hydrocarbon mixed gas having 4 or more carbon atoms.

In the present specification, a plurality of things “may be the same as or different from each other” means that a plurality of things “may be the same or all may be different, Only may be the same ".

P of the first ligand is a group formed by removing m hydrogen atoms from a saturated hydrocarbon compound which may have a substituent other than R ^a , and is an acyclic hydrocarbon group, a ring It may be a formula hydrocarbon group or a bridged cyclic hydrocarbon group. P in such a first ligand is preferably a saturated hydrocarbon group having 12 or less carbon atoms which may be substituted with a halogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. Further, it is more preferably a saturated hydrocarbon group having 3 to 12 carbon atoms having a cyclic structure, which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms, and a saturated hydrocarbon having 1 to 3 carbon atoms. It is more preferably a saturated hydrocarbon group having 5 to 10 carbon atoms having a cyclic structure which may be substituted with a group. The present inventors presume that when the carbon number of the saturated hydrocarbon group (excluding substituents) exceeds the upper limit, the selectivity of hydrocarbons having a low degree of unsaturation during hydrocarbon adsorption tends to decrease. To do.

Specific examples of the saturated hydrocarbon compound in which m hydrogen atoms are removed to form P include acyclic hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, Decane, cyclic hydrocarbon group, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, decalin, bridged cyclic hydrocarbon group, [2.2.2] -bicyclooctane, adamantane Are preferred, cyclohexane, decalin, [2.2.2] -bicyclooctane and adamantane are more preferred, and cyclohexane and adamantane are even more preferred.

R ^a of the first ligand may be a functional group having a coordination property to a metal ion, and includes “—CO ₂ ⁻ ”, “—CS ₂ ⁻ ”, “—C (═O) S ^−. , “—C (═O) N (R ^A ) ⁻ ”, “—SO ₃ ⁻ ”, “—PO ₄ (R ^A ) ⁻ ”, “—C≡N”, “—S ⁻ ”, “— Examples thereof include a group represented by any one selected from the group consisting of “O ⁻ ” and “—NH ⁻ ”. Among them, since the obtained metal complex easily forms an ordered structure, “—CO ₂ ⁻ ”, “—CS ₂ ⁻ ”, “—C (═O) S ⁻ ” and “—C (═O)” are used. ^A group represented by any one selected from the group consisting of “N (R ^A ) ⁻ ” is preferable, and a group represented by “—CO ₂ ⁻ ” is more preferable. Here, R ^A is a hydrogen atom or an alkyl group having 4 or less carbon atoms.

M of the first ligand may be an integer of 1 to 4, but a low-dimensional metal complex (the description of the low-dimensional metal complex will be described later) can be easily obtained. Since expression can be expected, it is preferably an integer of 1 to 2, and more favorable selective adsorption characteristics are exhibited, and there is a tendency that excessive low pressure (for example, less than 5 kPa) is not required to recover the adsorbed gas. More preferably 1. When m is an integer of 2 or more, a plurality of ^Ra may be the same or different from each other.

P of the first ligand may have a substituent other than ^Ra , and when the number of substituents is 2 or more, these substituents are the same as each other. May be different. Examples of the substituent other than R ^a include a halogen atom and a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted with a halogen atom. Such a saturated hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and more preferably one having 1 to 3 carbon atoms which may be substituted with a halogen atom. A saturated hydrocarbon group, more preferably an unsubstituted saturated hydrocarbon group having 1 to 3 carbon atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, a fluorine atom and a chlorine atom are preferable, and a fluorine atom is most preferable.

Wherein when the substituent other than R ^a is optionally substituted saturated hydrocarbon group by a halogen atom, a substituent other than the R ^a is, which may be linear or branched or cyclic, cyclic In some cases, it may be monocyclic or polycyclic. Among the substituents other than ^Ra , the saturated hydrocarbon group having 1 to 6 carbon atoms includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a sec-butyl group. Tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethyl Examples thereof include a butyl group, 2,3-dimethylbutyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group.

If the P has a substituent other than R ^a, wherein from the viewpoint of synthesis of the first ligand of the precursor becomes easier, the substituent other than R ^a is a methyl group, an ethyl group, n- propyl Group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group are more preferable, methyl group, ethyl group, n-propyl group An isopropyl group, a cyclopentyl group, and a cyclohexyl group are more preferable, and a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are particularly preferable. Most preferred is a methyl group. The metal complex may contain one of the first ligands alone or in combination of two or more.

The metal ion contained in the metal complex may be an ion of an arbitrary metal element, but is preferably an ion of a metal element selected from Groups 2 to 13 of the periodic table.

As such metal ions, the synthesis of metal complexes is relatively easy, so magnesium, aluminum, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, strontium, yttrium. More preferred is an ion of at least one metal selected from the group consisting of niobium, molybdenum, ruthenium, rhodium, cadmium, barium, lanthanum, tantalum and tungsten. As said metal complex, 1 type in the said metal ion may be included independently, or 2 or more types may be included in combination.

Further, as such metal ions, since the metal salt as a raw material is relatively inexpensive, the group consisting of magnesium, aluminum, calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc At least one metal ion selected from is more preferable, and since the synthesis of the metal complex is relatively easy, at least one selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper and zinc Metal ions are particularly preferred. Furthermore, as such a metal ion, since the synthesis | combination of a metal complex is very easy, the ion of copper, zinc, or cobalt is preferable, the ion of copper or cobalt is more preferable, and the ion of copper is further more preferable.

The metal ions are usually 1 to 7 valent cations. The cation is preferably divalent to hexavalent, more preferably divalent to tetravalent, and even more preferably divalent to trivalent since it is necessary to form a metal complex with a plurality of ligands. And most preferably it is divalent.

The metal complex used in the present invention includes, in addition to the first ligand, “a hetero atom having 2 to 4 atoms (for example, at least one element selected from the group consisting of N, O and S”). And a second ligand that satisfies both the conditions of “a heterocyclic compound not containing a double bond”.

