JPH09143164A - Separation of methylquinolines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrial method for efficiently separating both components from a mixture containing 2-methylquinoline and 8-methylquinoline. SOLUTION: In this method for recovering both components by adsorption separation method from a mixture containing 2-methylquinoline and 8- methylquinoline, a faujasite type zeolite is used as an adsorbing agent. The faujasite type zeolite includes preferably a Y type faujasite type zeolite substituted with potassium or silver ion. Since both components can efficiently be separated from a mixture containing 2-methylquinoline and 8-methylquinoline, the method is useful as the method for recovering high-purity 2-methylquinoline and/or 8-methylquinoline.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to separation of methylquinolines from a fraction containing methylquinolines such as coal tar fractions, particularly a mixture of methylquinolines containing 2-methylquinoline and 8-methylquinoline by an adsorption method. It is about how to do it.

[0002]

2. Description of the Related Art Coal tar derived from high-temperature carbonization of coal contains organic bases such as pyridine, methylpyridines, quinoline, methylquinoline and isoquinoline. These organic bases are indispensable as raw materials for organic synthesis of pharmaceuticals, agricultural chemicals, etc., and are collected from coal tar by distillation-acid extraction as organic base-containing fractions. Has been acquired.

However, among these organic bases, methylquinoline is 2-methylquinoline (boiling point: 24
6 ° C.) and 8-methylquinoline (boiling point: 247.8 ° C.) have close boiling points, so it is difficult to separate each component from the mixture by a distillation method which is a general-purpose separation technology. is there.

A clathrate compound separation method is known as a method for separating and recovering methylquinolines from a mixture of methylquinolines from coal tar fractions and the like (JP-A-61-161).
93165). In this method, a diol is mixed with a mixture of methylquinolines to form an inclusion compound with 2-methylquinoline, and methylquinoline having a boiling point close to that which cannot be obtained by a distillation method is separated. The inclusion compound is decomposed to recover 2-methylquinoline. However, this method has a limited recovery rate and has not been put to practical use.

In addition, a crude raw material separated from coal tar or the like is reacted with an acid to form a crystalline salt, and recrystallization is performed by washing or the like and then alkali-decomposed to obtain purified 2-methylquinoline (JP-A-62-62). 198665) and a method for obtaining purified 2-methylquinoline by azeotroping with alkylphenols (JP-A-1-26868). However, none of these methods has been put to practical use because the process is complicated, the separation cost is high, and the purification yield is low.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide:
An object of the present invention is to provide an industrial method for efficiently separating and recovering each component from a methylquinoline mixture containing methylquinoline and 8-methylquinoline.

[Means for Solving the Problems]

That is, the present invention relates to a method for separating both components from a methylquinoline mixture containing 2-methylquinoline and 8-methylquinoline by an adsorption separation method.
A method for separating methylquinolines, which is characterized by using a faujasite-type zeolite as an adsorbent,
The method for separating methylquinolines is preferably a Y-type faujasite-type zeolite as an adsorbent, and more preferably a Y-type faujasite-type zeolite substituted with potassium or silver ions.

The adsorbent used in the present invention is a faujasite type zeolite. The faujasite-type zeolite is a crystalline aluminosilicate represented by the following formula. 0.9 ± 0.2 M _{2 / n} O: Al ₂ O ₃ : xSiO ₂ : y
H ₂ O Here, M represents a cation and n represents its valence.
The faujasite-type zeolite of the above formula includes X-type and Y-type, X-type is x = 2 to 3, Y-type is x = 3 to 6, and y varies depending on the degree of hydration.

In the present invention, of the faujasite-type zeolites, the Y-type faujasite-type zeolite is the preferred adsorbent.

The faujasite-type zeolite used in the present invention may be of the hydrogen ion type or ammonium ion type, but is preferably one substituted with one or more metal ions. The amount of metal ion substitution is not limited, and part or all of the cations may be substituted. It is preferably 10% or more.

The metal ions to be substituted include, for example,
Sodium, potassium, silver, calcium, strontium, barium, zinc, lead, cerium, magnesium,
Examples include ions of copper, aluminum, zirconium, vanadium, molybdenum, manganese, iron, cobalt, nickel, platinum and the like.

