JPH01194925A - Composition for separating gas - Google Patents

Abstract

PURPOSE:To recover CO at high yield by mixing a reactive mixture which is obtained by mixing copper compd. with benzoins and/or ascorbic acids in a solvent with another reactive mixture which is obtained by mixing palladium compd. with alkenes in the solvent and thereby preparing the composition for separating gas. CONSTITUTION:A reactive mixture A is obtained by mixing copper compd. such as copper formate with benzoins such as benzoin and/or ascorbic acids in a solvent such as N-methyl imidazole. Further a reactive mixture B is obtained by mixing palladium compd. such as PdCl2 with alkenes such as ethylene in the solvent such as acetonitrile. The composition for separating gas is obtained by mixing both reactive mixtures. CO is absorbed at high efficiency and separated from the other gasses by holding this composition for separating gas on a membrane.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides (a) a copper compound and benzoins and/or ascorbic acids in a solvent, particularly at least one of imidazoles, pyridines, and polyethylene polyamines. A reaction mixture obtained by mixing in a solvent, and/or a reaction product of the reaction mixture and oxygen, and (b) a copper compound in a reaction mixture obtained by mixing a palladium compound and an alkene in a solvent. , benzoins, ascorbic acids, imidazoles, pyridines, and polyethylene polyamines are bonded to or supported on a membrane or particulate polymer carrier.

[Conventional technology and its problems]

It has become an important technology in the chemical industry, such as in the purification of raw material gas and in the production of raw materials for the synthesis of various chemical products.

Methods such as cryogenic separation, absorption liquid method, adsorption method, and membrane method are used to separate and concentrate carbon monoxide from gas mixtures, and it is necessary to use high-quality materials as equipment materials. Construction costs are high. Furthermore, power consumption increases due to low temperature operation. Furthermore, in order to prevent blockage accidents within the equipment, it is necessary to install pretreatment equipment to completely remove impurities from the gas.

The absorption liquid method has long been practiced using hydrochloric acid acidic cuprous chloride aqueous solution or ammoniacal cuprous chloride aqueous solution as an absorption liquid for carbon monoxide. There were drawbacks such as high generation and construction costs. In recent years, an absorption liquid method called the C08ORB process in which a toluene solution of copper aluminum chloride is used as an absorption liquid for carbon monoxide has been developed and put into practical use. This method has the advantage that the purity of the separated and purified carbon monoxide is high because impurities in the gas, especially carbon dioxide gas, which needs to be removed by pretreatment in the above method, are not absorbed.

However, when it comes into contact with a mixed gas containing water, hydrogen sulfide, ammonia, etc., the copper chloride/aluminum chloride complex in the absorbent reacts irreversibly with these impurities, inhibiting the absorbent's ability to absorb carbon monoxide. . Also, - heating is required for desorption of carbon oxide from the absorption liquid.

Regarding adsorption methods, an adsorption method using zeolite as an adsorbent has recently been developed, and practical equipment has started operating for converter gas and the like. This method allows operation at room temperature and small-scale equipment, and compared to the conventional absorption liquid method, there is no problem of solvent evaporation and stable contact operation can be obtained. Since the difference in Thoughtful name. Also, in the case of zeolite, carbon dioxide gas is more easily adsorbed than carbon monoxide, so
This needs to be removed in the first stage. Furthermore, adsorption must be performed under pressure and desorption must be performed under reduced pressure, resulting in high power costs.

Finally, regarding membrane methods, various polymer membranes have been studied as separation membranes for gas mixtures. However, when only ordinary polymer membranes are used, carbon monoxide is mixed with other gases,
For example, it has low permeability compared to hydrogen. Therefore, for example, when hydrogen is separated from a gas mixture containing excess hydrogen by passing it through a membrane, the gas permeation coefficient is small, but when the membrane is liquid, the gas solubility coefficient and diffusion coefficient become large, and therefore the permeation coefficient becomes large. You can. Furthermore, if such a liquid membrane contains a substance that selectively and reversibly interacts only with a certain gas, it is possible to further increase the permeability of that gas. On the other hand, the selective performance of a membrane is given by the difference in mutual solubility of gases in the membrane and the difference in the diffusion rate of gases in the membrane, so that it selectively and reversibly interacts only with the above-mentioned specific gases. When the substance is included in the film,
The solubility of only the gas increases, and the selection performance can be dramatically increased.

