JPS6046098B2 - Method for producing cyclohexylbenzene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing cyclohexylbenzene by hydrogenation condensation of benzene.

Conventionally, as a method for producing cyclohexylbenzene, a method using a catalyst in which a Group 8 metal is supported on a solid acid support (silica alumina or H-type zeolite) (J, Catalyst) has been used.
1ysisU, 385 (1969), Yukishikawa (1),
25 (1976) and JP-A-53-108952), and methods using supported palladium and molten salt (NaCl-AlCl3) as catalysts (Chem, Pharm, Bull,
29(1), 15 (1981) is known.

Furthermore, the hydrogenation catalyst, ^,, T■muJ-,muiLL゛, do1↓re, J-hJ, phase or mouth 1, the method of fusing (U
, S, P, 3153678). However, the activity of these catalysts is low, and a long reaction time is required to increase the benzene conversion rate, or the cyclohexylbenzene produced is further alkylated to produce a large amount of synchlorohexylpentene (Cls). This cannot be said to be a satisfactory method for industrially producing cyclohexylbenzene. In order to overcome the defects in the production method of cyclohexylbenzene by hydrogenation condensation of benzene, the present inventors have previously conducted various studies, and as a result, selected silicotungstic acid, phosphotungstic acid, and phosphomolybdic acid. By using at least one type of heteropolyacid and at least one metal selected from nickel, palladium, and ruthenium as a catalyst and adding a dehydrating and drying agent, C, It was discovered that cyclohexylbenzene could be produced with high selectivity while suppressing the formation of compound No. He invented a method using a catalyst in which an acid and the above-mentioned metals or their compounds were supported on silica gel, and filed a patent application (Japanese Patent Application Laid-Open No. 59-13742).
6) I did.

Subsequently, as a result of repeated discussions on catalyst preparation methods, we devised a preparation method, such as supporting the above-mentioned metal components on alumina, diatomaceous earth, or activated carbon carriers, which are usually used in hydrogenation catalysts, and then supporting the heteropolyacid. As a result, we have found a method for producing cyclohexylbenzene that allows use of carriers other than silica gel that are normally used for hydrogenation catalysts, and therefore allows for extremely simple preparation of the catalyst and ease of handling.
The present invention has been made based on this knowledge. At least one heteropolyacid selected from silicotungstic acid, phosphotungstic acid, and phosphomolybdic acid; and at least one metal selected from nickel, ruthenium, rhodium, palladium, and platinum (Group 8 metal). ) or its compound supported on a carrier such as alumina, diatomaceous earth, or activated carbon.When hydrogenating and condensing benzene, at least one selected from zeolite, silica gel, and alumina is added to the reaction system. The present invention provides a method for producing cyclohexylbenzene characterized by the presence of a dehydrating and drying agent.

The catalyst of the present invention can be prepared according to various methods, but typical examples include commercially available hydrogenation catalysts, or dissolving or suspending the Group 8 metal in a solvent such as water or acetic acid. The metal component is deposited on the carrier by immersing the carrier material in the solution, dried, and hydrogenated at high temperature. There is a method in which the heteropolyacid component is deposited on the catalyst by immersion in a solution of the heteropolyacid, dried, and then calcined in an inert gas. Ru.

The firing temperature used is 200 to 600°C, preferably 250 to 500°C. Among the catalyst components, silicotungstic acid and phosphotungstic acid are preferable as the heteropolyacid.

In this catalyst system, the presence of the heteropolyacid is cyclo,
Comparative Example 2 is essential for the production of hexylbenzene.
It is clear from this. The concentration of the heteropolyacid varies significantly depending on the carrier, but is used in the range of 1 to 200% of the carrier weight, preferably 5 to 150%. The Group 8 metal component includes organic acid salts such as formic acid and acetic acid, carbonates,
Can be added in the form of nitrates, chlorides, hydroxides, etc.
Other compounds can also be used as long as they are dissolved or suspended in the catalyst preparation solution.

