JPH11147984A - Molded article made of polymer-based adsorbent fine powder and molding method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded article having an adequate capacity for adsorbing org. substances and an adequate strength by forming the same from a fine powder of a polymeric adsorbent and a high-molecular binder (e.g. methylcellulose or polyvinyl alcohol). SOLUTION: The polymeric adsorbent comprises a synthetic polymer (e.g. a copolymer of a monovinyl compd. and a polyvinyl compd.), has a specific surface area of 800 m<2> /g or higher, pref. 1,200 m<2> /g or higher, and is used after ground into a fine powder having an average particle size of 40 μm or lower. The binder is used for binding the absorbent particles to each other and pref. has such a mol.wt. that the binder does not penetrate into the micropores of the adsorbent. A water-soluble polymer (e.g. methylcellulose or polyvinyl alcohol) is used as the binder. The amt. of the binder used is 5-10 wt.% of the adsorbent powder. A soln. of the binder, the adsorbent, and optionally a crosslinker for the binder are mixed, kneaded, extrusion molded into a diameter of about 1-10 mm, and dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded product obtained by molding a fine powder of a polymer-based adsorbent with a binder into large particles and a method for producing the same. More specifically, the present invention relates to a molded article made of a polymer-based adsorbent fine powder having a specific surface area of 800 m ² / g or more per dry weight and having practically sufficient strength.

[0002]

2. Description of the Related Art Recovering organic solvents such as hydrocarbons and halogenated hydrocarbons from contaminated gas is important from an economical point of view as well as from an environmental point of view.
In addition, collecting and removing organic substances present in water or an aqueous solution is an industrially important process, and is indispensable when recovering organic substances useful for medicine and the like from an aqueous solution such as a fermentation liquid. Activated carbon has often been used as an adsorbent for recovering / removing organic solvents from contaminated gas. However, activated carbon to which an organic solvent has been adsorbed requires high-temperature steam during regeneration due to its strong adsorption power. This causes undesired results such as decomposition of chlorinated solvents. Further, when a ketone solvent such as methyl ethyl ketone or cyclohexanone is adsorbed, a serious problem such as ignition occurs due to its catalytic action. In addition, inorganic adsorbents such as zeolite may be used, but in this case, too strong adsorption power,
Catalytic properties are a problem.

In order to avoid these problems, studies have been made on synthetic resin adsorbents having improved porosity and improved adsorbability. The synthetic resin-based adsorbent has features such as being able to freely control the pore diameter and having no catalytic activity. However, none of them has a small particle size and is practically unusable for removing / recovering substances from a fluid having a high flow rate, particularly a gas stream due to a problem of pressure loss.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention provides a polymer-based adsorbent fine powder which has a sufficient organic substance-adsorbing property and a sufficient strength and can be used at a high flow rate. And a method for producing a molded article comprising:

[0005]

That is, the gist of the present invention is as follows.
Forming a polymer adsorbent fine powder and a polymer binder, and pulverizing the polymer adsorbent to a particle size of 40 μm or less, and then using a polymer binder to obtain a polymer adsorbent fine powder and a polymer binder molded body And a method for recovering and removing organic matter from a fluid, characterized by using the adsorbent comprising the molded body and the adsorbent.

[0006] In a preferred embodiment of the molded article of the present invention,
The molded article has a specific surface area of 800 m ² / g or more per dry weight, the polymer binder is a molded article of methyl cellulose and / or polyvinyl alcohol, and the particle diameter of the polymer-based adsorbent fine powder is 40 μm The following molded articles and molded articles obtained by further crosslinking a polymer binder with a crosslinking agent may be mentioned. In a preferred embodiment of the method of the present invention for collecting and removing organic substances, the fluid is a gas, and the organic substance is a gaseous organic substance.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The polymer-based adsorbent is an adsorbent composed of a synthetic polymer, for example, a copolymer of a monovinyl compound and a polyvinyl compound, and has an adsorptivity to organic substances and the like. As the polymer-based adsorbent to be used, the larger the specific surface area, the better the adsorption performance, and therefore, it is preferable to use one having a large specific surface area. Such a polymer-based adsorbent can be produced by a known method, and has a specific surface area per dry weight of 800 cm ² / g or more, preferably 1000 m ² / g or more, more preferably 1200 cm ² / g or more. Those having a specific surface area are preferred. Such a polymer-based adsorbent having a high specific surface area can be obtained, for example, by a method described in JP-A-8-155297 by appropriately selecting production conditions. As an example, it is obtained by haloalkylating a styrene-divinylbenzene copolymer containing 2 to 6% by weight of divinylbenzene and then swelling in an inert organic liquid to form a bridge bond in the presence of a Friedel-Crafts catalyst. be able to. The polymer-based adsorbent thus obtained has a specific surface area of 1000 m ² / g or more.

In the present invention, the value of the specific surface area per dry weight is measured by a nitrogen adsorption BET method. The polymer-based adsorbent fine powder is obtained by pulverizing the polymer-based adsorbent with a pulverizer or the like to form fine particles. For the pulverization, a pulverizer such as a jet mill or a dyno mill can be applied. The pulverization does not reduce the specific surface area of the polymer adsorbent. Average particle size of pulverized product is 40μm
Or less, preferably 10 μm or less. If the pulverized particle size is larger than this, the mechanical strength of the molded body is significantly reduced.

In the present invention, a molded article is obtained by binding the polymer-based adsorbent fine powder with a binder. The binder herein refers to a substance that binds the fine powders, and any substance having this function may be used.However, a binder having a high molecular weight that does not enter the pores of the adsorbent is preferable, for example, methyl cellulose, Polyvinyl alcohol or the like can be used. The binder is used after being dissolved in a liquid such as water. It is preferable that a water-soluble polymer such as methylcellulose or polyvinyl alcohol is used after being dissolved in water. 5% by weight of binder
The content is at least 18% by weight and preferably at most 5% by weight and at most 10% by weight. If it exceeds 18% by weight, the specific surface area decreases, and the actual performance of removing organic substances decreases. On the other hand, if the content is less than 5% by weight, the mechanical strength of the molded body is reduced, and the molded product cannot be used in actual use.

By using a binder crosslinking agent in addition to the binder, it is possible to make the obtained molded body insoluble. When the binder is methyl cellulose or polyvinyl alcohol, a melamine resin, glutaraldehyde, or the like can be used as the binder crosslinking agent.
The details of the molding method will be described below.

A binder solution, a polymer-based adsorbent fine powder,
In some cases, a binder cross-linking agent and a liquid for dissolving the binder for adjusting the hardness are added, kneaded and homogenized with a kneader or the like, and then extruded with a vacuum extruder or the like to adjust the shape. Although the particle size can be controlled by changing the die diameter of the extruder, the diameter is preferably about 1 to 10 mm. Below this, a high pressure loss such as a gas flow causes a large pressure loss, making it practically difficult to use. Above this, there is a problem that the adsorption speed is reduced.

The extruded product is formed by drying the liquid or, if a binder cross-linking agent is used, by treating it at a temperature not lower than its reaction temperature. Obtainable. The molded body obtained in this way has a dry weight of 800
It has a specific surface area of at least m ² / g. Further, the molded article of the present invention has sufficient strength to withstand use at a flow rate.
As a measure of strength, for example, when the molded article of the present invention is used by filling it in a column, a molded article cut to a length of about 5 mm (extruded by a vacuum extruder having an arbitrary die diameter) is subjected to Autograph AGS. It is preferable that the breaking point strength measured using a -500B (manufactured by Shimadzu Corporation) while applying a load at 5 mm / min is about 1.0 kg / piece or more.

[0013]

The polymer-based adsorbent fine powder molded product obtained by the present invention has a specific surface area of 800 m ² / g or more and a
It has a strength of kg / piece or more. Due to its large specific surface area and excellent ventilation properties, it is used especially for the removal of organics from gas streams. Organic substances include volatile organic compounds such as methyl ethyl ketone, cyclohexanone, styrene, toluene, and ethylene dichloride. It is also used in the field of high flow rate conditions in liquid processing and in the field of liquid processing involving colloidal substances. In addition, when used in an upflow, there is an advantage that a high flow rate is possible due to a large particle diameter.

[0014]

The present invention will be described in more detail with reference to representative examples and comparative examples. In addition, the porous beads which are the polymer-based adsorbent raw materials used below were all obtained by the following method.

Reference Example Production of polymer-based adsorbent raw material (100 g of porous beads)
(Production) (Production of crosslinked copolymer beads) 97.1 g of styrene, 5.5 g of divinylbenzene (purity: 56.5%, others: ethylvinylbenzene), dibenzoyl peroxide (purity: 7)
5%, water is 1.37 g, and 25.6 g of polystyrene (average molecular weight: 45,000) are mixed, added to 667 ml of deionized water containing 0.64 g of polyvinyl alcohol and 0.04 g of methylene blue, and stirred to remove oil droplets. Formed. After the temperature was raised to 80 ° C., polymerization was carried out at 80 ° C. for 8 hours to obtain crosslinked polystyrene particles. The obtained particles were washed with water and toluene, and then toluene was distilled off and further dried.

(Haloalkylation of crosslinked copolymer beads)
40 g of the dried crosslinked polystyrene particles were suspended in chloromethyl methyl ether for 1 hour. Next, 20 g of zinc chloride was added, and the mixture was further stirred for 1 hour, heated to 50 ° C., and kept for 8 hours. The reactor was cooled, the reaction was stopped by adding water, and after washing with water, the chloromethylated crosslinked copolymer was dried.

(Production of porous beads) 50 g of chloromethylated crosslinked copolymer beads were swollen in 350 ml of ethylene dichloride for 1 hour. Thereto, 15 g of ferric chloride was added, and the mixture was further stirred for 1 hour. After the temperature was raised to 80 ° C., the temperature was further maintained for 8 hours and then cooled to stop the reaction. After distilling off ethylene dichloride, the porous beads of the post-crosslinked copolymer were dried to obtain a product. The specific surface area of the obtained porous beads per dry weight by a nitrogen adsorption BET method (all the specific surface areas described below were measured by this method) was 156.
It was 0 m ² / g.

Example 1 The beads obtained in the above reference example were pulverized with a jet mill to obtain a pulverized product having an average particle size of 7.1 μm. Particle size is measured by laser diffraction scattering type particle size distribution analyzer SK RAS
It is a value measured with ER MICRON SIZERLMS-24 (manufactured by Seishin Enterprise). 700 g of the adsorbent fine powder and 12,60 g of a 4.6% aqueous solution of methylcellulose (Metroze SM-100; manufactured by Shin-Etsu Chemical Co., Ltd.) were kneaded with a kneader until uniform, and extruded with a vacuum extruder having a die diameter of 5 mm. The obtained extrudate was air-dried for 48 hours, and then dried at 120 ° C. for 12 hours with a blow dryer to obtain a molded product. The specific surface area of the obtained molded body was 1060 m ² / g. After cutting to a length of about 5 mm, the crushing strength measured using an Autograph AGS-500B (manufactured by Shimadzu Corporation) at a load of 5 mm / min (hereinafter the crushing strength is measured by the same method) is 2
It was 0.2 kg / piece. The column was packed into a column having an inner diameter of 30 mm, and air was aerated at room temperature. The differential pressure between the inlet and outlet of the column was about 30 mmH ₂ O / m at a linear velocity of 0.10 m / s in terms of 1 m.

Example 2 900 g of the polymer-based adsorbent fine powder described in Example 1 and 4.6% methylcellulose (Metroze SM)
-100; Shin-Etsu Chemical) aqueous solution 1261 g, melamine resin (Sumi
63.8 g of tex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.) was kneaded with a kneader until uniform, and then extruded with a vacuum extruder having a die diameter of 5 mm. After drying the obtained extrudate for 48 hours,
Drying was performed at 120 ° C. for 12 hours using a blow dryer, and a crosslinking reaction was performed to obtain a molded product. The specific surface area of the obtained molded body is 1330 m ²
/ g. After cutting to a length of about 5 mm, the crushing strength measured by an autograph was 20.1 kg / piece.

Example 3 497 g of the polymer-based adsorbent fine powder described in Example 1 and 4.6% methyl cellulose (Metroze 90)
-SH4000; Shin-Etsu Chemical) aqueous solution 672g, melamine resin (Su
34.0 g of Mitex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.) was kneaded with a kneader until uniform, and extruded with a vacuum extruder having a die diameter of 5 mm. The obtained extruded product was air-dried for 24 hours, dried at 120 ° C. for 12 hours, and subjected to a crosslinking reaction to obtain a molded product. The specific surface area of the obtained molded body was 1310 m ² / g. After being cut to a length of about 5 mm, the crushing strength measured by an autograph was 31.8 kg / piece.

Example 4 The polymer-based adsorbent of Example 1 was pulverized with a jet mill to obtain 10.1 g of a polymer-based adsorbent fine powder having an average particle diameter of 5.1 μm and 10% methylcellulose (Metroze SM-100; manufactured by Shin-Etsu Chemical Co., Ltd.). After 20.0 g of the aqueous solution was kneaded in a mortar until uniform, it was extruded using a hydraulic extruder having a die diameter of 3 mm. The extrudate obtained is kept at 120 ° C for 12
After drying for a time, a molded product was obtained. The specific surface area of the obtained molded body was 730 m ² / g. The crushing strength measured by an autograph after cutting into a length of about 5 mm was 28.1 kg / piece.

Example 5 10.0 g of the polymer-based adsorbent fine powder of Example 4 and 2.3% methylcellulose (Metroze SM-1)
(00; Shin-Etsu Chemical Co., Ltd.) 20.0 g of an aqueous solution was kneaded in a mortar until uniform, and then extruded using a hydraulic extruder having a die diameter of 3 mm. The obtained extrudate was dried at 120 ° C. for 12 hours to obtain a molded product. The specific surface area of the obtained molded body is 1460 m ²
/ G. The crushing strength measured by an autograph after cutting into a length of about 5 mm was 0.7 kg / piece.

[Comparative Example 1] (When no binder was used) A synthetic adsorbent SP850 (Mitsubishi Chemical Co., Ltd.) (average particle size: 400 μm) composed of a styrene-divinylbenzene copolymer was packed in a column having an inner diameter of 30 mm, and air Was ventilated. The differential pressure between the inlet and outlet of the column is converted to 1m, and is approximately 1000
mmH was ₂ O / m.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101/00 C08L 101/00

Claims (9)

[Claims] 1. A molded article comprising a polymer-based adsorbent fine powder and a polymer binder. 2. The molded article according to claim 1, which has a specific surface area of 800 m ² / g or more per dry weight. 3. The molded article according to claim 1, wherein the polymer binder is methyl cellulose and / or polyvinyl alcohol. 4. The polymer-based adsorbent fine powder has a particle size of 40 μm.
The molded article according to any one of claims 1 to 3, which is: 5. The molded article according to claim 1, wherein the polymer binder is further crosslinked with a crosslinking agent. 6. The polymer adsorbent is pulverized to a particle size of 40 μm or less, and then a molded body comprising a polymer adsorbent fine powder and a polymer binder is obtained using a polymer binder. 5. The method for molding a molded article according to any one of 5. 7. An adsorbent comprising the molded article according to claim 1. 8. A method for recovering and removing organic matter from a fluid, comprising using the adsorbent according to claim 7. 9. The method of claim 8, wherein the fluid is a gas and the organic is a gaseous organic.