JPH10272366A - Aromatizing catalyst for lower hydrocarbon, and production of aromatic compound using the catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst for producing aromatic hydrocarbon such as benzene or naphthalene and hydrogen, by using a lower hydrocarbon such as natural gas, and a method for aromatizing lower hydrocarbon by using this catalyst. SOLUTION: The aromatizing catalyst for lower hydrocarbon consists of at least one kind of a metal selected from among zinc, gallium and cobalt and metallosilicate (1), molybdenum and at least one kind of a metal selected from among zinc, gallium, cobalt, chromium, ranthanum, neodium, samarium and yttrium and metallosilicate (2) and heteropolyacid containing at least one kind of a metal selected from among molybdenum, tungsten and vanadium and metallosilicate. In the presence of catalysts (1)-(3), lower hydrocarbon is reacted (4).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fragrance containing benzenes and naphthalenes as a main component which is useful as a raw material for chemical products such as chemical industry, chemicals and plastics from lower hydrocarbon-containing gases such as natural gas. A catalyst capable of simultaneously efficiently producing an aromatic hydrocarbon and high-purity hydrogen gas, and subjecting a lower hydrocarbon to a high-temperature catalytic reaction in the presence of the catalyst, the aromatic hydrocarbon being the main component The present invention relates to a method for producing an aromatic compound and hydrogen.

[0002]

2. Description of the Related Art Conventionally, aromatic hydrocarbons such as benzene, toluene and xylene are mainly produced from naphtha. Further, as a method for producing naphthalenes, a solvent extraction method of petroleum or the like, a non-catalytic thermal decomposition method of a gas such as natural gas or acetylene, and the like are employed. However, in these conventional methods, only a few percent of benzene and naphthalene can be obtained from raw materials such as coal and acetylene, and many aromatic compounds, hydrocarbons, tars, and insoluble carbon residues with low utility value can be obtained. There is a problem that it can be. Further, the solvent extraction method from coal has a disadvantage that a large amount of expensive organic solvent is required.

Further, in the method for producing naphthalene by thermal decomposition of methane and acetylene, the obtained naphthalenes can be obtained in spite of the fact that a reaction temperature of 1000 ° C. or more is required just to achieve a conversion of methane and acetylene of several percent. Is only 1% or less of converted methane and acetylene, and there is a problem in practical use.

In addition, as a method for producing naphthalenes using a catalyst, a method for producing naphthalenes by dehydrocondensation reaction of alkylbenzenes such as orthoxylene at a high temperature using a platinum-supported catalyst is also known. However, the conversion efficiency to naphthalenes is low, and the alkylbenzenes used as raw materials are expensive.

Further, as a method for producing hydrogen gas co-produced in the present invention, an aqueous gas (water gas shift) reaction, a thermal cracking method of crude oil, a hydrogen production method using ironmaking waste gas, and the like can be mentioned. Since the hydrogen gas produced by the above method also contains a large amount of sulfur, carbon monoxide, and the like, there was an industrial problem that required a large load and equipment in a purification process for removing these. .

On the other hand, as a method for producing hydrogen from an aromatic compound such as benzene from a lower hydrocarbon, particularly methane, a method is known in which methane is reacted in the presence of a catalyst in the absence of oxygen or an oxidizing agent. Molybdenum supported on ZSM-5 is effective as a catalyst in this case (JOURNAL OF CATALYSIS 165, 150 to 161).
(1997) and references therein. However,
Even when these catalysts are used, there are problems to be solved such as a large amount of carbon deposition and a low conversion of methane.

[0007]

SUMMARY OF THE INVENTION In view of the circumstances and problems of the prior art, the present invention relates to the use of aromatic compounds such as benzene and naphthalene, which are useful chemical raw materials, using lower hydrocarbon-containing gases such as natural gas. An object of the present invention is to provide an effective lower hydrocarbon conversion catalyst for simultaneously producing hydrogen gas and a method for producing an aromatic compound using the catalyst.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, completed the present invention. The present invention relates to a catalyst for aromatizing lower hydrocarbons comprising a metallosilicate and at least one selected from the group consisting of metals consisting of zinc, gallium and cobalt and compounds of these metals.

[0009] The present invention also relates to at least one selected from the group consisting of molybdenum and at least one compound selected from the group consisting of zinc, gallium, cobalt, chromium, lanthanum, neodymium, samarium and yttrium, and compounds of these metals. The present invention relates to a catalyst for aromatizing lower hydrocarbons comprising at least one of the above-mentioned compounds and a metallosilicate.

The present invention also relates to a catalyst for aromatizing lower hydrocarbons comprising a heteropolyacid containing at least one metal selected from molybdenum, tungsten and vanadium and a metallosilicate.

