JP2009148729A - Method for separating or separating/recovering water-soluble nitrogen-containing liquid medium from solvent or aqueous solution containing it, apparatus used therefor, and agent used for separation or separation/recovery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for separating a water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium, a method for separating/recovering the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium, both the method being excellent in yield, cost and environmental countermeasures, apparatuses used therefor, and an agent for separation or separation/recovery used therefor like an inorganic adsorbent and an extractant. <P>SOLUTION: The method for separating a water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium, includes a process wherein the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with the inorganic adsorbent to adsorb the water-soluble nitrogen-containing liquid medium by the inorganic adsorbent, and the inorganic adsorbent having adsorbed the water-soluble nitrogen-containing liquid medium is separated from the water-insoluble solvent. The separation method, apparatuses used therefor, and the agent for separation or separation/recovery used therefor like the inorganic adsorbent and extractant are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for separating the water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium, and the water-soluble nitrogen-containing liquid from an aqueous solution containing the water-soluble nitrogen-containing liquid medium. The present invention relates to a method for separating and recovering a liquid medium, an apparatus used therefor, and a separating or separating / recovering agent such as an inorganic adsorbent and an extractant used therefor.

  Conventionally, in a method for separating and recovering a water-soluble nitrogen-containing liquid medium in a solvent or an aqueous solution, a distillation method has been adopted. In the distillation method, the content of the water-soluble nitrogen-containing liquid medium in an aqueous solution is 20%. % Is often used, and a large amount of water is evaporated in the distillation tower, so that the energy cost is high and a large amount of carbon dioxide gas is discharged. Considering recent carbon dioxide emission regulations and high oil prices, there are problems in terms of environmental measures and costs.

  As a method other than the distillation method, a method based on an extraction treatment of a water-soluble nitrogen-containing liquid medium is known. For example, a method is known in which an aqueous solution containing N, N-dimethylformamide (DMF) and a hydrolyzate thereof at a low concentration is extracted with methylene chloride (Patent Document 1). However, although this extraction method shows high extraction efficiency, it is difficult to put into practical use. The extractant methylene chloride is carcinogenic and hardly decomposes in the natural environment, so its discharge into wastewater is strictly limited to 0.2 mg / L. However, about 12,800 mg / L is dissolved in the water after extraction, and it is difficult to remove it. In addition, since the boiling point of the extractant is low and it is volatile and easily escapes to the atmosphere, there is a problem that it cannot be used as an extractant today because it leaves an environmental problem.

  On the other hand, a method of extracting DMF with a substituted phenol is known (Patent Document 2). This method uses substituted phenols. However, like methylene chloride, substituted phenols are carcinogenic, and also have problems with wastewater regulations, which are difficult to use. In addition, a distillation method is used to separate the extractant after extraction and the water-soluble nitrogen-containing liquid medium, but the extractant still has a drawback of requiring a lot of energy.

  The water-soluble nitrogen-containing liquid medium is known to be complexed with metal atoms in organic solvents, and the target metals are cerium, neodymium, lanthanum, uranium, manganese, cobalt, nickel, cadmium, samarium, Europium, copper, and the like are known (Non-Patent Documents 1, 2, 3, and 4). In any of the above-mentioned documents, a method for separating a water-soluble nitrogen-containing liquid medium after forming a complex is not shown. In general, separation from complex materials after complex formation is often accompanied by difficulty, and for example, a phenylsiloxane-based catalyst containing copper and complexed with DMF is known as a stable reaction catalyst. (Non-Patent Document 5).

  As a method of separating the extracted N-alkylamides from the extractant, a method of separating by adsorbing to an ion exchange resin in addition to the distillation method is shown (Patent Document 3). However, the problem that the ion exchange resin is expensive and the cost is high such as the need for further processing for separating and recovering the adsorbed N-alkylamides cannot be solved.

Therefore, there is a need for a method for separating a water-soluble nitrogen-containing liquid medium in a solution that is highly efficient but inexpensive and hardly adversely affects the environment.
JP 2003-340441 A JP-A-53-77006 JP-A-55-141450 Polyhedron, 25 (7), 1700-1706 (2006). Russian Journal of Coordination Chemistry (Translation of Koordinatsionnaya Khimiya), 28 (3), 183-190 (2002). Chemical Communications (Cambridge), (18), 2043-2044 (1998). Thermochimica Acta, 307 (2), 143-147 (1997). Kinetics and Catalysis (Translation of Kinetika i Kataliz), 41 (3), 399-401 (2000).

  An object of the present invention is to provide a method for separating a water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium, which is highly efficient, low cost and excellent in environmental measures, and a water-soluble composition. To provide a method for separating and recovering the water-soluble nitrogen-containing liquid medium from an aqueous solution containing a nitrogen liquid medium, and an apparatus used therefor, and a separation or separation / recovery agent such as an inorganic adsorbent and an extractant used therefor. It is in.

1st this invention is the method of isolate | separating this water-soluble nitrogen-containing liquid medium from the water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium,
A water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with an inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble The present invention relates to a method including a step of separating the inorganic adsorbent adsorbing a nitrogen-containing liquid medium and the water-insoluble solvent.

  According to the first aspect of the present invention, a water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium is brought into contact with an aqueous solution containing the water-soluble nitrogen-containing liquid medium and a water-insoluble solvent. The water-soluble nitrogen-containing liquid medium is preferably extracted with an insoluble solvent, and the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is preferably separated from the aqueous phase.

  According to the first aspect of the present invention, the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium is further heated to desorb the water-soluble nitrogen-containing liquid medium from the inorganic adsorbent. It is preferable to include the process of collect | recovering.

The second aspect of the present invention is a method for separating and recovering the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
(1) An aqueous solution containing the water-soluble nitrogen-containing liquid medium is brought into contact with a water-insoluble extraction solvent, and the water-soluble nitrogen-containing liquid medium is extracted with the water-insoluble extraction solvent. Separating the extraction phase and the aqueous phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium;
(2) The extracted phase and an inorganic adsorbent are brought into contact, the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed. Separating the adsorbent from the water-insoluble extraction solvent; and (3) heating the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to thereby convert the water-soluble nitrogen-containing liquid medium into the water-soluble nitrogen-containing liquid medium. The present invention relates to a method including a step of desorbing and collecting from an inorganic adsorbent.

  According to the first and second aspects of the present invention, the inorganic adsorbent is preferably one or more anhydrous metal chlorides.

  According to the first and second aspects of the present invention, the metal chloride is preferably one or more metal chlorides selected from the group consisting of anhydrous cupric chloride and anhydrous calcium chloride.

  According to the first and second aspects of the present invention, it is preferable to use an anhydrous metal hydroxide as the adsorption aid for the inorganic adsorbent.

  According to the first and second aspects of the present invention, it is preferable that the anhydrous metal hydroxide as the adsorption aid is anhydrous aluminum hydroxide.

  According to the first and second present inventions, the water-insoluble solvent or the water-insoluble extraction solvent is preferably one or more liquid organic halides.

  According to the first and second aspects of the present invention, the organic halide as the water-insoluble solvent or the water-insoluble extraction solvent is preferably one or more alkyl bromides having 1 to 3 carbon atoms.

