JPS63208538A - Production of aromatic compound - Google Patents

Abstract

PURPOSE:To obtain an aromatic compound maintaining a stable state for a long period, having high added value, by converting a lower olefin by the use of a ZSM-5 type zeolite catalyst containing V and Zn at a specific temperature for a specific contact time. CONSTITUTION:A hydrocarbon raw material containing a lower olefin (especially trans-2-butene) is converted in the presence of a ZSM-5 type catalyst containing V and Zn at 200-600 deg.C under a condition of S/F=1-100g.hr/mol. (X is weight of catalyst; F is number of mols to be reacted per hour) to give aromatic hydrocarbon compound useful as high-octane gasoline base material and petrochemical products having high added value. The content of V based on the zeolite is 1-30wt.% calculated as V2O5, the atomic ratio of Zn/V is 1/10-1/1 and the catalyst is obtained by adding ZSM-5 type zeolite to a solution containing V and Zn, drying and calcining. The catalyst has low deterioration by coke.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention produces aromatic hydrocarbons, which are high-octane gasoline base materials and high value-added petrochemical products, by polymerizing, cyclizing, and dehydrogenating lower olefins. This invention relates to a method for catalytic conversion of compounds.

[Prior Art] In general, ZSM-5 type zeolite and other zeolite catalysts, as well as non-zeolite catalysts such as solid phosphoric acid catalysts, can be used as catalysts for producing aromatic hydrocarbon compounds from lower olefins. It has been known. However, in this reaction, it is not easy to stably obtain 06-C8 aromatics with high added value in high yield over a long period of time.

This is because this reaction not only produces 06-C8 aromatics, but also tends to generate coke, which causes catalyst deterioration, through the subsequent production of condensed aromatics. In this respect, among zeolites, ZSM-5 type zeolite is a zeolite that is less susceptible to deterioration due to coke formation due to its unique three-dimensional microstructure. However, eventually deterioration due to coke progresses gradually.

For example, JP-A-50-49233 describes a method for producing aromatic compounds by contacting O2-C4 paraffins, olefins, or mixtures thereof with crystalline aluminosilicate zeolites. Examples of zeolites include ZSM-5 type zeolide, zeolite β,
ZSM-12, and TEA-mordenite are mentioned. It is also stated that the above reaction is characterized in that only the crystalline aluminosilicate zeolite is needed and there is no need to use a hydrogenation/dehydrogenation functional component. However, it is stated that a hydrogenation/dehydrogenation functional component may be included if desired. These components include various metals. i.e. group IIB, group VIB, group VII
Metals, metal oxides, or V belonging to group B, group Vllll
Combinations of Group IB and Group Vll metals, sulfides or oxides are described as being included.

However, the effects of these metals or gold compounds and combinations thereof on zeolites are by no means arbitrary, and the optimal metal or combination of metals for a desired reaction is still not clear.

Further, JP-A-49-41322 describes that ZnH2SM-5 zeolite is excellent in the aromatization reaction of light naphtha and the like. However, it is still not sufficient for aromatic formation.

[Problems to be Solved by the Invention] An object of the present invention is to provide means for solving these problems.

[Means for Solving the Problems] In the present invention, as a result of intensive studies on the ZSM-5 type zeolide catalyst containing a wide variety of metals, the purpose of the present invention is to convert hydrocarbon raw materials containing lower olefins. In the method for producing aromatic compounds by
-hr/m01), and it has been found that aromatization of lower olefins can be suitably carried out by this method.

[Function] Hydrocarbon raw materials containing lower olefins include hydrocarbons containing ethylene, propylene, butene, and mixtures thereof.

The ZSM-5 type zeolite used here is disclosed in US Pat. No. 3,702,886 and British Patent No. 14,029.
Zeolite ZSM-5 described in Publication No. 81, Zeolite Z described in German Patent No. 2049755@ Publication
SM-8, and the zeolite ZSM-11 described in U.S. Pat. No. 3,709,979.

ZSM-5 type zeolites typically have silica/alumina (molar ratio) values from about 5 to infinity, giving characteristic xi diffraction patterns as shown in the above-mentioned patent publications, respectively. . The preferred silica/alumina (molar ratio) of the ZSM-5 type zeolite of the present invention is 20-200.

Methods for producing each of these ZSM-5 type zeolites are disclosed in the above-mentioned patent publications, but for example, ZSM-5 typically consists of silica, alumina, alkali metal sources, water, and a tetra-n-propylammonium compound. It is synthesized by hydrothermally treating a water slurry.

The ZSM-5 type zeolite used as a catalyst in the present invention is a hydrogen type zeolite in which the alkali metal cations normally present as cations after synthesis are completely or partially exchanged with protons by an ion exchange method. This exchange can be performed by using a known ion exchange technique to exchange ammonium ions with an aqueous ammonium salt solution, for example, an aqueous ammonium chloride solution, and then expel ammonium by calcination and exchange it with protons. It is also possible to directly exchange protons by treatment with an aqueous hydrogen chloride solution. After being treated with an aqueous ammonium chloride solution or an aqueous hydrogen chloride solution, it is thoroughly washed with water, dried, and then fired.

The firing conditions are not particularly limited, but the temperature is too high,
If it is carried out for too long, crystallization will proceed too much and crystal destruction will occur. Further, if the temperature is low or the firing time is too short, the firing effect cannot be obtained. Usually 300-600
°C for about 1 to 20 hours.