Further, the present invention provides a method for reacting a lower hydrocarbon at a high temperature in the presence of a metallosilicate and a catalyst comprising at least one selected from the group consisting of metals consisting of zinc, gallium and cobalt and compounds of these metals. The present invention also relates to a method for producing hydrogen and an aromatic compound containing an aromatic hydrocarbon as a main component.

[0012] The present invention also relates to at least one selected from the group consisting of molybdenum and at least one compound selected from the group consisting of zinc, gallium, cobalt, chromium, lanthanum, neodymium, samarium and yttrium, and compounds of these metals. The present invention relates to a method for producing hydrogen and an aromatic compound containing an aromatic hydrocarbon as a main component, wherein a lower hydrocarbon is subjected to a high-temperature contact reaction in the presence of a catalyst comprising at least one of the metallosilicate and a metallosilicate.

[0013] Further, the present invention provides a method for converting a lower hydrocarbon to a high temperature in the presence of a lower hydrocarbon aromatization catalyst comprising a heteropolyacid containing at least one metal selected from molybdenum, tungsten and vanadium and a metallosilicate. The present invention relates to a method for producing hydrogen and an aromatic compound containing an aromatic hydrocarbon as a main component.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION As the metallosilicate used in the aromatization catalyst of the present invention, for example, in the case of aluminosilicate, a porous material composed of silica and alumina such as molecular sieve 5A (UTA) and faujasite (N
aY) and a porous carrier such as NaX, ZSM-5, or ALPO-5 or VPI-5 containing phosphoric acid as a main component.
FSM- characterized by cylindrical pores (channels) of mesopores (10 to 100 °) containing zeolite carrier or silica as a main component and partially alumina as a component, characterized by comprising micropores and channels 16 or MCM-4
And a mesoporous porous carrier such as 1. In addition to aluminosilicate, titanosilicate composed of silica and titania can be used.

The metallosilicate used in the present invention preferably has a surface area of 200 to 1000 m ² / g, and has micro and mesopores in the range of 5 to 100 °. When the metallosilicate is, for example, aluminosilicate, the silica / alumina content ratio of a generally available porous carrier, silica / alumina = 1 to 8000, can be used. The silica / alumina ratio is preferably 10 to 100 in order to carry out the aromatization reaction of hydrogen at a practical lower hydrocarbon conversion and selectivity to aromatic compounds.

The catalyst for aromatizing a lower hydrocarbon comprising a metallosilicate and at least one metal selected from the group consisting of metals consisting of zinc, gallium and cobalt and their compounds, which is used in the catalyst of the present invention, comprises zinc, gallium and cobalt. It is obtained by supporting a precursor containing metallosilicate.

Examples of the precursor containing zinc, gallium and cobalt used in the catalyst of the present invention include halides such as chloride, bromide and the like of zinc, gallium and cobalt.
Examples thereof include mineral salts such as nitrates, sulfates and phosphates, and carboxylate salts such as carbonates, acetates and oxalates. When zinc, gallium and cobalt are supported on the metallosilicate, the weight ratio between the metal or its compound and the carrier can be applied to any range of the supporting amount.
~ 50%, preferably 0.01-40% is a good loading range.

As a method of supporting zinc, gallium and cobalt on the metallosilicate, the metallosilicate carrier is impregnated or supported by an ion conversion method from an aqueous solution of the above-mentioned metal precursor or a solution of an organic solvent such as alcohol. And heat treatment in an inert gas or oxygen gas. To explain the example of this method more specifically, first, for example, a metallosilicate carrier is impregnated and supported with an aqueous solution of zinc nitrate, and further dried to remove an appropriate amount of the solvent, and then in a nitrogen-containing oxygen stream or pure oxygen. 250-800 ° C, preferably 350-600 in air stream
The metallosilicate catalyst supporting zinc can be produced by heat treatment at ℃.

The catalyst of the present invention (1) molybdenum and / or its compound, (2) zinc, gallium, cobalt,
At least one metal selected from the group consisting of chromium, lanthanum, neodymium, samarium, yttrium and their compounds and / or their compounds (hereinafter abbreviated as the second component), and (3) metallosilicate The catalyst for aromatizing lower hydrocarbons can be produced by the following methods. That is, (1) molybdenum is first supported on the metallosilicate, and then the second component is supported.
(2) The metallosilicate first supports the second component, and then supports molybdenum. (3) Molybdenum and the second component are simultaneously supported on the metallosilicate. Among these methods, the method (1) is preferable.

Examples of the precursor containing molybdenum include ammonium paramolybdate, phosphomolybdic acid,
In addition to silicomolybdic acid, chlorides, halides such as bromide, nitrates, sulfates, mineral salts such as phosphates, carbonates,
Examples thereof include carboxylate such as acetate and oxalate. Examples of the precursor containing the second component include chlorides, halides such as bromide, nitrates, sulfates, mineral salts such as phosphates, carbonates, acetates, and oxalates of the second component. And the like.