  According to the first and second present inventions, the alkyl bromide is one or more selected from the group consisting of methylene bromide, ethyl bromide, n-propyl bromide, and isopropyl bromide. preferable.

  According to the first and second present inventions, the water-soluble nitrogen-containing liquid medium is selected from the group consisting of N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and pyridine. One or more are preferable.

  According to the first and second aspects of the present invention, the water-soluble nitrogen-containing liquid medium is preferably N, N-dimethylformamide.

  According to the second aspect of the present invention, it is preferable to further include a step of purifying the water-soluble nitrogen-containing liquid medium recovered in the step (3) by subjecting it to extraction treatment and / or distillation treatment.

  According to the second aspect of the present invention, it is preferable to further include a step of recovering the water-insoluble extraction solvent separated in the step (2) and reusing it as a water-insoluble extraction solvent.

  According to the second aspect of the present invention, the method further includes a step of recovering the inorganic adsorbent from which the water-soluble nitrogen-containing liquid medium has been desorbed in the step (3) and reusing it as an inorganic adsorbent. preferable.

A third aspect of the present invention is an apparatus for separating the water-soluble nitrogen-containing liquid medium from the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium,
A water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with an inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble The present invention relates to an apparatus including an adsorption separation unit that separates the inorganic adsorbent adsorbing a nitrogen-containing liquid medium and the water-insoluble solvent.

The fourth aspect of the present invention is an apparatus for separating and recovering the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
(A) contacting the aqueous solution containing the water-soluble nitrogen-containing liquid medium with a water-insoluble extraction solvent, and extracting the water-soluble nitrogen-containing liquid medium with the water-insoluble extraction solvent; An extraction / separation unit for separating an extraction phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium and an aqueous phase;
(B) contacting the extracted phase with an inorganic adsorbent, adsorbing the water-soluble nitrogen-containing liquid medium with the inorganic adsorbent, and adsorbing the water-soluble nitrogen-containing liquid medium; An adsorption separation unit for separating the adsorbent and the water-insoluble extraction solvent; and (C) the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to heat the water-soluble nitrogen-containing liquid medium. It is related with the apparatus containing the desorption collection | recovery part which desorbs and collect | recovers from this inorganic adsorption agent.

  5th this invention relates to the inorganic adsorption agent of the water-soluble nitrogen-containing liquid medium containing 1 or more types selected from the group which consists of anhydrous cupric chloride, anhydrous calcium chloride, and anhydrous aluminum hydroxide .

6th this invention is the method of isolate | separating this water-soluble nitrogen-containing liquid medium from the aqueous solution containing a water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble The present invention relates to a method comprising the steps of: extracting a nitrogen-containing liquid medium, and separating an aqueous phase and an extraction phase comprising the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium.

The seventh aspect of the present invention is an apparatus for separating the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble The present invention relates to an apparatus comprising an extraction / separation unit that extracts a nitrogen-containing liquid medium and separates an extraction phase composed of the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium and an aqueous phase.

  The eighth aspect of the present invention is an extraction comprising one or more alkyl bromides having 1 to 3 carbon atoms for extraction of the water-soluble nitrogen-containing liquid medium from an aqueous solution containing the water-soluble nitrogen-containing liquid medium. It relates to the agent.

  According to the present invention, a water-soluble nitrogen-containing liquid medium can be separated or separated and recovered from a solvent or aqueous solution containing it at high efficiency and at low cost.

1st this invention is the method of isolate | separating this water-soluble nitrogen-containing liquid medium from the water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium, Comprising: Water containing this water-soluble nitrogen-containing liquid medium The inorganic adsorbent obtained by bringing an insoluble solvent into contact with an inorganic adsorbent, adsorbing the water-soluble nitrogen-containing liquid medium by the inorganic adsorbent, and adsorbing the water-soluble nitrogen-containing liquid medium And a step of separating the water-insoluble solvent (adsorption separation step).
Specifically, a water-insoluble solvent 4 containing a water-soluble nitrogen-containing liquid medium (a solvent containing a nitrogen-containing liquid medium) and an inorganic adsorbent 5 are introduced into, for example, the adsorption separation unit 20 in FIG. Then, the water-insoluble solvent 4 containing the water-soluble nitrogen-containing liquid medium (nitrogen-containing liquid medium) and the inorganic adsorbent 5 are brought into contact with each other by means of, for example, stirring and mixing. Alternatively, both may be brought into contact by passing a solvent 4 containing a nitrogen-containing liquid medium through a column packed with an inorganic adsorbent 5. The nitrogen-containing liquid medium can be adsorbed on the inorganic adsorbent 5 by contact, and after the adsorption, the inorganic adsorbent 7 adsorbing the nitrogen-containing liquid medium from the water-insoluble solvent 6 is removed by a known means such as a filter. By separating, the nitrogen-containing liquid medium can be separated as the inorganic adsorbent 7 that has adsorbed the nitrogen-containing liquid medium from the solvent 4 containing the nitrogen-containing liquid medium. By this operation, the concentration of the nitrogen-containing liquid medium in the solvent 4 containing the nitrogen-containing liquid medium is reduced to approximately one or less.

In the present invention, the water-soluble nitrogen-containing liquid medium is a water-soluble nitrogen-containing liquid medium (for example, an organic solvent). For example, acid amides, nitriles, heterocyclic nitrogen compounds, nitro compounds, alkylamines, alkyleneamines, aniline, and other amines can be mentioned.
Examples of the acid amides include formamide, N, N-dimethylformamide, acetamide, N, N-dimethylacetamide, pyrrolidone, and N-methylpyrrolidone.
Examples of nitriles include acetonitrile and acetone cyanohydrin.
Examples of the heterocyclic nitrogen compound include pyridine, methylpyridine, dimethylpyridine, quinoline, isoquinoline, morpholine, ethylmorpholine, and phenylmorpholine.
Examples of the nitro compound include nitroalkane and nitrobenzene.
Examples of the alkylamines include mono-, di-, trimethylamine, mono-, diethylamine, and propylamine.
Examples of the alkylene amines include ethylene diamine, propylene diamine, diethylene triamine, and tetraethylene pentamine.
Examples of other amines include cyclohexylamine, mono-, di-, triethanolamine, n-butylmonoethanolamine, dimethylethanolamine, diethylethanolamine, ethyldiethanolamine, n-butyldiethanolamine, and triisopropanolamine. .
As the water-soluble nitrogen-containing liquid medium, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and pyridine are preferable, and N, N-dimethylformamide is particularly preferable.

In the present invention, the water-insoluble solvent is not limited as long as it is a water-insoluble solvent in which the water-soluble nitrogen-containing liquid medium can be dissolved. For example, liquid organic halides, organic acid esters, ketones, and mixtures thereof are preferable.
Examples of organic acid esters include acetate esters, propionate esters, butyrate esters, and mixtures thereof.
Examples of the organic halide include organic chlorinated products, organic brominated products, and mixtures thereof. An organic bromide is preferable, and an alkyl bromide having 1 to 3 carbon atoms and a mixture thereof are particularly preferable. Examples of the alkyl bromide having 1 to 3 carbon atoms include methyl bromide, methylene bromide, tribromomethane, ethyl bromide, ethylene bromide, tribromoethane, n-propyl bromide, n-propylene bromide, Examples thereof include isopropyl bromide, isopropylene bromide, tribromopropane and mixtures thereof, and methylene bromide is particularly preferred.