Also, the content of vanadium in zeolite is V2O5
The ratio of zinc to vanadium is preferably in the range of 1 to 30% by weight, and the atomic ratio of Zn/V to vanadium is 1/10 to 1/1. The reason is that outside this range, the aromatic yield and selectivity will drop significantly, making it impossible to sufficiently produce aromatics.

The method for incorporating these metals into ZSM-5 type zeolite is not particularly limited, and methods such as dry mixing or wet impregnation may be employed.

There are no particular restrictions on the raw material zinc, but zinc nitrate, zinc hydroxide, zinc sulfate, zinc oxalate, zinc acetate, etc. are used, and zinc nitrate is preferably used.

As vanadium raw materials, vanadium bromide, vanadium chloride, vanadium fluoride, vanadium iodide, vanadium oxide, vanadium sulfate, vanadium sulfide, vanadium tripropoxide, vanadium triethoxide, ammonium vanadate, etc. are used, and vanadium acid is preferable. Ammonium is used.

A preferred method for containing vanadium and zinc is to first prepare a solution containing a predetermined amount of vanadium and zinc, add ZSM-5 type zeolite thereto, and mix well. Heat and stir as necessary. Once the zeolite is thoroughly mixed in the gold BWj liquid, the catalyst is dried. Although there are no particular restrictions on the drying method, it is preferable to conduct the drying so that the metal is uniformly dispersed in the zeolite. For example, a rotary evaporator or a hot air dryer may be used, or both may be used in combination. After drying, the catalyst is activated by firing. Firing is carried out in air or in an oxygen-containing gas. Firing temperature is 300~600℃, firing time is 1~
20 hours is preferred.

After calcination, most of the vanadium and zinc are substantially in the form of oxides. The catalyst thus prepared as W4 may be used as it is, or may be used in the reaction with the addition of a diluent. Silica, alumina, etc. are used as the diluent.

The reaction method is preferably a flow method. Also fixed floor.

Either a fluidized bed or a moving bed can be used, and these may be used in combination. Preferred reaction conditions are temperature = 200-600°C.
, W/F=1 to 100 (Q·hr/mo I), and if it deviates from this range, it will not be able to fully exhibit its function as a catalyst, and a sufficient amount of aromatic product will not be obtained. The pressure is not particularly limited, but is preferably 0 to 3 C1/cdG. Further, an inert gas may be accompanied with the raw material as necessary. Nitrogen, argon, carbon dioxide, helium, steam, etc. are used as the inert gas.

Note that the W/F (Q - h r/mol
) indicates that the raw materials were reacted at a rate of Fmol per hour using contact WWQ, and is a value corresponding to the contact time.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples unless it departs from the gist of the present invention. Throughout this specification, all temperatures are in degrees Celsius, and parts and percentages are by weight unless otherwise specified.

11 Wataru Uni 4 JP-A-50-5335 (British Patent No. 140298)
According to Publication No. 1), the silica/alumina (molar ratio) is 4.
Zeolite ZSM-5 of No. 1 was synthesized. This zeolite was identified as zSM-5 by X-ray diffraction. Next, the synthesized zeolite was ion-exchanged with 1N hydrochloric acid, and then calcined in air at 520°C for 5 hours.

To this ZSM-5 (hereinafter, the same ZSM-5 was used in all Examples and Comparative Examples), aqueous solutions of ammonium vanadate and zinc nitrate were added to ZSM-5 at a concentration of 5% by weight as V2O5, and Zn/■=1/4~
Add so that the ratio is 3/4 (atomic ratio), stir and mix 5 times.
I did it for an hour.

Thereafter, this was dried and further calcined at 520° C. for 5 hours to prepare a catalyst.

Trans-2-butene/N2=2/3 (volume ratio) was used as a raw material, and an atmospheric fixed bed flow reactor was used for the reaction. The reaction conditions were a temperature of 500-℃ and a contact time of W/F.
=9.0 [7-hr/mo I). The reaction products were analyzed by gas chromatography. In these reactions, the catalyst maintained constant activity for over 20 hours. The reaction results are shown in Table 1.

Comparative Example 1 In Example 1, the reaction was carried out using ZSM-5 containing 5% by weight of vanadium as V2O5 as a catalyst. The results are shown in Table 1.

In Example 1, the reaction was carried out using 828M-5 as a catalyst. The results are shown in Table 1.

In Example 1, the reaction was carried out using ZSM-5 containing 10% by weight of vanadium as V2O5 as a catalyst. The results are shown in Table 1.

[Effect of the invention] ZSM-containing vanadium and zinc according to the invention
By using the Type 5 zeolite catalyst, C6 to C8 aromatics with high added value can be obtained in high yield from hydrocarbon raw materials containing lower olefins, and catalyst deterioration due to coke is small, so it can be used for a long time. A high yield of 06-C8 aromatic components can be obtained relatively stably over time.

Patent applicant: Japan Petrochemical Co., Ltd. Yui-ma;

Claims (3)

[Claims] (1) In a method for producing aromatic compounds by converting hydrocarbon raw materials containing lower olefins, using a ZSM-5 type zeolite catalyst containing vanadium and zinc, temperature = 200 to 600 ° C., W / F = 1 to A production method that converts raw materials under conditions of 100 (g・hr/mol). (2) The production method according to claim 1, wherein the lower olefin is trans-2-butene. (3) Vanadium content is 1 to 30 as V_2O_5
2. The production method according to claim 1, wherein the content of zinc is Zn/V in atomic ratio of 1/10 to 1/1 in weight percent (based on zeolite).