JPS61183235A - Production of chlorobenzene - Google Patents

Abstract

PURPOSE:To make it possible to reuse a catalyst and improve easily the yield without forming by-products, by chlorinating benzene with chlorine to give the titled compound useful as a raw material compound for agricultural chemicals and various industrial chemicals. CONSTITUTION:Benzene is chlorinated with chlorine in the presence of mordenite type zeolite as a catalyst to give the aimed compound. The chlorination reaction is carried out at about 5-80 deg.C, preferably about 50-70 deg.C. The above-mentioned catalyst is one of crystalline aluminosilicate compounds, and may be synthetic or naturally occurring material. The mordenite type zeolite is a molecular sieve having a very regular and definite diameter and further tunnels or holes of uniform mechanism. Synthetic mordenite type zeolite is particularly preferred. The amount to be used is 0.1-20wt.%, preferably 1-10wt.% based on the benzene.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing lolobenzene, which is useful as a raw material compound or solvent for dyes, agricultural chemicals, and various industrial chemicals.

(Prior Art) Various catalysts have been proposed for the production of chlorobenzene by chlorinating benzene to chlorine. For example, methods are known in which Lewis acids such as ferric chloride, antimony trichloride, antimony pentachloride, aluminum chloride, and titanium tetrachloride are used alone or in combination with sulfur compounds such as iron sulfide and carbon disulfide. It is being When benzene is chlorinated using chlorine using these catalysts, it is possible to produce high-purity chlorobenzene without by-products such as benzene hexachloride (hereinafter abbreviated as BHC). In order to remove the catalyst, a process such as washing with hydrochloric acid water is required, and it is generally impossible to reuse the recovered catalyst.

Furthermore, in recent years, several reports have been made on the chlorination of benzene using zeolite as a catalyst.

For example, in Japanese Patent Publication No. 49-10658, Φ chlorination is carried out using Y-type zeolite as a catalyst carrier. In addition, JP-A-57-77651 reports a method for producing dichlorobenzene by gas phase reaction using zeolite with an average pore size of 5 to 13A, but in liquid phase reaction, the chloride generated It is stated that because the adsorption power of hydrogen to zeolite is greater than that of benzene, the activity of zeolite is significantly reduced, which poses a practical problem. Furthermore, JP-A-59-165529 reports liquid phase chlorination using an L-type zeolite catalyst;
By-products are seen.

(Problems to be Solved by the Invention) The present inventors have conducted extensive research on benzene chlorination catalysts and have surprisingly found that among various zeolites, chlorobenzene can be produced in high yield only when mordenite type is used. It has been found that the catalyst can be obtained at a high yield, without producing any harmful by-products such as BHC, and that the used catalyst can be removed by simple operations such as filtration, and it is also possible to reuse the recovered catalyst. . When other commonly available zeolites such as A, X, Y, and L types are used as catalysts, the chlorination reaction hardly progresses or BHC is produced as a by-product, which is not suitable as a production method. The present invention was completed based on this knowledge.

(Means for Solving the Problems) That is, the present invention provides a method for producing chlorobenzene, which is characterized by reacting benzene and chlorine in the presence of mordenite-type zeolite.

The benzene used in the present invention can be used as a commercially available product, but it can also be used by reducing the water content to 50 ppm or less by using a dehydrating agent such as an ion exchange resin or molecular sieve, or an azeotropic dehydration operation. It is desirable to do so.

In addition, the mordenite type zeolite used in the present invention is one of crystalline alkinosilicate compounds, and there are also synthetic products,
Molecular sieves, some of which occur naturally, have tunnels or pores of a uniform structure with a very regular and constant diameter, and synthetic mordenite-type zeolites are particularly preferred. The ideal chemical formula is NagA/, sS14oOg
g ・24H20 or (Na*O)n @ (Aj4
03)4* (8104)4) ・24H20 However, as a general property of zeolite, it is possible to exchange sodium ions with cations such as hydrogen, potassium, ammonium, etc. 5iOB/A-t, tos The ratio is within a range that does not collapse the mordenite structure, for example 1.
It is also possible to vary from 0 to 150.

In this way, mordenite has a high silica to alumina ratio compared to general zeolites, so it has a unique ability to undergo complete acid exchange from the initial sodium type to the hydrogen type, and is extremely stable against acids and alkalis. Excellent. When it is used as a chlorination catalyst as in the present invention, it is particularly advantageous that it has excellent acid resistance, and we believe this is the reason why it can be reused repeatedly.

The ion-exchangeable cation of the mordenite-type zeolite used in the present invention is usually available as a sodium ion, but essentially any one may be used, and at least one selected from -valent or divalent metals, hydrogen, and ammonium ions may be used. It is a type of cation. Particularly preferred are sodium or hydrogen ions.

Ion exchange methods for these cations are well known to those skilled in the art with knowledge of the production of crystalline aluminosilicates, and typically involve ion exchange of an aqueous nitrate solution of one or more cations to be exchanged into the zeolite. It is preferable that the treatment liquid be brought into contact with zeolite for ion exchange. It is also preferable to use an aqueous solution of other soluble salts such as chlorides in place of nitrates. Further, the cations may be subjected to the ion exchange treatment using a single ion exchange solution, or may be divided and treated several times. The method may be a batch method or a continuous method. The temperature at this time ranges from 20 to 100℃, but in order to speed up the exchange rate, it is necessary to
00°C is preferred. After ion exchange treatment, for example;
It is necessary to wash thoroughly with water until NO3- and Ct- ions are no longer detected.

