JPH04366199A - Preparation of liquid hydrocarbon mixture from lower olefin - Google Patents

Abstract

PURPOSE:To improve the yield of liquid hydrocarbons and prolong the catalyst lift by the use of a composite catalyst. CONSTITUTION:A composite catalyst is prepared by mixing physically a pentasil- type zeolite catalyst with a hydrogen activation catalyst containing gallium, zinc, platinum, molybdenum, cobalt or nickel in a weight ratio of 1:4. The composite catalyst is packed in a reactor, through which a feedstock gas containing lower olefins is passed at a temperature of 350-600 deg.C, a weight hourly space velocity of 1-50hr<-1> and a total pressure of 0.1-20atm, thereby reacting the olefins.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for producing a liquid hydrocarbon mixture containing aromatic hydrocarbons in the presence of a catalyst using lower olefins such as ethylene and propylene or gas compositions containing these as raw materials. .

0002

BACKGROUND OF THE INVENTION Recently, research has been actively conducted to use natural gas to produce liquid fuel by partially oxidizing methane, its main component, into ethane and ethylene, which are then polymerized. In this case, it is an important issue to efficiently convert ethylene, one of the products, into liquid fuel. Zeolite catalysts have conventionally been used as catalysts for producing liquid hydrocarbons useful as gasoline fractions from lower olefins such as ethylene and propylene. For example, Mobil Corporation of the United States discloses a method for producing a gasoline fraction from an olefin-containing mixture using a zeolite catalyst in Japanese Patent Application Laid-open No. 103292/1983 as a method for producing lead-free high octane gasoline. are doing.

0003

However, it is generally observed that the activity of zeolite catalysts rapidly decreases due to the precipitation of carbon-like substances produced during the reaction. A catalyst whose activity has decreased can be regenerated by burning the deposited carbonaceous material with air or oxygen. This reaction-regeneration cycle is said to be the fate of zeolite catalysts, and it goes without saying that the longer the activity remains under the same conditions and the fewer times the catalyst is regenerated, the better it will be economically. do not have. Therefore, it is desired to develop a technology for producing liquid fuel efficiently using lower olefins, particularly ethylene, as a raw material, while reducing the number of times the catalyst is regenerated as much as possible.

The purpose of the present invention is to improve the yield of liquid hydrocarbons and reduce the number of times the zeolite catalyst is regenerated when producing a liquid hydrocarbon mixture containing aromatic hydrocarbons from lower olefins such as ethylene. The purpose is to provide a method.

[0005]

[Means for Solving the Problems] The present inventors have discovered that when converting lower olefins such as ethylene or gas compositions containing these into liquid hydrocarbon mixtures containing aromatic hydrocarbons, the yield of liquid hydrocarbons can be improved. As a result of intensive research with the aim of improving the performance of zeolite catalysts and extending the life of the zeolite catalyst, we discovered that the problem could be solved by using a composite catalyst consisting of pentasil-type zeolite and a hydrogen-activated catalyst.

That is, the gist of the present invention is to provide a method for producing a liquid hydrocarbon mixture containing an aromatic hydrocarbon using a lower olefin or a gas composition containing a lower olefin as a raw material in the presence of a catalyst. Production of a liquid hydrocarbon mixture using a lower olefin as a raw material, characterized by using a composite catalyst prepared by physically mixing a hydrogen activated catalyst with a catalyst that can be converted into a liquid hydrocarbon mixture containing aromatic hydrocarbons. It lies in the method.

[0007] In the present invention, the above composite catalyst includes:
Consisting of pentasil type zeolite or a catalyst obtained by modifying it with hydrogen ions or alkaline earth metals, and one or two metals selected from the group consisting of gallium, zinc, platinum, molybdenum, cobalt, or nickel, or their oxides. Prepared by physically mixing catalysts. Such a composite catalyst is packed into a reactor, and lower olefins such as ethylene or raw materials containing these are added to the reactor.
Normally, weight hourly space velocity (WHSV) 0.1-400h
A liquid hydrocarbon mixture containing aromatic hydrocarbons can be obtained by reacting under conditions of r-1, temperature of 200 to 700°C, and pressure of 0.1 to 100 atm (10 to 10,132 kilopascals). . Normally, lower olefins such as ethylene are converted into a liquid hydrocarbon mixture containing aromatic hydrocarbons using only a pentasil-type zeolite catalyst.In this case, a composite catalyst prepared by physically mixing a hydrogen-activated catalyst with a zeolite catalyst is used. Not only can the production rate of liquid hydrocarbons containing aromatics be significantly increased, but also the lifetime of the zeolite catalyst can be extended in many cases; The fact that it is more effective when used as a hydrogen activation catalyst than when used for commercial purposes was extremely unexpected.

The present invention will be explained in detail below. In the present invention, a composite catalyst is used in which a zeolite catalyst and a hydrogen-activated catalyst are mixed at a certain ratio to convert lower olefins such as ethylene into a liquid hydrocarbon mixture containing aromatic hydrocarbons. First, the zeolite catalyst is preferably a catalyst that can be used as a raw material for liquid fuel for automobiles, and can produce a high proportion of light aromatic hydrocarbons, particularly benzene, toluene, and xylenes. As such a zeolite catalyst, a pentasil type zeolite can be mentioned. Pentasil type zeolite is a general term for synthetic zeolites, which are aluminosilicates and zeolites made of silica and alumina, and have ten five-membered rings made of oxygen atoms and silicon or aluminum atoms, which form unique pores. be. More specifically, ZS is a special synthetic zeolite developed by Mobil Corporation in the United States.
M-5, ZSM-11, ZSM-12, ZSM-23,
Refers to ZSM-35, ZSM-48 type zeolites, and zeolites with structures similar to these. In the present invention, any of these can be used, but in particular ZSM-5
Type zeolites are preferred. The molar ratio of silica and alumina (SiO2/Al2O
3 ratio) is preferably 15-3000, most preferably 20-100.

As the pentasil type zeolite, a calcined product obtained by hydrothermally synthesizing and removing the organic base can be used as it is, but it may also be modified with hydrogen ions. Hydrogen ion modification can be performed, for example, as follows. Dissolve 40g of ammonium nitrate (special grade reagent) in 1000ml of distilled water, and add ZS to this.
After adding 10 g of M-5 type zeolite and stirring at 80°C for 3 hours, the zeolite was filtered from the solution. This zeolite is further suspended in the above aqueous ammonium nitrate solution and treated in the same manner. This operation is repeated 10 times in total to complete the hydrogen ion modification. Thereafter, it is first dried in air at 120°C for 15 hours, and then fired in air at 550°C for 2 hours.

In order to better achieve the objects of the present invention, it is necessary to further modify the hydrogen ion-modified zeolite with an alkaline earth metal. As alkaline earth metals used for modification, magnesium and calcium are particularly preferred. Modification can be carried out using salts, oxides, and hydroxides of these alkaline earth metals by an ion exchange method, an impregnation method, or the like. Examples of modification by ion exchange method are as follows. 32 g of magnesium nitrate (special grade reagent) is dissolved in 500 ml of distilled water, 5 g of ZSM-5 type zeolite modified with hydrogen ions is added thereto, and the mixture is stirred at 80° C. for 3 hours. After filtering the zeolite from the solution, it is further suspended in the above magnesium nitrate solution,
Similar processing is performed a total of 5 times. Then, first in the air, 1
Dry at 20°C for 15 hours, then dry in air at 550°C for 2 hours.
Bake for an hour.

On the other hand, hydrogen activation catalysts are usually prepared using organic salts of gallium, zinc, platinum, molybdenum, cobalt or nickel, inorganic salts such as chlorides and nitrates, or oxides and hydroxides. . In some cases,
These can also be supported on a carrier such as silica, alumina, or activated carbon. The hydrogen activated catalyst is prepared as follows. A predetermined amount of a metal compound is dissolved in distilled water, a predetermined amount of alumina is added thereto, the solution is left under reduced pressure for 30 minutes, and then evaporated to dryness in a steam bath. Thereafter, it is first dried in air at 120°C for 15 hours, and then fired in air at 550°C for 2 hours.

In the method of the present invention, the hydrogen-activated catalyst thus obtained and the pentasil type zeolite catalyst are mixed at a weight ratio of 1:1 to 1:10, preferably 1:4. Mixing may be performed between solid powders,
Alternatively, they may be mixed in the form of a slurry using a suitable dispersion medium. These catalysts may be used as they are in the reaction, but
It may be used after firing in air or in a nitrogen stream. Also,
Depending on the case, reduction may be carried out in a gas stream such as hydrogen or carbon monoxide. Platinum, chromium, contained in the mixed catalyst
The metal content of zinc or gallium is 0.1 to 15% by weight in terms of metal, respectively, 0.1 to 5% by weight for platinum and gallium, 0.5 to 10% by weight for molybdenum, cobalt, and nickel. Regarding zinc, 1 to 20% by weight is preferred.

