JPH0217211B2 - - 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 reaches 9-10 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 particularly used for various wastewater treatment, blowing into various furnaces, medical purposes, etc. However, 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, this method using an oxygen complex has the disadvantage 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. In addition, Japanese Patent Application Laid-open No. 59-12707 states,
A method is disclosed in which oxygen is selectively permeated and separated 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 this membrane method, the ratio of oxygen and nitrogen permeation rates is large;
It is necessary that the permeation rate of the complex be high, and for this purpose, the rate of reaction between oxygen and the complex, the diffusion coefficient of the resulting oxygen complex, etc. are considered to be important factors. However, Chemical Reviews, Vol. 79, p. 139, cited in JP-A-59-12707, (1979)
), Canadian Journal of Chemistry
Many oxygen complexes have been discovered and studied, as shown in Vol. 54, p. 342 (1976), Journal of the American Chemical Society, Vol. 102, p. 3285 (1980), etc. However, in order to stably and reversibly adsorb and desorb oxygen, bulky ligands are required, and the molecules of oxygen complexes inevitably have to be 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. The present invention was achieved by discovering the groundbreaking fact that a complex obtained by reacting with a salt has the ability to reversibly adsorb and desorb oxygen despite its relatively low molecular weight. That is, the present invention uses (A) a Co salt and (B) an amine compound or a derivative thereof having a unit of the general formula (-NH- _CH2 - _CH2 - _CH2 ) _-o (wherein n is an integer of 3 or more). The present invention relates to an oxygen selective separation material made of a reaction product obtained by contact. In addition, in order to obtain the above oxygen selective separation material, contact (A)
and (B) in the presence of an axial base, or
It is obtained by adding an axial base to the reaction product of (A) and (B). The present invention also relates to a gas selective permeable membrane containing these oxygen 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. As the Co salt of (A), the (-NH-CH ₂ -CH _2
-CH2 ) _-o (n is an integer of 3 or more) units or derivatives thereof, or anything that forms a complex with the various axial bases to be added may be used, especially Examples include, but are not limited to, the following Co compounds. That is, cobalt oxide, cobalt hydroxide, halides such as cobalt fluoride, cobalt chloride, cobalt bromide, and cobalt iodide, and 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 tetrafluoroborate, cobalt oxalate, cobalt tartrate, and cobalt acetate, and their hydrates, and double salts such as cobalt alum,
Examples include organic cobalt compounds such as cobaltocene, but the valence of cobalt can be arbitrarily selected. Among the above cobalt salts, divalent cobalt salts are preferred, and inorganic salts are particularly preferred. (B) Amine compounds having the unit (-NH-CH ₂ -CH ₂ -CH ₂ ) _-o (n is an integer of 3 or more) include all substances that have such a chemical structure in the molecule. . The range of n is 3 to 100,000, preferably 3 to 10,000, most preferably 3 to 1,000. Examples of such compounds include the following compounds. That is, the above amine compound is converted into X(-NH
-CH ₂ -CH ₂ -CH ₂ )- _o As Y, X and Y are not particularly limited, but for example, X is a hydrogen atom, Y
Compounds having amino groups at both ends of the molecule where is represented by an amino group include tripropylenetetramine, tetrapropylenepentamine, pentapropylenehexamine, hexapropyleneheptamine,
