JPH0363415B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a gas selective separation material, particularly a gas selective separation material useful for separating oxygen. Oxygen is one of the most widely and widely used gases, and its applications include welding and cutting steel materials, iron manufacturing such as blowing into blast furnaces, open hearths, and converters, various metal refining applications, Used as a chemical raw material for manufacturing various petrochemical products, cement in the ceramic industry,
It is known for its uses, including the use of oxygen-enriched air, for manufacturing refractories, glass, etc., for activated sludge treatment of urban sewage and general industrial wastewater, and for medical purposes. The amount of oxygen used in Japan has reached 9 to 10 billion ^cubic meters, most of which is used for the iron and steel industry. [Prior Art] Industrial production of oxygen has been carried out since the beginning of this century by a cryogenic separation method. This method is considered to be the most suitable method when producing large amounts of oxygen using large-scale equipment, but it requires an extremely large amount of energy, and when used on-site, etc. It is necessary to once fill it into a pressure-resistant container and transport it, which results in a significant increase in cost. Also, as a method for producing oxygen on a relatively small to medium scale, a method has recently appeared that separates oxygen from air at high concentrations by utilizing the difference in the amount of nitrogen and oxygen adsorbed onto adsorbents such as zeolite, molecular sieves, and carbon. It is used for various wastewater treatment, blowing into various furnaces, medical purposes, etc., but the power consumption required to produce oxygen is high, and the cost of producing oxygen is high. In addition, as a special method, methods using metal complexes are being researched. It has been known for a long time that the cobalt salt of Schizuf's base combines with oxygen to form an oxygen complex, but the complex itself decomposes during repeated adsorption and desorption of oxygen, making it difficult to use as an economical system. Ta. Research to improve durability has continued, including research by the US Air Force in the late 1960s, and relatively durable products such as fluorine-substituted material called fluorine have been discovered. However, the method using this oxygen complex has the drawback that oxygen absorption must be carried out at around room temperature, such as 27 to 38°C, and oxygen release must be carried out at a high temperature, for example, 82°C, which requires raising and lowering the temperature for operation. It was hot. JP-A-59-12707 discloses a method for selectively permeating and separating oxygen from the air using a membrane in which a solution containing an oxygen complex is held on a porous membrane support. In this method, oxygen can be continuously separated using the pressure difference on both sides of the membrane while keeping the temperature constant. In such a membrane method, it is necessary that the ratio of oxygen and nitrogen permeation rates is large, and the oxygen permeation rate is high.
For this purpose, important factors include the rate of reaction between oxygen and the complex and the diffusion coefficient of the resulting oxygen complex. However, Chemical Reviews, Vol. 79, p. 139, cited in the above-mentioned JP-A-59-12707,
(1979), Canadian Journal of Chemistry, Vol. 54, p. 3424 (1976), Journal of Chemistry, Vol.
The American Chemical Society Volume 102
3285 (1980), etc., although many oxygen complexes have been discovered and studied, bulky ligands are still required to stably and reversibly adsorb and desorb oxygen. was required, and the molecules of oxygen complexes had to inevitably become large molecules. With this, a large diffusion coefficient cannot be expected. On the other hand, various cobalt complexes having relatively small molecular weight ligands have been studied, but to date no substance that reversibly adsorbs and desorbs oxygen has been found. [Purpose of the Invention] We conducted extensive research with the aim of searching for complexes with relatively small ligands that adsorb and desorb oxygen quickly and reversibly. Although the amine compounds having the unit -CH ₂ -CH ₂ -CH ₂ )- _o (n is an integer of 2 or more) or the complexes obtained by reacting derivatives of these amine compounds have a relatively low molecular weight, It was previously discovered that it has the ability to reversibly adsorb and desorb oxygen. Furthermore, as a result of intensive studies on the separation materials obtained in this way, we found that when carbon dioxide is present as the (C) component in addition to the above (A) and (B) components, the performance of the gas selective separation materials obtained is dramatically improved. We have discovered the surprising fact that gas-selective separation materials have epoch-making performance. That is, the present invention provides (A) a Co salt, (B) an amine compound having a unit represented by the general formula (-NH- _CH2 - _CH2 - _CH2 ) _-o (n is an integer of 2 or more), or any of these. This invention relates to a gas selective separation material obtained by contacting a derivative of an amine compound and (C) a gas containing 0.04% by volume or more of carbon dioxide in the presence of an axial base. Furthermore, the present invention also relates to a gas selective separation material obtained by contacting (A), (B), and (C) in the presence of a mainly non-aqueous solvent. The present invention also relates to a gas selective permeable membrane containing these gas selective separation materials and a gas selective absorption liquid containing these gas selective separation materials. [Structure of the Invention] Next, the content of the present invention will be explained in detail. The cobalt salt of (A) is (B) an amine compound having a unit represented by the general formula (-NH- _CH2 - _CH2 - _CH2 ) _-o (n is an integer of 2 or more), or these amine compounds. The following Co compounds are preferred, although there are no limitations as long as they form a complex with derivatives of or various axial bases to be added. That is, halides such as cobalt oxide, cobalt hydroxide, cobalt fluoride, cobalt chloride, cobalt bromide, and cobalt iodide, as well as their hydrates, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt cyanide, and cobalt thiocyanate. , inorganic and organic acid salts such as cobalt perchlorate, cobalt periodate, cobalt tetrafluoroporate, cobalt oxalate, cobalt tartrate, and cobalt acetate, and their hydrates, as well as double salts of cobalt such as alum,
Examples include organic cobalt compounds such as cobaltocene, but the cobalt valence can be arbitrarily selected. Among the above cobalt salts, divalent cobalt salts are preferred, inorganic salts are particularly preferred, and Co(SCN) ₂ ,
_CoF2 , _CoCl2 , _CoBr2 , _CoI2 , Co( _ClO4 ) ₂ , Co
(BF ₄ ) ₂ is exemplified as the most preferred cobalt salt. Component (B) is an amine compound having a unit represented by the general formula (-NH- _CH2 - _CH2 - _CH2 ) _-o (n is an integer of 2 or more), and has such a chemical structure in its molecule. Including all substances that have The range of n is 2 to 100,000, preferably 2 to 10,000, most preferably 2 to 10,000.
A range of 1000 is selected. As such a compound,
The following compounds are exemplified. That is, assuming that the above amine compound is X(-NH- _CH2 - _CH2 - _CH2 ) _-oY ,
and Y are not particularly limited, but examples of compounds having amino groups at both ends of the molecule where X is a hydrogen atom and Y is an amino group include dipropylenetriamine, N,N'-bis-(3-aminopropyl ) Methylamine, N,N'-bis-(3-aminopropyl)phenylamine, tripropylenetetramine, tetrapropylenepentamine, pentapropylenehexamine, hexapropyleneptamine, oligopropyleneimine, and polypropyleneimine. As a compound where X is a hydrogen atom and Y has a constituent unit other than an amino group, Y is -COO ^- , -CRO,

