JPH0246011B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for selectively producing 1,4-dialkylbenzene useful as a starting material for various functional polymers. (Prior art) Regarding the selective production method of 1,4-dialkylbenzene using a catalyst obtained by subjecting crystalline aluminosilicate to various treatments, in recent years, the crystalline aluminosilicate ZSM-5 developed by Mobil Oil Company has been developed.
A method using a catalyst prepared by treating mordenite with various metal oxides (see JP-A-56-145227 and JP-A-56-133223), a method using a catalyst obtained by treating mordenite with a silicate ester (JCS Chem.
Commun, 819 (1982), Chem Lett, 737
(1983)] are known. (Problem to be solved by the invention) The method of treating ZSM-5 with a metal oxide certainly has a high selectivity of 1,4-isomer at over 90%, but since it involves an impregnation process in a metal solution, However, since it also blocks the pores of the crystalline aluminosilicate, it has the disadvantage of significantly reducing its activity. In addition, the selection rate for 1,4-bodies is at most 95%,
It was difficult to achieve a much higher selectivity than that. On the other hand, in the method of treating mordenite with silicate ester, the selectivity for 1,4-isomers is only 70% at most.
The selection rate was by no means satisfactory. (Means for Solving the Problems) As a result of intensive studies to develop a catalyst with high activity and high selectivity, the present inventors found that the silica/alumina molar ratio is 10 or more and the control index is 1 to 15. We have discovered that 1,4-dialkylbenzene can be obtained from monoalkylbenzene with an extremely high selectivity of over 95% and in high yield by using a catalyst prepared by treating crystalline aluminasilicate with a silicate ester-containing gas. , we have completed the present invention. That is, the present invention converts monoalkylbenzene into 1,4-dialkylbenzene in the gas phase by converting crystalline aluminosilicate with a silica/alumina molar ratio of 10 or more and a control index of 1 to 15 in a silicate ester-containing gas. The present invention provides a method for producing 1,4-dialkylbenzene, which uses a catalyst that is treated and then calcined in an oxygen-containing gas. The crystalline aluminosilicate used in the present invention has a silica/alumina molar ratio of 10 or more and a control index in the range of 1 to 15. The control index used here is an index representing the ratio of cracking speeds of n-hexane and 3-methylpentane as described in J. Catal 67 , 218 (1981). This control index was determined by diluting an equal mixture of n-hexane and 3-methylpentane five times with helium.
It is determined by the following formula from the amount of n-hexane and 3-methylpentane remaining when flowing over the catalyst at a temperature range of 260 to 510°C. Control index = log (residual n-hexane)/log (residual 3-hexane)
Methylpentane) When measuring, it is necessary to select the LHSV appropriately so that the overall conversion rate is 10 to 60%, and it is usually 0.05 to 60%.
It is carried out in the range of 1.0hr ^-1 . This control index is related to the size of pores in crystalline aluminosilicate; for example, those with large pores having a 12-membered ring structure are
-Because both methylpentane can enter the vacancy,
The control index will be 1 or less. Furthermore, in the case of small pores having an 8-membered ring structure, n-hexane preferentially enters the pores and cracks them, so the control index becomes a large value of 30 or more. The crystalline aluminosilicate in the present invention is
It has medium-sized pores with a control index value of 1 to 15. The silica/alumina molar ratio used in the present invention is
A crystalline aluminosilicate with a control index of 1 to 15 is defined as a crystalline aluminosilicate having an X-ray diffraction pattern shown in the table below in an X-ray diffraction diagram (this manufacturing method is disclosed in Japanese Patent Application No. 57-228283). There is.
This aluminosilicate is hereinafter referred to as AZ-1).
ZSM-5 (see U.S. Patent No. 3702886) and ZSM-11 (Japanese Unexamined Patent Application Publication No. 1983-1989) developed by Mobil Oil.
52699), but AZ-1 is particularly preferred.

