JPH0336813B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to the production of pseudokyumene (1,
The present invention relates to a method for producing 2,4-trimethylbenzene) and/or duurene (1,2,4,5-tetramethylbenzene). The present invention particularly relates to a method for efficiently obtaining pseudokyumene and duurene with high purity and selectivity with respect to their respective homologous isomer components by using a specific iron aluminosilicate as a catalyst.

[Prior Art] Many natural and synthetic crystalline aluminosilicates are known as zeolites. These crystalline aluminosilicates have pores with various three-dimensional structures, and some of them are used industrially as catalysts for converting hydrocarbons. In particular, a method for producing hydrocarbons, mainly gasoline fractions, from methanol or dimethyl ether using partially crystalline aluminosilicate as a catalyst has been studied. For example, ZSM-5 zeolite manufactured by Mobil Oil Co., Ltd. is known to be excellent as a catalyst for the reaction among various crystalline aluminosilicates. generation has been observed.
Furthermore, the synthesis of metallosilicates having a similar steric arrangement of silica to ZSM-5 and catalytic reactions using the metallosilicates are also known.

[Problem that the invention seeks to solve]

However, these metallosilicates
Methanol and/or
Although the production of pseudokymene and durene from dimethyl ether has been observed, the yield and selectivity thereof are low, and no product has been found that meets the objectives of the present invention.

[Means for solving problems]

The present inventors were searching for a catalyst that would improve the yield of pseudokyumene and duurene and produce them with high purity in terms of selectivity with homoisomer components, and found that in the ZSM-5 system, of that skeleton
We found that the yield of Duurene to pseudokyumene increases as the SiO ₂ /Al ₂ O ₃ ratio increases, and we further investigated ways to improve the yield and the selectivity. The present inventors have discovered that iron aluminosilicate, which is synthesized with a large portion of Al substituted with iron during synthesis, can dramatically improve yield and selectivity, leading to the completion of the present invention.

That is, the present invention uses pentasil-type zeolite containing iron and aluminum as a catalyst in its skeleton so that the ratio of iron to aluminum is 10 or more when producing pseudokyumene and/or duurene using methanol and/or dimethyl ether as raw materials. This is a method for producing pseudokyumene and/or duurene, which is characterized by using a zeolite catalyst as a main component.

The present invention will be explained in detail below.

The catalyst used in the method of the present invention is mainly composed of crystalline pentasil-type zeolite containing iron and aluminum in its skeleton. Here, the crystalline silicate containing iron and aluminum in its skeleton is preferably one whose silica skeleton structure is similar to ZSM-5, but the ratio of silicon to iron and aluminum is not particularly limited, but usually, Those with an atomic ratio of 20 or more are easy to synthesize and stable. Further, a ratio of iron to aluminum of 10 or more gives preferable results.
This is because the aluminum of the skeleton exhibits its ability with a small amount, but in combination with that ability, the iron of the skeleton is required in a much larger amount than aluminum in order to achieve the purpose of the present invention. This is because. This (pental type zeolite)
There are various methods to prepare, but in general,
It can be prepared by adding an aluminum source, various silica sources, an iron source, and a crystallizing agent to an aqueous medium and subjecting it to a hydrothermal reaction treatment. In addition, when reducing the aluminum concentration in the skeleton to a trace amount, the various silica sources normally used generally contain the necessary trace amount of aluminum, without intentionally using a separate aluminum source. ,
Various silica sources, iron sources, and crystallizing agents may be used as raw material systems. For example, such iron aluminosilicate is prepared as follows. That is,
An aqueous sodium silicate solution is mixed with an aqueous solution containing an iron salt such as iron nitrate, a crystallizing agent such as concentrated sulfuric acid, and a crystallizing agent such as tetrapropylammonium bromite, and sodium chloride is added as a mineralizing agent. Adjust the pH and keep it heated in an autoclave. After holding for the required time, a sodium type iron aluminosilicate is obtained through the processes of cooling, filtering/washing, drying and calcination. Furthermore, the proton type iron aluminosilicate can be obtained by treating this sodium type iron aluminosilicate with an aqueous ammonium nitrate or ammonium chloride solution to make it into an ammonium type, and then firing it. At this time, by inserting an operation in which a binder such as alumina sol is added and molded, a zeolite catalyst in the form of a molded body can be obtained.

