JP2019026571A - Method for producing aromatic compound - Google Patents

Abstract

To provide a novel method that produces an aromatic compound, stably in high yield, in the presence of a catalyst containing zeolite, using hydrocarbons as the raw material.SOLUTION: A method for producing an aromatic compound includes a reaction to occur under a contact reaction condition of 450°C or more and less than 650°C and higher than 0 MPa G and less than 0.8 MPa G, using an aliphatic hydrocarbon and/or an alicyclic hydrocarbon as the raw material, in the presence of a catalyst containing zeolite having a 10 membered ring skeleton structure.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a novel aromatic compound, and in particular, using an aliphatic hydrocarbon and / or an alicyclic hydrocarbon as a raw material in the presence of a catalyst containing a zeolite having a 10-membered ring skeleton structure, A method for producing an aromatic compound in a high yield is provided.

  In many cases, benzene, toluene, xylene (hereinafter collectively referred to as aromatic compounds) decomposes a raw oil (for example, naphtha) obtained by petroleum refining in a thermal decomposition reactor, It can be obtained by separating and purifying an aromatic compound by distillation or extraction from the obtained thermal decomposition product. In the production of aromatic compounds by these production methods, aliphatic and / or alicyclic hydrocarbons are included as thermal decomposition products other than aromatic compounds. Therefore, since aliphatic and / or alicyclic hydrocarbons are produced simultaneously with the production of aromatic compounds, the production of aromatic compounds is commensurate with the production of aliphatic and / or alicyclic hydrocarbons. Adjustments were made and the production volume was naturally limited.

  In addition, it is proposed to produce an aromatic compound by bringing an aliphatic or alicyclic hydrocarbon raw material into contact with a catalyst mainly containing a medium pore size zeolite at a temperature of about 400 ° C. to about 800 ° C. (For example, Patent Documents 1 and 2, Non-Patent Documents 1 to 4). These production methods have the advantage that the aromatic compounds can be produced from surplus hydrocarbon raw materials, as compared with the production method of aromatic compounds by pyrolysis, which has a low added value.

Japanese Patent No. 3741455 Japanese Patent No. 3264447

Industrial & Engineering Chemistry Research Vol. 31, 995 (1992) Industrial & Engineering Chemistry Research Volume 26, 647 (1987) Applied Catalysis Volume 78, 15 (1991) Microporous and Mesoporous Materials 47, 253 (2001)

  However, these methods for producing aromatics have the problem of a decrease in catalytic activity over time due to carbon deposition and the like, and as a result, it is difficult to stably achieve a high aromatic yield over a long period of time. It becomes.

  Therefore, the present invention provides a novel aromatic compound production method capable of obtaining a high aromatic yield over a long period of time in an aromatic production method for producing an aromatic compound from a hydrocarbon raw material. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventor can maintain a high aromatic yield over a long period of time by using a catalyst containing a specific zeolite and under a specific catalytic reaction condition. The present inventors have found that this is a possible stable manufacturing method and have completed the present invention.

  That is, the present invention uses an aliphatic hydrocarbon and / or an alicyclic hydrocarbon in the presence of a catalyst containing a zeolite having a 10-membered ring skeleton structure, and is 450 ° C. or higher and lower than 650 ° C. and higher than 0 MPaG and 0.000. The present invention relates to a method for producing an aromatic compound, wherein the reaction is carried out under a catalytic reaction condition of less than 8 MPaG.

  The present invention is described in detail below.

  The catalyst for producing an aromatic compound used in the production method of the present invention is not particularly limited as long as it contains a zeolite having a 10-membered ring skeleton structure. Specifically, it comprises AEL, EUO, FER, HEU, MEU, MEL, MFI, NES type, etc., and it is a catalyst for producing aromatic compounds that are more efficient in reaction selectivity, productivity, etc. Since it is a production method that makes it possible to efficiently produce an aromatic compound when it comes into contact with a hydrocarbon raw material, it preferably contains MEL or MFI type, and particularly includes MFI type. It is preferable that For example, the MFI type indicates an aluminosilicate compound belonging to the structure code MFI defined by the International Zeolite Society.

The zeolite is not limited in its SiO ₂ / Al ₂ O ₃ (molar ratio), and among them, it constitutes a catalyst excellent in heat resistance, reaction selectivity and productivity, and is excellent in reaction selectivity and productivity. since the manufacturing _method, it is preferable SiO 2 / _Al 2 _{O 3} (molar ratio) is 20 to 200. In addition, since the zeolite has excellent reaction selectivity and productivity, it is preferable that the zeolite does not contain a structure directing agent such as tetrapropylammonium in the pores.

