JPH0446250B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for selectively producing ethylbenzene, which is useful as a raw material for styrene. (Prior art) Regarding the method of ethylating benzene in the gas phase, a method using crystalline aluminosilicate ZSM-5 as a catalyst (see Japanese Patent Publication No. 56-44050) developed by Mobil Oil Company in recent years is known. ing. However, if ZSM-5 is used as a catalyst as it is, it is not practical because it produces many by-products such as toluene and ethyltoluene.Mobil Oil Co., Ltd. has developed a method using a catalyst in which ZSM-5 is treated with phosphorus oxide ( (Refer to Japanese Patent Application Laid-Open No. 51-57688), and a process known as the Mobile-Basier process has actually been commercialized using this catalyst. (Problem to be solved by the invention) However, ZSM treated with phosphorus oxide
The method using -5 does have a high selectivity to ethylbenzene and diethylbenzene, reaching 97% in some cases, but it is difficult to achieve extremely high selectivity close to 99%, and there is also the problem of low activity. It was hot. (Means for Solving the Problems) The present inventors have made intensive studies to develop a highly active catalyst with a selectivity to ethylbenzene and diethylbenzene close to 99%, and as a result, the X-ray diffraction diagram It was discovered that when a crystalline borosilicate having the diffraction pattern shown in Table 1 is used as a catalyst, ethylbenzene and diethylbenzene can be obtained with an extremely high selectivity of nearly 99%, leading to the completion of the present invention.

[Table] However, X-ray diffraction analysis uses CuKα rays. That is, the present invention is characterized in that a crystalline borosilicate having a diffraction pattern shown in Table 1 in an X-ray diffraction diagram is used as a catalyst when benzene is reacted with ethylene in a gas phase. It provides a method of conversion. The crystalline borosilicate having the diffraction pattern shown in Table 1 used in the present invention is AZ-2
It is a crystalline borosilicate with a unique crystal structure called (see Japanese Patent Application No. 59-84169). The crystalline borosilicate used in the present invention is
Silica feed material, alumina feed material, boron oxide feed material, sodium feed material, water and 1,8
- Heating a composition containing diamino-4-aminomethyloctane and having a molar ratio of each component in the following range to a temperature of 100 to 250°C and reacting for a sufficient time to form crystals. Manufactured by. Na/ _SiO2 = 0.01 to 0.5 _H2O / _SiO2 = 2 to 100 1,8-diamino-4-aminomethyloctane/ _SiO2 = 0.1 to _{10 Al2O3} / _SiO2 = 0 to 0.05 _{B2O 3} /SiO ₂ =0.005-0.5 Crystalline borosilicate obtained in this way
AZ-2 is a conventionally known borosilicate,
For example, it has an X-ray diffraction pattern that is clearly different from that of borosilicate (see JP-A-53-55500), which is similar to zeolite ZSM-5. Table 2 shows an example of X-ray diffraction data of crystalline borosilicate AZ-2 produced by the above method and crystalline borosilicate similar to zeolite ZSM-5 produced based on JP-A-53-5550. Ta.

[Table] As is clear from Table 2, AZ-2 of the present invention is
It can be seen that the relative intensity of each peak is significantly different compared to ZSM-5 similar crystalline borosilicate. In particular, the strongest peak of AZ-2 is 2θ = 8.9°, while that of ZSM-5 similar borosilicate is 23.2°, and the intensity ratio of 2θ = 8.9° and 23.2° in each X-ray diffraction pattern of both. AZ
-2 is about 5 times that of ZSM-5 similar borosilicate. In addition, the intensity ratio between the two diffraction angles (2θ) of 7.9° and 8.9° is significantly different. That is, ZSM−
The intensity ratio of 2θ=8.9° to 2θ=7.9° for 5-similar borosilicate is about 0.8, whereas that of AZ-2 is about 5, and the difference in intensity ratio between the two is about 6 times. The reaction temperature in the present invention is in the range of 200 to 600°C, preferably 300 to 500°C. Further, the pressure may be normal pressure or increased pressure, and a preferable range is normal pressure to 20 kg/cm ² . The present invention is carried out by a gas phase flow method, but it can be carried out using only benzene and ethylene or a diluent such as nitrogen or hydrogen. Particularly when hydrogen is used as a diluent, the activity may be reduced. This is preferable because it has the advantage that it becomes extremely small. The benzene/ethylene molar ratio in the present invention is 1
-20, preferably 2-10. Further, when hydrogen is used as a diluent, the hydrogen/ethylene molar ratio is in the range of 0.5 to 20, preferably 1 to 10. (Effects of the Invention) According to the method of the present invention, ethylbenzene and diethylbenzene can be produced with higher yield and extremely high selectivity compared to the conventional method using ZSM-5 treated with phosphorus oxide as a catalyst. Obtainable. This becomes extremely advantageous in industrial implementation. (Example) Example 1 1,8-diamino-4-aminomethyloctane
20 g of boric acid (H ₃ BO ₃ ), and 1 g of sodium hydroxide were dissolved in 34 g of water, and 40 g of silica sol (30% by weight SiO ₂ ) was further added to obtain a homogeneous solution. 8 g of 20% sulfuric acid was added dropwise to this solution while stirring to obtain a homogeneous gel. Furthermore, after stirring this gel at high speed at 10,000 rpm in a homogenizer,
Crystallization was carried out by standing at 180°C for 70 hours in a Teflon-lined pressure vessel. After overwashing the obtained product, it was incubated at 120°C for 5
FIG. 1 shows the X-ray diffraction pattern after drying for an hour and then calcining in air at 500° C. for 6 hours. From this diffraction pattern, this product was identified as crystalline borosilicate AZ-2. Further, the SiO ₂ /B ₂ O ₃ molar ratio determined from chemical analysis was 30. Using this crystalline borosilicate AZ-2 as a catalyst, benzene and ethylene were reacted. The experimental conditions were: benzene/ethylene molar ratio = 4.0;
WHSV (benzene standard) = 4.0hr ^-1 , reaction temperature 400
The test was carried out at ℃ and normal pressure. Table 3 shows the results 2 hours and 6 hours after the start of the reaction.

