JPS62197145A - Adsorbent - Google Patents

Abstract

PURPOSE:To enhance the adsorbing capacity of DMF or alcohol, by preparing an adsorbent of a polar org. solvent from a copolymer consisting of vinyl phyridine and/or quaternized vinyl pyridine and a monomer represented by a specific general formula. CONSTITUTION:At least, vinyl pyridine (VP) and/or quaternized vinyl pyridine (QVP) and a monomer represented by formula [wherein R1 is hydrogen or a 1-6C alkyl group and R2 is -COR3, -COOR3 or -OCOR3 (wherein R3 is a 1-6C alkyl group)] are copolymerized by employing a usual radical polymerization method. This copolymer is formed into a fibrous or powdery form to obtain an adsorbent. In the copolymer composition of the aforementioned copolymer, it is necessary to set (VP+QVP) to 5-80mol% and the monomer represented by the formula to 95-20mol%. The obtained adsorbent is enhanced in the adsorbing quantity of a polar org. solvent per specific surface area.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an adsorbent, in particular an adsorbent for polar organic solvents.

The adsorbent of the present invention is capable of selectively adsorbing organic solvents in water, and can be used for wastewater treatment, pure water production, separation of alcohol from aqueous alcohol solutions, and the like.

[Conventional technology 1] Amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMAC) and polar organic solvents such as lower alcohols mix well with water, so it is difficult to remove them from water, and they are generally used as activated sludge. The method of decomposition is taken by the law.

[Problems to be solved by the invention] This activated sludge method is said to be advantageous in terms of cost when treating large amounts of wastewater, but when the amount of wastewater is small or in areas where land prices are high, If there are large fluctuations in quantity and quality, there are problems such as increased land and equipment costs and the inability to respond to fluctuations in the quantity and quality of wastewater.

From this point of view, removal methods using adsorbents or membranes are said to be more advantageous, but the polar organic solvents mentioned above have a strong interaction with water, and currently cloth is not contained in water. No adsorbent that effectively adsorbs trace amounts of polar organic solvents or a method for efficiently separating alcohol from aqueous alcohol solutions has yet to be found.

The present invention provides an adsorbent suitable for separating lower alcohols such as methanol, ethanol, and butanol, polyhydric alcohols such as glycerin, and polar organic solvents such as amide solvents such as DMF and DMAc contained in water from water. It's about doing.

[Means for Solving the Problems] That is, the gist of the present invention is to solve at least vinylpyridine (hereinafter referred to as V
P) and/or quaternized vinyl pyridine (QVP) and monomer A represented by formula (I) as copolymerization components, and the composition of the copolymer is (VP+QVP). ): 5-80 mol% Monomer A
:95 to 20 mol%.

CH2= CRI(R2)...(I) (However, R1 is hydrogen or C1 to C6 alkyl group, R3 is C to C6 alkyl The adsorbent of the present invention contains 5 to 80 moles of vp and/or QVP. %, preferably 10 to 70 mol %, and 95 to 20 mol %, preferably 90 to 30 mol % of a vinyl monomer represented by the above formula (T) (referred to as monomer A) as a second component. .

Examples of the monomer A include CINC6 vinyl alkyl ketones such as methyl vinyl ketone and ethyl vinyl ketone, acrylates or methacrylates such as methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate, vinyl acetate, vinyl propionate, vinyl butyrate, etc. vinyl esters.

If the structure of the monomer A is other than formula H), or if the composition of the copolymer deviates from the above-mentioned range, the adsorption properties of the adsorbent for polar organic solvents will deteriorate, which is not preferred.

The vinylpyridine used in the present invention may be 4-vinyl and lysine or 2-vinylpyridine, but 4-vinylpyridine is preferably used from the viewpoint of ease of raw material handling.

As long as vP and/or QVP and monomer A are each 5 mol % or more and 20 mol % or more, one or more other monomers that can be copolymerized with these monomers may be copolymerized. Examples of such monomers include styrene, styrene derivatives such as α-methylstyrene, acrylonitrile, α
- Known monovinyl compounds such as methylacrylonitrile, vinyl chloride, acrylamide, hydroxyethyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate can be mentioned. Further, it is preferable to use a crosslinkable monomer as the other monomer because a crosslinkable polymer can be obtained and handling becomes easy. As such a crosslinking monomer, divinyl compounds such as divinylbenzene, ethylene glycol dimethacrylate, and ethylene-bis-acrylamide are preferably used. The crosslinking monomer preferably accounts for 3 to 50 mol% of the copolymer.