  In the present invention, the concentration of the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent can vary over a wide range and is not particularly limited. For example, it is 0.005% by weight or more, preferably 0.05% by weight or more, particularly It is 0.1% by weight or more. The upper limit of the concentration is the saturation concentration of the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent. The water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium may previously remove solid impurities by filtration or the like.

  In the present invention, adsorption means adsorption in a broad sense and includes both physical adsorption and chemical adsorption.

  According to the first invention, the water-insoluble solvent includes a water-soluble nitrogen-containing liquid medium and may further include a small amount of water. The concentration of the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent is not particularly limited, but the concentration is lowered in order to minimize the amount of inorganic adsorbent used and the number of repetitions of the process. For example, it is 10% by weight or less, preferably 5% by weight or less, more preferably 1% by weight or less, and particularly preferably 0.2% by weight or less.

The inorganic adsorbent is not limited as long as it adsorbs a water-soluble nitrogen-containing liquid medium and does not dissolve in a water-insoluble solvent, and examples thereof include anhydrous metal chloride. As anhydrous metal chlorides, alkaline earth and transition metal chlorides can be used.
As the anhydrous metal chloride, for example, divalent and trivalent metal chlorides such as magnesium chloride, calcium chloride, manganese chloride, cobalt chloride, ferric chloride, cupric chloride, and zinc chloride are preferable. In particular, the metal chloride is preferably anhydrous cupric chloride and / or anhydrous calcium chloride. These anhydrous metal chlorides may be used alone or in combination of two or more.
Although most metal chlorides form hydrates, metal chloride hydrates are preferably used as anhydrides because of their low property of adsorbing water-soluble nitrogen-containing liquid media.

In the present invention, in addition to the inorganic adsorbent, an anhydrous metal hydroxide can be used as an adsorption aid. As the adsorption aid, for example, hydroxides of elements of Group 1, Group 2 and Group 3 can be used. For example, divalent and trivalent metal hydroxides such as magnesium hydroxide, calcium hydroxide, ferric hydroxide, copper hydroxide, and aluminum hydroxide are preferable. In particular, anhydrous aluminum hydroxide is preferred.
These anhydrous metal hydroxides may be used alone or in combination of two or more. The adsorption aid functions to increase the effect of the inorganic adsorbent adsorbing the water-soluble nitrogen-containing liquid medium in the organic bromide. In addition, the adsorbent aid functions to agglomerate the inorganic adsorbent that has adsorbed the water-soluble nitrogen-containing liquid medium in a water-insoluble solvent, so that when used in combination with an inorganic adsorbent, The inorganic adsorbent adsorbing the water-soluble nitrogen-containing liquid medium can be easily separated.
The combination of the adsorbent and the adsorption aid is preferably anhydrous cupric chloride, anhydrous calcium chloride, and anhydrous aluminum hydroxide.

The water-insoluble solvent contains not only a water-soluble nitrogen-containing liquid medium but also a small amount of water. The adsorption ratio between water-soluble nitrogen-containing liquid medium and water by inorganic adsorbent varies depending on the type of water-insoluble solvent, but the inorganic adsorbent after adsorption is more water-soluble than nitrogen-containing liquid medium. About 3 to 10 times. Therefore, the amount of the inorganic adsorbent used in the adsorption separation from the water-insoluble solvent taking in water and the water-soluble nitrogen-containing liquid medium is an amount commensurate with the water-soluble nitrogen-containing liquid medium contained. If the amount is larger than the equivalent amount, a sufficient effect can be obtained.
In general, the amount of the inorganic adsorbent is preferably 1 to 15% by weight of the amount of the water-insoluble solvent used.
For example, when methylene bromide is used as a water-insoluble solvent (organic bromide) and anhydrous cupric chloride is used as an inorganic adsorbent, water-soluble nitrogen-containing nitrogen in a water-insoluble solvent (organic bromide) If the content of the liquid medium is about 0.1% by weight, the use ratio of the inorganic adsorbent (anhydrous cupric chloride) is 3 to 10% by weight with respect to the water-insoluble solvent (organic bromide), That is, it is preferable to contact the inorganic adsorbent 30 to 100 times by weight with respect to 1 weight of the water-soluble nitrogen-containing liquid medium.

  On the other hand, the desirable use ratio of the adsorption aid varies depending on the kind of adsorption aid to be used and the particle size, but it is preferably about 0.1% by weight to 2% by weight with respect to the water-insoluble solvent. If the use ratio is too low, the effect is small, and if it is too high, the heat energy for heat treatment to be reused is wasted. Further, the adsorption aid is preferably brought into contact with the adsorption aid 0.5 to 10 times by weight, preferably 1 to 2 times by weight, with respect to 1 weight of the water-soluble nitrogen-containing liquid medium.

  The amount and use ratio of the inorganic adsorbent and adsorption aid depend on the type and particle size of the inorganic adsorbent and adsorption aid used, and the concentration of the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent. It depends on how much water is desired to be reduced, depending on the water content in the water-insoluble solvent, and further on the contact method between the water-insoluble solvent and the inorganic adsorbent.

  The inorganic adsorbent adsorbs the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent by contacting with the water-insoluble solvent. It is desirable to do. However, for example, when packing in a column through which a water-insoluble solvent passes, it is also effective to increase the particle size of the inorganic adsorbent so that it can easily pass through the liquid. It is also possible to use it after forming into a shape.

According to the first invention, in some cases, the step of adsorbing the water-soluble nitrogen-containing liquid medium from the water-insoluble solvent, the step of removing water in the water-insoluble solvent, and the step of removing the water-soluble nitrogen-containing liquid medium It is also effective to use the inorganic adsorbent efficiently by dividing it into adsorption steps.
In the present invention, if necessary, the process can be repeated a plurality of times, and the concentration of the water-soluble nitrogen-containing liquid medium in the water-insoluble solvent is, for example, 0.005 wt% or less, particularly 0.002 wt% or less. be able to.

  According to the first aspect of the present invention, a water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium is brought into contact with an aqueous solution containing the water-soluble nitrogen-containing liquid medium and a water-insoluble solvent. It can be obtained by extracting the water-soluble nitrogen-containing liquid medium with an insoluble solvent and separating the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium from the aqueous phase. That is, the step of extracting and separating (extracting and separating step) can be performed in advance on a water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium.

  In the present invention, the extraction conditions (extraction separation conditions) are a temperature of 0 ° C. to the boiling point of the extractant, preferably 5 to 30 ° C., and the contact time for extraction is not particularly limited, but for example 1 to 20 minutes is there. The extraction step is performed at least once, but may be performed twice or more if necessary. Performing the extraction step multiple times is particularly effective when the concentration of the water-soluble nitrogen-containing liquid medium in the aqueous solution is high or when the concentration of the water-soluble nitrogen-containing liquid medium in the aqueous phase after extraction is low. . When the concentration of the water-soluble nitrogen-containing liquid medium in the aqueous phase after extraction is 0.1% by weight or less, the aqueous phase can be directly treated by the wastewater treatment facility.