Of these, periodic tables Ia, IIa, II
A metal ion selected from groups b, IIIa and VIII is preferable, and examples thereof include ions of potassium, sodium, magnesium, calcium, strontium, barium, zinc, iron, cobalt and nickel.

Particularly, as the adsorbent of the present invention, Y-type faujasite type zeolite substituted with potassium or silver ions is most preferable.

The ion exchange method for these cations is carried out by bringing the zeolite into contact with an aqueous solution of a water-soluble salt of an ion to be exchanged, for example, hydrochloride, nitrate, sulfate, carbonate or the like. The metal ion concentration of the aqueous solution varies depending on the type of the metal salt, but is preferably about 1 to 10% by weight. The method may be a batch type or a flow type. The contact may be repeated several times as necessary. The temperature at this time may be about 20 to 100 ° C. The ion exchange amount varies depending on the type of ions, but can be arbitrarily set depending on the concentration of the solution, the temperature at the time of ion exchange, and the like.

Y-type zeolite and X used in the present invention
The shape of the type zeolite is appropriately selected according to the method of contacting the substance to be separated and the zeolite, and may be a compression molded product, a molded product by spray drying, or a powder.

Further, as the releasing agent used in the present invention,
Known elimination agents can be used, for example, ethers such as diethyl ether, isopropyl ether, n-propyl ether and anisole, for example, ethyl acetate,
Esters such as n-propyl acetate, n-butyl acetate, isopropyl acetate, isobutyl acetate, for example, ketones such as acetone, methyl ethyl ketone, n-propyl ketone, cyclohexanone, for example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol , N-butanol and other alcohols, such as pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, pyridines such as 2,6-dimethylpyridine and 2,5-dimethylpyridine, or acetonitrile. can give. Of these, esters, alcohols, pyridines, acetonitrile and the like are preferable, and particularly,
Ethyl acetate, butyl acetate, methanol, isopropyl alcohol, pyridine, acetonitrile are most suitable.

As the methylquinoline mixture, 2,6-
Any one containing methylquinoline and 8-methylquinoline may be used, but boiling point 24 recovered from coal tar, coal liquefied oil or the like through operations such as distillation and acid extraction is preferable.
It is a fraction containing components in the range of 0 to 250 ° C. It is desirable to remove acidic components such as phenols and heavy components such as pitch in advance.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The method for adsorbing and separating a methylquinoline mixture by the method of the present invention may be a chromatographic preparative method or a continuous adsorbing and separating method using a simulated moving bed.

The continuous adsorption separation method using a simulated moving bed is as follows:
This is an industrial process in which a plurality of adsorption towers are installed and the adsorption, concentration, and desorption operations are carried out in each tower, and these towers are sequentially switched to carry out each operation continuously. First, a methylquinoline-containing fraction or a feedstock diluted with a diluent as necessary is brought into contact with a faujasite-type zeolite adsorbent to selectively adsorb strongly adsorbed components, while weakly adsorbed components as raffinate. Separate (adsorption operation). Next, the raffinate rich in weakly adsorbed components is further contacted with an adsorbent to adsorb the remaining strongly adsorbed components, and the weakly adsorbed components of the raffinate are concentrated (concentration operation). Further, the strongly adsorbed component that has been adsorbed is desorbed from the adsorbent by the desorbent, and is recovered as an extract together with the desorbent (desorption operation).

The adsorption / separation operation of the present invention can be carried out in either the gas phase or the liquid phase. However, it is preferable to carry out the adsorption / separation operation in the liquid phase because lowering the temperature can suppress side reactions. As operating conditions, the temperature is from room temperature to 350 ° C., preferably 5
The pressure is preferably 0 to 250 ° C. and the pressure is from atmospheric pressure to 50 kg / cm ² · G.

[0021]

The present invention will be described in detail below with reference to examples. In Examples and Comparative Examples, the adsorption characteristics were determined according to the following (1).
It is represented by the separation coefficient α in the equation.

[0022]

(Equation 1)

In the following Examples and Comparative Examples, 2-methylquinoline was used as the A component and 8-methylquinoline was used as the B component.
As the component, α is calculated. Also, the amounts of each component are based on weight.