[Table] Example 2 Using the catalyst obtained in Example 1, benzene/
The reaction was carried out at an ethylene molar ratio of 2, a WHSV of 6.0 hr ^-1 , a reaction temperature of 420° C., and normal pressure. Table 4 shows the results for 4 hours after the start of the reaction.

[Table] Example 3 Using the catalyst obtained in Example 1, benzene/
Ethylene/ _H2 molar ratio = 4/1/4, WHSV =
The reaction time was 4.0 hr ^-1 , the reaction temperature was 420°C, and the pressure was 3 Kg/cm ² (gauge pressure). Table 5 shows the results for 3 hours, 80 hours, and 170 hours after the start of the reaction.

[Table] Example 4 1,8-diamino-4-aminomethyloctane
640g, boric acid 16g, sodium hydroxide 32g with water
A homogeneous solution was obtained in addition to 1100 g. To this solution, 1300 g of silica sol (30% by weight SiO ₂ ) was added with stirring to obtain a homogeneous solution. Furthermore, this solution
260 g of 20% sulfuric acid was added and stirred at high speed at 5000 rpm in a mixer to obtain a homogeneous gel. The resulting gel was placed in a Teflon-lined autoclave and heated to 170°C.
It was crystallized for 90 hours. After overwashing the obtained product, it was incubated at 120°C for 5
The X-ray diffraction pattern after drying for an hour and calcining in air at 500° C. for 8 hours is shown in FIG. From this diffraction pattern, this product is AZ-
It was identified as 2. Further, the SiO ₂ /B ₂ O ₃ molar ratio of this product determined by chemical analysis was 45. Using this crystalline borosilicate AZ-2,
Benzene/ethylene/ _H2 molar ratio = 5/1/3,
WHSV=6.0hr ^-1 , reaction temperature 440℃, pressure 5Kg/ ^cm2
(gauge pressure). Table 6 shows the buildup at 20 hours and 60 hours after the start of the reaction.

[Table] Comparative example Dissolve 5 g of aluminum sulfate and 10 g of tetrapropylammonium bromide in 350 g of water, and add Q brand silicate aqueous solution (Na ₂ O = 8.9% by weight,
150 g of SiO ₂ =28.9% by weight, H ₂ O = 62.2% by weight) was added and stirred to obtain a homogeneous gel. 50 g of 20% H ₂ SO ₄ was added dropwise to this gel while stirring to promote gelation. This gel was placed in a Teflon-lined autoclave and crystallized at 150°C for 20 hours with stirring. After over-washing the obtained product, it was dried at 120°C for 3 hours and calcined in air at 500°C for 4 hours. The X-ray diffraction pattern of this product is ZSM-5
It matched the diffraction pattern of Further, the silica/alumina molar ratio determined by fluorescent X-ray analysis was 50. This ZSM-5 was added to a 1N ammonium chloride aqueous solution.
After ion exchange at 60°C for 24 hours, the product was filtered, washed, dried at 120°C for 6 hours, and air-calcined at 500°C for 5 hours to obtain H-ZSM-5. 10 g of the obtained H-ZSM-5 was mixed with 4 ml of trimethyl phosphorite in 50 c.c. of n-octane in a flask.
cc was added to the solution. The mixture was heated at reflux temperature for 80 hours with a gradual flow of nitrogen.
The mixture was then evaporated to dryness, the resulting solid was washed with pentane, and then dried at 120°C for 10 hours.
It was baked at 500°C for 3 hours. The amount of phosphoric oxide supported in the obtained product was 8.2% by weight. Using this phosphorus-containing H-ZSM-5 as a catalyst,
Benzene/ethylene molar ratio=5.5, WHSV=
The reaction was carried out at 4.0 hr ⁻¹ , reaction temperature 420° C., and normal pressure. Table 7 shows the results for 4 hours after the start of the reaction.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 shows the X-ray diffraction pattern of the crystalline borosilicate obtained in Example 1, and FIG. 2 shows the X-ray diffraction pattern of the crystalline borosilicate obtained in Example 4.

Claims (1)

[Claims] 1. Gas-phase ethylation of benzene, characterized in that a crystalline borosilicate having a diffraction pattern shown in the table below in an X-ray diffraction diagram is used as a catalyst when benzene is reacted with ethylene in the gas phase. Law. [Table] However, X-ray diffraction analysis uses CuKα rays.