Many examples are known of such membranes containing substances that selectively and reversibly interact only with certain gases. 7), Separation of olefins using silver nitrate aqueous solution (Special Publication No. 33-3/I≠2)
Separation of nitric oxide using a formamide solution of ferrous chloride (A, I Ch E Journal v
OL/A There was a drawback that a thick hydrochloric acid aqueous solution had to be used. Further, when the pressure is reduced on the secondary side (outflow side) of permeation, there is a problem that water vapor and hydrogen chloride gas permeate and mix with other gases.

As mentioned above, various methods for separating carbon monoxide have been developed, but each has its advantages and disadvantages, and improvements have been desired to address the problems.

The reaction mixture obtained by mixing a copper compound and benzoins and/or ascorbic acids in a solvent, especially a solvent containing at least one of imidazoles, pyridines, and polyethylene polyamines, is a gas, especially a carbon oxide separation and purification process. Furthermore, it has the property of preventing the oxidation of copper compounds that occurs in the presence of oxygen through the reducing action of benzoins and/or ascorbic acids, and reduces the ability to absorb carbon monoxide due to the oxidation of copper compounds. The inventors of the present invention have disclosed in Japanese Patent Application No. 62-0272/l, Japanese Patent Application No. 1.2-0.
272/7 is a method in which an alkene is oxidized with amardium (n) and the generated zero-valent palladium is returned to divalent palladium using a copper compound. In this reaction, oxidized copper is reduced to monovalent copper.

The present inventor has discovered that radium (
7) We further researched the possibility of using the above reaction using the 7/l'ken complex as a gas selective separation material, and investigated the possibility of using the above reaction using the 7/l'ken complex as a gas selective separation material.
In particular, if a reaction mixture of a palladium compound and an alkene is added to a reaction mixture obtained by using the solvent as a solvent containing at least one of imidazoles, pyridines, and polyethylene polyamines, it is possible to remove the copper compound once reduced by contact with oxygen. A substance that does not reduce the carbon monoxide absorption capacity of a reaction mixture of benzoins and/or ascorbic acids, is non-corrosive, is chemically mild, and is useful as a gas selective separation material using a reagent that is inexpensively available. Research aimed at developing gas-selective permeable membranes, gas-selective absorption liquids, and gas-selective adsorbents using these substances led to the development of a new separation technology.

[Means for solving problems]

The present invention provides a reaction mixture obtained by mixing a copper compound and benzoins and/or ascorbic acids in a solvent, and
b) A gas separation composition comprising a reaction mixture obtained by mixing a palladium compound and an alkene in a solvent.

The gas separation composition of the present invention is particularly effective for separating and purifying carbon oxide among gases, but is also thought to be effective for separating and purifying olefins, separating and removing oxygen, and the like.

First, the copper compound used as a component of the gas-selective separation material comprising the gas-selective absorption liquid and the gas-selective permeable membrane of the present invention will be explained. Conventional carbon monoxide absorption liquids mainly use monovalent copper salts.
DICTIONARYGthEdition (Mc
GRAW-HILL BOOK COMPANY)
Goo≠7~l-copper compounds and HANDB described on Hirota page
OOK of CHEMISTRY and PHYS
IC8j 7th Edition (CRCPRE
SS) B-/0ri~B-iiλ Copper compounds described on pages are exemplified.