  And, the primary particle size and the agglomerated size of the zeolite are not limited at all, and among others, it is particularly excellent in its handleability and provides a production method excellent in reaction selectivity and productivity. It is preferable that the average particle diameter (hereinafter referred to as PD) ≦ 100 nm. In addition, PD can be measured by the method of selecting 10 or more arbitrary particles from the photograph of a scanning electron microscope (SEM) or a transmission electron microscope (TEM), and calculating | requiring the surface area average diameter, for example.

The acid amount of the zeolite is not particularly limited, but is preferably 0.1 to 1.0 mmol / g, and more preferably 0.1 to 0.6 mmol / g. Here, in the case of a zeolite having an acid amount exceeding 1.0 mmol / g, coke adheres easily when used in a hydrocarbon conversion / isomerization reaction, and the conversion / isomerization reaction is rapidly deactivated. . When the zeolite has an acid amount of less than 0.1 mmol / g, the activity during the conversion / isomerization reaction of the hydrocarbon is low.
The acid sites of the zeolite may be distributed either inside or outside the micropores (the surface of the zeolite). However, since the production method stably maintains the reaction selectivity and productivity, It is preferable that these have no acid sites and are distributed only inside the micropores. Here, the surface acid point of the zeolite indicates the acid point existing on the surface of the zeolite as the term implies. Normally, zeolite has acid sites on its surface and (micro) pores, and having no acid sites on the surface can be said to have acid sites only in (micro) pores. It is. And since preparation and acquisition as a zeolite are easy, it is preferable that it is a zeolite which has the surface which is not coat | covered with a silicate, a dialkylamine reagent, etc. on the surface.

  As a method for confirming the acid point on the surface of the zeolite (the acid point does not exist on the surface), any method can be used as long as the confirmation is possible. (Characterization of acid sites on the external surface of zeolites, Reaction Kinetics and Catalysis Letters, vol. 67, p. 281) (p. 281). 2,4-dimethylquinoline has an adsorption property with acid sites (—OH) present in zeolite (including inside the pores), but the (micro) pore diameter of zeolite is 2,4-dimethylquinoline. If it is smaller than the molecule, it cannot penetrate into the (micro) pores and cannot adsorb to the acid sites in the (micro) pores. That is, it adsorbs only on the acid sites on the zeolite surface. Therefore, when adsorption of 2,4-dimethylquinoline to the acid sites (—OH) present on the zeolite surface is not observed, it can be determined that there are no acid sites on the zeolite surface.

  The form of the catalyst for producing the aromatic compound containing the zeolite is not limited in any way. For example, the zeolite powder is used as a catalyst as it is, the compression molding is used as a specific shape, a binder, etc. It can be used in any form, such as mixing with and forming into a specific shape.

In the method for producing an aromatic compound of the present invention, an aromatic compound is provided by a catalytic reaction of an aliphatic hydrocarbon and / or an alicyclic hydrocarbon as a raw material in the presence of a catalyst containing the zeolite, The carbon number of the aliphatic hydrocarbon and / or the alicyclic hydrocarbon is not particularly limited, and preferably has 2 to 6 carbon atoms. Examples thereof include saturated hydrocarbons, unsaturated hydrocarbons, alicyclic hydrocarbons, mixtures thereof and the like. More specifically, ethane, ethylene, propane, propylene, cyclopropane, n-butane, isobutane. 1-butene, 2-butene, isobutene, butadiene, cyclobutene, cyclobutane, n-pentane, 1-pentane, 2-pentane, 1-pentene, 2-pentene, 3-pentene, n-hexane, 1-hexane, 2 -Hexane, 1-hexene, 2-hexene, 3-hexene, hexadiene, cyclohexane, methylcyclopentane, and a mixture thereof. When supplying aliphatic hydrocarbons and / or alicyclic hydrocarbons as source gas, the source gas is selected from a single gas and an inert gas such as nitrogen, hydrogen, carbon monoxide, and carbon dioxide. It can also be used as a single or mixed gas diluted. The supply of the aliphatic hydrocarbon and / or alicyclic hydrocarbon as the raw material is not particularly limited as a ratio of the volume of the raw material gas to the catalyst volume, and for example, a space velocity of about ¹ h ^{−1 to} 50000 h ^−1. Can be mentioned.

  The conditions for the catalytic reaction between the catalyst for producing an aromatic compound comprising the zeolite and the aliphatic hydrocarbon and / or alicyclic hydrocarbon are 450 ° C. or higher and lower than 650 ° C., and 0 MPaG The condition is high and less than 0.8 MPaG. Here, when the temperature is lower than 450 ° C., the production of olefins and alkanes is large and the efficiency is inferior. On the other hand, even if it is 650 degreeC or more, the manufacturing efficiency of an aromatic compound does not change, and only the heat-resistant reaction apparatus more than necessary is needed. Moreover, when it is under reduced pressure or 0 MPaG, the production efficiency of the aromatic compound is inferior. On the other hand, when the pressure is 0.8 MPaG or more, the deactivation of the catalyst due to coking becomes remarkable, resulting in poor production efficiency.