Next, a method for producing a liquid hydrocarbon mixture containing aromatic hydrocarbons from a gas containing lower olefins using the catalyst obtained above will be described. The reaction takes place at a temperature of 20
0 to 700°C, preferably 350 to 600°C, weight hourly space velocity 0.1 to 400 hr-1, preferably 1 to 50
hr-1, total pressure 0.1 to 100 atm (10 to 1013
2 kilopascals), preferably 0.1 to 20 atm (10
~2026 kilopascals). As raw materials, in addition to lower olefins such as ethylene and propylene, gases containing these can be used as raw materials. An example of the latter is a gas containing ethane and ethylene produced by a partial oxidation reaction of methane. These raw materials can also be diluted with water vapor or an inert gas such as nitrogen, helium, or argon and then supplied onto the catalyst. The aromatic hydrocarbon product and the unreacted raw material are separated and purified by known methods. This reaction may be carried out in any reaction format as long as the above raw materials are supplied as a gas and can be brought into sufficient contact with the solid catalyst, such as a fixed bed reaction method, a fluidized bed reaction method, a moving bed reaction method, etc. However, the object of the present invention can be achieved.

[0014]

[Examples] The present invention will be explained below based on Examples, but the present invention is not limited thereto. Example 1 (1) Preparation of catalyst a) Preparation of H-Z5 catalyst 40 g of ammonium nitrate (reagent grade) was added to 1000 g of distilled water.
ml, 10 g of ZSM-5 type zeolite was added thereto, and the mixture was stirred at 80°C for 3 hours. After filtering the zeolite from the solution, the same treatment as above was performed on the zeolite 10 times in total. Then, in air at 120℃ for 15
It was dried for an hour and then fired in air at 550°C for 2 hours. b) Preparation of Ga + H-Z5 catalyst (composite catalyst) 9.50 g of alumina was added to a solution of 3.00 g of gallium nitrate (special grade reagent) dissolved in 25 ml of distilled water, left for 30 minutes under reduced pressure, and then placed in a steam bath. It was evaporated to dryness. After that, it was dried in the air at 120°C for 15 hours, and then in the air at 550°C.
It was baked for 2 hours. The catalyst powder obtained here and H-Z5
The catalysts were weighed out at a weight ratio of 1:4 and mixed in a mortar. (2) Reaction The catalyst powder obtained in step (b) above was heated to a pressure of 400 kg/cm2.
This was then crushed into granules of 20 to 40 mesh, and 1 g of the tablets were filled into a quartz glass reaction tube with an inner diameter of 10 mm. The reaction was carried out under atmospheric pressure using a mixed gas of ethylene diluted with nitrogen (C2 H4 /N2 = 20
/80: volume ratio), W/F=10g・h/m
The test was carried out at 400°C. The product released from the reaction tube was directly introduced into a gas chromatograph and analyzed. The results are shown in Table 1.

[Table 1] The experimental conditions in Table 1 are: reaction temperature: 400°C, catalyst amount: 1.
00g, W/F=10g·h/mol, reaction gas composition: C2H4/N2=20/80. Table 1
In the equation, the ethane conversion rate indicates the proportion of ethane reacted, and the selectivity indicates the proportion of reaction products produced. In addition, in the table, C1
, C2, C3, and C4 have carbon numbers of 1, 2, and 3, respectively.
, 4 represents a hydrocarbon. Further, C5 + aliphatic represents a hydrocarbon having 5 or more carbon atoms, aromatic represents an aromatic hydrocarbon, and the sum of both represents a liquid hydrocarbon mixture.

Comparative Example 1 A reaction was carried out under the same conditions as in Example 1 (2) using only the H-Z5 catalyst prepared in Example 1 (1) A). The results are shown in Table 2.

[Table 2] The experimental conditions in Table 2 are the same as in Table 1.

Example 2 (1) Preparation of catalyst a) Preparation of Mg-Z5 catalyst 32 g of magnesium nitrate (reagent special grade) was added to 500 m of distilled water.
1, add 5 g of H-Z5 catalyst, and heat to 80°C.
The mixture was stirred for 3 hours. After filtering the zeolite from the solution, the same treatment as above was performed on the zeolite five times in total. Thereafter, it was dried in air at 120°C for 15 hours, and further baked in air at 550°C for 2 hours. B) Preparation of Ga+Mg-Z5 (composite catalyst) A catalyst was prepared in the same manner as in (1) B) of Example 1, except that the Mg-Z5 catalyst obtained in A) above was used as the zeolite. (2) The reaction was carried out in the same manner as (2) of Reaction Example 1. The results are shown in Table 3.