The second ligand may be a monocyclic group, a condensed ring group, or a group to which a monocyclic group is linked. Triethylenediamine (1,4-diazabicyclo [2.2 .2] octane), piperazine, 2,5-dimethylpiperazine, 3,3′-bipiperidine, 4,4′-bipiperidine, 1,3-di- (4-piperidyl) propane, hexamethylenetetramine, 1,4- Examples include dioxane and 1,4-dithiane, and one of these may be used alone, or two or more may be used in combination. As such a second ligand, at least one selected from the group consisting of triethylenediamine, piperazine, 4,4′-bipiperidine, and hexamethylenetetramine is used because the stability of the metal complex can be further improved. Preferably, triethylenediamine or piperazine is more preferable, and triethylenediamine is most preferable.

In addition to the first ligand, the metal complex used in the present invention has the following formula (2):

(In the formula (2), Q is an R ^a substituent other than may have an unsaturated hydrocarbon group; R ^a and m R ^a and each of the first in the ligand independently It is synonymous with m.)
May further contain a third ligand represented by:

When such a third ligand is included, the absolute difference between the number of carbon atoms in the P structure of the first ligand and the number of carbon atoms in the Q structure of the third ligand The value is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and further preferably an integer of 0 to 2. When this difference exceeds the upper limit, the present inventors infer that the selectivity of hydrocarbons with a low degree of unsaturation during hydrocarbon adsorption tends to decrease.

Q of the third ligand is a group formed by removing m hydrogen atoms from an unsaturated hydrocarbon compound which may have a substituent other than ^Ra , and is an acyclic hydrocarbon group. Or a cyclic hydrocarbon group. Q of such a third ligand is preferably an unsaturated hydrocarbon group having 12 or less carbon atoms, which may be substituted by a halogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. . Further, it is more preferably an unsaturated hydrocarbon group having 3 to 12 carbon atoms having a cyclic structure, which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms, and a saturated hydrocarbon group having 1 to 3 carbon atoms. It is more preferably an unsaturated hydrocarbon group having 5 to 10 carbon atoms having a cyclic structure, which may be substituted with a hydrogen group.

Specific examples of the unsaturated hydrocarbon compound in which m hydrogen atoms are removed to form Q include butene, pentene, hexene, heptene, octene, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclopentadiene. 1,2,3,4-tetrahydronaphthalene, benzene, naphthalene, anthracene, etc., preferably cyclopentene, cyclohexene, cycloheptene, cyclopentadiene, benzene, naphthalene, more preferably cyclohexene, benzene, naphthalene. . More preferred is benzene.

Q of the third ligand may have a substituent other than R ^a , and a preferable example thereof is a substituent other than R ^a in P of the first ligand. Synonymous with example. Moreover, as said metal complex, 1 type in the said 3rd ligand may be included independently, or 2 or more types may be included in combination.

In the present invention, regarding the quantitative ratio of the metal ions and the respective ligands contained in the metal complex, the selectivity of hydrocarbons due to the degree of unsaturation during hydrocarbon adsorption is further improved or more suitable. From the viewpoint of being applicable to the recovery of gas (hydrocarbon) having adsorbed pressure, it is preferable that the following relationships are satisfied.

That is, first, regarding the metal ion and the first ligand contained in the metal complex, the molar ratio represented by [metal ion]: [first ligand] is 1.0: 0. The range is preferably 5 to 1.0: 4.0, more preferably 1.0: 0.8 to 1.0: 3.0, and 1.0: 1.0 to 1 More preferably, it is in the range of 0.0: 2.0.

Moreover, when the said metal complex further contains the said 3rd ligand in addition to the said 1st ligand, about the said metal ion, the said 1st ligand, and the said 3rd ligand, [ The molar ratio represented by [metal ion]: [first ligand + third ligand] is preferably in the range of 1.0: 0.5 to 1.0: 4.0, The range is more preferably 1.0: 0.8 to 1.0: 3.0, and still more preferably 1.0: 1.0 to 1.0: 2.0.

Furthermore, the ratio of the third ligand in the metal complex is 100: 0 to 20:80 in a molar ratio represented by [first ligand]: [third ligand]. A range is preferable. When P of the first ligand is composed of an acyclic hydrocarbon group or a cyclic hydrocarbon group, the molar ratio represented by [first ligand]: [third ligand] is , 100: 0 to 50:50 is more preferable, and when P of the first ligand includes a bridged cyclic hydrocarbon group, [first ligand]: [third The molar ratio represented by the ligand] is preferably in the range of 100: 0 to 20:80.

Further, when the metal complex further contains the second ligand in addition to the first ligand, the metal ion and the second ligand contained in the metal complex ]: The molar ratio represented by [second ligand] is preferably in the range of 1.0: 0.2 to 1.0: 3.0, and 1.0: 0.3 to 1 The range is more preferably 0.0: 2.0, and still more preferably 1.0: 0.3 to 1.0: 1.0.

Further, in the present invention, from the viewpoint that the selectivity of hydrocarbons due to the degree of unsaturation at the time of hydrocarbon adsorption is more improved or that a more suitable pressure tends to be applied to recovering the adsorbed gas, Preferably, the complex is a metal complex that forms an integrated structure having a one-dimensional (linear) or two-dimensional (planar) dimensionality by being linked by an ionic bond and a coordinate bond. It is more preferable that the metal complex form an integrated structure. For example, in the one-dimensional integrated structure, the metal complex has a divalent metal ion, the first ligand having one functional group coordinated to the metal ion, and two heteroatoms. And the second ligand, the molar ratio represented by [metal ion]: [first ligand]: [second ligand] is 2: 4: 1. Tend to be able to get when. In the two-dimensional integrated structure, the metal complex includes a divalent metal ion, the first ligand having two functional groups coordinated to the metal ion, and two heteroatoms. And the second ligand, the molar ratio represented by [metal ion]: [first ligand]: [second ligand] is 3: 3: 1. Tend to be able to get when.

In this invention, in order to form the above-mentioned metal complex, it further has auxiliary ligands other than said 1st ligand, said 2nd ligand, and said 3rd ligand. Also good. Examples of such auxiliary ligands include triethylamine, water, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, acetone, Examples include pyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, and methyl ethyl ether, and water, N, N-dimethylformamide, and N, N-diethylformamide are preferable. These auxiliary ligands 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, since the separation efficiency between hydrocarbons having a low degree of unsaturation and hydrocarbons having a high degree of unsaturation can be further increased. The regular structure here means that at least one peak derived from the unit cell is observed at 15 ° (2θ) or less, preferably 12 ° or less, more preferably 10 ° or less by measurement of powder X-ray diffraction. The ordered structure is characterized, and the peak is preferably 3 ° (2θ) or more, more preferably 4 ° 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.