In equation (1), if α is 1.0,
There is no selective adsorption between A and B components. Α is 1.0
If it is larger, the component A is selectively adsorbed, and if it is smaller than 1.0, the component B is selectively adsorbed. Therefore, it can be seen that the more the α is larger than 1.0 or smaller than 1.0, the easier the separation and separation of the A component and the B component are from the A component and the B component.

Example 1 A commercially available Na-substituted Y-type faujasite zeolite (silica / alumina ratio: 5.5) was calcined at 350 ° C. for 4 hours,
Cooled in a dessicator. 10 g of this adsorbent and 5 raw materials
0.1 g was placed in a flask and shaken at 50 ° C. for 3 hours to bring them into sufficient contact. The composition ratio of the raw materials was 2-methylquinoline: 8-methylquinoline: n-pentadecane: isooctane = 2: 2: 46: 0.1 (weight ratio). Then, the liquid phase mixture after contact with the adsorbent was analyzed by gas chromatography, and α in the formula (1) was determined from the composition ratio. Isooctane was added as an internal standard substance for gas chromatography analysis. Table 1 shows the results.

Example 2 Instead of the Na-substituted Y-type faujasite zeolite of Example 1, a commercially available K-substituted Y-type faujasite zeolite (silica / alumina ratio: 5.7) was used as an adsorbent. The experiment was conducted in the same manner as in Example 1. Table 1 shows the results.

Example 3 Fe (Na) Y type zeolite was prepared by partially substituting sodium in the Na-substituted Y type faujasite zeolite of Example 1 with iron ions by an ion exchange method. Using this as an adsorbent, an experiment was performed in the same manner as in Example 1. Table 1 shows the results.

Example 4 Ni (Na) Y type zeolite was prepared by partially substituting sodium of the Na-substituted Y type faujasite zeolite of Example 1 with nickel ions by an ion exchange method. Using this as an adsorbent, an experiment was performed in the same manner as in Example 1. Table 1 shows the results.

Example 5 An Ag (Na) Y type zeolite was prepared by partially substituting sodium in the Na-substituted Y type faujasite zeolite of Example 1 with silver ions by an ion exchange method. Using this as an adsorbent, an experiment was performed in the same manner as in Example 1. Table 1 shows the results.

Example 6 Zn (Na) Y type zeolite was prepared by partially substituting sodium of the Na-substituted Y type faujasite zeolite of Example 1 with zinc ions by an ion exchange method. Using this as an adsorbent, an experiment was performed in the same manner as in Example 1.
Table 1 shows the results.

Example 7 A Mg (Na) Y type zeolite was prepared by partially substituting sodium in the Na-substituted Y type faujasite zeolite of Example 1 with magnesium ions by an ion exchange method. Using this as an adsorbent, an experiment was performed in the same manner as in Example 1. Table 1 shows the results.

Example 8 Instead of the Na-substituted Y-type faujasite zeolite of Example 1, a commercially available HY-type faujasite zeolite (silica / alumina ratio: 5.6) was used as an adsorbent. An experiment was conducted in the same manner as in. Table 1 shows the results.

Example 9 Instead of the Na-substituted Y-type faujasite zeolite of Example 1, a commercially available Na-substituted X-type faujasite zeolite (silica / alumina ratio: 2.5) was used as an adsorbent. The experiment was conducted in the same manner as in Example 1. Table 1 shows the results.

Comparative Example The same experiment as in Example 1 was conducted using a commercially available Na-substituted mordenite type zeolite as an adsorbent in place of the Na-substituted Y type faujasite zeolite of Example 1. Table 1 shows the results.

[0035]

[Table 1]

[0036]

According to the separation method of the present invention, since both components can be efficiently separated from the mixture containing 2-methylquinoline and 8-methylquinoline, the high-purity 2-
It is useful as a method for recovering methylquinoline and / or 8-methylquinoline.

Claims (3)

[Claims] 1. A method for separating both components from a methylquinoline mixture containing 2-methylquinoline and 8-methylquinoline by an adsorption separation method, wherein a faujasite-type zeolite is used as an adsorbent. Method for separating quinolines. 2. The method for separating methylquinolines according to claim 1, wherein the adsorbent is Y-type faujasite zeolite. 3. The method for separating methylquinolines according to claim 1, wherein the adsorbent is Y-type faujasite-type zeolite substituted with potassium or silver ions.