Particularly desirable copper compounds include cuprous chloride, cupric chloride, cuprous bromide, ferric bromide, ferrous iodide, cuprous fluoride, cupric fluoride, and cuprous thiocyanate. - copper, cupric thiocyanate, cupric cyanide, cupric cyanide, cupric hydroxide,
Cupric perchlorate, cupric perchlorate, cupric periodate, cupric sulfate, cupric nitrate, cupric phosphate, cupric tungstate, cupric borofluoride, °Copper salts of various organic acids, such as cupric formate, cupric acetate, cupric propionate, cupric cealate, cupric tartrate, cupric citrate, cupric benzoate, palmitin cupric acid, cupric laurate, cupric salicylate, cupric oleate, cupric stearate,
Examples include cupric acetylacetone, glycerin derivatives, hydrates of the above-mentioned copper compounds, coordination compounds of ammonia, amines, pyridines and imidazoles, as well as oxides resulting from the reaction of the above-mentioned copper compounds with oxygen, etc. These may be used alone, provided that R1 represents hydrogen or a hydrocarbon group, R2 represents hydrogen, a hydrocarbon group, or an acetyl group, and the hydrogen of the phenyl group in the general formula may be substituted with another group). Indicates the compound represented, benzoin, hydrobenzoin, benzoin oxime, α-methylbenzoin, α
- Ethyl benzoin, benzine methyl ether, benzine ethyl ether, pentuine isopropyl ether, benzoin isobutyl ether, pentuine acetate, ≠-methoxybenzoin, 3'-bromo-≠-dimethylaminobenzoin, etc. When the amount of the gas-selective separation material is small, a range of preferably O0j moles to j moles, most preferably a range of 1 mole to 3 moles is selected.

Next, the ascorbic acids used in the present invention will be described. Generally, sugars can be used, but ascorbic acids are particularly preferred. The ascorbic acids referred to herein refer to compounds represented by the general formula %, and include any of the D-form, L-form, and DL-form. Specific examples include L-ascorbic acid, L-ascorbyl stearade, L-ascorhyluhalmitate, L+, ascorbyl civalmitate, potassium L-ascorbate, and sodium L-ascorbate. These may be used alone or in combination.

The ratio of ascorbic acids to copper compounds is not particularly limited, but if the ratio of ascorbic acids to copper compounds is small, the gas-selective separation material will have a lower carbon monoxide absorption performance and will not be affected by impurities such as oxygen. In addition, when the ratio of copper compound to suluascorbic acid is large, dissolution in the solvent becomes difficult. Generally, the ascorbic acid is in the range of 0.1 mol to 10 mol per mol of the copper compound,
The range is preferably 0.15 to 5 moles, most preferably 1 to 3 moles.

Next, the solvent used to dissolve and react the copper compound, benzoin or ascorbic acid of the present invention will be described. As the solvent, any compound capable of decomposing copper compounds, benzoins or ascorbic acids may be used. However, thylenetriamine, triethylenetetramine,
Polyalkylene polyamines such as tetraethylenepentamine, heptaethyleneoctamine, and nonaethylenedecamine are used alone or in combination with other solvents.

Great Organic Chemistry (Breakfast Shoten, Showa≠λ) as imidazoles
Examples include the compounds described in Vol. IS/pages 73 to 2j7, the compounds described as pyridines in Vol. 76, pages 1 to λ6 of the same literature, and the compounds described in vol. 76, pages 7g to g2 as ethylenediamines. be done. Among these, compounds that are liquid at room temperature, have a high boiling point, and have a low vapor pressure at room temperature are optimal.

Solvents that can be used with the above imidazoles, pyridines, and ethylenediamines can dissolve these compounds, copper compounds, benzoins, or ascorbic acids well,
Any solvent may be used as long as it has a high boiling point and low vapor pressure at room temperature, such as ketones, esters, ethers, alcohols, amines, amides and other nitrogen-containing compounds, sulfur-containing compounds, phosphorus-containing compounds, nitrogen-containing compounds, etc. Rogen compounds can be used alone or in combination. A suitable solvent is dimethylated. Although it is desirable that the resulting solution be a homogeneous solution, it can also be used in a slurry state containing non-bath components. The volume ratio of the imidazoles, pyridines, and polyethylene polyamines in the above solvent to the total solvent can be arbitrarily selected within the range of o", ioo to ioo", and o.