  There is no restriction | limiting as the reaction format, For example, not only a fixed bed, a transport bed, a fluidized bed, a moving bed, a multitubular reactor but a continuous flow type, an intermittent flow type, a swing type reactor, etc. can be used.

  The aromatic compound obtained by the production method of the present invention is not particularly limited as long as it belongs to the category referred to as an aromatic compound. For example, benzene, toluene, xylene, trimethylbenzene, ethylbenzene, propylbenzene, butylbenzene , Naphthalene, methylnaphthalene and the like, and benzene, toluene and xylene are particularly preferable.

  The present invention provides a novel fragrance capable of obtaining a high aromatic compound yield over a long period of time in an aromatic compound production method for producing an aromatic compound from raw materials such as aliphatic hydrocarbons and / or alicyclic hydrocarbons. It provides a method for producing a group compound, and is very useful industrially.

  Hereinafter, the present invention will be specifically described by way of examples.

  The catalyst for producing zeolite / aromatic compound having a 10-membered ring skeleton structure used in the examples was measured and defined by the following method.

-Measurement of SiO ₂ / Al ₂ O ₃ molar ratio-
The SiO ₂ / Al ₂ O ₃ molar ratio of zeolite is such that MFI type zeolite is dissolved in a mixed aqueous solution of hydrofluoric acid and nitric acid, and this is inductively coupled plasma by a general ICP apparatus (trade name: OPTIMA3300DV, manufactured by PerkinElmer). Measured by emission spectroscopic analysis (ICP-AES).

~ Measurement of powder X-ray diffraction ~
Using an X-ray diffractometer (Spectris Co., Ltd., (trade name) X'pert PRO MPD), a tube voltage of 45 kV and a tube current of 40 mA were used in the atmosphere using CuKα1. The range of 5-60 degrees was analyzed at 0.04 degrees / step, 4 degrees / minute. In addition, the background corrected by the absorptance of the direct beam is removed. The presence or absence of the peak was confirmed visually.

~ 2,4-Dimethylquinoline adsorption infrared absorption spectroscopy ~
Infrared absorption spectroscopy is performed using a general FT-IR measurement device ((trade name) Varian 660-IR, manufactured by Agilent Technologies) with components for IR measurement devices under vacuum ((trade name) multi-mode cell). , Manufactured by ST Japan Co., Ltd.). The sample was molded into a disk, placed in a cell, heated to 400 ° C. at 10 ° C./min under vacuum evacuation, and held for 2 hours. After cooling to 150 ° C., an infrared absorption spectrum before 2,4-dimethylquinoline adsorption was measured. 2,4-dimethylquinoline gas was introduced, adsorbed for 10 minutes, evacuated at 150 ° C. for 1 hour, and the infrared absorption spectrum after adsorption of 2,4-dimethylquinoline was measured. The difference between the infrared absorption spectrum after adsorption of 2,4-dimethylquinoline and the spectrum before adsorption was taken, and the change in infrared absorption due to adsorption was measured.

-Aromatic compound production apparatus and production method thereof-
The aromatic compound-producing catalyst obtained in the examples was produced by the following method and evaluated.

  A fixed bed gas phase flow reactor using a stainless steel reaction tube (inner diameter 16 mm, length 600 mm) was used. The middle stage of a stainless steel reaction tube was filled with an aromatic compound production catalyst, pre-heated under a flow of dry air, and then fed with a raw material gas. And heating used the ceramic tube furnace, and controlled the temperature of the catalyst layer. The reaction outlet gas and the reaction liquid were collected, and the gas component and the liquid component were individually analyzed using a gas chromatograph. The gas component was analyzed using a gas chromatograph (manufactured by Shimadzu Corporation, (trade name) GC-1700) equipped with a TCD detector. As the filler, PorapakQ (trade name) manufactured by Waters or MS-5A (trade name) manufactured by GL Science was used. The liquid component was analyzed using a gas chromatograph (manufactured by Shimadzu Corporation, (trade name) GC-2015) equipped with an FID detector. A capillary column (manufactured by GL Sciences, (trade name) TC-1) was used as the separation column.

  The reaction conditions were set as follows.

(Aromatic compound production conditions)
Feed gas: hydrocarbon feed gas catalyst weight: 1 g.
Catalyst shape: Zeolite powder was molded at 400 kgf / cm ² for 1 minute and then pulverized into a lump shape of about 1 mm.
Circulating gas: mixed gas of 50 mol% of raw material gas + 50 mol% of nitrogen, 200 Nml / min (pretreatment conditions)
Catalyst temperature: 600 ° C.
Circulating gas: Air 100 Nml / min.
Pressure: 0 MPaG.