Furthermore, before using zeolite as a catalyst, it is necessary to remove the water of crystallization in advance. Normally, the crystallization water content can be reduced at temperatures above 100°C, preferably '
Most of the water of crystallization can be removed by heating at 500 to 600°C.

The shape of the zeolite used in the present invention may be in the form of a powder, a crushed lump, or a molded product obtained by compression molding, extrusion molding, marmerizer molding, or the like.

In order to chlorinate benzene by the method of the present invention, 0.1 to 2
Chlorine is mixed and introduced in a proportion of 0% by weight, preferably 1 to 10% by weight. The amount of chlorine introduced into the reaction system is not particularly limited and may be selected appropriately depending on various conditions, but it is usually an amount sufficient to produce chlorobenzene, that is, an amount stoichiometrically equivalent to benzene, or If the amount is less than that, unreacted benzene can be recovered. Furthermore, an inert gas such as nitrogen may be used during the reaction. The above reaction may be carried out under reduced pressure or increased pressure, but is usually carried out at normal pressure.

Although the chlorination reaction in the present invention proceeds over a wide range of temperatures, the temperature range is generally about 5 to 80°C, more preferably about 50 to 70°C.

The method of the present invention can be carried out by either a batch method or a continuous method. In addition, the raw materials benzene and chlorine are all consumed by chlorobenzenes, and there is almost no chlorine that escapes.There are no highly toxic by-products such as BHC other than the purple chloride that is generated with this, and therefore it is not suitable for the purpose. It is extremely easy to separate and purify chlorobenzene. The method for separating chlorobenzene from the reaction solution is as follows:
Although not particularly limited, - Grain pressure can be obtained at the required purity by distillation using a rectification column having an appropriate separation capacity.

(Effects of the Invention) Thus, according to the method of the present invention, chlorobenzene can be obtained with high purity and high yield by chlorination of benzele, and the catalyst can be reused. Furthermore, it is suitable for producing chlorobenzene, as post-reaction treatment operations are easy.
The effect is extremely high.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Benzene 117F (1°5 mol) and H-mordenite type zeolite powder, which had been previously dehydrated to sp. Of(6,0% by weight
) and raise the temperature to 70°C while passing nitrogen gas. Next, the nitrogen gas was stopped, and while maintaining the same temperature, chlorine gas was blown in at a rate of 1α7f/hour for 75 hours with stirring, and the composition of the reaction liquid at the time of 2.5 hours, 5.0 hours, and 75 hours was measured using a gas chromatograph. Analyzed by. The results are shown in the table below.

It should be noted that almost 100% of the blown chlorine reacted, and titration analysis showed that there was almost no dissipation of unreacted chlorine. Furthermore, there was no particular problem in reusing the zeolite recovered separately after the reaction was completed.

In addition, the H-mordenite type zeolite used in the reaction was a powdered product named Zeolon 900H manufactured by Two-Tone Co., Ltd. in the United States.
The product was activated by heating at 00°C for 3 hours.

In addition, the Yotsuro flask was affected by BI (C) due to the influence of school lights.
In order to avoid by-products, the outer surface was painted over with commercially available black paint.

Example 2 A reaction was carried out using the same apparatus and method as in Example 1, using as a catalyst a Na-mordenite type zeolite powder product manufactured by Two-Tone Corporation in the United States, whose trade name is Zeolon 90ONa, and containing 9% by weight of zO. The results of gas chromatograph analysis are shown in the table below. In addition, the amount of chlorine released in this reaction was small, and it was possible to reuse the zeolite.

Example 3 Using the same equipment and method as in Example 1, H-mordenite type zeolite (product name: Zeolon 900H, manufactured by Two-Tone Corporation, USA) was ion-exchanged with a potassium nitrate aqueous solution as a catalyst to produce a 10.0% H-mordenite type zeolite. The reaction was performed using % heavy needles.

The results of gas chromatograph analysis are shown in the table below.

In this reaction, the amount of chlorine escaped during the 15-hour reaction was 16% of the amount of blown chlorine, which was slightly larger.

Comparative Examples 1 to 4 Using the same equipment and method as in Example 1, Na-X type zeolite (Molecular Sheep 13X manufactured by Union Showa Co., Ltd.) was used as a catalyst.
), K-Y type zeolite (Toyo Soda Kogyo Department T8Z-52
0KOA), Na-A type zeolite (Molecular Sheep 4A manufactured by Union Showa Co., Ltd.), and Ni-L type zeolite (Toyo Soda Kogyo Co., Ltd.'m'rsZ-500KOA) were used in amounts of &0% by weight and reacted for 5 hours. The results of analysis by gas chromatography and the reaction rate of blown chlorine are shown in the table below, and the results show that most of the chlorine had no catalytic effect or produced harmful HCs as by-products.

Claims (1)

[Claims] A method for producing chlorobenzene by chlorinating benzene with chlorine, the method comprising using mordenite-type zeolite as a catalyst.