The temperature at which the copper compound and benzoins or ascorbic acids are mixed in a solvent is not particularly limited, but is usually 0 to 200°C.
It is preferable to carry out under an inert gas flow within the range of .

As the palladium compound used in the present invention, an alkene complex of palladium can be formed by reaction with rutin. Alkenes include tehaethylene, propylene,
Copper compound is 0.0/~ for 1 mole of butenes and Hente derivatives
ioo mole range, especially 0. A range of / to io moles is preferred.

As a method for producing a palladium alkene complex, a complex of a palladium compound and a nitrile is first formed, and for example, a complex of 0 to nitrile is formed.
An example is a method of reacting with an alkene compound at 750° C. and normal pressure or increased pressure.

Solvents that dissolve palladium nitrile complexes or palladium alkene complexes include, but are not limited to, alcohols, ethers, esters, ketones, amides,
Examples include sulfoxides, glycols, and nitriles, but it is preferable to use 2) IJ2 itself, which forms a nitrile complex.

The order in which the copper compound, benzoins or ascorbic acids, and palladium alkene complexes are reacted and mixed with each other is not particularly limited, but the copper compound and benzoins or ascorbic acids are first reacted in a solvent, and then a solution of the palladium alkene complex is reacted with the copper compound and benzoins or ascorbic acids. It is preferable to add Palladium may be produced and its solution added to the solution of the copper compound.

Next, a method for separating a specific gas, particularly carbon oxide, using the gas separation composition of the present invention will be explained.

In the first method, a gas mixture is brought into contact with the gas separation composition or a solution containing the same, and a specific gas, particularly carbon oxide, is selectively absorbed therein, and then the pressure and/or temperature is changed. By repeating the operation of releasing the absorbed gas, specific gases, especially carbon oxides, can be separated. In this case, the pressure at which the gas separation composition is made to absorb gas may be any pressure greater than zero; however, in order to increase selectivity, a low pressure below /atmospheric pressure is required, and in order to increase the gas absorption rate, /atmosphere It is preferable to carry out the process at a higher pressure than above. Usually the pressure is between θ and 10 atm, preferably 0. /~3
It is done under atmospheric pressure. Furthermore, in order to release the absorbed gas at room temperature, it is usually carried out under reduced pressure. The arson of the gas is carried out at a pressure of o, i to O, S atmospheres, although any pressure below /atmospheres may be used. The temperature at which gas is absorbed is not particularly limited, but it is easier to absorb gas at a lower temperature, so a temperature of usually less than 100° C., preferably less than 0° C. is employed. There is also no particular restriction on the temperature at which the gas is released, but in this case, a high temperature is preferable in terms of increasing the release rate. Usually, a temperature of at least room temperature, preferably 47°C to 300°C, is employed. When gas is released at a high temperature like this, it is not necessarily necessary to perform it under reduced pressure, but it can also be performed at a pressure of 7 atmospheres or more. Of course, absorption can be done by changing both pressure and temperature conditions.
Release can also be carried out, in which case it is absorbed at low temperature and high pressure,
It is preferable to release at high temperature and low pressure.

Furthermore, as a second method, the composition for gas separation of the present invention is held on a membrane serving as a support, and a specific gas, particularly carbon oxide, is selectively absorbed from a mixed gas, and the pressure is lowered on other surfaces of the membrane. Certain gases, especially carbon oxides, can be selectively separated by passing through the membrane. In this case, the support used to hold the gas separation composition is not particularly limited as long as it is a membrane that is permeable to gas.

For example, the gas separation composition in liquid form may be filled into the pores of a porous support, or it may be wrapped in a crosslinkable polymer network formed on a support membrane. Examples include a method of burying the material, a method of holding it as a liquid film with a certain thickness on a support film, and a method of holding it by dissolving or dispersing it in aligned molecules such as liquid crystal formed on a support. be done.

The type of membrane material used as the support is not particularly limited, but includes regenerated cellulose, cellulose ester, polycarbonate, polyester, Teflon, nylon, acetyl cellulose, polyacrylonitrile, polyvinyl alcohol, polymethyl methacrylate, polysulfone, polyethylene, polypropylene. , polyvinylpyridi/
, polyphenylene oxide, polyphenylene oxide sulfonic acid, polybenzimidazole, polyimidazopyrrolone 9, boribiverazinamide, polystyrene, polyamino acid, polyurethane, polyamino acid polyurethane copolymer, polysiloxane, polysiloxane polycarbohydrate copolymer , polytrimethylvinylsilane, collagen, polyion complex, polyurea, polyamide, polyimide, polyamideimide, and these supports can be used in any of the shapes of a flat plate, a tube, a spiral, and a hollow fiber. These supports may be entirely porous, may be an anisotropic film having a dense layer only on the surface, or may be a homogeneous film. Alternatively, the surface may be coated with a thin film of another material by a method such as vapor deposition, coating, polymerization, or plasma polymerization. The overall thickness is not particularly limited, but is preferably in the range of 10 to 1000 microns. Such a support can also be used by being superimposed on a support made of another material.

The thickness of the layer of the gas separation composition held on these supports can be several angstroms or more, and is not particularly limited.

However, when the liquid film of the gas separation composition is used without stirring, it is preferable that the film be thinner in order to obtain a higher permeation rate. Moreover, if it is too thin, the permeation rate of gases other than the target gas to be separated will increase, resulting in a decrease in separability, which is not preferable. The most suitable membrane thickness is used for the gas and gas separation set. In addition, when a liquid film is used under stirring, there is no problem even if the film is thick, but the actual thickness of the film existing as a diffusion layer on the surface of the support film is the same as that without stirring. It is preferable that

Various methods can be used to separate gases, including a method in which a membrane holding a gas separation composition on a support is used to create a partial pressure difference between the gases to be separated on both sides of the membrane; A method is used in which a container containing the gas separation composition is placed separately from the membrane cell, and a pump is used to guide this liquid to the surface of the support membrane of the membrane cell (the -(' side of the membrane)) for circulation. In the latter case, the above-mentioned gas separation composition, which has absorbed, for example, carbon oxide on the membrane surface, is introduced into another container,
For example, carbon monoxide can be released under reduced pressure, or conversely, carbon monoxide can be absorbed into a liquid in a reservoir.
By reducing the pressure on the secondary side of the membrane in the membrane cell, the dissolved or combined gas is continuously dissociated and desorbed and guided to the primary side of the membrane, and the liquid that has lost carbon oxide is stored in a reservoir. It is also possible to dissolve the carbon monoxide again. In this case, the temperatures of the membrane cell and the reservoir can be made different to facilitate the removal of carbon oxide. The temperature of the membrane cell portion can be, for example, in the range of 0 to 200°C.

+m small 1δ As a third method, the gas separation composition is dispersed into particles,
11. , .

is called a carrier (for example, if the specific gas is carbon monoxide, it is called a co carrier), but in a fluid carrier membrane in which a carrier-containing solution is held on a support membrane, it selectively binds to the carrier. Gases and other gases behave differently in the pressure dependence of their solubility in carrier solutions. In the pressure range below 1 atm, the former gas has a certain amount of solubility in the carrier solution and a certain pressure. That is, in a small pressure region, the amount of dissolved material changes greatly with a slight change in pressure, but in a pressure region of nearly 7 atmospheres, the amount of dissolved material does not change much even if the pressure is changed. On the other hand, the latter gas has a constant ratio of dissolved amount to pressure and follows Henry's law. Therefore, adjusting the range is a desirable method to obtain high selectivity. If the purpose of correspondence is to remove carbon monoxide and obtain a partner gas, adjusting the pressure to a high pressure higher than atmospheric pressure is a desirable method in terms of increasing the production rate of the partner gas.