[Table] X-ray diffraction analysis is performed using Cukα radiation.
However, the relative intensity of either the 8.7±0.2 or 8.9±0.2 diffraction lines is set to 100. As the silicate ester used in the present invention,
Methyl silicate, ethyl silicate, n-propyl silicate, iso-propyl silicate, n-butyl silicate,
Examples include tert-butyl silicate, but particularly preferred are methyl silicate and ethyl silicate. These silicate esters can be used alone or in a gaseous state with a suitable diluent, but the concentration of the silicate ester is between 1 and
100% by volume, preferably 5-100% by volume. Further, as the diluent, nitrogen, helium, argon, air, water vapor, etc. can be used, but nitrogen is preferred. The temperature at which crystalline aluminosilicate is treated with these silicate ester-containing gases is not particularly limited as long as the silicate ester can be maintained in the gas phase, but it is usually 100 to 500°C, preferably 200 to 400°C. It is done within a range. Further, the pressure during treatment with these silicate ester-containing gases is not particularly limited as long as the silicate ester can be maintained in the gas phase, and may be reduced pressure, normal pressure, or increased pressure. In addition to the gas phase treatment mentioned above, liquid phase impregnation treatment can be considered as a method for silicate ester treatment, but when comparing gas phase treatment and liquid phase impregnation treatment, liquid phase impregnation treatment is a process called impregnation method. There are fundamental problems with this method, such as difficulty in reproducibility and the problem of greatly reducing activity. This decrease in activity does not make much of a difference in reactions that proceed relatively easily, such as the methylation reaction of toluene with methanol, but is noticeable in reactions that proceed relatively slowly, such as the disproportionation reaction of toluene. . in this regard,
To explain based on the comparative example described later, in the comparative example, the zeolite of the present invention was subjected to liquid phase impregnation treatment, but the formation of toluene disproportionation under the same conditions as in Example 3 of the present invention was compared. It can be seen that the conversion rate is extremely low. As described above, liquid phase impregnation treatment cannot achieve the high activity and high selectivity that are the objectives of the present invention. In the present invention, the crystalline aluminosilicate treated with a silicate ester-containing gas needs to be fired in an oxygen-containing gas, and the oxygen concentration in the gas at that time is 5 to 100% by volume, preferably 10 to 30% by volume. % by volume, and air is usually used. Also, the temperature during this firing is 300 to 700℃, preferably 350 to 700℃.
It is in the range of 600℃. The amount of silica supported by treating the crystalline aluminosilicate with a silicate ester in this way is preferably at least 0.1% by weight, based on the original crystalline aluminosilicate;
More preferably, it is 0.5 to 10% by weight. If the supported amount is very small, the effect of improving the selectivity of 1,4- isomers will be small; on the other hand, if it is too large, the 1,4-
Although the selectivity of the body becomes extremely high, the activity is significantly reduced. The monoalkylbenzene used in the present invention is a monoalkylbenzene having an alkyl group having 1 to 3 carbon atoms, and specifically includes toluene,
Examples include ethylbenzene and isopropylbenzene. Examples of the 1,4-dialkylbenzene in the present invention include paraxylene, paraethyltoluene, paradiethylbenzene, paradiisopropylbenzene, and paracymene. The production of 1,4-dialkylbenzene from monoalkylbenzene includes an alkylation reaction using alcohol or olefin, and a disproportionation reaction from monoalkylbenzene alone. Alcohols used in the alkylation reaction include methanol, ethanol, n- or iso-propanol, and olefins include ethylene, propylene and the like. In carrying out the present invention, the reaction temperature varies depending on the reaction raw materials and the type of reaction, but in order to maintain the reaction system in the gas phase, a temperature of at least 200°C is required, and a temperature of 700°C or higher is required. Since the selectivity is extremely low, the preferred temperature is usually 300 to 600.
A range of degrees Celsius is used. Furthermore, the reaction pressure may be reduced pressure, normal pressure, or increased pressure, and the reaction method is preferably a flow method such as a fixed bed or a fluidized bed. (Effects of the invention) According to the method of the present invention, the activity is higher than that of the conventional method of treating crystalline aluminosilicate with a metal oxide, and the selectivity for the 1,4-isomer is also extremely high at over 95%. Become. This becomes extremely advantageous in industrial implementation. (Example) Example 1 1,8-diamino-4-aminomethyloctane
100g, aluminum sulfate (Al ₂ (SO ₄ )) ₃ .
18H ₂ O) 5g, sodium hydroxide 5g and water 150g
Add 200g of silica sol (30% SiO ₂ )
was added to obtain a homogeneous solution. To this solution, 30 g of 20% sulfuric acid was added dropwise while stirring to obtain a homogeneous gel. Furthermore, put this gel in a homogenizer,
Mixed for 10 minutes at 10000 rpm. This gel was stored at 180℃ and 45℃ in a Teflon-lined stainless steel pressure container.
The mixture was allowed to stand for a period of time for crystallization. After filtering and washing the obtained product, it was heated to 120℃.
The mixture was dried at 500°C for 6 hours and then fired at 500°C for 6 hours. The X-ray diffraction pattern of this product is shown in the drawing.
From this diffraction pattern, this product is AZ-1
was identified. Further, the silica/alumina molar ratio determined from fluorescent X-ray analysis was 80, and the control index measured at 315°C was 13.0. 10g of this AZ-1 was molded into 10 to 20 meshes and filled into a glass reaction tube, and nitrogen gas containing 20% by volume of ethyl silicate was heated at 300°C.
It was run for 20 minutes at SV1000hr ^-1 . Then increase the temperature to 500
The temperature was raised to ℃ and baking was performed for 2 hours while blowing air. The amount of supported silica determined by weight analysis of the obtained catalyst was 2.5% by weight. This catalyst was used to synthesize diethylbenzene from ethylbenzene and ethylene. The experimental conditions were: ethylbenzene/ethylene/H ₂ molar ratio = 5/1/4, WHSV 4.0hr ^-1 , reaction temperature 350
The test was carried out at a temperature of 3 kg/cm 2 at a pressure of 3 kg/cm ² . Table 1 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

[Table] Example 2 Using the catalyst obtained in Example 1, a synthesis reaction of ethyltoluene from toluene and ethylene was carried out. The experimental conditions were: toluene/ethylene/ _H2 molar ratio = 4/1/4, WHHSV4.0hr ^-1 , pressure 3.0Kg/
cm ² , and the reaction temperature was 400°C. 2-3 hours, 10-11 hours, 20-21 hours after starting the reaction
Table 2 shows the time results.

[Table] Example 3 Using the catalyst obtained in Example 1, a toluene disproportionation reaction was carried out. The experimental conditions were: H ₂ /toluene molar ratio 2.5, WHSV 2.0hr ^-1 , reaction temperature 500℃,
The pressure was 10Kg/cm ² . Table 3 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

[Table] Example 4 Using the catalyst obtained in Example 1, a disproportionation reaction of ethylbenzene was carried out. The experimental conditions were H ₂ /
The reaction was carried out at an ethylbenzene molar ratio of 2.5, a WHSV of 2.0 hr ^-1 , a reaction temperature of 350°C, and a pressure of 3.0 Kg/cm ² . Table 4 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

[Table] Example 5 10 g of AZ-1 obtained in Example 1 was molded into 10 to 20 meshes and filled into a glass reaction tube, and nitrogen gas containing 25% by volume of methyl silicate was added.
It was run for 20 minutes at 320°C and SV 1500hr ^-1 . Thereafter, the temperature was raised to 500°C and baking was performed for 2 hours while blowing air. The amount of supported silica determined from weight analysis of the obtained catalyst was 3.0% by weight. This catalyst was used to synthesize diethylbenzene from ethylbenzene and ethylene. The experimental conditions were: ethylbenzene/ethylene molar ratio 3.0;
The reaction was carried out at a WHSV of 4.0 hr ^-1 , a reaction temperature of 360°C, and normal pressure. The results for 2 to 3 hours after the start of the reaction were: ethylbenzene conversion rate 20%, diethylbenzene selectivity 90%,
The proportion of para isomer in diethylbenzene was 99%. Example 6 Using the catalyst obtained in Example 5, a xylene synthesis reaction from toluene and methanol was carried out. The experimental conditions were: toluene/methanol molar ratio 2;
The reaction was carried out at a WHSV of 4.0 hr ^-1 , a reaction temperature of 450°C, and normal pressure. The results for 2 to 3 hours after the start of the reaction were as follows: toluene conversion rate was 35%, xylene selectivity was 94%, and the proportion of para-isomer in xylene was 97%. Example 7 Using the catalyst obtained in Example 5, a toluene disproportionation reaction was carried out. The experimental conditions were: H ₂ /toluene molar ratio 3.0, WHSV 3.0hr ^-1 , reaction temperature 460℃,
The pressure was 8.0Kg/cm ² . Table 5 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

[Table] Example 8 1,8-diamino-4-aminomethyloctane
2000 g of aluminum sulfate, 150 g of aluminum sulfate, and 150 g of sodium hydroxide were dissolved in 5000 g of water, and 4000 g of silica sol (30% SiO ₂ ) was added to obtain a homogeneous solution. Add 500 g of 20% sulfuric acid to this solution while stirring.
was added to obtain a homogeneous gel. Furthermore, this gel was placed in a homogenizer and mixed at 10,000 rpm for 20 minutes. This gel was crystallized by standing at 165° C. for 60 hours in a Teflon-lined stainless steel pressure container. After filtering and washing the obtained product, it was heated to 120℃.
The mixture was dried at 500°C for 6 hours and then fired at 500°C for 6 hours. Based on the X-ray diffraction pattern of this product, this product was identified as AZ-1. In addition, the silica/alumina molar ratio determined from fluorescent X-ray analysis was 45 and 315.
The control index measured in °C was 13. 50g of this AZ-1 was molded into 10 to 20 meshes and filled into a glass reaction tube, and nitrogen gas containing 30% by volume of ethyl silicate was heated at 320℃.
It was run for 25 minutes at SV2000hr ^-1 . Then increase the temperature to 550
℃ and baked for 4 hours while blowing air. The amount of supported silica determined from weight analysis of the obtained catalyst was 2.5% by weight. This catalyst was used to synthesize ethyltoluene from toluene and ethylene. The experimental conditions were
Toluene/ethylene/ _H2 molar ratio = 4/1/4,
The reaction was carried out at a WHSV of 4.0 hr ⁻¹ , a reaction temperature of 420° C., and a pressure of 5 Kg/cm ² . Table 6 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

[Table] Example 9 Using the catalyst obtained in Example 8, a synthesis reaction of cymene from toluene and propylene was carried out. The experimental conditions were: toluene/propylene/H ₂ molar ratio = 5/1/4, WHSV 8.0hr ^-1 , reaction temperature 320
The test was carried out at a temperature of 2.0 kg/cm ² at a pressure of 2.0 kg/cm 2 . Table 7 shows the results for 2 to 3 hours and 10 to 11 hours after the start of pressure.

[Table] Example 10 20 g of AZ-1 obtained in Example 8 was molded into 10 to 20 meshes, filled into a glass reaction tube, and heated with nitrogen gas containing 8% by volume of methyl silicate at 200°C.
It was run for 10 minutes at SV3000hr ^-1 . Then 3 at 500℃
Baked with air flowing for hours. The amount of supported silica determined from the weight analysis of the obtained catalyst was 0.5% by weight. This catalyst was used to synthesize diethylbenzene from ethylbenzene and ethylene. The experimental conditions were: ethylbenzene/ethylene molar ratio 4.0;
The reaction was carried out at a WHSV of 3.0 hr ^-1 , a reaction temperature of 350°C, and normal pressure. The results for 3 to 4 hours after the start of the reaction were: ethylbenzene conversion rate of 10%, diethylbenzene selectivity of 92%,
The proportion of para isomer in ethylbenzene was 96%. Example 11 Dissolve 5 g of aluminum sulfate and 10 g of tetrapropylammonium bromide in 350 g of water, and then 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 with stirring at 150°C for 20 hours. 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 In addition, the silica/alumina molar ratio determined by fluorescent X-ray analysis was 50,320℃.
The control index measured at was 10.5. 10g of this ZSM-5 was molded into 10 to 20 meshes, filled into a glass reaction tube, and nitrogen gas containing 20% by volume of ethyl silicate was heated at 300℃ and SV1000hr ^-1.
I ran it for 40 minutes. Then, increase the temperature to 500℃,
Firing was carried out for 3 hours while blowing air. The amount of supported silica determined from weight analysis of the obtained catalyst was 6.2% by weight. Using this catalyst, a disproportionation reaction of ethylbenzene was carried out. The experimental conditions were H ₂ /ethylbenzene molar ratio 3.0, WHSV 2.0 hr ⁻¹ , reaction temperature 340° C., and pressure 2.0 Kg/cm ² . Table 8 shows the results 2 to 3 hours and 10 to 11 hours after the start of the reaction.

[Table] Example 12 100 g of octamethylene diamine, 5 g of aluminum sulfate, and 5 g of sodium hydroxide were uniformly dissolved in 150 g of water, and silica sol (30%
200 g of SiO ₂ ) was added, and further 20 g of 20% H ₂ SO ₄ was added dropwise to obtain a homogeneous gel. This gel was placed in a Teflon-lined stainless steel pressure-resistant container, and heated to 150℃ for 40 minutes.
Stir for a while to crystallize. The obtained product was overwashed, dried at 120°C for 3 hours, and then air-calcined at 500°C for 4 hours. The X-ray diffraction pattern of this product is ZSM-11
It matched the diffraction pattern of The silica/alumina molar ratio of this product was 30, and the control index measured at 320°C was 9.0. 20 g of this ZSM-11 was molded into 10 to 20 meshes, filled in a glass reaction tube, and nitrogen containing 15% by volume of methyl silicate was flowed at 300° C. and SV 1300 hr ⁻¹ for 30 minutes. Thereafter, the temperature was raised to 520°C and baking was performed for 2 hours while blowing air. The amount of supported silica determined from weight analysis of the obtained catalyst was 6.5% by weight. This catalyst was used to synthesize diethylbenzene from ethylbenzene and ethylene. The experimental conditions were: ethylbenzene/ethylene molar ratio 2.8;
The reaction was carried out at a WHSV of 4.0 hr ^-1 , a reaction temperature of 350°C, and normal pressure. The results for 2 to 3 hours after the start of the reaction were 50% ethylbenzene conversion, 92% diethylbenzene selectivity,
The composition of para isomer in diethylbenzene was 95%. Comparative example AZ obtained in Example 1 after firing at 500℃ for 6 hours
-1 20g was added to 100g of ethyl silicate and refluxed for 8 hours. After that, it was filtered, washed with n-hexane, dried at 120℃ for 8 hours, and further heated to 550℃ for 6 hours.
Baked for an hour. Using the obtained catalyst molded into 10 to 20 meshes as a catalyst, toluene disproportionation reaction was carried out under the same conditions as in Example 3. Table 9 shows the results 2 to 3 hours and 20 to 21 hours after the start of the reaction.

【table】 [Brief explanation of drawings]

The drawing shows the X of AZ-1 obtained in Example 1.
The line diffraction pattern is shown.

Claims (1)

[Claims] 1 monoalkylbenzene in a gas phase of 1,4
- When converting to dialkylbenzene, silica/
1,4-dialkylbenzene characterized by using a catalyst obtained by treating a crystalline aluminosilicate with an alumina molar ratio of 10 or more and a control index of 1 to 15 with a silicate ester-containing gas, and then calcining it in an oxygen-containing gas. Manufacturing method. 2. The method according to claim 1, wherein the crystalline aluminosilicate has a diffraction pattern shown in the table below in an X-ray diffraction diagram. [Table] [Table] X-ray diffraction analysis is performed using Cukα radiation. However, the relative intensity of either the 8.7±0.2 or 8.9±0.2 diffraction lines is set to 100. 3. The method according to claim 1 or 2, wherein the monoalkylbenzene is a monoalkylbenzene having an alkyl group having 1 to 3 carbon atoms. 4. The method according to claim 1 or 2, wherein the 1,4-dialkylbenzene is paraxylene, paraethyltoluene or paradiethylbenzene.