In the present invention, in the combination of VP and QVP, vP
It is preferable to use QVP alone rather than using only QVP because hydrophilicity is improved and adsorption treatment becomes easier, and it is preferable that QVP is contained in the copolymer in an amount of 5 mol % or more. QV
When using P, vP may be quaternized in one step, but it is convenient and preferable to synthesize a copolymer using VP and then quaternize vP in the copolymer. . For quaternization, known amine quaternization agents such as methyl iodide and benzyl bromide can be used.

Copolymerization of these monomers can be carried out by ordinary radical copolymerization, including suspension polymerization, emulsion polymerization, bulk polymerization,
Various polymerization forms such as solution polymerization can be used.

The adsorbent made of this copolymer can take various forms such as fibrous and powder, but is preferably in the form of fine particles.

In the case of fine particles, if the copolymer is not a crosslinked polymer, the copolymer can be dissolved in a solvent and coated on the surface of porous glass or silica gel as a support. In the case of a particulate crosslinked polymer, it is preferable that the surface area measured by the BET method after drying be 10♂/g or more, since this increases the amount of polar organic solvent adsorbed per unit weight. The surface area of the crosslinked polymer increases as the crosslinking density increases, but if the crosslinking density is too high, the degree of swelling in an aqueous solution will decrease and the fine particles will be easily destroyed, so the surface area should be 1000 m''/g or less. In the case of these fine particles, the particle size is preferably 0.1 to 3 mm.

The specific surface area of the adsorbent of the present invention can be adjusted by adjusting the crosslinking density in the case of a crosslinked material, the particle size and fiber denier in the case of a non-crosslinked material, and further by the combination of a blowing agent.

The adsorbent of the present invention may be put into an aqueous solution containing a polar organic solvent to adsorb the organic solvent and then filtered to recover the adsorbent, or it may be packed in a column and used as a fixed bed or a fluidized bed. In the case of a fibrous material, it may be placed in a flow path of an aqueous solution containing a polar organic solvent to be adsorbed. In order to desorb the polar organic solvent adsorbed on the adsorbent, for example, heated air may be applied to the adsorbent adsorbed with the organic solvent, and the vaporized organic solvent may be guided to a cooled trap and collected.

The adsorbent after solvent recovery can be used again for solvent adsorption.

[Example] The present invention will be further explained below using Examples.

Example 1 A bead-shaped crosslinked polymer consisting of 40 mol% of methyl vinyl ketone (MVK), 40 mol% of 4-vinylpyridine, and 20 mol% of divinylbenzene as monomer A was synthesized by a suspension polymerization method. That is, 16 g of polyvinyl alcohol with a degree of polymerization of 2000 was added to a third flask containing 4fi ion-exchanged water and uniformly dissolved while stirring at 95 to 100°C.

Next, the inside of the flask was cooled to 60° C. while purging with nitrogen gas. Separately, 4-vinylpyridine (4-VP) 53.3g divinylbenzene (DVP) 54.7g methylhinylketone (MVK) 35.5g toluene
192g Azoisobutyronitrile 1.0
A solution was prepared in which 2 g was dissolved, and the atmosphere was replaced with nitrogen at room temperature for 15 minutes.

While purging the flask with nitrogen gas,
The mixture was heated to 0° C., and a solution containing the monomer 1 initiator and the like was added while stirring at a rotational speed of 1100 rpm, followed by polymerization for 6 hours. After the reaction was completed, the particulate polymer was filtered off, thoroughly washed with ion-exchanged water, and dried. The average particle size of the obtained particles was about 0.3 mm.

The copolymer beads were treated with benzyl bromide to give 4
- About 60% of the vinylpyridine was quaternized. The specific surface area of the beads was 66 m''/g.

12.6 mfi of this resin was packed in a jacketed glass column with an inner diameter of 10 mm, and 6% ethanol was added to the column at 30°C.
．． The liquid was passed through at a rate of 21 ml/min. (This corresponds to a liquid flow rate that allows the same amount of liquid as the resin volume to flow in one hour.) No ethanol was detected in the effluent until the liquid flow rate was 10 mIL. When the amount of liquid passed exceeds 10 ml, a small amount of ethanol is detected in the effluent, and when the amount of liquid passed exceeds 30 ml,
When mfi was reached, the ethanol concentration in the effluent matched that in the stock solution. When the adsorption amount of ethanol per dry resin was calculated from this, it was found that an extremely high adsorption amount was obtained at t7omg/g resin.