Example 1
Only the MFI type diffraction peak was clearly observed by X-ray diffraction, the average particle diameter was 41 nm, the SiO ₂ / Al ₂ O ₃ molar ratio was 68, the acid amount was 0.24 mmol / g, -Zeolite that was confirmed to have no acid sites on the surface by dimethylquinoline absorption infrared absorption spectrometry was used as a catalyst for the production of aromatic compounds, ethylene was used as a raw material, and aromatic compounds were produced under the conditions described above. . The reaction pressure was 0.2 MPaG. The reaction temperature was 600 ° C.

  Table 1 shows the raw material gas circulation time and the aromatic yield.

  A high aromatic yield was stably obtained with a raw material gas circulation time of 230 minutes.

実施例２
原材料をエチレンの代わりに、１−ブテンとした以外は実施例１と同様の方法にて芳香族化合物の製造を行った。反応圧力は０.２ＭＰａＧであった。

Example 2
An aromatic compound was produced in the same manner as in Example 1 except that 1-butene was used instead of ethylene. The reaction pressure was 0.2 MPaG.

  Table 1 shows the raw material gas circulation time and the aromatic yield.

  A high aromatic yield was stably obtained with a raw material gas circulation time of 230 minutes.

Example 3
Only the MFI type diffraction peak was clearly observed by X-ray diffraction, the average particle diameter was 40 nm, the SiO ₂ / Al ₂ O ₃ molar ratio was 54, the acid amount was 0.21 mmol / g, -Zeolite that was confirmed to have acid sites on the surface by dimethylquinoline absorption infrared absorption spectrometry was used as a catalyst for the production of aromatic compounds, ethylene was used as a raw material, and aromatic compounds were produced under the conditions described above. . The reaction pressure was 0.2 MPaG. The reaction temperature was 600 ° C.

Table 1 shows the raw material gas circulation time and the aromatic yield.
A high aromatic yield was stably obtained with a raw material gas circulation time of 230 minutes.

Comparative Example 1
An aromatic compound was produced in the same manner as in Example 1 except that the reaction pressure was changed to 0.2 MPaG instead of 0.2 MPaG.

  Table 1 shows the raw material gas circulation time and the aromatic yield.

  Although the aromatic yield was stable for 230 minutes of the raw material gas circulation time, the aromatic yield was lower than that of Example 1 and the aromatic production efficiency was poor.

Comparative Example 2
An aromatic compound was produced in the same manner as in Example 1, except that the raw material was 1-butene instead of ethylene and the reaction pressure was 0 MPaG instead of 0.2 MPaG.
Table 1 shows the raw material gas circulation time and the aromatic yield.

  Although the aromatic yield was stable for 230 minutes of the raw material gas circulation time, the aromatic yield was low compared to Example 2 and the aromatic production efficiency was poor.

  The present invention provides a novel aromatic compound production method capable of obtaining a high aromatic compound yield over a long period of time in an aromatic compound production method for producing an aromatic compound from a hydrocarbon raw material. It is very useful industrially.

Claims (6)

  Contact using an aliphatic hydrocarbon and / or an alicyclic hydrocarbon as a raw material in the presence of a catalyst containing a zeolite having a 10-membered ring skeleton structure and not lower than 450 ° C. and lower than 650 ° C. and higher than 0 MPaG and lower than 0.8 MPaG A process for producing an aromatic compound, wherein the reaction is carried out under reaction conditions.   The method for producing an aromatic compound according to claim 1, wherein the zeolite having a 10-membered ring skeleton structure is MEL type or MFI type zeolite. The method for producing an aromatic compound according to claim 1 or 2, wherein the zeolite having a 10-membered ring skeleton structure is a zeolite satisfying the following characteristics (a) to (c).
(A) The average particle diameter (PD) is PD ≦ 100 nm.
(B) There are no acid sites on the surface.
(C) The acid amount is 0.1 to 1.0 mmol / g. The zeolite having a 10-membered ring skeleton structure is a zeolite having a SiO ₂ / Al ₂ O ₃ (molar ratio) of 20 ≦ SiO ₂ / Al ₂ O ₃ ≦ 200. The manufacturing method of the aromatic compound in any one.   The method for producing an aromatic compound according to any one of claims 1 to 4, wherein the aliphatic hydrocarbon and / or the alicyclic hydrocarbon is a hydrocarbon having 2 to 6 carbon atoms.   The method for producing an aromatic compound according to any one of claims 1 to 5, wherein the aromatic compound contains at least one of the group consisting of benzene, toluene and xylene.