In the present invention, the metal complex is represented by the following formula (3):

(In Formula (3), P ¹ is a halogen atom or a saturated hydrocarbon group having 12 or less carbon atoms which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms, and m ¹ is 1 to 2) And the second ligand which is a heterocyclic compound containing a heteroatom having 2 to 4 atoms and no double bond. B and the following formula (4):

(In Formula (4), Q ¹ is a halogen atom or an unsaturated hydrocarbon group having 12 or less carbon atoms which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms; m ¹ is 1 to 2; Is an integer.)
It is preferable that the metal complex contains a third ligand C represented by the formula (I) and at least one metal ion selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper, and zinc. .

P ¹ of the ligand A is a saturated hydrocarbon having 12 or less carbon atoms which may be substituted with a halogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms in the P of the first ligand. A group formed by removing m hydrogen atoms from a compound, and a preferable example is as described in the first ligand. In addition, m ¹ of the ligand A is an integer of 1 to 2 out of m of the first ligand, and a low-dimensional compound is easily obtained, and better selective adsorption characteristics are expected. Since it is possible, it is preferably 1.

The metal ion contained in the metal complex is an ion of at least one metal selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper and zinc among the above metal ions. Such a metal ion is preferably a copper, zinc or cobalt ion, more preferably a copper or cobalt ion, and even more preferably a copper ion because the synthesis of the metal complex is extremely easy.

Moreover, the preferable example of the said ligand B is synonymous with the preferable example of said 2nd ligand. Q ¹ of the ligand C is an unsaturated carbon atom having 12 or less carbon atoms which may be substituted with a halogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms in the Q of the third ligand. A group obtained by removing m hydrogen atoms from a hydrogen compound, and a preferable example is as described in the third ligand.

In addition, the method for producing the metal complex used in the present invention is not particularly limited, but the ligand or a precursor thereof (the precursor of the first ligand and the second ligand as necessary). A ligand and / or a precursor of a third ligand) are reacted in a solvent with a metal salt comprising the metal ion (and, if necessary, a counter ion and crystal water) or a hydrate thereof. It is preferable to manufacture by. As the solvent used here, solvents such as water, methanol, ethanol, 2-propanol, tetrahydrofuran, acetone, acetonitrile, N, N-dimethylacetamide, N, N-diethylacetamide, chloroform and the like can be used. May further add another auxiliary ligand.

The functional groups in the precursor of the first ligand and the precursor of the third ligand include “—CO ₂ A”, “—CS ₂ A”, “—C (═O)”. “SA”, “—C (═O) N (R ^A ) A”, “—SO ₃ A”, “—PO ₄ (R ^A ) A”, “—C≡N”, “—SA”, “— Examples are groups represented by any one selected from the group consisting of “OA” and “—NHA”. Here, A is a hydrogen atom, an alkali metal atom or an ammonium ion which may be substituted with an alkyl group, preferably a hydrogen atom.

In the production of the metal complex, the molar ratio of the precursor of the first ligand, the second ligand, the precursor of the third ligand, and the metal salt to be reacted is the same as that of each metal salt. It is necessary to adjust according to the coordination ability of the ligand.

The preferred ratio of the precursor of the first ligand and the precursor of the third ligand to be reacted is the ratio of the first ligand contained in the metal complex to be produced to the above-mentioned It is also necessary to adjust based on the ratio with the third ligand. Further, the yield of the ligand or the precursor thereof to be reacted may be improved by making the ligand or the precursor thereof in excess of the stoichiometric ratio compared to the metal salt. In some cases, the amount of ligand used excessively can be reduced by carrying out the reaction at a high concentration.

The metal salt is preferably fluoride, chloride, bromide, nitrate, sulfate, perchlorate, acetate, tetrafluoroborate, tetraphenylborate, hexafluorophosphate, hexafluorosilicic acid. Salts, hydrates thereof, or combinations thereof. Nitrate, sulfate, perchlorate, acetate, tetrafluoroborate are preferred because they are highly available and the coordinating power of the counter anion is preferably low enough not to interfere with the intended reaction. , Hexafluorophosphates or hydrates thereof, more preferably nitrates, sulfates, acetates or hydrates thereof.

The reaction temperature at the time of reacting the ligand or the precursor thereof with the metal salt is preferably 0 ° C. or higher and 200 ° C. or lower, more preferably 10 ° C. or higher and 150 ° C. or lower. More preferably, it is 10 degreeC or more and 100 degrees C or less, More preferably, they are 20 degreeC or more and 60 degrees C or less. Such a reaction is preferably carried out under a pressure of 0.01 to 10 MPa, more preferably carried out under a pressure of 0.05 to 1 MPa, and even more preferably carried out under a pressure of 0.08 to 0.12 MPa. Usually, it is performed under normal pressure. The reaction time is usually 1 minute to 1 week, preferably 5 minutes to 120 hours.

As a reaction vessel used for such a reaction, an open vessel or a closed vessel such as an autoclave can be used. The reaction vessel can be heated by using a liquid or gaseous heat medium, 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 solvent may be adsorbed in the pores, it is preferable to dry the metal complex in order to remove these. As such drying, vacuum drying under room temperature or heating conditions is preferable.

When obtaining a metal complex having the second ligand, the precursor of the first ligand (and the precursor of the third ligand as necessary) and the metal salt It is also possible to adopt a stepwise synthesis method in which an intermediate is synthesized in advance, and then the second ligand is added to the intermediate to obtain the metal complex.

In the adsorption separation method of the present invention, the above-mentioned metal complex is mixed with the hydrocarbon mixture gas having 4 or more carbon atoms, that is, hydrocarbons having 4 or more carbon atoms, the same carbon number, and different degrees of unsaturation. By bringing the mixed gas containing at least two kinds into contact with each other, hydrocarbons having a specific degree of unsaturation or less in the mixed gas are selectively adsorbed on the metal complex. Such metal complexes may be one kind or may contain two or more kinds.