[Formula] -O ^- , -OR, -CSS ^- , CRS,

[Formula] -S ^- , -SR, -CONHR, -NHCOR, -CN, -CH=N-, -C=N-, -NH ^- , -
Compounds having functional groups such as NR ^- , -NR ₂ (where R is H and an organic group) are exemplified, and H (-NH-CH _{2
-CH2- CH2} ) _-2OH ,H(-NH- _CH2 - _CH2-
CH2 ) _-2NHR , H(-NH- _CH2 - _CH2 - _CH2 ) _-2N
( _CH3 ) ₂ , H(-NH- _CH2 - _CH2 ^- _CH2 ) _-2NHCO-
−C ₁₇ H ₃₅ , etc. In addition, when n is an integer of 3 or more, in addition to the above functional group, -F,
-Cl, -Br, -I, -R (where R is an organic group) are exemplified, H(-NH- _CH2 - _CH2 - _CH2 ) _{-3NHCH2 - CH2-
CH2FH} (-NH-CH2 _{- CH2} - _CH2 )-
₃ NHCH ₂ CH ₂ CH ₂ OH H (-NH-CH ₂ -CH ₂ -CH ₂ )- ₃ NHCH ₂ CH ₂ -
_CH2CH3H (-NH _{- CH2} - _{CH2 - CH2} ) _-3NH - _CH2CH2-
Examples include CH ₂ (-polystyrene). Even when X is an organic group, Y can have the same functional group as mentioned above. As a specific example, CH ₃ (-
NH−CH ₂ −CH ₂ −CH ₂ )− ₂ NH ₂ , C ₆ H ₅ (−NH−
CH ₂ −CH ₂ −CH ₂ )− ₂ NH ₂ , C ₃ H ₇ (−NH−CH ₂ −
CH ₂ −CH ₂ ) − ₂ NH(CH ₃ ), CH ₃ (−NH−CH ₂ −
CH ₂ −CH ₂ ) − ₂ N(CH ₃ ) ₂ , C ₁₇ H ₃₃ (−NH−CH ₂ −
_CH2 − _CH2 ) _−2NH ( _CH3 ), _C15H31 ( _−NH − _CH2−
CH ₂ −CH ₂ )− ₂ NH−C ₁₅ H ₃₁ , (Polystyrene) [(——NH−CH ₂ CH ₂ CH ₂ )− ₂ NH ₂ ] ₅₀ , (Polyuthalene) (—NH−CH ₂ −CH Examples include ₂ - _CH2 ) _-3NH (-polyurethane). Furthermore, when n is an integer of 4 or more, -F, -Cl, -Br, -I, - as Y
R, (where R is an organic group) is exemplified, and CH ₃ (-NH-
CH ₂ −CH ₂ −CH ₂ ) − ₃ F, CH ₃ (−NH−CH ₂ −CH ₂
−CH ₂ )− ₃ CH ₃ , CH ₃ (−NH−CH ₂ −CH ₂ −CH ₂ )−
Examples include compounds such as ₃ CH=CH ₂ . Also general formula