According to the first aspect of the present invention, the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium is further heated to desorb the water-soluble nitrogen-containing liquid medium from the inorganic adsorbent. A recovery step (desorption recovery step) can be included.
Specifically, the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium is heated. As a result, the adsorption state is released, and the water-soluble nitrogen-containing liquid medium and the contained water are in a gaseous state and separated from the inorganic adsorbent. The separated desorption gas (water-soluble nitrogen-containing liquid medium) is recovered. The heating conditions are a temperature of 100 to 300 ° C., preferably 150 to 250 ° C. under atmospheric pressure, and the time varies depending on the heating temperature, for example, 10 to 100 minutes.

The second aspect of the present invention is a method for separating and recovering the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
(1) An aqueous solution containing the water-soluble nitrogen-containing liquid medium is brought into contact with a water-insoluble extraction solvent, and the water-soluble nitrogen-containing liquid medium is extracted with the water-insoluble extraction solvent. Separating the extraction phase and the aqueous phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium;
(2) The extracted phase and an inorganic adsorbent are brought into contact, the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed. Separating the adsorbent from the water-insoluble extraction solvent; and (3) heating the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to thereby convert the water-soluble nitrogen-containing liquid medium into the water-soluble nitrogen-containing liquid medium. The present invention relates to a method including a step of desorbing and recovering from an inorganic adsorbent. In terms of this method, the water-insoluble extraction solvent of the second invention has the same meaning as the water-insoluble solvent of the first invention, and the same examples are exemplified. In addition, the description of the water-soluble nitrogen-containing liquid medium, the inorganic adsorbent, the adsorption aid, etc. in the second invention has the same meaning as the same word in the first invention, Illustrated. Other conditions and the like can also refer to the above-described aspect of the first invention.

In the method of the second aspect of the present invention, the step (1) comprises contacting an aqueous solution containing a water-soluble nitrogen-containing liquid medium with a water-insoluble extraction solvent, and using the water-insoluble extraction solvent, the water-soluble nitrogen-containing liquid. This is a step of extracting a medium and separating an extraction phase made of a water-insoluble extraction solvent containing a water-soluble nitrogen-containing liquid medium and an aqueous phase.
Specifically, in FIG. 2, an aqueous solution 1 containing a water-soluble nitrogen-containing liquid medium is introduced into the extraction / separation unit 10 in FIG. 2, and the water-insoluble extraction solvent 2 and, for example, a stirring / mixing means, etc. The contact is made by a known means. Thereby, a water-soluble nitrogen-containing liquid medium is extracted from the aqueous solution into a water-insoluble extraction solvent. After extraction, the aqueous phase 3 and the extraction phase 4 are phase separated. Phase separation can be performed by standing, but other known means such as centrifugation can also be used.

  In the present invention, the concentration of the water-soluble nitrogen-containing liquid medium in the aqueous solution can be in a wide range and is not particularly limited, but is, for example, 0.05% by weight or more, preferably 0.1% by weight or more. The upper limit of the concentration is the saturation concentration of the water-soluble nitrogen-containing liquid medium in water. For the aqueous solution containing the water-soluble nitrogen-containing liquid medium, the water-soluble nitrogen-containing liquid medium may be concentrated, for example, by distillation, before extraction with a water-insoluble extraction solvent.

In the present invention, the water-insoluble extraction solvent is a solvent that is insoluble in water and suitable for extraction of the above-mentioned water-soluble nitrogen-containing liquid medium. For example, liquid organic halides, organic acid esters, ketones, and mixtures thereof are preferable.
Examples of organic acid esters include acetate esters, propionate esters, butyrate esters, and mixtures thereof.
Examples of the organic halide include organic chlorinated products, organic brominated products, and mixtures thereof. An organic bromide is preferable, and an alkyl bromide having 1 to 3 carbon atoms and a mixture thereof are particularly preferable. Examples of the alkyl bromide having 1 to 3 carbon atoms include methyl bromide, methylene bromide, tribromomethane, ethyl bromide, ethylene bromide, tribromoethane, n-propyl bromide, n-propylene bromide, Examples thereof include isopropyl bromide, isopropylene bromide, tribromopropane and mixtures thereof, and methylene bromide is particularly preferred.

In the present invention, in the step (2), the extraction phase and an inorganic adsorbent are brought into contact, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble nitrogen-containing liquid is adsorbed. This is a step of separating the inorganic adsorbent adsorbing the medium and the water-insoluble extraction solvent.
Specifically, in FIG. 2, the extraction phase 4 obtained in step (1) (that is, a water-insoluble extraction solvent containing a water-soluble nitrogen-containing liquid medium) and the inorganic adsorbent 5 are mixed with an adsorption separation unit. Then, the extraction phase 4 and the inorganic adsorbent 5 are brought into contact with each other by means of, for example, stirring and mixing. Alternatively, both may be brought into contact by passing the extraction phase 4 through a column filled with the inorganic adsorbent 5. By contact, the water-soluble nitrogen-containing liquid medium can be adsorbed on the inorganic adsorbent 5, and after the adsorption, the inorganic adsorbent 7 that has adsorbed the water-soluble nitrogen-containing liquid medium from the water-insoluble extraction solvent 6 is, for example, By separating by a known means such as a filter, the water-soluble nitrogen-containing liquid medium can be separated from the extraction phase 4 as the inorganic adsorbent 7 having adsorbed the water-soluble nitrogen-containing liquid medium. As a result of this operation, the concentration of the water-soluble nitrogen-containing liquid medium in the extraction phase 4 is lowered to about one-tenth or less. The description of each part in this method can refer to the above aspect of the first aspect of the present invention.

In step (2), in some cases, the step of adsorbing the water-soluble nitrogen-containing liquid medium from the extraction phase is divided into a step of removing moisture in the extraction phase and a step of adsorbing the water-soluble nitrogen-containing liquid medium. It is also effective to use an inorganic adsorbent efficiently.
In the present invention, if necessary, the step (2) can be repeated a plurality of times, and the concentration of the water-soluble nitrogen-containing liquid medium in the extraction phase is, for example, 0.005% by weight or less, particularly 0.002% by weight or less. can do.

In the present invention, in step (3), the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium is heated, and the water-soluble nitrogen-containing liquid medium is desorbed from the inorganic adsorbent and recovered. It is a process to do.
Specifically, in FIG. 2, the inorganic adsorbent 7 (adsorbed with the water-soluble nitrogen-containing liquid medium) obtained in the step (2) is introduced into the desorption / recovery unit 30 and heated. As a result, the adsorption state is released, and the water-soluble nitrogen-containing liquid medium and the contained water are in a gaseous state and separated from the inorganic adsorbent 5. The separated desorption gas (water-soluble nitrogen-containing liquid medium) 8 is recovered. The heating conditions are a temperature of 100 to 300 ° C., preferably 150 to 250 ° C. under atmospheric pressure, and the time varies depending on the heating temperature, for example, 10 to 100 minutes. For the description of this method, reference can be made to the above aspect of the first invention.