The mechanism of action when the metal complex is used as an adsorbent is not clear, but in the state where the metal complex of the present invention adsorbs hydrocarbons, the first arrangement expected to be a part of the pore surface is used. It is known that the ligand P does not have a π-electron system, and when the metal complex of the present invention has a second ligand, the second ligand does not have a π-electron. The present inventors presume that this may be one of the factors that exhibit an adsorption behavior different from that of the metal complex of the gas adsorbent. For this reason, the present inventors consider that the interaction between the metal complex and the hydrocarbon having a high degree of unsaturation does not become strong, and that a highly selective adsorption characteristic is exhibited with respect to a hydrocarbon having a low degree of unsaturation. .

In the present invention, by selectively adsorbing hydrocarbons having a specific degree of unsaturation in the mixed gas to the metal complex, hydrocarbons having a specific degree of unsaturation and other hydrocarbons, that is, And hydrocarbons having a degree of unsaturation greater than the specified degree of unsaturation. The specific degree of unsaturation can be set to the target degree of unsaturation by adjusting the temperature and / or pressure according to the type of mixed gas or metal complex as described later. Further, with respect to the mixed gas containing other hydrocarbons, the temperature and / or pressure conditions are further adjusted to selectively adsorb hydrocarbons having a specific degree of unsaturation below the metal complex, and Hydrogen and hydrocarbons with a higher degree of unsaturation can be further separated. In the present invention, for example, when adsorbing and separating a mixed gas of a straight-chain hydrocarbon having 4 carbon atoms, n-butane and a hydrocarbon having a higher degree of unsaturation (1-butene and 1,3- Or hydrocarbons with a degree of unsaturation below 1-butene (n-butane and 1-butene) and hydrocarbons with a higher degree of unsaturation (1,3-butadiene, etc.) can do.

The hydrocarbon obtained by separation by the adsorption separation method of the present invention may have a composition ratio different from that of the mixed gas before separation, but the separated product is preferably 80 mol% or more, and 90 mol% or more. Is more preferably 95% or more, and particularly preferably 98% or more.

Moreover, the hydrocarbon obtained by the recovery after the adsorption may be different from the mixed gas before the separation, but the recovered material is preferably 80 mol% or more, more preferably 90 mol% or more. Preferably, it is 95% or more, more preferably 98% or more.

In the adsorptive 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, as a specific process for separating hydrocarbons having a specific degree of unsaturation and hydrocarbons having a higher degree of unsaturation using the metal complex described above, for example, a pressure swing adsorption method (pressure fluctuation) Adsorption method: Pressure Swing Adsorption, Temperature Swing Adsorption Method (Temperature Swing Adsorption) and Permeation Separation Method (Membrane Separation), and Pressure Swing Adsorption Method are Preferred.

In the pressure swing adsorption method, the hydrocarbon complex gas having 4 or more carbon atoms is brought into contact with the metal complex under a first predetermined pressure (adsorption pressure), and the hydrocarbon having a specific degree of unsaturation or less is brought into contact with the metal complex. It is preferable to include an adsorption step for highly selectively adsorbing the metal complex. 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. Introduced into the space, hydrocarbons with a specific degree of unsaturation or less are adsorbed and concentrated on the metal complex with high selectivity, and the hydrocarbon depletion and unsaturation are larger than the specific degree of unsaturation. Hydrogen is 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 step (regeneration step), the pressure in the space where the metal complex that selectively adsorbs hydrocarbons having a specific degree of unsaturation is arranged is reduced to a desired desorption pressure, The hydrocarbons adsorbed on the complex are discharged from the space by desorbing from the metal complex.

Before the pressure is changed to the second predetermined pressure (desorption pressure), a small amount of hydrocarbon having a low degree of unsaturation is fed, so that the degree of unsaturation in the space is larger than the specific degree of unsaturation. Hydrogen may be replaced with a hydrocarbon having a lower degree of unsaturation.

Note that, in such a pressure swing adsorption method, the obtained hydrocarbon having a specific degree of unsaturation or lower or a hydrocarbon having a higher degree of unsaturation has a low purity, and the higher-purity hydrocarbon is obtained. When a device is required, the number of steps can be two or more. In that 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 object to be separated and the metal complex used, and the adsorption temperature is preferably 173 to 373K, more preferably 223 to 353K. More preferably, it is 253 to 353K, and most preferably 273 to 333K. The adsorption pressure varies depending on the working temperature and the metal complex used, but is preferably 0.04 kPa to 3 MPa, more preferably 3 kPa to 3 MPa, and even more preferably 10 kPa to 2 MPa. More preferably, it is 30 kPa to 2 MPa, and particularly preferably 100 kPa to 2 MPa.

The adsorption pressure includes adsorption of one hydrocarbon (hydrocarbon having a specific degree of unsaturation) and the other hydrocarbon (hydrocarbon having a degree of unsaturation greater than the specific degree of unsaturation). A pressure that increases the difference from the amount is employed, preferably a pressure that is 2 times or more, more preferably 5 times or more, and even more preferably 10 times or more. On the other hand, as the desorption pressure, a pressure at which the adsorption amount of hydrocarbons having the specified degree of unsaturation or less is 50% or less of the saturated adsorption amount is adopted, preferably 20% or less, more preferably 10%. Hereinafter, more preferably, a pressure of 5% or less is employed.

The desorption conditions of the adsorbed components in the pressure swing adsorption method are determined by the separation object and the metal complex used. The desorption pressure varies depending on the object to be separated, the operating temperature, and the metal complex used. However, if the gas recovery pressure is too low, a recompression load is required to store or use the gas. It is preferable to collect by. Such pressure is preferably 1 kPa or more, more preferably 2 kPa or more, and further preferably 5 kPa or more. More preferably, it is 10 kPa to 2 MPa, and particularly preferably 20 kPa to 1.5 MPa. According to the method for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms according to the present invention, it is adsorbed in a pressure region that can be used without requiring excessive pressure reduction (for example, less than 1 kPa or less than 5 kPa) in practice. The recovered gas can be recovered. Further, according to the method for adsorbing and separating hydrocarbon mixed gas having 4 or more carbon atoms of the present invention, it is possible to recover the adsorbed gas in a pressure region that does not require an excessively high pressure of 50 kPa or less (preferably 1 kPa to 50 kPa). it can. The desorption temperature is preferably 223 to 373K. In the desorption step, it is not always necessary to positively increase the temperature, but it is preferable to compensate for the latent heat necessary for desorption, and it may be preferable to adjust the temperature and keep the temperature.