Furthermore, in order to control the activity of these metals, they may be supported together with other metals. The concentration of this Group 8 metal compound is
Although it varies significantly depending on the type of supported metal, the weight of the support is 0.
．． A range of 0.05 to 50% is used, preferably 0.1 to 50%.
It is 30%. When using a noble metal having a high benzene hydrogenation activity, it is preferable to lower the supported concentration and increase the heteropolyacid concentration in order to improve the selectivity of cyclohexylbenzene. When carrying out the method of the present invention, first the above-mentioned dehydrating/desiccating agent is added to the reaction system.

In this case, benzene brought into contact with a dehydrating/desiccating agent may be used. For example, even if a reaction is carried out with a catalyst in which only Pd-alumina is supported on the carrier and zeolite,
Although xylbenzene is not produced (Comparative Example 2), when a catalyst in which silicotungstic acid and Pd-alumina are supported on the carrier is coexisting with a dehydrating/desiccating agent such as zeolite, the yield and selectivity of cyclohexylbenzene are significantly increased. (Comparison of Example 1 and Comparative Example 1). As the dehydrating/desiccating agent, any desiccant used industrially can be used, but Molecular Sieve 10x, 13x, silica gel, and alumina gel are preferred. The amount used is 0.05-5
g/20g benzene range is suitable, 0.1-2g
/20g benzene is preferred. The method of the invention can be carried out without or in a solvent.

Any solvent inert to the reaction, such as cyclohexane, can be used. It is desirable that the raw material benzene has as little water content as possible. In the method of the present invention, the reaction temperature is usually 50 to 300°C, preferably 100 to 250°C,
The reaction hydrogen pressure is 1 to 300k9/Cltl, preferably 10
~150k9/Cri.

The lower the reaction temperature, the higher the selectivity of cyclohexane;
Moreover, if the reaction temperature is too high, decomposition of the reaction products will occur, which is disadvantageous. Next, the present invention will be explained in more detail based on examples.

Example 1 0.275 g of silicotungstic acid (using a reagent dried to a constant weight at 110°C) was dissolved in water, and commercially available 0.5% Pd-alumina (manufactured by Nippon Engelhard Co., Ltd., spherical) was dissolved in water. 1 g was added, the powder was stirred for three times, the water was evaporated using a rotary vacuum evaporator, the water was dried at 110°C, the powder was transferred to a glass tube, and the three powders were dried at 325°C in a nitrogen stream to prepare a catalyst. .

0.5 g of this catalyst was placed in a 80 m1 (7) SUS3 autoclave with an internal volume equipped with a gas inlet, a pressure gauge, and a thermometer insertion tube, with 20 g of benzene, 1 molecular sieve, and 13 x
(1/16 pellets) and a Teflon-coated stirring bar, and after replacing the inside with nitrogen, hydrogen gas was added at room temperature for 5 minutes.
It was press-fitted to 0 kg/d.

While stirring with a magnetic stirrer, reduce the reaction temperature to 2.
It was heated to 00°C. The reaction was started when the reaction temperature was reached. After 87 minutes of reaction time, cyclohexylbenzene 4
．． 90g/0.71g of cyclohexane was obtained. There was no trace of Cl8 compound formation. Comparative Example 1 Using the method of Example 1 except for molecular sieve 13x, a reaction was carried out for 7 minutes, and cyclohexylbenzene 3.21
1.42 g of g1 cyclohexane was obtained.

Comparative Example 2 In Example 1, silicotungstic acid was not supported,
Using 0.5 g of commercially available 0.5% Pd-alumina as it was, 6 powders were reacted under the reaction conditions of Example 1 to obtain 3.11 g of cyclohexane.

No formation of cyclohexylbenzene was observed. Example 2 Using the method of Example 1, 0.35 g of silicotungstic acid was dissolved in water, and 1 g of commercially available 0.5% Pt-alumina (manufactured by Nippon Engelhard Co., Ltd., in pellet form) was added. According to the method of Example 1, using 0.5 g of a catalyst prepared by drying at 350'C for 1 hour in a nitrogen stream, 20 g of benzene, 13 x 0.5 g of molecular sieve, and a reaction temperature of 210 C for 42 minutes. The reaction yielded 3.30 g of cyclohexylbenzene and 1.49 g of cyclohexane.