In the present invention, the desorption gas (water-soluble nitrogen-containing liquid medium) recovered in the desorption / recovery step of the first invention or the step (3) of the second invention is used, for example, as shown in FIG. Is added to the water extraction purification unit 50 and / or the first distillation column 53, and further, a step (step (4)) for purification by subjecting it to extraction treatment and / or distillation treatment is added and included in the desorption gas. Water vapor and other impurity solvents that may be removed may be removed.
The extraction conditions are a temperature of 0 ° C. to the boiling point of the extractant, preferably 10 to 30 ° C., and the time is 1 to 60 minutes, preferably 5 to 10 minutes.
The distillation conditions are a temperature between the boiling point of the water-soluble nitrogen-containing liquid medium and the boiling point of the extractant, preferably the temperature in the vicinity of their midpoint, and the time varies depending on the heating temperature, but is, for example, 10 to 100 minutes. .

  In the present invention, the water-insoluble extraction solvent separated in the adsorptive separation step of the first invention or the step (2) of the second invention is further recovered, for example, in the extraction solvent tank 40 in FIG. For example, a step (step (5)) may be added which is introduced into the extraction / separation unit 10 in FIG. 3 and reused as a water-insoluble extraction solvent. The water-soluble nitrogen-containing liquid medium in the aqueous solution can be extracted again by the water-insoluble extraction solvent after contacting with the inorganic adsorbent. That is, a water-insoluble extraction solvent can be used repeatedly.

  In the present invention, the inorganic adsorbent from which the water-soluble nitrogen-containing liquid medium has been desorbed in the desorption recovery step of the first invention or the step (3) of the second invention is, for example, shown in FIG. A step of recovering from the desorption recovery unit 30 and re-introducing it into the adsorption separation unit 20 in FIG. 3 and reusing it as an inorganic adsorbent (step (6)) can be added. The inorganic adsorbent after desorption can adsorb the water-soluble nitrogen-containing liquid medium again. That is, the inorganic adsorbent can be used repeatedly.

  In the present invention, in addition to these steps, known means can be combined as desired, and a transfer pump can be used as necessary to transfer the fluid between the steps of the method of the present invention. Moreover, as needed, aqueous solution can be filtered beforehand and a solid substance can be removed.

A third aspect of the present invention is an apparatus for separating the water-soluble nitrogen-containing liquid medium from the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium,
A water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with an inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble The present invention relates to an apparatus including an adsorption separation unit that separates the inorganic adsorbent adsorbing a nitrogen-containing liquid medium and the water-insoluble solvent.

4th this invention is an apparatus which collect | recovers this water-soluble nitrogen-containing liquid medium from the aqueous solution containing a water-soluble nitrogen-containing liquid medium,
(A) contacting the aqueous solution containing the water-soluble nitrogen-containing liquid medium with a water-insoluble extraction solvent, and extracting the water-soluble nitrogen-containing liquid medium with the water-insoluble extraction solvent; An extraction / separation unit for separating an extraction phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium and an aqueous phase;
(B) contacting the extracted phase with an inorganic adsorbent, adsorbing the water-soluble nitrogen-containing liquid medium with the inorganic adsorbent, and adsorbing the water-soluble nitrogen-containing liquid medium; An adsorption separation unit for separating the adsorbent and the water-insoluble extraction solvent; and (C) the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to heat the water-soluble nitrogen-containing liquid medium. It is related with the apparatus containing the desorption collection | recovery part which desorbs and collect | recovers from this inorganic adsorption agent.

  As shown in FIG. 2, the apparatus of the present invention includes an extraction / separation unit 10, an adsorption / separation unit 20, and a desorption / recovery unit 30 as essential components. The symbols in the figure are an aqueous solution 1 containing a water-soluble nitrogen-containing liquid medium, a water-insoluble extraction solvent 2, an aqueous phase 3, an extraction phase 4, an inorganic adsorbent 5, a water-insoluble extraction solvent 6, and a water-soluble extraction medium. These are the inorganic adsorbent 7 adsorbing the nitrogen-containing liquid medium, the water-soluble nitrogen-containing liquid medium 8, the extraction / separation unit 10, the adsorption / separation unit 20, and the desorption / recovery unit 30.

  The apparatus of the present invention will be described in detail with reference to FIG. 3, but the embodiment shown in FIG. 3 is merely an example and includes any means, but the present invention is limited to such an embodiment. It is not a thing.

  An aqueous solution containing a water-soluble nitrogen-containing liquid medium is introduced into the aqueous solution injection line 101, and is introduced into the extraction / separation unit 10 via the aqueous solution injection lines 102 and 103 via the transfer pump P1.

  The extraction phase from the extraction / separation unit 10 is composed of a water-insoluble extraction solvent containing a water-soluble nitrogen-containing liquid medium (an extraction solvent containing a water-soluble nitrogen-containing liquid medium). Then, it is introduced into the adsorption separation unit 20 and comes into contact with an inorganic adsorbent. In the adsorption separation unit, the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent and separated from the water-insoluble extraction solvent (extraction solvent). The inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium is introduced into the desorption / recovery unit 30 via the inorganic adsorbent transfer line 142 adsorbed by the water-soluble nitrogen-containing liquid medium. The extraction solvent is stored in the extraction solvent tank 40 via the extraction solvent transfer line 125 and can be reused in the extraction separation unit 10.

  The desorption / recovery unit 30 is heated and separated into a desorption gas and an inorganic adsorbent. The inorganic adsorbent is returned to the adsorption separation unit 20 again through the inorganic adsorbent transfer line 141 after desorption.

  The desorption gas from the desorption recovery unit 30 is a gas of a water-soluble nitrogen-containing liquid medium, and this can be recovered as it is. Alternatively, the water-soluble nitrogen-containing liquid medium can be recovered by condensation through the cooling tower 31.

  In order to extract and purify impurities such as water after the desorption gas from the desorption recovery unit 30 is condensed in the first cooling tower 31, the water-soluble nitrogen-containing liquid medium and the water transfer line 161 are used. Then, it transfers to the 1st water extraction refinement | purification part 50 through the water-soluble nitrogen-containing liquid medium and the water transfer line 162 via the transfer pump P6. Further, the water extraction / purification phase is passed through the water extraction / purification phase transfer line 163, the transfer pump P7, the water extraction / purification phase transfer line 164, the second water extraction / purification part 51, and the water extraction / purification phase transfer line 165. Then, the water can be passed through the third water extraction / purification unit 52 via the transfer pump P8 and the water extraction / purification phase transfer line 166. For example, methylene bromide can be used as an extractant for extraction and purification of impurities such as water. The extraction and purification phase from the third water extraction and purification unit 52 is transferred to the second water extraction and purification unit 51 via the extraction and purification phase transfer line 168. The extraction and purification phase from the second water extraction and purification unit 51 is transferred to the first water extraction and purification unit 50 via the extraction and purification phase transfer line 169. The extraction efficiency of impurities such as water can be increased by transferring the water extraction purification phase and the extraction purification phase.

  In the third water extraction and purification unit 52, the desorption gas condensate from which impurities have been extracted and purified is passed through the extraction and purification phase transfer line 170 to the first distillation column 53, and the water-soluble nitrogen-containing liquid medium transfer line. 171 is transferred to the second cooler 54, and the water-soluble nitrogen-containing liquid medium is recovered via the water-soluble nitrogen-containing liquid medium transfer line 172, so that distillation purification is performed after extraction purification, and the remaining extraction solvent Such impurities can be removed by distillation. The impurity extraction solvent removed by the distillation column 53 is returned to the third water extraction / purification unit 52 via the distillation solvent transfer line 173.