Next, the hydrocarbon separation apparatus of the present invention suitable for carrying out the adsorption separation method of the present invention will be described. The separation apparatus includes a separation unit including the metal complex described above, and an introduction unit that introduces the hydrocarbon mixed gas having 4 or more carbon atoms into the separation unit, and contacts the mixed gas with the metal complex. By selectively adsorbing hydrocarbons having a specific degree of unsaturation in the mixed gas to the metal complex, hydrocarbons having a specific degree of unsaturation and hydrocarbons having a higher degree of unsaturation, and Is a device for separating the.

The hydrocarbon separation apparatus preferably further includes pressure control means for controlling the pressure of the space in which the metal complex is arranged in the separation means, and the pressure control means provides a first predetermined pressure. Under the condition that the mixed gas is brought into contact with the metal complex and the hydrocarbons having a specific degree of unsaturation or less are selectively adsorbed onto the metal complex so that the adsorption step can be performed. Is preferred.

Further, in that case, after selectively adsorbing hydrocarbons having a specific degree of unsaturation to the metal complex, the pressure is changed to a second predetermined pressure by the pressure control means, and adsorbed to the metal complex. It is preferable that the above-described desorption step can be performed by desorbing the hydrocarbon.

FIG. 1 shows a preferred embodiment of this hydrocarbon separation apparatus.

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. Further, a control means 4 (for example, PLC) is electrically connected to the compressor 2, the decompressor 3, and the valves V1 to V6 so that their operations can be controlled. Moreover, it is preferable that the separation apparatus of the present invention further includes a temperature control means capable of controlling the temperature.

When separating hydrocarbons using the separation apparatus shown in FIG. 1, for example, the following control is performed. 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). Subsequently, the raw material gas is introduced into the adsorption tank 1 by the compressor 2 under the pressure, and hydrocarbons having a specific degree of unsaturation or less are selectively adsorbed and concentrated on the metal complex, and the hydrocarbons are depleted. And hydrocarbons having a degree of unsaturation greater than the specified degree of unsaturation 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, thereby concentrating hydrocarbons having a specific degree of unsaturation or less adsorbed on the metal complex. The component is desorbed from the metal complex and discharged as a second product gas.

The preferred embodiment of the hydrocarbon separation apparatus has been described above. However, the present invention is not limited to the above-described embodiment. For example, when one of the compressor and the decompressor serves as both the introduction unit and the pressure control unit, Either one may be sufficient. 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.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. Analysis and evaluation in the following examples and comparative examples were respectively 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>
Equipment: 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) Single-crystal X-ray structure analysis The obtained single crystal was mounted on a gonio head, and single-crystal X-ray structure analysis was performed using a single-crystal X-ray diffractometer. Details of measurement and analysis conditions are shown below.
<Measurement and analysis conditions>
Equipment: Rigaku Corporation R-AXIS RAPID
X-ray source: MoKα (λ = 0.10773Å) 50 kV 100 mA
Detector: Imaging plate collimator: Φ0.8mm
Analysis software: Yadokari-XG 2009.

(3) Elemental analysis About carbon, hydrogen, and nitrogen, it quantified using the carbon, hydrogen, and nitrogen simultaneous measuring apparatus. Details of the measurement conditions are shown below.
<Measurement conditions>
Apparatus: MICRO CORDER JM10 manufactured by J Science Lab Co., Ltd.
Combustion temperature: 950 ° C
Burning time: 4 minutes.

(4) Measurement of adsorption / desorption isotherm Measurement was performed by a volume method using an automatic specific surface area / pore distribution measuring apparatus. 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: BELSORP-miniII manufactured by Nippon Bell Co., Ltd.
Pressure program: 5 kPa or less → 120 kPa → 10 kPa or less Equilibrium waiting time: 300 seconds.

[Cu ₂ (chc) ₄ ] and [Cu ₂ (bza) ₄ ] used in the following synthesis examples are as follows:
J. et al. Chem. Soc. 1965, p. 6466-6477
According to the method described in 1. Structural formulas of [Cu ₂ (chc) ₄ ] and [Cu ₂ (bza) ₄ ] are shown below.

The structural formula of [Cu ₂ (adc) ₄ (H ₂ O) ₂ ] used in the following synthesis examples is shown below.

(Synthesis Example 1)
Under air, 0.250 g (0.395 mmol) of [Cu ₂ (chc) ₄ ] was added to 50 mL of methanol, and the mixture was stirred at 298 K for 30 minutes. Then, 1,4-diazabicyclo [2.2.2] octane 047 g (0.415 mmol) was added. Then, it stirred at 298K for 24 hours. The deposited metal complex was collected by suction filtration, washed with methanol, and further dried at 298K and 5 Pa for 2 hours to obtain 0.2454 g (yield 83%) of the target 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: cyclohexanecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 4: 1.
Measured value C: 52.68, H: 7.41, N: 3.25 (%)
Theoretical value C: 54.60, H: 7.55, N: 3.75 (%).

In addition, it is thought that the structure (one-dimensional structure) of the metal complex obtained in Synthesis Example 1 has a structure as shown in the following structural formula.

(Synthesis Example 2)
Under air, 70 mL of a 5: 1 chloroform: methanol solution was added to 0.284 g (0.45 mmol) of [Cu ₂ (chc) ₄ ], and the mixture was dissolved by stirring at 298 K for 5 minutes. Subsequently, 10 mL of a solution of chloroform: methanol 5: 1 was added to 0.030 g (0.05 mmol) of [Cu ₂ (bza) ₄ ] and dissolved by stirring at 298 K for 5 minutes. Solution B was added to Solution A, and the mixture was stirred at 298 K for 10 minutes, 0.056 g (0.5 mmol) of 1,4-diazabicyclo [2.2.2] octane was added, and the mixture was stirred at 298 K for 24 hours. The deposited metal complex was collected by suction filtration, washed with chloroform, and further dried at 298 K and 5 Pa for 2 hours to obtain 0.3129 g (yield 83%) 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 as follows: copper ion: cyclohexanecarboxylate ion: benzenecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 3.6. : 0.4: 1.
Actual measurement C: 54.47, H: 7.04, N: 3.61 (%)
Theoretical value C: 54.78, H: 7.25, N: 3.76 (%).