Example 3 By the method of Example 1, phosphotungstic acid 0.275
g in water, add 1 g of commercially available 0.5% Pd-alumina spheres, stir, dry and further dissolve in a nitrogen stream for 3
0.5 g of catalyst dried at 75°C and 20 g of benzene
Using 13 x 1.5 g of g1 molecular sieves, the reaction was carried out at a reaction temperature of 205° C. for 67 minutes according to the method of Example 1 to obtain 4.91 g of cyclohexylbenzene and 0.75 g of cyclohexane.

Example 4 By the method of Example 1, tungstic acid 1
．． 0.125 g of a catalyst prepared from 20 g of commercially available 2% Pd and 1 g of activated carbon particles (manufactured by Nippon Engelhard Co., Ltd.), and 20 g of Molecular Sieve 13 x 0.75 g and 1 benzene.
9 using the method of Example 1 at a reaction temperature of 220°C.
0 minute reaction, cyclohexylbenzene 3.12g1
1.59 g of cyclohexane was obtained.

Example 5 0.25 g of silicotungstic acid was prepared by the method of Example 1.
and 1 g of a commercially available 0.5% Ru-alumina catalyst (manufactured by Nippon Engelhard Co., Ltd.).
Using the method of Example 1 using 1.5 g of silica gel and 20 g of benzene dried at 35° C. at a reaction temperature of 225° C.
The reaction was carried out for 3.09 g of cyclohexylbenzene and 1.75 g of cyclohexane.

Example 6 By the method of Example 1, phosphotungstic acid 0
．． Example 1 Using 0.5 g of a catalyst prepared from 275 g and a commercially available 0.5% Rh-alumina catalyst, and 0.5 g of alumina spheres (Neobead C-4, manufactured by Mizusawa Chemical Co., Ltd.) dried at 450°C and 20 g of benzene. By the method of
After reacting at 5°C for 27 minutes, cyclohexylbenzene 2.
67g/1.97g of cyclohexane was obtained.

Example 1 Dissolve 4.9533 g of Ni(NO3)2.6H in water, add 10 g of diatomaceous earth, stir for 1 hour, evaporate water using a rotary vacuum evaporator, transfer to a glass tube, and heat at 300 m1/min. 1 g of the catalyst ring-regenerated at 450°C for 1 hour in a hydrogen stream was added to an aqueous solution of 0.5 g of silicotungstic acid, stirred and dried according to the method of Example 1, and pulverized at 300°C in a nitrogen stream. 0.5 g of the dried catalyst and 0.5 g of Zeolum F9 (manufactured by Toyo Soda) dried at 450°C and 20 g of benzene were added, and the reaction temperature was 195°C according to the method of Example 1.
Cyclohexylbenzene・3.71g1
1.23 g of cyclohexane was obtained.

Example 8 Using the method of Example 7, Ni(NO3)2.6F[
204.9533g and Irc'4●H2OO. O458
0.5 g of a catalyst prepared by adding 1 g of a catalyst prepared by adding 10 g of diatomaceous earth to an aqueous solution of 1 g, stirring, drying, and hydrogenating it to an aqueous solution of 0.6 g of phosphomolybdic acid; Using 75 g and 20 g of benzene, the reaction was carried out according to the method of Example 1 at a reaction temperature of 200° C. for 3 minutes,
Cyclohexylbenzene 0.39g 1 cyclohexane 2
．． 55g was obtained.

Claims (1)

[Claims] 1 At least one heteropolyacid selected from silicotungstic acid, phosphotungstic acid, and phosphomolybdic acid, and at least one metal selected from nickel, ruthenium, rhodium, palladium, and platinum or a compound thereof. When hydrogenating and condensing benzene in the presence of a catalyst supported on a carrier such as alumina, diatomaceous earth, or activated carbon, at least one dehydrating and drying agent selected from zeolite, silica gel, and alumina is present in the reaction system. A method for producing cyclohexylbenzene, characterized by: