JPS61171507A - Purification of organic solvent - Google Patents

Abstract

PURPOSE:To easily separate and remove a metal and moisture, by contacting an org. solvent containing a minute amount of a metal and moisture with a dried porous strong acidic cation exchange resin having a sulfonic acid group. CONSTITUTION:A sulfonic acid group is introduced into a polymer having physical fine pores, which was obtained by polymerizing styrene and divinylbenzene by a special method, as an exchange group to obtain a porous strong acidic cation exchange resin which is, in turn, dried to usually adjust the water content thereof to 0.2% or less, pref., 0.03% or less. Thus obtained cation exchange resin is contacted with an org. solvent containing a minute amount of a metal and moisture to adsorb the metal and moisture. The metal is desorbed by contacting an aqueous hydrochloric acid solution with the ion exchange resin and moisture is desorbed by the drying treatment of said resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for purifying an organic solvent containing trace amounts of metal and water. For more information.

The present invention relates to a method for simultaneously removing trace amounts of metal and water contained in an organic solvent by bringing the organic solvent into contact with a specific processing agent.

[Conventional technology]

Organic solvents manufactured and stored in chemical factories usually contain trace amounts of metals leached from the inner surfaces of equipment such as piping and storage tanks.
Contains iron. Organic solvents are used by lumberjacks, but trace amounts of metals often have a negative effect on some applications.

For example, it thermally decomposes cordichloroethane and acts as an agent to cause abnormal coking.

This increases the frequency of decoking, shortens the life of the pyrolysis equipment, and also leads to a decrease in the production amount of vinyl chloride monomer. Therefore, it is important to reduce the iron concentration in the raw material l, - dichloroethane as much as possible. It has become necessary.

In addition, organic solvents used for semiconductor applications are required to have as low a metal content as possible in response to improved performance.

Conventionally, various methods have been known to separate metals, such as iron, from organic solvents that contain trace amounts of iron. The law is known.

[Problem that the invention seeks to solve]

However, although it is easy to separate and remove the metals in the organic solvent in the method (2) above, it requires utilities such as a large amount of heat source to distill the organic solvent, so it is not necessarily an industrially advantageous method. I can't say that. Furthermore, in many cases, it is not possible to simultaneously separate and remove trace amounts of water contained in the organic solvent using the distillation method. For example, in the case of l,-1 dichloroethane that contains trace amounts of water and iron, the iron is separated and removed by distillation, but the water forms an azeotrope with the co-dichloroethane and the water is absorbed on the distillate side. This poses a problem in that the 7 columns cannot separate and remove the water as it distills off.

Next, although it is easy to separate and remove the metals in the organic bath agent in the method (2) above, there is a problem in that the organic solvent is contaminated by the elution of impurities contained in the adsorbent. In addition, depending on the type of adsorbent, the organic solvent itself is adsorbed by the adsorbent, resulting in a large loss, and in some cases, there is also the problem that a small amount of water in the organic solvent cannot be adsorbed and separated at the same time.

[Means for solving problems]

The present inventors #: t% In view of the prior art, as a result of intensive study on a method for industrially advantageous separation and removal of metals and water from organic solvents containing trace amounts of metals and water,
By bringing the organic solvent into contact with a dried porous strongly acidic cation exchange resin having sulfonic acid groups,
It was discovered that metals and water are adsorbed on the ion exchange resin and can be easily separated and removed from the organic solvent.

The present invention has now been completed.

That is, the gist of the present invention is to simultaneously remove metals and water by bringing an organic solvent containing trace amounts of metal and water into contact with a dry, porous, strongly acidic cation exchange resin having sulfonic acid groups. %@hf7:, *“71ゝ*,
IICWf;E:,・1 The present invention will be explained in more detail below.

In the method of the present invention, examples of the organic solvent containing trace amounts of metal and water to be treated include organic solvents used for various purposes that have been packaged or stored in chemical factories and the like. It is particularly suitable for application to organic solvents used in applications where trace amounts of metals and moisture have an adverse effect. For example, 1, Kojik, which is used as a raw material for chlorination and nil monomer production, is
Examples include organic solvents such as lactones such as butyrolactone. In addition, the trace amount of metal mainly includes iron. This is caused by metals leaching from equipment such as piping and storage tanks during the production of organic solvents, or metals leaching from containers used during organic solvent transportation, such as tanks, drums, and ships. be.

The porous strongly acidic cation exchange resin used in the method of the present invention is known per se, and is made of physical pores [hereinafter referred to as macropores] obtained by polymerizing styrene and divinylbenzene in a special method. ] (hereinafter referred to as porous polymer) into which a sulfonic acid group is introduced as an exchange group. This is a resin with many macropores with a pore size of several hundred to several thousand 1 inside, and has a large surface area and pore volume, compared to conventional gel-type strong acid cation exchange. Distinguished from resin. The porous strongly acidic cation exchange resins include porous strongly acidic cation exchange resins in which sulfonic acid groups are introduced into a porous polymer with a normal degree of crosslinking, and high acid cation exchange resins in which sulfonic acid groups are introduced into a porous polymer with a high degree of crosslinking. Examples include porous strongly acidic cation exchange resins, etc.
It can be arbitrarily selected from commercially available porous strongly acidic cation exchange resins. Also, the unit of water is gr.

Although the adsorption amount per unit does not change, the equilibrium adsorption amount of metals, such as iron, increases in the case of porous type strong acid cation exchange resins and high porous type strong acid cation exchange resins. that of the cation exchange resin shows the maximum value. Therefore, highly porous type strongly acidic cation exchange resin.

This shows the most excellent effect in achieving the object of the present invention.

Furthermore, the above porous strongly acidic cation exchange resin used in the method of the present invention may have an exchange group of either R type or Na type.

The porous strongly acidic cation exchange resin described above must be dry; before it is brought into contact with an organic solvent containing trace amounts of metal and moisture, it is dried to reduce its moisture content to usually 0.2. % or less, particularly when the water concentration of the processing solvent is desired to be several ppm or less, it is desirable to keep the water content below o, oy %. Conventionally known methods are employed for drying the ion exchange resin, such as drying at room temperature in a nitrogen stream, drying with a hot air stream at a temperature of 100-110°C, or azeotropic drying with water. Examples include drying by azeotropic distillation in the presence of an azeotropic agent to form a mixture.

Either a batch method or a continuous method can be employed as a method for bringing the organic solvent containing trace amounts of metal and water into contact with the above-mentioned strongly acidic cation exchange resin according to the method of the present invention.

In the case of a batch method, the above-mentioned strongly acidic cation exchange resin is added to an organic solvent containing trace amounts of metal and water in a weight ratio of 14% or more (depending on the adsorption capacity), Normally 3 at a temperature of 700°C or less, preferably at room temperature
More than 0 minutes.

Preferably, stirring is carried out for one hour or more.

Further, in the case of a continuous method, an organic solvent containing trace amounts of metal and water is passed through a packed bed filled with the above-mentioned strongly acidic cation exchange resin in an upward flow or a downward flow.

The passing conditions for the organic solvent are usually such that the temperature of the passing liquid is ioo°C.
Hereinafter, preferably at room temperature, the linear velocity O03~/, Or
IL/hr and with the superficial velocity of the ion exchange resin maintained at a packed bed height equal to or greater than the length of the adsorption zone, usually
This is done within the range of ``Ohr'' or less.

f, iie, lj method "" trace amount 0941 t, &lHe
Strongly acidic cation exchange resins can be easily regenerated by desorbing metals, such as iron, in the form of iron chloride from the strongly acidic cation exchange resins by contacting them with aqueous hydrochloric acid. In addition, the strongly acidic cation exchange resin moistened with the regenerated water can be dried into a container by the drying method described above to regenerate the strongly acidic cation exchange resin. an azeotrope forming a boiling mixture;
For example, aromatic hydrocarbons such as xylene and toluene, /
A method of drying by azeotropic distillation in the coexistence of a halogenated hydrocarbon such as Kodichloroethane is advantageous as a method to be carried out industrially.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 4rnl of a porous strongly acidic cation exchange resin (manufactured by Mitsubishi Chemical Corporation @ 4, trade name: Diaion PK-Co/AH type) with a moisture content of Q, /Jidochi or less was filled into a flask, and the mixture was poured from the top. Crude dichloroethane containing 0.00 ppm of water and 2 ppm of iron was added dropwise at a rate of 0.11117 min to the ion exchange resin layer, and a portion of the dichloroethane solution at the outlet of the ion exchange resin layer was added. It was directly connected to a Karl Fischer moisture meter, and the H and O degrees were measured at regular intervals, and at the same time, the Fe # degree was also measured in part by atomic absorption spectrometry.

For H and O, the breakthrough point is J wtppm, and for Fs, it is 0. /wtppm as the breakthrough point, the amount of moisture adsorption is approximately IA data & I (ry Re5in), and the adsorption amount of iron is /, 0 / my -Fe/Ji
'-fflry Re5in.

The example resin was a Hibo 2S type strong acidic cation exchange resin (manufactured by Mitsubishi Chemical Corporation, trade name: Diaion HPK-&, tH type).
The treatment was carried out under the same conditions as in Example 1, except that the conditions were changed. As a result, the amount of moisture adsorbed is approximately 10 to 10 - He O
/I! -With dry resin, the adsorption amount of iron is
The material was my-Fe/Jil-dryResin.

Comparative example! Gel-type strongly acidic cation exchange resin (Mitsubishi Chemical Corporation)
All treatments were carried out under the same conditions as in Example 1, except that the treatment was changed to a Diaion 5x-1BNa type (manufactured by Diaion Co., Ltd.). The result is that the amount of moisture adsorbed at room temperature is approximately 5~Q 4tm9LO/hry Re
Blm, and there was no adsorption ability for iron at all immediately after the initial liquid flow.

Example 3 In Example, 2 VC, 1 of the solvent to be treated, 1 of Kodichloroethane, water/4 Q pp, and iron! , O
The treatment was carried out under the same conditions as in Example 1, except that isobutyl alcohol containing ppm was used. As a result, the adsorption amount Fi of ago is 7.7■-Ha O/I ar
y Re5in b Adsorption amount of iron is /,, g m9-
It was Fe/1-dry Re5in.

〔Effect of the invention〕

According to the method of the present invention, trace amounts of metal and water can be easily separated and removed at the same time by bringing an organic solvent containing trace amounts of water and metals, such as iron, into contact with a specific porous ion exchange resin.

Claims (1)

[Claims] (1) An organic solvent that simultaneously removes metals and water by contacting an organic solvent containing trace amounts of metal and water with a dry porous strongly acidic cation exchange resin having sulfonic acid groups. Purification method.