  Although the aqueous phase from the extraction / separation unit 10 can be discharged as it is, the aqueous phase from the extraction / separation unit 10 is introduced into the second extraction / separation unit 11 and the third extraction / separation unit 12, and the extraction operation is repeated. Thus, the extraction rate (recovery rate) of the water-soluble nitrogen-containing liquid medium can be increased. In that case, the aqueous phase from the extraction / separation unit 10 is transferred to the second extraction / separation unit 11 via the aqueous phase transfer line 104, the transfer pump P <b> 3, and the aqueous phase transfer line 105. The aqueous phase from the section 11 is introduced into the third extraction / separation section 12 via the aqueous phase transfer line 106, the transfer pump P4, and the aqueous phase transfer line 107. The aqueous phase from the third extraction / separation unit 12 is discharged from the aqueous phase transfer line 108. Similarly, the extraction phase from the second extraction / separation unit 11 and the third extraction / separation unit 12 can be introduced into the extraction / separation unit 10 to repeat the extraction operation. In that case, the extraction phase from the third extraction separation unit 12 is transferred to the second extraction separation unit 11 via the extraction phase transfer line 122, and the extraction phase from the second extraction separation unit 11 is transferred to the extraction phase. The sample is transferred to the extraction / separation unit 10 via the transfer line 123.

  The aqueous phase from the third extraction / separation unit 12 can be discharged as it is via the transfer pump P5. However, the extraction solvent can be optionally removed by solvent extraction purification in the solvent extraction purification unit 60. As an extractant for the extraction solvent, for example, hexane or octane can be used. In order to remove the extraction solvent by distillation purification, it is introduced into the solvent extraction / purification unit 60 via the transfer pump P5 via the aqueous phase transfer line 109, and only water (drainage) is discharged via the aqueous phase discharge line 110. . The solvent extraction / purification phase of the solvent extraction / purification unit 60 is transferred to the second distillation column 61 via the solvent extraction / purification phase transfer line 181, and the extracted solvent vapor from the second distillation column 61 passes through the vapor transfer line 182, Returned to the extraction and purification unit 60. The extraction solvent from the second distillation column 61 is cooled by the third cooler 62 and transferred to the extraction solvent tank 40 through the extraction solvent transfer line. The extraction solvent stored in the extraction solvent tank 40 is returned to the extraction / separation unit 12 through the extraction solvent transfer line 121 via the transfer pump P2.

  And 5th this invention relates to the adsorbent composition of the water-soluble nitrogen-containing liquid medium containing 1 or more types selected from the group which consists of anhydrous cupric chloride and anhydrous calcium chloride.

6th this invention is the method of isolate | separating this water-soluble nitrogen-containing liquid medium from the aqueous solution containing a water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble The present invention relates to a method comprising the steps of: extracting a nitrogen-containing liquid medium, and separating an aqueous phase and an extraction phase comprising the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium. The description of each part in this method can refer to the above aspects of the first and second aspects of the present invention.

The seventh aspect of the present invention is an apparatus for separating the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble The present invention relates to an apparatus comprising an extraction / separation unit that extracts the nitrogen-containing liquid medium and separates an extraction phase made of the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium and an aqueous phase. The description of each part in this apparatus can refer to the above aspect in the third invention.

The eighth aspect of the present invention is an extraction containing one or more alkyl bromides having 1 to 3 carbon atoms for extraction of the water-soluble nitrogen-containing liquid medium from an aqueous solution containing the water-soluble nitrogen-containing liquid medium. It is an agent.
For the description of the alkyl bromide for extraction of this water-soluble nitrogen-containing liquid medium, reference can be made to the above embodiment.

An example of recovery from an aqueous solution of a soluble water-soluble nitrogen-containing liquid medium uniformly dispersed in water, for example, N, N-dimethylformamide (hereinafter abbreviated as “DMF”) will be described.
The DMF concentration in the aqueous solution and the DMF concentration in methylene bromide in the examples were determined by an internal standard method using a gas chromatograph.

  Example for step (1) (extracting DMF in water with methylene bromide)

[Example 1]
200 g of an aqueous solution containing 1% by weight of DMF is placed in a separatory funnel, and 2000 g of methylene bromide is added thereto, followed by shaking for 5 minutes, and an extraction operation (first time) is performed to extract the methylene bromide extraction phase from the aqueous phase. separated. To the remaining aqueous phase, 2000 g of fresh methylene bromide was added, and the extraction operation (second time) was performed by shaking again for 5 minutes to separate the methylene bromide extraction phase. After the same operation was repeated once more (third time), the DMF concentration in the aqueous phase was 0.063 wt%.
As a result of the above operation, the recovery rate of DMF in the aqueous solution by the extraction three times reached 93.7%.
The results are shown in Table 1.

[Examples 2 to 4]
200 g of an aqueous solution containing 5% by weight of DMF was placed in a separatory funnel, 2000 g of methylene bromide was added thereto, followed by extraction with shaking for 5 minutes, and then the DMF concentration in the separated aqueous phase was 2.03% by weight. became. As a result, the recovery rate of DMF in the aqueous solution by one extraction operation reached 59.4%.
Similarly, when the concentration of DMF in the aqueous solution is different, the results obtained in the same manner as in Example 2 are shown in Examples 3 and 4 in Table 1.

[Examples 5 to 10]
200 g of an aqueous solution containing 10% by weight of DMF was placed in a separatory funnel, 1000 g of methylene bromide was added thereto, followed by extraction by shaking for 5 minutes, and then the DMF concentration in the separated aqueous phase was 5.30% by weight. became. As a result, the recovery rate of DMF in the aqueous solution by one extraction operation reached 47.0%.
Similarly, in the case where the types of water-insoluble extraction solvents are different, the results obtained in the same manner as in Example 5 are shown in Examples 6 to 10 in Table 2.

[Examples 11 to 14]
200 g of an aqueous solution containing 10% by weight of DMF was placed in a separatory funnel, 2000 g of methylene bromide was added thereto, followed by extraction by shaking for 5 minutes, and then the DMF concentration in the separated aqueous phase was 3.70% by weight. became. As a result, the recovery rate of DMF in the aqueous solution by one extraction operation reached 63.0%. 2000 g of new methylene bromide was added to the aqueous phase after this treatment, and the same extraction operation was repeated 2 to 4 times.
The results are shown in Table 3 and FIG.
In FIG. 4, the number of extractions 0 is the DMF concentration before the extraction operation, and 1 to 4 corresponds to Examples 11 to 14 in order.

[Examples 15 to 17]
200 g of an aqueous solution containing 10% by weight of DMF was placed in a separatory funnel, and 1000 g of 5-fold weight of methylene bromide was added thereto, followed by extraction by shaking for 5 minutes, and then the DMF concentration in the separated aqueous phase was 5. It became 30% by weight. As a result, the recovery rate of DMF in the aqueous solution by one extraction operation reached 47.0%.
Similarly, when the weight ratio of methylene bromide with respect to the aqueous solution is different, the results obtained in the same manner as in Example 15 are shown in Examples 16 to 17 in Table 4.

