JPH0513933B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing para-dialkylbenzene with good selectivity by alkylating toluene or benzene. Conventionally, as a method for producing xylene and the like by alkylating toluene and benzene, a method using a crystalline aluminosilicate as a catalyst has been known (Japanese Patent Laid-Open Nos. 51-57688 and 52-120292). However, in this method, the disproportionation reaction occurs at the same time, resulting in a low xylene selectivity.
Selectivity for dialkylbenzene is low. Furthermore, a method using crystalline borosilicate as a catalyst has been proposed (Japanese Unexamined Patent Publication No. 53-55500), but in this case too, the selectivity for para-dialkylbenzene is low and side reactions are likely to occur, making it difficult to use. There was a problem that a large amount of by-products were produced with low carbon dioxide. An object of the present invention is to overcome these drawbacks of the prior art and to efficiently produce para-dialkylbenzene with high selectivity while suppressing side reactions. That is, the present invention provides a method for producing para-dialkylbenzene by alkylating toluene or benzene in the presence of a catalyst.
The present invention provides a method for producing para-dialkylbenzene, which uses a composition comprising (A) zeolite, (B) fluorine, and (C) a compound of a metal of group a of the periodic table. As mentioned above, the catalyst used in the method of the present invention includes (A)
This is a composition consisting of zeolite, (B) fluorine, and (C) a compound of a group a metal of the periodic table. Here, the zeolite (A) may be either natural or synthetic zeolite, and various types such as X type, Y type, A type, and even ZSM type can be used. In addition to aluminosilicate zeolite, borosilicate,
Boroaluminosilicate, gallosilicate, galloaluminosilicate, etc. can also be used. Among these, crystalline zeolites having a SiO ₂ /M ₂ O ₃ (M represents aluminum, gallium or boron) molar ratio of 12 or more are particularly preferred. Specifically, crystalline aluminosilicates include a group of aluminosilicates called pentasilphamylies.
ZSM-5, ZSM-11, ZSM-12, ZSM-23,
Representative examples include ZSM-35, ZSM-38, and ZSM-48. Also, those described in JP-A-51-57688 and JP-A-52-120292 may be used. On the other hand, as crystalline borosilicate,
For example, JP-A-53-55500, JP-A-55-7598
Publication No. 1984-84313, Japanese Patent Publication No. 1984-84313
Examples include crystalline borosilicate described in JP-A No. 123817 and JP-A-57-129820. Furthermore, various crystalline boroaluminosilicates can be used; for example, JP-A-55
Examples include those described in Publication No.-6752. Next, the (B) component of the catalyst, fluorine, is usually
(A) Allow it to exist in a form introduced into zeolite.
This introduction is carried out by fluorinating the zeolite using various techniques. There are various fluorine sources used here, such as chlorofluorocarbon gas, hydrofluoric acid, sodium fluoride, ammonium fluoride, boron trifluoride, and monofluoroacetic acid. Next, there are various compounds of group a metals of the periodic table which are component (C) of the catalyst, and they may be used alone or in combination of two or more. Here, the metals of group a of the periodic table include beryllium,
There are magnesium, calcium, strontium, and barium, and among these, magnesium and calcium are preferred. Examples of compounds of metals of group a of the periodic table include salts and hydroxides of the above metals, such as calcium nitrate, calcium acetate, and magnesium nitrate. The catalyst used in the method of the present invention is the above-mentioned (A), (B),
Any composition may be used as long as it is composed of component (C), and there are no particular restrictions on its manufacturing method. But in general,
(A) component zeolite is first fluorinated,
Next, a method of impregnating a compound of a metal of group a of the periodic table, which is the component (C), or a method of impregnating the zeolite, which is the component (A), with a compound of a metal of group a of the periodic table, which is the component (C). and then fluorination treatment. Specifically, the above-mentioned fluorination treatment method is as follows:
Zeolite is contacted with organic fluorine compounds such as chlorofluorocarbon gas at 400 to 600℃, or treated with hydrofluoric acid,