After the adsorption experiment was completed, air heated to 80° C. was sent into the column from the top of the column, and the effluent was collected in a trap cooled with dry ice/methanol, and an 18% aqueous ethanol solution was collected. Furthermore, when the above experiment was repeated again using the copolymer particles after ethanol recovery, almost the same amount of ethanol as the first time was recovered.

Example 2 An experiment was conducted in the same manner as that used for ethanol adsorption in Example 1, except that a 0.1% DMF aqueous solution was used instead of a 6% ethanol aqueous solution, and the DMF adsorbed on the resin was The amount of

In addition, commercially available Amberlite resins XAD-4 and XAD-7
A similar experiment was conducted using , and the adsorption amount of DMF was determined for each.

The results are shown in Table 1.

Table 1 In Table 1, the specific surface area is determined by BET after drying each resin.
This is required by law. Table 1 shows that the resin of the present invention has a larger adsorption capacity per unit surface area than commercially available resins.

Examples 3 to 7 4-vinylpyridine was used as the first component, monomer A shown in Table 2 was used as the second component, and crosslinkable monomers consisting of divinyl monomers shown in Table 2 were used as the third component. Suspension polymerization was carried out to obtain the structure shown in , and the obtained bead-shaped crosslinked polymer (particle size 0.2 to 0.3 m)
m) was quaternized using benzyl bromide to the percentage shown in the table. Also, one that does not contain monomer A (Comparative Example 1),
One that does not contain vP or QVP (comparative example 2), monomer A
A bead using another monomer instead of (Comparative Example 3.4) was also synthesized, and using these beads, a selective adsorption experiment of ethanol from an aqueous ethanol solution was conducted in the same manner as in Example 1, and the adsorption capacity was determined. Ta.

The results are shown in Table 2.

VAc: vinyl acetate, DVB divinylbenzene, EMA: ethyl methacrylate, ST: styrene, A
N: Acrylonitrile Example 8 The same adsorbent used in Example 5 was packed in the same column as used in Example 1, and a polar organic solvent aqueous solution having the stock concentration shown in Table 3 was prepared in Example 3. Adsorption experiments of various polar organic solvents were conducted under the same conditions as in 1. The results are shown in Table 3.

Example 9 A terpolymer consisting of 4-VP, MMA, and EGDMA was synthesized using the same polymerization procedure as in Example 1, except that the composition was changed as shown in Table 4. The obtained fine particulate copolymer was prepared in Example 1.
4-VP was quaternized to 60% in the same manner as in Example 1, and after washing, the amount of ethanol adsorption was measured in the same manner as in Example 1. The results are summarized in Table 4.

[Effects of the Invention] As described below, the adsorbent of the present invention has a large adsorption amount of polar organic solvents per specific surface area, and has a high adsorption capacity for polar organic solvents in water, which conventionally could not be effectively adsorbed and removed using ion exchange resins, activated carbon, etc. Polar organic solvents such as DMF and alcohol can be adsorbed and removed using the adsorbent of the present invention, which not only enables low-energy solvent recovery in industries that use these solvents, but also facilitates wastewater treatment. It is also useful for environmental purification.

Claims (1)

[Scope of Claims] 1) At least vinyl pyridine (hereinafter referred to as VP) and/or quaternized vinyl pyridine (hereinafter referred to as QVP) and a compound of the formula (
It is a copolymer consisting of monomer A represented by I) as a copolymerization component, and the composition in the copolymer is in the range of (VP + QVP): 5 to 80 mol% Monomer A: 95 to 20 mol% An adsorbent for polar organic solvents. CH_2=CR_1(R_2)...(I) (However,
R_1 is hydrogen or an alkyl group of C_1 to C_6, R_2
▲There are mathematical formulas, chemical formulas, tables, etc.▼or▲There are mathematical formulas, chemical formulas, tables, etc.▼or▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_3 is an alkyl group of C_1 to C_6) 2) Quaternized vinyl pyridine 5 mol% as a copolymer component
The adsorbent for a polar organic solvent according to claim 1, characterized in that the adsorbent contains at least the following. 3. The adsorbent for polar organic solvents according to claim 1 or 2, further comprising a crosslinkable monomer as a copolymerization component. 4. The adsorbent for polar organic solvents according to claim 3, wherein the copolymer contains 3 to 75 mol% of the crosslinking monomer. 5. The adsorbent for polar organic solvents according to claim 3 or 4, wherein the copolymer is a particulate crosslinked copolymer having a specific surface area of 10 m^2/g or more.