[Formula] and

Examples of compounds include cyclic amines represented by [Formula] (where R represents an organic group and a difunctional group such as CO, NR', S, O, etc.)

【formula】

[Formula] can be given. Next, the above general formula (-NH- _CH2 - _CH2 - _CH2 ) _-o
A derivative of an amine compound having a unit (n is an integer of 2 or more) will be explained. The derivative mentioned here has the formula (-NH-CH ₂ -CH ₂ -
Compounds obtained by chemically bonding all or part of the H of CH ₂ ) _-o with other atoms, functional groups, oligomers, polymers, etc. Also obtained by partially eliminating hydrogen It means a compound having an unsaturated bond and a compound having a substituent other than the above H and an unsaturated bond at the same time. For more details, for example

[Formula] (A is a functional group substituted with H, etc.) or (-NH- _{CH 2} -CH ₂ =CH) - does not mean only compounds having a substituted or dehydrogenated repeating unit. , for example n=3
in the case of (However, A and B are functional groups substituted with H, etc.) (-NH-CH ₂ -CH ₂ -CH) (=N-CH ₂ CH ₂ -CH ₂
)(-NH-CH ₂ -CH ₂ -CH ₂ )- (-NH-CH ₂ -CH ₂ -CH ₂ )(-NH-CH ₂ -CH=
CH) (-NH-CH ₂ -CH ₂ -CH ₂ )- At least one H of the three repeating units
It means a structure in which H is substituted or in which H in at least one of the three repeating units is dehydrogenated. Although the above description has been made using the case where n=3 as an example, the same applies to the case where n is an integer of 4 or more. Also included are cyclic bodies in which two substituted functional groups, oligomers, polymers, etc. are bonded to each other at other ends. For example, such a structure is (However, E is a functional group substituted with H, etc.) Compounds having the following units are exemplified. When substituting or dehydrogenating (-NH- _CH2 - _CH2 - _CH2 ) _-o (n is an integer of 2 or more), the number of substituents and the number of unsaturated bonds are not limited. Examples of functional groups, oligomers, and polymers substituting H in the above general formula include the following. Functional groups include halogen atoms such as F, Cl, Br, and I, carboxyl groups, or metal salts thereof (-
COOH, -COOM), sulfonyl group ( _-SO3H ),
Sulfinyl group (-SO ₂ H), acid anhydride (-CO-
O-CO), oxycarbonyl group (-COOR), haloformyl group (-COX), carbamoyl group (-
CONH ₂ ), hydrazinocarbonyl group (-
CONHNH ₂ ), imide group (-CO-NH-CO-),
Amidino group

[Formula] Nitrile group (-CN), isocyano group (-NC), formyl group (-
CHO), carbonyl group (C=O), hydroxyl group (-
OH), alkoxy group (-OR), phenoxy group