(Synthesis Example 3)
Under atmosphere, 60 mL of a solution of chloroform: methanol 5: 1 was added to 0.253 g (0.4 mmol) of [Cu ₂ (chc) ₄ ] and dissolved by stirring at 298 K for 5 minutes. Subsequently, 15 mL of a solution of chloroform: methanol 5: 1 was added to 0.061 g (0.1 mmol) of [Cu ₂ (bza) ₄ ], and the mixture was dissolved by stirring at 298 K for 5 minutes. Solution B was added to Solution A, and the mixture was stirred at 298 K for 10 minutes, 0.056 g (0.5 mmol) of 1,4-diazabicyclo [2.2.2] octane was added, and the mixture was stirred at 298 K for 24 hours. The precipitated metal complex was collected by suction filtration, washed with chloroform, and further dried at 298 K and 5 Pa for 2 hours to obtain 0.2913 g (yield 78%) of the target 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 as follows: copper ion: cyclohexanecarboxylate ion: benzenecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 3.2 : 0.8: 1.
Measured value C: 54.63, H: 6.89, N: 3.68 (%)
Theoretical value C: 54.96, H: 6.94, N: 3.77 (%).

(Synthesis Example 4)
Under air, 51 mL of a solution of chloroform: methanol 5: 1 was added to 0.242 g (0.38 mmol) of [Cu ₂ (chc) ₄ ] and dissolved by stirring at 298 K for 5 minutes. Subsequently, 12 mL of a 5: 1 chloroform: methanol solution was added to 0.012 g (0.02 mmol) of [Cu ₂ (bza) ₄ ], and the mixture was dissolved by stirring at 298 K for 5 minutes. Solution B was added to Solution A, and the mixture was stirred at 298 K for 10 minutes, 0.045 g (0.4 mmol) of 1,4-diazabicyclo [2.2.2] octane was added, and the mixture was stirred at 298 K for 24 hours. The precipitated metal complex was collected by suction filtration, washed with chloroform, and further dried at 298 K and 5 Pa for 2 hours to obtain 0.2312 g (yield 77%) 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: cyclohexanecarboxylate ion: benzenecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 3.8. : 0.2: 1.
Measured value C: 54.23, H: 7.40, N: 3.79 (%)
Theoretical value C: 54.69, H: 7.40, N: 3.75 (%).

(Synthesis Example 5)
Under air, 54 mL of a solution of chloroform: methanol 5: 1 was added to 0.211 g (0.33 mmol) of [Cu ₂ (chc) ₄ ], and the mixture was dissolved by stirring at 298 K for 5 minutes. Subsequently, 16 mL of a solution of chloroform: methanol 40: 1 was added to 0.073 g (0.083 mmol) of [Cu ₂ (adc) ₄ (H ₂ O) ₂ ] and dissolved by stirring at 298 K for 5 minutes. Was solution B. Solution B was added to Solution A, and the mixture was stirred at 298 K for 10 minutes, 0.046 g (0.413 mmol) of 1,4-diazabicyclo [2.2.2] octane was added, and the mixture was stirred at 298 K for 24 hours. The precipitated metal complex was collected by suction filtration, washed with chloroform, and further dried at 298 K and 5 Pa for 2 hours to obtain 0.2259 g (yield 69%) of the target 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. As a result of elemental analysis, the composition ratio (molar ratio) was as follows: copper ion: cyclohexanecarboxylate ion: adamantanecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 3.4. : 0.6: 1.
Measured value C: 56.23, H: 7.60, N: 3.65 (%)
Theoretical value C: 56.11, H: 7.55, N: 3.60 (%).

(Synthesis Example 6)
Under atmosphere, 56 mL of a solution of 5: 1 chloroform: methanol was added to 0.255 g (0.4 mmol) of [Cu ₂ (chc) ₄ ] and dissolved by stirring at 298 K for 5 minutes. Subsequently, 42 mL of a solution of chloroform: methanol 5: 1 was added to 0.184 g (0.3 mmol) of [Cu ₂ (bza) ₄ ] and dissolved by stirring at 298 K for 5 minutes. Furthermore, 42 mL of a solution of chloroform: methanol 40: 1 was added to 0.264 g (0.3 mmol) of [Cu ₂ (adc) ₄ (H ₂ O) ₂ ] and dissolved by stirring at 298 K for 5 minutes. C. Solution B and solution C were added to solution A, and the mixture was stirred at 298 K for 10 minutes, and then 0.14 g (1.0 mmol) of 1,4-diazabicyclo [2.2.2] octane was added and stirred at 298 K for 24 hours. The deposited metal complex was collected by suction filtration, washed with chloroform, and further dried at 298 K and 5 Pa for 2 hours to obtain 0.6084 g (yield 75%) 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: cyclohexanecarboxylate ion: benzenecarboxylate ion: adamantanecarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 2: 1.6: 1.2: 1.2: 1.
Actual value C: 57.94, H: 6.74, N: 3.46 (%)
Theoretical value C: 58.02, H: 6.73, N: 3.49 (%).

(Synthesis Example 7)
Under air, 30 ml of N, N-dimethylformamide was added to 0.873 g (3.0 mmol) of cobalt nitrate hexahydrate and 0.500 g (3.0 mmol) of trans-1,4-cyclohexanedicarboxylic acid at 298 K for 5 minutes. Stir to dissolve. To this was added 30 ml of an acetonitrile solution of 0.146 g (1.3 mmol) of 1,4-diazabicyclo [2.2.2] octane, and the mixture was stirred at 298 K for 3 hours. The results of single crystal X-ray structural analysis of the precipitated crystals are shown below.
Monoclinic (C2 / c)
a = 30.8367 (15) Å
b = 9.7474 (4) Å
c = 18.4200 (8) Å
α = 90.0000 °
β = 11.8298 (15) °
γ = 90.0000 °
V = 4850.4 (4) ^{３ 3}
Z = 4
R = 0.0638
Rw = 0.2038
The composition of the skeleton of the obtained metal complex was cobalt ion: trans-1,4-cyclohexanedicarboxylate ion: 1,4-diazabicyclo [2.2.2] octane = 3: 3: 1. The obtained crystal structure is shown in FIG.

The precipitated metal complex was collected by suction filtration, and then dried at 298K and 5 Pa for 2 hours to obtain 0.151 g (yield 15.5%) of the target 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: cobalt ion: trans-1,4-cyclohexanedicarboxylate ion: 1,4-diazabicyclo [2.2.2] octane: N, N -Dimethylformamide = 3: 3: 1: 3.
Actual value C: 44.05, H: 6.07, N: 6.92 (%)
Theoretical value C: 45.98, H: 6.23, N: 6.87 (%).

(Comparative Synthesis Example 1)
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, 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. 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 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 (%).

Example 1
With respect to the metal complex obtained in Synthesis Example 1, adsorption isotherms of 1,3-butadiene and 1-butene at 273 K were measured by a capacitance method. The results are shown in FIG. 11. In the range of 30 to 110 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 6 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. This shows that 1,3-butadiene can be purified by selectively adsorbing and separating 1-butene from a mixed gas of 1,3-butadiene and 1-butene.

(Example 2)
With respect to the metal complex obtained in Synthesis Example 2, the adsorption isotherms of 1,3-butadiene, 1-butene and n-butane at 273 K were measured by the capacitance method. The results are shown in FIG. 12. In the range of 10 to 25 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 2 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. In addition, in the range of 10 to 25 kPa, the n-butane adsorption amount exceeded the 1,3-butadiene adsorption amount, and the value of n-butane adsorption amount / 1,3-butadiene adsorption amount was about 3 times the maximum. From the results, it was confirmed that the adsorption property has selectivity. As a result, 1-butene and n-butane are selectively adsorbed and separated from a mixed gas of 1,3-butadiene, 1-butene and n-butane, respectively, and 1,3-butadiene and 1-butene are purified. I understand that I can do it.

Example 3
With respect to the metal complex obtained in Synthesis Example 3, the adsorption isotherms at 273 K of 1,3-butadiene, 1-butene and n-butane were measured by the capacitance method. The results are shown in FIG. 13. In the range of 5 to 6 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 30 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. In the range of 4.6 to 6 kPa, the n-butane adsorption amount exceeds the 1,3-butadiene adsorption amount, and the n-butane adsorption amount / 1,3-butadiene adsorption amount is about 60 times maximum. From these results, it was confirmed that the adsorption characteristics have selectivity. As a result, 1-butene and n-butane are selectively adsorbed and separated from a mixed gas of 1,3-butadiene, 1-butene and n-butane, respectively, and 1,3-butadiene and 1-butene are purified. I understand that I can do it.

Example 4
For the metal complex obtained in Synthesis Example 4, the adsorption isotherms at 273 K of 1,3-butadiene, 1-butene and n-butane were measured by the capacitance method. The results are shown in FIG. 14. In the range of 16 to 32 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 4 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. In addition, in the range of 16 to 32 kPa, the n-butane adsorption amount exceeded the 1,3-butadiene adsorption amount, and the value of n-butane adsorption amount / 1,3-butadiene adsorption amount was about 7 times at maximum. From the results, it was confirmed that the adsorption property has selectivity. As a result, 1-butene and n-butane are selectively adsorbed and separated from a mixed gas of 1,3-butadiene, 1-butene and n-butane, respectively, and 1,3-butadiene and 1-butene are purified. I understand that I can do it.

(Example 5)
With respect to the metal complex obtained in Synthesis Example 5, the adsorption isotherms at 273 K of 1,3-butadiene, 1-butene and n-butane were measured by a volumetric method. The results are shown in FIG. 15. In the range of 11 to 14 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 5 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. In addition, in the range of 10 to 14 kPa, the n-butane adsorption amount exceeded the 1,3-butadiene adsorption amount, and the value of n-butane adsorption amount / 1,3-butadiene adsorption amount was about 20 times at maximum. From the results, it was confirmed that the adsorption property has selectivity. As a result, 1-butene and n-butane are selectively adsorbed and separated from a mixed gas of 1,3-butadiene, 1-butene and n-butane, respectively, and 1,3-butadiene and 1-butene are purified. I understand that I can do it.

(Example 6)
With respect to the metal complex obtained in Synthesis Example 6, adsorption isotherms of 1,3-butadiene and 1-butene at 273 K were measured by a capacitance method. The results are shown in FIG. 16. In the range of 11 to 14 kPa, the 1-butene adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of 1-butene adsorption amount / 1,3-butadiene adsorption amount is 5 at the maximum. Since it was about double, it was confirmed that the adsorption property has selectivity. This shows that 1,3-butadiene can be purified by selectively adsorbing and separating 1-butene from a mixed gas of 1,3-butadiene and 1-butene.

(Example 7)
With respect to the metal complex obtained in Synthesis Example 1, desorption isotherms of 1,3-butadiene and 1-butene at 303 K were measured by a capacitance method. The results are shown in FIG. 17, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessively low pressure in practice.

(Example 8)
With respect to the metal complex obtained in Synthesis Example 2, desorption isotherms of 1,3-butadiene, 1-butene and n-butane at 303 K were measured by a capacitance method. The result is shown in FIG. 18, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessive pressure reduction in practice.

Example 9
For the metal complex obtained in Synthesis Example 3, the adsorption isotherms of 1,3-butadiene, 1-butene and n-butane at 303 K were measured by the capacitance method. The results are shown in FIG. 19, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessively low pressure in practice.

(Example 10)
With respect to the metal complex obtained in Synthesis Example 4, the desorption isotherms of 1,3-butadiene, 1-butene and n-butane at 303 K were measured by the capacitance method. The results are shown in FIG. 20, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessively low pressure in practice.

(Example 11)
For the metal complex obtained in Synthesis Example 5, the desorption isotherms of 1,3-butadiene, 1-butene and n-butane at 303 K were measured by the capacitance method. The results are shown in FIG. 21, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessive pressure reduction in practice.

Example 12
With respect to the metal complex obtained in Synthesis Example 6, desorption isotherms of 1,3-butadiene and 1-butene at 303 K were measured by a capacitance method. The results are shown in FIG. 22, and the adsorbed gas can be recovered in a pressure region of 5 kPa or more that can be used without requiring excessive pressure reduction in practice.