Possible methods include contact treatment with sodium fluoride, ammonium fluoride, boron trifluoride, monofluoroacetic acid, etc. in a liquid phase. Furthermore, when preparing zeolite, a fluorine source can be added in the hydrothermal reaction stage along with a silica source, alumina source, gallium source, boron source, etc., so that the resulting crystalline zeolite can contain fluorine. In this case, the fluorine source is preferably a water-soluble compound such as hydrofluoric acid or sodium fluoride. Further, the impregnation treatment with a compound of a group A metal of the periodic table may be carried out by a conventional method such as immersing zeolite in an aqueous solution of the metal compound to be impregnated, or adding zeolite powder and stirring. The composition consisting of components (A), (B), and (C) obtained by such treatment is molded as it is or with the addition of a suitable binder such as alumina, and then molded with 550%
A catalyst calcined at ~1000°C may be used as a catalyst in the method of the present invention. The method of the present invention uses toluene or benzene as a raw material and calkylates it with an alkylating agent in the presence of the above-mentioned catalyst to produce para-dialkylbenzene. There are various alkylating agents used here, including methylating agents such as methyl alcohol, dimethyl ether, methyl chloride, and methyl bromide, as well as ethyl alcohol, ethylene, diethyl ether, propylene, n-butene, and isobutene. The amount of this alkylating agent to be used may be determined as appropriate depending on the reaction conditions, the type of desired product, etc., but usually the ratio of toluene or benzene to alkylating agent is 20:1 to 1:5 ( (molar ratio), preferably 10:1 to 1:2 (molar ratio). The method of the present invention uses toluene or benzene as a raw material and a suitable alkylating agent,
Further, the above-mentioned catalyst may be used, and other conditions are not particularly limited. General conditions: reaction temperature 300-650℃, preferably 400-600℃
C, the reaction pressure is normal pressure to 10 Kg/cm ² G, and the weight hourly space velocity (WHSV) is 0.1 to 20 hr ⁻¹ , preferably 1 to 10 hr ⁻¹ . According to the method of the present invention as described above, para-dialkylbenzenes such as para-xylene, para-ethyltoluene, para-isopropyltoluene, etc. can be obtained with high selectivity and yield, and at the same time,
Since the catalyst life is extremely long, continuous operation can be performed while maintaining high catalyst activity for a long period of time. Therefore, the method of the present invention can be applied to terephthalic acid, p-
It is extremely effective as an industrial method for producing para-dialkylbenzene, which is a raw material for methylstyrene, p-cresol, etc., and has high utility value. Next, the present invention will be explained in more detail using reference examples, working examples, and comparative examples. Reference Example 1 (Preparation of crystalline aluminosilicate) 7.5 g of aluminum sulfate was dissolved in 250 ml of water,
Furthermore, 17.6 g of concentrated sulfuric acid and 26.3 g of tetra-n-propylammonium bromide were dissolved in this to make liquid A, and water glass (J sodium silicate 3
No.: Nihon Kagaku Kogyo Co., Ltd.) was dissolved in 250 ml of water to obtain liquid B, and further 79.0 g of sodium chloride was dissolved in 122 ml of water to form liquid C. Next, the above solutions A and B were simultaneously added dropwise to solution C over 10 minutes at room temperature. The resulting mixture was placed in an autoclave and heat-treated at 170°C for 20 hours. After cooling, the contents were filtered, washed with water, and heated to 120°C.
Let dry for 12 hours. X-ray diffraction analysis of the product confirmed that it was ZSM-5. The obtained ZSM-5 was calcined at 550°C for 6 hours to obtain 56.5 g of sodium type ZSM-5. This sodium form ZSM-5 was added to a 1N ammonium nitrate aqueous solution weighing 5 times its weight, and the mixture was refluxed for 8 hours. Thereafter, the mixture was cooled and left to stand, and the supernatant was removed by decantation. Furthermore, after repeating the reflux and decantation operations three times, the contents were filtered and washed with water, dried at 120°C for 12 hours, and ammonium-type ZSM
-5 was obtained. The SiO ₂ /Al ₂ O ₃ ratio of this product was 90 (molar ratio). Reference Example 2 (Preparation of crystalline borosilicate) Boric acid 0.29g, concentrated sulfuric acid 3.9g and tetra-n-
5.8g of propylammonium bromide and 55ml of water
Solution A added to water glass (J Sodium Silicate No. 3:
Solution B was prepared by adding 46.9 g of sodium chloride (manufactured by Nihon Kagaku Kogyo Co., Ltd.) to 55 ml of water, and solution C was prepared by dissolving 17.4 g of sodium chloride in 27 ml of water. Solutions A and B were then added dropwise to solution C simultaneously. The obtained solution was placed in an autoclave and heated at a reaction temperature of 170°C for 20 hours. After cooling, the contents were filtered and washed with water.
Dry at ℃ for 12 hours. The mixture was further calcined at 550° C. for 6 hours to obtain 13.4 g of sodium type crystalline borosilicate. Also, this product was found to be ZSM-5 by X-ray diffraction.