Next, in producing pseudokyumene and/or duurene of the present invention, methanol and/or dimethyl ether are used as raw materials, and pentasil containing the already mentioned iron and aluminum as catalysts such that the ratio of iron to aluminum is 10 or more. It is carried out using a zeolite catalyst whose main component is type zeolite. This raw material can be determined as appropriate depending on the desired reaction product and conditions, but there is no major difference in the products obtained from methanol or dimethyl ether, and the products obtained are similar even if water is mixed in the raw material. The conditions may be selected so that a product of . As for specific reaction conditions, the reaction temperature is usually 250-650℃.
C, preferably 320 to 500 C, the reaction pressure is normal pressure to slightly elevated pressure, and the liquid hourly space velocity is 0.1 to 5 hr ^-1 . If the conversion reaction is carried out under such conditions, pseudokyumene and durene can be obtained in high yield and with very high selectivity among isomers.

As described above, the present invention reveals that a zeolite catalyst containing iron aluminosilicate as a main component works very effectively in producing pseudokyumene and/or duurene using methanol and/or dimethyl ether as raw materials. This is a technology with high industrial value.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 26.44 g of iron nitrate, 83.62 g of tetrapropylammonium bromide, and 76.00 g of sodium chloride.
Dissolved in 346.48g of water, and further added to this solution.
After adding 0.44 g of H ₂ SO ₄ , it was thoroughly mixed with a solution of 202.80 g of J. Sodium Silicate No. 3 diluted with 253.52 g of water. The resulting mixture was heated in an autoclave and kept at 180°C for 5 days.
After the reaction was completed, the autoclave was cooled, the contents were washed with water, dried at 120°C for 6 hours, and then calcined at 550°C for 3 hours under a stream of air to obtain sodium type iron aluminosilicate. When the obtained iron aluminosilicate was subjected to powder X-ray diffraction, it showed a pentasil type zeolite pattern as shown in FIG. In addition, chemical elemental analysis revealed that SiO ₂ /
Al ₂ O ₃ =1500, SiO ₂ /Fe ₂ O ₃ =26. 35% by weight of alumina binder was added to the obtained iron aluminosilicate powder to form a molded product, which was dried again and then fired at 550° C. for 3 hours in a stream of air. Thereafter, 5 ml of a 2.2N ammonium nitrate aqueous solution was added per 1 g of the molded product, and the procedure of natural refluxing for 2 hours was repeated 4 times to perform ammonium ion exchange. The obtained ammonium type zeolite molded body was dried and then calcined in an air stream at 550°C for 3 hours to obtain a proton type catalyst.

A normal pressure flow reactor was filled with 5 ml of this catalyst, and methanol was used as a raw material at a reaction temperature of 335°C.
The methanol conversion reaction was continued for 4 hours under the condition of LHSV 0.25 hr ^-1 . The results showed a yield of 10.3% for pseudokyumene on a carbon basis, and selectivity between isomers.
98.7%, duurene was obtained with a yield of 10.8% and a selectivity between isomers of 98.4%.

Example 2 Instead of 26.44 g of iron nitrate in Example 1, 25.59 g of iron nitrate and 0.36 g of aluminum nitrate, or
24.03g iron nitrate and 1.80g aluminum nitrate, or 13.22g iron nitrate and 11.86g aluminum nitrate
(Comparative example), all of the iron aluminosilicate obtained showed a pattern of pentasil type zeolite, and chemical elemental analysis showed that the Fe ₂ O ₃ /Al ₂ O ₃ was 31 and 10, respectively. ,as well as
1.1 (comparative example) is shown. Example 1 shows the results of determining the yield of Duurene in the same manner as in Example 1.
The results are shown in Figure 2.

The above results show that the yield of Duurene is improved when the iron aluminosilicate of the present invention is used.

〔Effect of the invention〕

According to the present invention, by using a specific iron aluminosilicate as a catalyst, pseudoquinone and/or durene can be produced from methanol and/or dimethyl ether with high purity, high yield, and good selectivity.

[Brief explanation of the drawing]

Figure 1 is a powder X-ray diffraction pattern showing an example of the iron aluminosilicate used as a catalyst in the present invention, and Figure 2 is a graph showing the relationship between the iron aluminosilicate used as a catalyst and the yield of Duurene. .

Claims (1)

[Claims] 1 When producing pseudokyumene and/or duurene using methanol and/or dimethyl ether as raw materials, iron and aluminum are used as catalysts at a ratio of iron to aluminum of 10.
A pseudokymene and/or characterized in that it uses a zeolite catalyst whose main component is pentasil-type zeolite contained in its skeleton as described above.
Or how to make Duuren.