Examples include oligopropylene imine and polypropylene imine. As a compound in which X has 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 ^- , -NR ^- , -NR ₂ (However, R is H and an organic group)
Compounds having functional groups such as H(-NH
−CH ₂ −CH ₂ −CH ₂ )− ₃ OH, H(−NH−CH ₂ −
_CH2 − _CH2 ) ₋₃ NHR, H(−NH− _CH2 − _CH2 − _CH2 ) ₋₃ N( _CH3 ) ₂ , H(−NH− _CH2 − _CH2 − _CH2 ) ₋₃ NHCO ^- −C ₁₇ H ₃₅ etc. In addition, when n is an integer of 4 or more, in addition to the above functional groups, -F, -Cl, -Br,
-I, -R (where R is _an organic group) are exemplified, H(-NH- _CH2 - _CH2 - _CH2 ) _{-4NHCH2-
CH2CH2FH} (-NH- _{CH2 - CH2} - _CH2 )-
₄ NHCH ₂ CH ₂ CH ₂ OH H (-NH-CH ₂ -CH ₂ -CH ₂ )- ₄ NHCH ₂ CH ₂ -
_CH2CH3H (-NH _{- CH2} - _{CH2 -CH2 ) -4NH} - _CH2CH2-
Examples include CH ₂ (-polystyrene). Even when X is an organic group, Y can have the same functional group as mentioned above. Specific examples include CH ₃ (-NH-CH ₂ -CH ₂ -CH ₂ )- ₃ NH ₂ , C ₆ H ₅ ( −NH−CH ₂ −CH ₂ −CH ₂ )− ₃ NH ₂ , C ₃ H ₇ (−NH−CH ₂ −CH ₂ −CH ₂ )− ₃ NH(CH ₃ ), CH ₃ (−NH−CH ₂ −CH ₂ −CH ₂ ) − ₃ N(CH ₃ ) ₂ , C ₁₇ H ₃₃ (−NH−CH ₂ −CH ₂ −CH ₂ )− ₃ NH(CH ₃ ), C ₁₅ H ₃₁ (−NH−CH ₂ −CH ₂ −CH ₂ )− ₃ NH−
C ₁₅ H ₃₁ , (Polystyrene) [(-NH-CH ₂ CH ₂ CH ₂ )-
₃ NH ₂ ] ₅₀ , (Polyurethane) (-NH-CH ₂ -CH ₂ -CH ₂ )-
Examples include ₄ NH (-polyurethane). Furthermore, when n is an integer of 4 or more, examples of Y include -F, -Cl, -Br, -I, -R, (where R is an organic group), and CH ₃ (-NH-CH ₂ -CH ₂ - CH ₂ ) ₋₄ F, CH ₃ (−NH−CH ₂ −CH ₂ −CH ₂ ) ₋₄ CH ₃ , CH ₃ (−NH−CH ₂ −CH ₂ −CH ₂ ) ₋₄ CH=CH _2, etc. Examples include compounds. 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
Derivatives of amine compounds having units of (n is an integer of 3 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. Similarly, compounds obtained by partially eliminating hydrogen. It means a compound having a saturated 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
-CH=CH)- does not mean only compounds having repeating units of substituted or dehydrogenated products such as _o , but for example when n=3 (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 explanation was given as an example when n=3, the same applies when 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 3 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 (Q _O2 /Q _N2 ). The amount of gas absorbed was measured as follows. That is, a predetermined amount of the selective separation material or its solution was poured into a glass container with a known volume, and then the inside of the container was depressurized and degassed. After sufficient degassing, the gas to be measured was introduced while the container was maintained at 23°C, and the amount absorbed was measured using a gas burette. To measure the absorption amount in a solution state, the absorption amount of the solvent used alone was measured as a blank, and this was subtracted to determine the absorption amount of the separating agent. Example 1 (a) Preparation of separation agent 2.6 ml of tripropylenetetramine in a 50 ml flask
ml and 1.75g of cobalt thiocyanate,
When stirred under nitrogen, the reaction generates a slight exotherm.
After 10 minutes, add dimethyl sulfoxide (hereinafter simply
After adding 20 ml of DMSO and heating to 40°C for 2 hours, a deep red homogeneous solution was obtained. (b) Measurement of gas permeation rate Separation agent 10 prepared in (a) was placed in the gas permeation measurement cell.
ml was taken out and air was circulated at a rate of 0.5/min. Next, the secondary side pressure was adjusted to 2 mmHg, and the permeated gas was analyzed by gas chromatography, and it was found that the oxygen concentration was 50.1%. Also, the oxygen permeation rate Q _O2 at this time is 2.2×10 ^-6 and α is
It was 3.8. Example 2 (a) Preparation of separation agent 2.6 ml of tripropylenetetramine and 1.75 g of cobalt thiocyanate were prepared in exactly the same manner as in Example 1.
After reacting, add 11.5 ml of 1-thylimidazole and react for 10 minutes, then add 10 ml of DMSO and heat at 40°C.
After stirring for 2 hours, a deep red solution was obtained. (b) Measurement of gas permeation rate When an air gas permeation test was conducted in the same manner as in (b) of Example 1, the oxygen concentration of the permeated gas was 84.1%.
It was hot. Moreover, Q _O2 at this time was 7.9×10 ⁻⁶ and α was 20. 1- as axial base
It was found that the use of methylimidazole not only increases α and significantly improves the selective separation, but also significantly increases the speed. (c) Measurement of gas absorption amount 5 ml of separation agent prepared in (a) in a 25 ml glass container
After sufficient degassing, the amount of oxygen absorbed was measured using a gas burette. The actual amount of oxygen absorbed is
It was determined by subtracting the amount of oxygen absorbed from the DMSO-1-methylimidazole mixture. As a result, the amount of oxygen absorbed was 47.9 ml, which corresponded to 0.79 oxygen molecules per cobalt atom. The separation agent was degassed under reduced pressure and the amount of oxygen absorbed was measured again and found to be 36.1 ml. This indicates that the separating agent reversibly adsorbs and desorbs oxygen. Examples 3 and 4 A separating agent was prepared in exactly the same manner as in Example 2(a) except that 2.5 g of cobalt acetate tetrahydrate and 3 ml of 1-methylimidazole were used instead of cobalt thiocyanate. A solution was obtained. Using this solution, gas permeation performance was measured in the same manner as in Example 1(b). The results are shown in Table 1,
It can be seen that the selective separation varies depending on the oxygen concentration of the measurement gas. Comparative Example 1 A separation material was prepared in exactly the same manner as in Example 3, except that 1.4 ml of dipropylene triamine was used instead of tripropylene tetramine, and a reddish-purple solution was obtained. The gas permeation performance using this separation material is shown in Table 1. (-NHCH ₂ CH ₂ CH ₂
) − _o shows that n is required to be 3 or more. Comparative Example 2 A separation material was prepared in exactly the same manner as in Example 2, except that 1.9 ml of tetraethylenepentamine and 4 ml of 1-methylimidazole were used instead of tripropylenetetramine, and a dark brown solution was obtained. The gas permeability performance is shown in Table 1 (-
It can be seen that NHCH ₂ CH ₂ ) _-o (n=4) has poor oxygen permselectivity. Example 5 Tripropylenetetramine in a 50ml flask
2.6 ml of toluene and 10 ml of toluene were charged, and 1.5 g of methyl iodide was gradually added dropwise under a nitrogen atmosphere, resulting in a violent exothermic reaction to obtain a triene-insoluble tripropylenetetramine-methyl derivative. After reacting at 40℃ for 2 hours, volatile components were distilled off under reduced pressure, and then the mixture was further distilled under reduced pressure.
Heating to 150°C gave a waxy solid. After adding 1.0 g of cobalt thiocyanate to this tripropylenetetramine-methyl derivative and reacting at 50°C for 2 hours, 15 ml of DMSO and 2 ml of 1-methylimidazole were added and heated to 70°C to obtain a deep red solution. . The gas permeation performance is shown in Table 1, and it can be seen that the selective separation performance was greatly improved by using the methyl derivative of tripropylenetetramine.

〔Effect of the invention〕

The oxygen 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 and (B) an amine compound having a unit of the general formula (-NH-CH ₂ -CH ₂ -CH ₂ ) _-o (wherein n is an integer of 3 or more), or An oxygen selective separation material consisting of a reaction product obtained by contacting the derivative. 2. In the separation material according to claim 1, the contact is carried out in the presence of an axial base, or
Or an oxygen selective separation material obtained by adding an axial base to the reaction product.