It was found that it has a type structure. Next, the obtained borosilicate was mixed with 5 times the weight of 1
The mixture was added to a normal aqueous ammonium nitrate solution, heated under reflux for 8 hours, and the solid matter was filtered. Furthermore, after repeating the reflux and filtration operations three times, the solid was washed with water.
It was dried at 120°C for 12 hours to obtain ammonium type crystalline borosilicate. SiO ₂ /B ₂ O ₃ of this =
90 (molar ratio). Reference Example 3 (Preparation of crystalline gallosilicate) 2.34 g of gallium nitrate, 4.42 g of concentrated sulfuric acid, and 6.58 g of tetra-n-propylammonium bromide
52.78 g of solution A, water glass (J Sodium Silicate No. 3, manufactured by Nihon Kagaku Kogyo Co., Ltd.) dissolved in 62 ml of water, was dissolved in 62 ml of water.
Solution B and sodium chloride dissolved in ml 19.75
Solution C was prepared by dissolving g in 30 ml of water. Solutions A and B were then added dropwise to solution C at the same time.
The resulting mixture was placed in an autoclave and reacted at a reaction temperature of 170°C for 24 hours. After cooling, the contents of the autoclave were filtered and washed with water, dried at 120°C for 12 hours, and further calcined at 600°C for 6 hours to obtain 9.6 g of sodium crystalline gallosilicate. Next, the obtained gallosilicate was added to 5 times the weight of 1N ammonium nitrate solution, heated at 80° C. for 8 hours, cooled, and filtered. Furthermore, after repeating the heating and filtration operations three times, the solid material was washed with water and heated to 120°C for 16 days.
After drying for hours, an ammonium type crystalline gallosilicate was obtained. The resulting gallosilicate _SiO2 and
The composition ratio of Ga ₂ O ₃ was SiO ₂ /Sa ₂ O ₃ =90 (molar ratio). Example 1 (1) NH ₄ type ZSM-5 powder 20 obtained in Reference Example 1
g and hydrogen fluoride aqueous solution (hydrogen fluoride content 47% by weight)
Put 20g and 180g of water into a flask and heat to 80℃.
and stirred for 4 hours. Thereafter, the solid matter was filtered, washed with water, and dried at 120°C for 12 hours. (2) 4 g of the fluorine-containing aluminosilicate obtained by the method (1) above, 0.51 g of calcium nitrate tetrahydrate, and 40 g of water were placed in a flask, heated to 80° C., and stirred for 6 hours. The mixture was then transferred to an evaporating dish, evaporated to dryness, and then dried at 120°C for 12 hours. Then 800
A catalyst was obtained by calcining at ℃ for 2 hours. (3) 2 g of the catalyst pellets obtained in (2) above were packed into a flow reactor, and a 2/1 (molar ratio) mixture of toluene/methyl alcohol was supplied as a raw material. The methylation reaction was carried out at a reaction temperature of 600°C, a WHSV of 9hr ^-1 and a normal pressure. 4 from the start of the reaction
The reaction results after hours are shown in Table 1. Example 2 (1) NH ₄ type ZSM-5 powder 4 obtained in Reference Example 1
g, calcium nitrate tetrahydrate 1.68 g and water 40 g
was placed in a flask, heated to 80°C, and stirred for 6 hours. The mixture was then evaporated to dryness in an evaporating dish.
After drying at 120°C for 12 hours, it was fired at 800°C for 2 hours. The above-described loading operation of calcium nitrate was repeated on the obtained calcined product to obtain a composition in which a total of 20 parts by weight of calcium oxide was blended with 100 parts by weight of zeolite. (2) Fill a catalyst preparation tube with 4 g of the composition obtained in (1) above, and heat it at 550°C.
2,2-tetrafluoro-1,2-dichloroethane) was fed at a rate of 70 ml/min for 2 hours to perform fluorination treatment to obtain a catalyst. The fluorine content of the obtained catalyst was 4.6 wt%. (3) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (2) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Example 3 (1) NH ₄ type ZSM-5 powder 10 obtained in Reference Example 1
g was filled into a catalyst preparation tube, and after calcining at 600℃ for 5 hours, 2 ml of Freon-114 was added at 70ml/min at 550℃.
The fluorination treatment was carried out by supplying the solution for a certain amount of time. The fluorine content of the obtained fluorine-containing zeolite was 0.2 wt%. (2) 16.0 g of magnesium oxide powder, 14.1 g of calcium acetate dihydrate, 9.6 g of acetic acid, and 165 g of water were placed in a three-necked flask, heated to 80°C, and stirred for 6 hours to prepare calcium with a solid content of 10% by weight. A magnesium slurry solution was obtained. (3) 4 g of the fluorine-containing aluminosilicate powder obtained in the above (1) and 10 g of the slurry solution obtained in the above (2) were kneaded and molded. Next, after drying at 120℃ for 12 hours, it was dried at 800℃ for 2 hours.
A catalyst was obtained by firing for a period of time. (4) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (3) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Example 4 (1) 4 g of NH ₄ type crystalline borosilicate obtained in Reference Example 2, 0.84 g of calcium nitrate tetrahydrate
g and 40 g of water were stirred at 80°C for 6 hours, then evaporated to dryness and dried at 120°C for 12 hours. This powder was filled into a catalyst preparation tube and fired at 600℃ for 2 hours.
The fluorination treatment was carried out by supplying the solution at a rate of ml/min for 2 hours to obtain a composition with a fluorine content of 4.5 wt%. (2) Add alumina sol to the composition obtained in (1) above so that the alumina content after firing is 20wt%, mold it, dry it at 120℃ for 15 hours, and further
A catalyst was obtained by calcining at ℃ for 2 hours. (3) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (2) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Example 5 (1) 4 g of the NH ₄ type gallosilicate powder obtained in Reference Example 3 was filled into a catalyst preparation tube and fired at 600°C for 6 hours.
13 (1,1,1-trifluorochloromethane)
was introduced at a feed rate of 70 ml/min, and the fluorination treatment was carried out for 3 hours. Thereafter, air was introduced for 1 hour to remove organic components to obtain a fluorine-containing composition. (2) 4 g of the fluorine-containing composition obtained in (1) above, 0.84 g of calcium nitrate, and 40 g of water were stirred at 80° C. for 6 hours, and water was evaporated to dryness. Then, after drying at 120℃ for 12 hours, at 600℃,
It was baked for 6 hours. (3) The fired product obtained in (2) above has an alumina content.
Alumina sol was added to the mixture to give a concentration of 20% by weight, molded, dried at 120°C for 15 hours, and further calcined at 800°C for 2 hours to obtain a catalyst. (4) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (3) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Comparative Example 1 (1) The fluorine-containing aluminosilicate powder obtained in Example 1 (1) was directly calcined at 800° C. for 2 hours to obtain a catalyst. (2) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (1) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Comparative Example 2 (1) NH ₄ type ZSM-5 powder 4 obtained in Reference Example 1
g, calcium nitrate tetrahydrate 0.84 g and water 40 g
The mixture was stirred at 80° C. for 6 hours, then transferred to an evaporating dish and evaporated to dryness. Next, after drying at 120°C for 12 hours, the mixture was calcined at 800°C for 2 hours to obtain a catalyst. (2) A methylation reaction was carried out in the same manner as in Example 1 (3) except that the catalyst obtained in (1) above was used. Table 1 shows the reaction results 4 hours after the start of the reaction. Comparative Example 3 The same procedure as in Example 1 was conducted except that a hydrogen chloride aqueous solution (hydrogen chloride content: 36% by weight) was used instead of the hydrogen fluoride aqueous solution. As a result, the toluene conversion rate after 4 hours from the start of the reaction was
The xylene yield was 75%, and the para-xylene selectivity was 60%. Example 6 2 g of the catalyst pellets obtained in Example 2 (2) were packed into a flow reactor, and toluene and ethylene were supplied as raw materials at a molar ratio of 4/1. The ethylation reaction was carried out at a toluene feed rate of WHSV4hr ^-1 , a reaction temperature of 400°C, and a normal pressure. The reaction results 4 hours after the start of the reaction were a toluene conversion rate of 15% and an ethyltoluene selectivity of 98%, of which the para-ethyltoluene ratio was 79%.

[Table] Produced aromatic fraction Paraxylene **

Claims (1)

[Claims] 1. In producing para-dialkylbenzene by alkylating toluene or benzene in the presence of a catalyst, (A) zeolite, (B) fluorine, and (C) a metal from group a of the periodic table. 1. A method for producing para-dialkylbenzene, the method comprising using a composition comprising the following compounds. 2. The method according to claim 1, wherein the catalyst is a composition obtained by fluorinating zeolite and then impregnating it with a compound of a group a metal of the periodic table. 3. The method according to claim 1, wherein the catalyst is a composition obtained by impregnating zeolite with a compound of a group a metal of the periodic table and then fluorinating it. 4 (A) SiO ₂ /M ₂ O ₃ (M represents aluminum, gallium or boron) in zeolite
12. The method according to claim 1, wherein the molar ratio is 12 or more. 5. The method according to claim 2 or 3, wherein the zeolite is an aluminosilicate and the compound of metal of group a of the periodic table is a salt of calcium or magnesium.