From the above results, it was found that the extraction efficiency of DMF in the aqueous solution increases as the weight ratio with respect to the aqueous solution of methylene bromide increases.

Step (2) (Adsorption of DMF in methylene bromide with metal chloride)

[Examples 18 to 20]
200 g of the extraction phase obtained in Example 1 was put in a glass container, 10 g of powdered anhydrous cupric chloride was added thereto and stirred for 5 minutes, and the DMF concentration in the extraction phase (methylene bromide) was 0.00. It decreased from 064% by weight to 0.003% by weight. By this adsorption operation, the reduction rate of the DMF concentration in methylene bromide was 95.3%.
In the extraction operation of Example 1, the same operation was performed on the second and third extraction solutions, and Examples 19 and 20 were obtained.
The results are shown in Table 5.

[Examples 21 and 22]
When 200 g of methylene bromide containing 0.1% by weight of DMF was put in a glass container and 20 g of powdered anhydrous calcium chloride reagent was added thereto and stirred for 5 minutes, the DMF concentration in methylene bromide was 0.015% by weight. Declined. By this adsorption operation, the rate of decrease in DMF concentration in methylene bromide was 85%. The same operation was performed when the added amount of anhydrous calcium chloride was 10 g.
The results are shown in Table 6.

[Examples 23 to 26]
200 g of methylene bromide containing 0.1% by weight of DMF is put in a glass container, and 20 g of a powdery mixture containing 10% by weight of anhydrous cupric chloride and 90% by weight of anhydrous calcium chloride is added thereto and added for 5 minutes. Upon stirring, the DMF concentration in methylene bromide dropped to 0.002% by weight. By this adsorption operation, the rate of decrease in DMF concentration in methylene bromide was 98.0%. The same operation was performed when the amount of inorganic adsorbent added was 10 g, 6 g, and 2 g.
The results are shown in Table 7.

[Example 27]
200 g of methylene bromide containing 0.1% by weight of DMF was placed in a glass container, and 10 g of a powdery mixture containing 20% by weight of anhydrous cupric chloride and 80% by weight of anhydrous calcium chloride was added. When 2 g of anhydrous aluminum hydroxide was added thereto and stirred for 5 minutes, the DMF concentration in methylene bromide was lowered to 0.002% by weight. By this adsorption operation, the rate of decrease in DMF concentration in methylene bromide was 98.0%.

Step (3) (DMF is separated by heating metal chloride adsorbing DMF)

[Example 28]
In [Example 24], a mixture of anhydrous cupric chloride and anhydrous calcium chloride separated from methylene bromide was heated at 200 ° C. for 30 minutes to volatilize DMF and water, and 8.6 g of anhydrous cupric chloride. And a mixture of anhydrous calcium chloride was obtained. The recovered DMF was 0.18 g. Further, 8.6 g of the inorganic adsorbent used for one-time adsorption and desorbed by heating was used again, and the odor containing 0.1% by weight of DMF was used. When added to 172 g of methylene chloride and stirred for 5 minutes, the DMF concentration in methylene bromide dropped to 0.004% by weight. The rate of decrease in DMF concentration in methylene bromide by this adsorption operation was 96.0%, which was the same as when an unused inorganic adsorbent was used.

[Example 29]
In [Example 27], a mixture of anhydrous cupric chloride, anhydrous calcium chloride and anhydrous aluminum hydroxide separated from methylene bromide was heated at 120 to 160 ° C. for 30 minutes under a reduced pressure of 200 to 300 mmHg to obtain DMF. Volatilization was performed to obtain a mixture of 10.5 g of anhydrous cupric chloride, anhydrous calcium chloride and anhydrous aluminum hydroxide. The recovered DMF was 0.19 g.
When 10.5 g of this mixture was used as an inorganic adsorbent and added to 175 g of methylene bromide containing 0.1% by weight of DMF and stirred for 5 minutes, the DMF concentration in methylene bromide was reduced to 0.002% by weight. The decrease rate of the DMF concentration in methylene bromide by this adsorption operation was 98.0%, which was equivalent to the case of using an unused inorganic adsorbent.

  From Examples 28 and 29 above, after heating the metal chloride adsorbing DMF, DMF in methylene bromide was again adsorbed on the metal chloride, and the metal chloride was repeatedly used to separate DMF by heating. I understand that I can do it.

In the first to fifth aspects of the present invention, the separation or separation / recovery limit of the water-soluble nitrogen-containing liquid medium is as low as 0.1% or less, and it is solid-liquid separation. Hard to affect the environment. In addition, since there is little contamination by the inorganic adsorbent and there is no need to adjust the content of the water-soluble nitrogen-containing liquid medium in the aqueous solution, the water-soluble nitrogen-containing liquid medium can cope with both high and low concentrations. Therefore, the water-soluble nitrogen-containing liquid medium can be separated or recovered with high efficiency and low cost from the water-insoluble solvent or aqueous solution containing it. In particular, since the water-insoluble (extraction) solvent and the inorganic adsorbent used in the method of the present invention can be reused, the yield is high, the cost is low, and the environmental measures are excellent.
In the sixth to eighth aspects of the present invention, methylene bromide can be easily removed from water. For example, the concentration of a water-soluble nitrogen-containing liquid medium can be removed below the measurement limit by hexane / octane extraction (conventional use). About 82 ppm of methylene chloride left by octane extraction). In addition, methylene bromide is not regulated by wastewater, is not a regulated substance under the Act on Promotion of Improvement in Management, etc. of Understanding the Release of Specific Chemical Substances into the Environment (PRTR Law), and it is also photodegradable and biodegradable. And has very little impact on the environment. Separation after completion of methylene bromide extraction is easy due to the large specific gravity of 2.5, and the boiling point is easy to handle at about 97 ° C., which is an excellent water-soluble nitrogen-containing liquid medium extractant. .

It is a system flow figure showing one mode of the device of the present invention. It is a system flow figure showing one mode of the device of the present invention. It is a system flow figure showing one mode of the device of the present invention. It is a figure which shows the N, N- dimethylformamide density | concentration in the water phase after extraction operation of Examples 11-14 of this invention.