(Example 13)
For the metal complex obtained in Synthesis Example 7, adsorption isotherms of 1,3-butadiene and n-butane at 273 K were measured by a volumetric method. The results are shown in FIG. 23. In the range of 0.04 to 1.2 kPa, the n-butane adsorption amount exceeds the 1,3-butadiene adsorption amount, and the value of n-butane adsorption amount / 1,3-butadiene adsorption amount is obtained. Shows a maximum of about 6 times, confirming that the adsorption characteristics are selective. This shows that 1,3-butadiene can be purified by selectively adsorbing and separating n-butane from a mixed gas of 1,3-butadiene and n-butane.

(Comparative Example 1)
With respect to the metal complex obtained in Comparative Synthesis Example 1, adsorption / desorption isotherms of 1,3-butadiene, 1-butene and n-butane at 273 K were measured by a volumetric method. The results are shown in FIG. 24. Only 1,3-butadiene having a high degree of unsaturation was adsorbed.

As explained above, according to the present invention, carbonization such as a mixed gas of 1,3-butadiene, 1-butene and n-butane has 4 or more carbon atoms, the carbon number is the same, and the degree of unsaturation is different. Even in a mixed gas containing at least two kinds of hydrogen, the degree of unsaturation is higher by selectively adsorbing hydrocarbons having a specific degree of unsaturation (for example, 1-butene and n-butane). It is possible to purify hydrocarbons (eg 1,3-butadiene). Further, the adsorbed hydrocarbon (gas) can be recovered in a temperature range (for example, 25 ° C.) that does not require an excessive temperature increase for practical use.

Therefore, the present invention is very useful as a technique for reducing the size of an apparatus for separating or purifying a hydrocarbon gas having 4 or more carbon atoms or for saving energy.

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, 5 ... Cobalt atom, 6 ... oxygen atom, 7 ... carbon atom, 8 ... hydrogen atom, 9 ... nitrogen atom.

Claims (9)

1. The metal complex containing a ligand represented by the following formula (1) (hereinafter sometimes referred to as “first ligand”) and a metal ion has 4 or more carbon atoms and has Contacting a mixed gas containing at least two kinds of hydrocarbons having the same and different degrees of unsaturation to selectively adsorb hydrocarbons having a specific degree of unsaturation among the mixed gases to the metal complex. A method for adsorbing and separating a hydrocarbon mixed gas having 4 or more carbon atoms.
   

   

   (In the formula (1), P is ^a saturated hydrocarbon group which may have a substituent other than R ^a ; R ^a is a functional group having a coordination property to ^a metal ion; And when m is an integer of 2 or more, a plurality of R ^a may be the same or different from each other.)
2. The P of the first ligand is a saturated hydrocarbon group having 3 to 12 carbon atoms having a cyclic structure, which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms. An adsorption separation method of a hydrocarbon mixed gas having 4 or more carbon atoms as described.
3. R ^{a of} the first ligand is composed of “—CO ₂ ⁻ ”, “—CS ₂ ⁻ ”, “—C (═O) S ⁻ ” and “—C (═O) NR ^A— ”. The carbon atom having 4 or more carbon atoms according to claim 1 or 2, which is a group represented by any one selected from the group (wherein R ^A is a hydrogen atom or an alkyl group having 4 or less carbon atoms). Adsorption separation method of hydrogen mixed gas.
4. The carbon according to any one of claims 1 to 3, wherein the metal ion is an ion of at least one metal selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper, and zinc. A method for adsorbing and separating a hydrocarbon mixed gas having a number of 4 or more.
5. The metal complex further includes a second ligand that is a heterocyclic compound that includes a heteroatom having 2 to 4 atoms and does not include a double bond. An adsorption separation method of a hydrocarbon mixed gas having 4 or more carbon atoms according to claim 1.
6. The adsorption of a hydrocarbon mixed gas having 4 or more carbon atoms according to any one of claims 1 to 5, wherein the metal complex further contains a third ligand represented by the following formula (2). Separation method.
   

   

   (In the formula (2), Q is an R ^a substituent other than may have an unsaturated hydrocarbon group; R ^a and m R ^a and each of the first in the ligand independently It is synonymous with m.)
7. In the metal complex, the molar ratio represented by [first ligand]: [third ligand] is in the range of 100: 0 to 20:80. The method for adsorption separation of a hydrocarbon mixed gas having 4 or more carbon atoms according to any one of the above.
8. The metal complex is
   A first ligand A represented by the following formula (3);
   A second ligand B which is a heterocyclic compound containing 2 to 4 heteroatoms and no double bond;
   A third ligand C represented by the following formula (4);
   Ions of at least one metal selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper and zinc;
   The method for adsorbing and separating a hydrocarbon mixed gas having 4 or more carbon atoms according to any one of claims 1 to 7, which is a metal complex containing.
   

   

   (In Formula (3), P ¹ is a halogen atom or a saturated hydrocarbon group having 12 or less carbon atoms which may be substituted by a saturated hydrocarbon group having 1 to 8 carbon atoms, and m ¹ is 1 to 2) (It is an integer.)
   

   

   (In the formula (4), Q ¹ is a halogen atom or a C 1-8 saturated hydrocarbon group which may be carbon number 12 or less substituted by unsaturated hydrocarbon group; m ¹ is the formula (3 ) It is synonymous with m ^{1 in the} inside.)
9. A separating means comprising a metal complex containing a ligand represented by the following formula (1) and a metal ion;
   An introduction means for introducing a mixed gas containing at least two hydrocarbons having 4 or more carbon atoms, the same carbon number, and different degrees of unsaturation into the separation means,
   By bringing the mixed gas into contact with the metal complex, hydrocarbons having a specific degree of unsaturation or less in the mixed gas are selectively adsorbed on the metal complex, and hydrocarbons having a specific degree of unsaturation or less are not adsorbed. Separating hydrocarbons with higher saturation,
   An apparatus for separating a hydrocarbon mixed gas having 4 or more carbon atoms.
   

   

   (In the formula (1), P is ^a saturated hydrocarbon group which may have a substituent other than R ^a ; R ^a is a functional group having a coordination property to ^a metal ion; And when m is an integer of 2 or more, a plurality of R ^a may be the same or different from each other.)

Images