[Table 3] The experimental conditions in Table 3 are the same as in Table 1.

Comparative Example 2 A reaction was carried out under the same conditions as in Example 1 (2) using only the Mg-Z5 catalyst prepared in Example 2 (1) A). The results are shown in Table 4.

[Table 4] The experimental conditions in Table 4 are the same as in Table 1.

Comparative Example 3 Using 3.00 g of gallium nitrate (special grade reagent), Example 1
A Ga-Z5 catalyst was prepared in the same manner as in (1) (a), and reacted under the same conditions as in (2) of Example 1. The results are shown in Table 5.

[Table 5] The experimental conditions in Table 5 are the same as in Table 1.

Example 3 A Zn+H-Z5 catalyst was prepared in the same manner as in (1) b) of Example 1 except that 2.24 g of zinc nitrate (special grade reagent) was used, and the same procedure as in (2) of Example 1 was carried out. The reaction was carried out under the same conditions. The results are shown in Table 6.

[Table 6] The experimental conditions in Table 6 are the same as in Table 1.

Example 4 A Pt+H-Z5 catalyst was prepared in the same manner as in (1) b) of Example 1, except that 1.33 g of chloroplatinic acid (special grade reagent) was used. ) was reacted under the same conditions. The results are shown in Table 7.

[Table 7] The experimental conditions in Table 7 are the same as in Table 1.

Example 5 Ammonium paramolybdate (special grade reagent) 0.92 g
Mo+H-
A Z5 catalyst was prepared and reacted under the same conditions as in Example 1 (2). The results are shown in Table 8.

[Table 8] The experimental conditions in Table 8 are the same as in Table 1.

Example 6 Except for using 2.47 g of cobalt nitrate (special grade reagent),
A Co+H-Z5 catalyst was prepared in the same manner as in Example 5,
The reaction was carried out under the same conditions as in Example 1 (2). Table 9 shows the results.
Shown below.

[Table 9] The experimental conditions in Table 9 are the same as in Table 1.

Example 7 Using 2.48 g of nickel nitrate (special grade reagent), H-Z5
Example 5 except that Mg-Z5 catalyst was used instead of the catalyst.
A Ni+Mg-Z5 catalyst was prepared in the same manner as above, and reacted under the same conditions as in Example 1 (2). The results are shown in Table 10.

[Table 10] The experimental conditions in Table 10 are the same as in Table 1.

[0024]

[Effects of the Invention] According to the method of the present invention, as can be seen from the above results, the production rate of liquid hydrocarbons can be significantly increased, and the catalyst life can be extended, which has great industrial value. .

Claims (5)

[Claims] Claim 1. A method for producing a liquid hydrocarbon mixture containing an aromatic hydrocarbon in the presence of a catalyst using a lower olefin or a gas composition containing the lower olefin as a raw material, wherein the lower olefin is a liquid hydrocarbon mixture containing an aromatic hydrocarbon. A method for producing a liquid hydrocarbon mixture using a lower olefin as a raw material, the method comprising using a composite catalyst prepared by physically mixing a hydrogen-activated catalyst with a catalyst that can be converted into a liquid hydrocarbon mixture. 2. As a catalyst capable of converting the lower olefin into a liquid hydrocarbon mixture containing aromatic hydrocarbons, a pentasil-type zeolite or a zeolite modified with hydrogen ions or an alkaline earth metal is used as a hydrogen-activated catalyst. A method for producing a liquid hydrocarbon mixture using a lower olefin as a raw material according to claim 1, wherein a metal compound containing one or two of gallium, zinc, platinum, molybdenum, cobalt, or nickel is used as the raw material. [Claim 3] The pentasil type zeolite is ZSM.
A method for producing a liquid hydrocarbon mixture using the lower olefin of claim 2 as a raw material, which is a -5 type synthetic zeolite. 4. The method for producing a liquid hydrocarbon mixture using a lower olefin as a raw material according to claim 2 or 3, wherein the alkaline earth metal for modifying the pentasil type zeolite is magnesium or calcium. 5. The method for producing a liquid hydrocarbon mixture using a lower olefin as a raw material according to any one of claims 1 to 4, wherein the lower olefin is ethylene or propylene.