In this way, a gas separation composition can be produced as a by-product in iron manufacturing using a fluid carrier membrane in which a gas separation composition is held on a membrane serving as a support. In addition, when a small amount of carbon monoxide present in the feed gas is removed, the pressure is adjusted to at least /atmosphere so that a gas from which carbon oxide has been removed can be obtained at a higher production rate.

The gas that has passed through the fluid carrier membrane can also be fed to another fluid carrier membrane.

In this case, one or more stages of fluid carrier membranes are connected in series. One advantage of such a method is that higher concentrations of gas (eg carbon oxide) can be obtained by repeating the selective separation. Another advantage is that the fluid carrier membrane selectively reacts impurity gases in the gas mixture (e.g. carbon dioxide, oxygen, ammonia, hydrogen sulfide, sulfur dioxide, nitrogen oxide gas, etc. in carbon oxide) with the respective impurity gases. The fluidic carrier membrane of the present invention allows the fluidic carrier membrane of the present invention to be used to remove the gas, and finally obtain the target gas, such as carbon oxide, with high purity.

Hereinafter, fluid activated carbon, silica, alumina, silica alumina, zeolite, and other carriers that hold the gas separation composition in their membranes can be used.

〔Example〕

Next, the present invention will be explained with examples.

Implementation: Copper formate 0,3 m mot in a 30, l flask.
2 rttl of Hengein OJ mmots N-methylimidazole was collected and reacted at 30° C. for 3θ minutes to obtain a yellowish brown solution (Solution A). 200.1 flask with palladium chloride 4mmots acetonitrile/20r
The rtl was collected and reacted with stirring at room temperature under nitrogen atmosphere all day and night. When 20.1 of the solution was blown into the solution, the color changed from yellowish brown to green, and the copper compound was oxidized. (Solution C) /0ral of solution B in solution C (Pd: Oi m
When the mixture was heated to 65° C., the color changed from green to reddish brown and the copper compound was reduced. (Solution D) The amount of carbon monoxide absorbed in the solution was measured and was 0 per copper compound/mot.
．． A 7 mot of carbon monoxide was absorbed.

molten LDK air 2 j' me (02: 0,2
j r1m□t) and r O-t 700 at O℃
It reacted for a minute. The color of the solution changed again to green due to the oxidation of the copper compound (solution E).

The amount of carbon monoxide absorbed in solution E is 0 per copper compound/mat.
0.2/mot, and the carbon monoxide absorption performance decreased significantly due to the oxidation of the copper compound.

Finally the solution EK bath solution / Ome (Pd= o, r
mmoj) was added again, the temperature was raised to 70°C, and while blowing ethylene, the reaction was carried out for 7 minutes. It can be used advantageously mainly for the separation of carbon monoxide.For example, it can be used as synthesis gas obtained by steam reforming or partial oxidation of hydrocarbons such as natural gas, light naphtha, and heavy oil, and as a by-product gas in coal gasification and steel manufacturing. Mainly carbon monoxide can be separated in high yield from the resulting mixed gas containing carbon monoxide, and can be used as a raw material for various chemical reactions.

Claims (3)

[Claims] (1) A composition for gas separation consisting of a reaction mixture obtained by mixing (a) a copper compound and a benzoin and/or an aqueous reaction mixture, and (b) a palladium compound and an alkene in a solvent. (2) (a) A reaction product of a reaction mixture obtained by mixing a copper compound and benzoins and/or ascorbic acids in a solvent and oxygen, and (b) a reaction product of a palladium compound and an alkene in a solvent. Composition for gas separation consisting of the resulting reaction mixture (3) The solvent used for mixing the copper compound and benzoins and/or ascorbic acids is imidazoles,
The composition for gas separation according to item 1 or 2, characterized in that the solvent contains one or more selected from pyridines and polyethylene polyamines.