〔Example〕

The content of the present invention will be explained below with reference to Examples. In the Examples of the present application, the gas permeation rate was measured as follows. That is, a flat membrane made of polytrimethylvinylsilane was installed as a base membrane in a cylindrical glass cell with an outer diameter of 45 mm, and a solution or slurry containing the selective separation material to be tested was injected onto the top of the membrane.
The permeation test gas was passed through with stirring. On the other hand, the permeation rate Q was determined by reducing the pressure below the base membrane (secondary side) and analyzing the amount of gas permeated within a certain period of time using gas chromatography. Note that Q in this example is a value measured at 30° C. unless otherwise specified, and its unit is cc/cm ² ·sec·cmHg. Further, α represents the velocity ratio of oxygen to nitrogen (Qo ₂ /QN ₂ ). Reference example 1 (a) Preparation of separation material Place tripropylenetetramine in a 50ml flask.
When 2.6 ml of cobalt thiocyanate and 1.75 g of cobalt thiocyanate are charged and stirred under nitrogen, a slight heat is generated and the reaction occurs. 1-methylimidazole 3.9 after 10 minutes
ml and reacted for 10 minutes, then added 10 ml of dimethyl sulfoxide (hereinafter referred to as DMSO) and heated at 40°C.
After stirring for 2 hours, a deep red homogeneous solution was obtained. (b) Measurement of gas permeation rate The separation material prepared in (a) was placed in the gas permeation measurement cell.
10 ml was taken out, and air (containing about 0.03% by volume of carbon dioxide gas) was passed through it at a rate of 0.5/min. Next, adjust the secondary pressure to 2 mmHg,
Analysis of the permeated gas by gas chromatography revealed that the oxygen concentration was 60.8%.
Further, the oxygen permeation rate Qo ₂ at this time was 2.3×10 ⁻⁶ and α was 5.9. Example 1 After measuring the gas permeation performance shown in Reference Example 1(b), the gas permeation performance was measured by flowing air mixed with 10% by volume of carbon dioxide gas at the same speed, and the oxygen concentration of the permeated gas was 91.8%. , Qo ₂ is 1.3×10 ^-6 and α is 37.9
It was hot. It was found that α can be significantly improved by increasing the concentration of carbon dioxide by mixing carbon dioxide. Example 2 After contacting the separation agent obtained in Reference Example 1 with carbon dioxide gas introduced at a flow rate of 30 ml/min for 10 minutes at room temperature, gas permeation performance was measured in the same manner as in Reference Example 1. The oxygen concentration of the permeated gas is 76.8%, Qo ₂ is 2.6×
10 ^-6 and α are 12.6, indicating that contact treatment with carbon dioxide gas particularly improves selectivity. Example 3 The reaction was carried out in exactly the same manner as in Reference Example 1 except that 4.2 ml of dipropylene triamine was used instead of tripropylene tetramine.
A deep red homogeneous solution was obtained. Using this separation material, the gas permeation performance by air was measured in the same manner as in Reference Example 1, and the results shown in Table 1 were obtained. Further, in the same manner as in Example 1, the gas permeation performance of air mixed with 10% by volume of carbon dioxide gas was measured. Display the results -
Shown in 1. It can be seen that α is improved by mixing carbon dioxide gas. Example 4 The reaction was carried out in exactly the same manner as in Reference Example 1(a) except that 1.3 g of cobalt chloride was used instead of cobalt thiocyanate, and a deep red homogeneous solution was obtained. Using this separation material, we measured the gas permeation performance with air in the same manner as in Reference Example 1(b) and the gas permeation performance with air mixed with carbon dioxide gas in the same manner as in Example 1, and the results shown in Table 1 were obtained. Ta. Comparative Example 1 A reaction was carried out in exactly the same manner as in Reference Example 1 except that 6 g of 4-dimethylaminopyridine was used instead of 1-methylimidazole.
A dark red homogeneous solution was obtained at °C. Using this separation material, gas permeation performance was measured in the same manner as in Reference Example 1(b), except that a mixed gas prepared from pure oxygen and pure nitrogen was used as the measurement gas and the measurement was performed at 40°C. The results are shown in Table 1, and it can be seen that both Qo ₂ and α are small in a system that does not contain carbon dioxide. Example 5 In the measurement of gas permeation performance in Comparative Example 1, air and air mixed with 10% by volume carbon dioxide were used as the measurement gas, and the secondary pressure was changed to 1.5 mmHg at 30
When measurements were carried out at ℃, the results shown in Table 1 were obtained.
It can be seen that the coexistence of carbon dioxide significantly improves Qo ₂ and α. Example 6 The reaction was carried out in exactly the same manner as in Comparative Example 1 except that 7.1 ml of ethyl benzoate was used instead of 4-dimethylaminopyridine, and a dark reddish-brown homogeneous solution was obtained. Reference example 1 using this separation material
The gas permeation performance with air and the gas permeation performance with air mixed with 10% by volume of carbon dioxide gas were measured in the same manner as in Example 1, and the results shown in Table 1 were obtained.

〔Effect of the invention〕

The gas selective separation material according to the present invention has particularly excellent oxygen separation ability and is therefore useful in a wide range of industrial fields.

Claims (1)

[Claims] 1 (A) Co salt, (B) an amine compound having a unit represented by the general formula (-NH-CH ₂ -CH ₂ -CH ₂ ) _-o (n is an integer of 2 or more), or A gas selective separation material obtained by contacting a derivative of these amine compounds and (C) a gas containing 0.04% by volume or more of carbon dioxide in the presence of an axial base. 2. A gas selective separation material according to claim 1, which is obtained by contacting (A), (B), and (C) in the presence of a primarily non-aqueous solvent.