Explanation of symbols

1 Aqueous solution containing water-soluble nitrogen-containing liquid medium
2 Water-insoluble extraction solvent, extraction solvent
3 Water phase
4 Water-insoluble solvent containing water-soluble nitrogen-containing liquid medium, extraction phase
5 Inorganic adsorbent
6 Water-insoluble solvent, water-insoluble extraction solvent, extraction solvent
7 Inorganic adsorbent adsorbing water-soluble nitrogen-containing liquid medium
8 Water-soluble nitrogen-containing liquid medium
10 Extraction and separation unit
11 Second extraction / separation section
12 Third extraction / separation section
20 Adsorption separation unit
30 Desorption recovery unit
31 First cooler
40 Extraction solvent tank
50 First water extraction and purification section
51 Second water extraction and purification section
52 Third water extraction and purification section
53 First distillation column
54 Second cooler
60 Solvent extraction and purification section
61 Second distillation column
62 Third cooler
P1 transfer pump
P2 transfer pump
P3 transfer pump
P4 transfer pump
P5 transfer pump
P6 transfer pump
P7 Transfer pump
P8 Transfer pump
101 Waste liquid injection line
102 Waste liquid injection line
103 Waste liquid injection line
104 Water phase transfer line
105 Water phase transfer line
106 Water phase transfer line
107 Water phase transfer line
108 Water phase transfer line
109 Water phase transfer line
110 Water phase discharge line
121 Extraction solvent transfer line
122 Extraction phase transfer line
123 Extraction phase transfer line
124 Extraction phase transfer line
125 Extraction solvent transfer line
141 Inorganic adsorbent transfer line after desorption
142 Water-soluble nitrogen-containing liquid medium and inorganic adsorbent transfer line
161 Water-soluble nitrogen-containing liquid medium and water transfer line
162 Water-soluble nitrogen-containing liquid medium and water transfer line
163 Water extraction and purification phase transfer line
164 Water extraction purification phase transfer line
165 Water extraction purification phase transfer line
166 Water extraction and purification phase transfer line
167 Moisture transfer line
168 Extraction and purification phase transfer line
169 Extraction and purification phase transfer line
170 Extraction and purification phase transfer line
171 Vapor transfer line for water-soluble nitrogen-containing liquid medium
172 Water-soluble nitrogen-containing liquid medium transfer line
173 Distillation solvent transfer line
181 Solvent extraction purification phase transfer line
182 Steam transfer line
183 Extraction solvent transfer line

Claims (22)

A method for separating the water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium,
A water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with an inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble A method comprising a step of separating the inorganic adsorbent adsorbing the nitrogen-containing liquid medium and the water-insoluble solvent.   A water-insoluble solvent containing a water-soluble nitrogen-containing liquid medium is brought into contact with an aqueous solution containing the water-soluble nitrogen-containing liquid medium and a water-insoluble solvent, and the water-insoluble solvent is contained by the water-insoluble solvent. The method according to claim 1, which is obtained by extracting a nitrogen liquid medium and separating the water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium from the aqueous phase.   The method further comprises heating the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to desorb and recover the water-soluble nitrogen-containing liquid medium from the inorganic adsorbent. Or the method of 2. A method for separating and recovering the water-soluble nitrogen-containing liquid medium from an aqueous solution containing the water-soluble nitrogen-containing liquid medium,
(1) An aqueous solution containing the water-soluble nitrogen-containing liquid medium is brought into contact with a water-insoluble extraction solvent, and the water-soluble nitrogen-containing liquid medium is extracted with the water-insoluble extraction solvent. Separating the extraction phase and the aqueous phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium;
(2) The extracted phase and an inorganic adsorbent are brought into contact, the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed. Separating the adsorbent from the water-insoluble extraction solvent; and (3) heating the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to thereby convert the water-soluble nitrogen-containing liquid medium into the water-soluble nitrogen-containing liquid medium. A method comprising a step of desorbing and recovering from an inorganic adsorbent.   The method according to claim 1, wherein the inorganic adsorbent is one or more anhydrous metal chlorides.   6. The method of claim 5, wherein the metal chloride is one or more metal chlorides selected from the group consisting of anhydrous cupric chloride and anhydrous calcium chloride.   The method according to any one of claims 1 to 6, wherein an anhydrous metal hydroxide is used as an adsorption aid for the inorganic adsorbent.   8. The method of claim 7, wherein the anhydrous metal hydroxide is anhydrous aluminum hydroxide.   The method according to claim 1, wherein the water-insoluble solvent or the water-insoluble extraction solvent is one or more liquid organic halides.   The method according to claim 9, wherein the organic halide is one or more alkyl bromides having 1 to 3 carbon atoms.   The method according to claim 10, wherein the alkyl bromide is one or more selected from the group consisting of methylene bromide, ethyl bromide, n-propyl bromide, isopropyl bromide.   The water-soluble nitrogen-containing liquid medium is at least one selected from the group consisting of N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and pyridine. The method of any one of Claims.   The method according to claim 12, wherein the water-soluble nitrogen-containing liquid medium is N, N-dimethylformamide.   14. The method according to claim 4, further comprising (4) a step of purifying the water-soluble nitrogen-containing liquid medium recovered in step (3) by subjecting it to extraction treatment and / or distillation treatment. the method of.   Furthermore, (5) The method of any one of Claims 4-14 including the process of collect | recovering this water-insoluble extraction solvent isolate | separated in process (2), and reusing as a water-insoluble extraction solvent.   Further, (6) including the step of recovering the inorganic adsorbent from which the water-soluble nitrogen-containing liquid medium has been desorbed in step (3) and reusing it as an inorganic adsorbent. The method according to claim 1. An apparatus for separating the water-soluble nitrogen-containing liquid medium from a water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium,
A water-insoluble solvent containing the water-soluble nitrogen-containing liquid medium is brought into contact with an inorganic adsorbent, and the water-soluble nitrogen-containing liquid medium is adsorbed by the inorganic adsorbent, so that the water-soluble An apparatus comprising an adsorption separation unit for separating the inorganic adsorbent adsorbing the nitrogen-containing liquid medium and the water-insoluble solvent. An apparatus for separating and recovering the water-soluble nitrogen-containing liquid medium from an aqueous solution containing the water-soluble nitrogen-containing liquid medium,
(A) contacting the aqueous solution containing the water-soluble nitrogen-containing liquid medium with a water-insoluble extraction solvent, and extracting the water-soluble nitrogen-containing liquid medium with the water-insoluble extraction solvent; An extraction / separation unit for separating an extraction phase comprising the water-insoluble extraction solvent containing a nitrogen-containing liquid medium and an aqueous phase;
(B) contacting the extracted phase with an inorganic adsorbent, adsorbing the water-soluble nitrogen-containing liquid medium with the inorganic adsorbent, and adsorbing the water-soluble nitrogen-containing liquid medium; An adsorption separation unit for separating the adsorbent and the water-insoluble extraction solvent; and (C) the inorganic adsorbent adsorbed by the water-soluble nitrogen-containing liquid medium to heat the water-soluble nitrogen-containing liquid medium. An apparatus including a desorption / recovery unit that desorbs and recovers the inorganic adsorbent from the inorganic adsorbent.   An adsorbent composition for a water-soluble nitrogen-containing liquid medium, comprising at least one selected from the group consisting of anhydrous cupric chloride, anhydrous calcium chloride, and anhydrous aluminum hydroxide. A method for separating a water-soluble nitrogen-containing liquid medium from an aqueous solution containing a water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble Extracting the nitrogen-containing liquid medium, and separating the aqueous phase and the extraction phase comprising the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium. An apparatus for separating the water-soluble nitrogen-containing liquid medium from the aqueous solution containing the water-soluble nitrogen-containing liquid medium,
An aqueous solution containing the water-soluble nitrogen-containing liquid medium is contacted with one or more alkyl bromides having 1 to 3 carbon atoms as a water-insoluble extraction solvent, and the water-soluble extraction solvent is used to bring the water-soluble An extraction / separation unit for extracting the nitrogen-containing liquid medium and separating an extraction phase comprising the water-insoluble extraction solvent containing the water-soluble nitrogen-containing liquid medium and an aqueous phase.   An extractant comprising one or more alkyl bromides having 1 to 3 carbon atoms for extraction of the water-soluble nitrogen-containing liquid medium from an aqueous solution containing the water-soluble nitrogen-containing liquid medium.

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