When molybdenum is supported on the metallosilicate support, the weight ratio of the metal to the support is 0.001 to 50.
%, Preferably 0.01 to 40% is a good supporting range, and the weight ratio of the second component to the carrier is 0.001 to 50%, preferably 0.01 to 40% is a good supporting range. However, the sum of the weight ratio of molybdenum to the carrier and the weight ratio of the second component to the carrier is 0.001% to 50%, preferably 0.0% to 50%.
The loading range is 1 to 40%. Further, the method of supporting the metal on the metallosilicate and the method of heat treatment can be carried out in the same manner as the above-described method.

The catalyst for aromatizing a lower hydrocarbon comprising a heteropolyacid containing at least one metal selected from molybdenum, tungsten or vanadium and a metallosilicate used in the present invention supports the heteropolyacid on the metallosilicate. Can be manufactured. Examples of the heteropolyacid include 12-phosphomolybdic acid, 12-phosphotungstic acid, 12-phosphomolybdenum tungstic acid, 12-phosphomolybdenumvanadic acid, and the like.
When the heteropolyacid is supported on the metallosilicate, the weight ratio of the metal and the carrier (molybdenum, tungsten and / or vanadium metal contained in the heteropolyacid used and the weight ratio of the metal and the carrier) is 0.001 to 50%, preferably 0.
The loading range is from 01 to 40%. Further, the method of supporting the heteropolyacid on the metallosilicate and the method of heat treatment can be performed in the same manner as the above-described method.

The catalyst used in the present invention can be used in any form of powder or pellet and other shapes. The lower hydrocarbon conversion catalyst used in the present invention has a catalyst activation process including a pretreatment with hydrogen gas, hydrazine, a metal hydride such as BH ₃ , NaH, AlH _3, etc. in order to shorten the induction period for generating an aromatic compound. May be applied.

The lower hydrocarbon used as a raw material in the present invention preferably contains at least 50% by weight, preferably at least 70% by weight of methane. If the methane content is within this range, saturated and unsaturated hydrocarbons having 2 to 6 carbon atoms may be additionally contained.
Examples of these include ethane, ethylene, propane, propylene, n-butane, isobutane, n-butene and isobutene.

The lower hydrocarbon conversion reaction of the present invention is carried out in a batch or flow-through reaction mode.
It is preferable to carry out the reaction in a flow-type reaction system such as a moving bed or a fluidized bed. The reaction is performed by lowering the lower hydrocarbon raw material in the gas phase in the absence of oxygen at 300 to 800 ° C, preferably 450 to 800 ° C.
This is done by contacting the catalyst at 775 ° C. The reaction is suitably carried out at 0.1 to 10 atm, preferably 1 to 7 atm. The weight hourly space velocity (WHSV) is 0.1 to 10, preferably 0.5 to 5.0. Unreacted raw materials recovered from the reaction product can be recycled to the aromatization reaction.

[0026]

The present invention will be described in more detail with reference to the following examples. The methane conversion, hydrocarbon selectivity, hydrocarbon distribution and hydrogen generation rate were defined as follows. Methane conversion rate = (Mole number of raw material methane−Mole number of unreacted methane) / Mole number of raw material methane × 100 (%) Hydrocarbon selectivity = Mole number of methane converted to methane / (Mole number of raw material methane−Mole number of unreacted methane) ) × 10
0 (%) Distribution of hydrocarbon = Mole number of methane equivalent of hydrocarbon of interest / Mole number of methane equivalent of all generated hydrocarbons × 100
(%) Hydrogen generation rate = nmol number of hydrogen generated per second per gram of catalyst

Example 1 Preparation method of a catalyst in which zinc, gallium and cobalt are supported on HZSM-5: 0.21 g of zinc nitrate is dissolved in 3 ml of distilled water, and HZSM-5 (silica / alumina ratio = 23)
(Surface area 800 m ² / g, pore diameter = 7 °) powder 1.5
g, and evaporated to dryness using a rotary vacuum evaporator with sufficient stirring to obtain an HZSM-5 carrier of zinc nitrate. This is placed in a quartz reaction tube (1.2φ length 30c).
mV type), then pure oxygen gas (40ml / min,
(1 atm), baking at 400 ° C for 4 hours, 3%
(Hereinafter, referred to as Zn (3)
%) / HZSM-5). Similarly,
Co (2%) / HZSM-5 catalyst and Ga (2%) / H
A ZSM-5 catalyst was prepared.

Example 2 Using the supported HZSM-5 catalyst prepared in Example 1, an aromatization reaction of methane was carried out. Co (2%) / HZSM
0.3 g of -5 catalyst (silica / alumina ratio = 23) was charged into a quartz reactor (inner diameter: 8 mm) of a fixed bed flow type reactor, and 7.5 ml of methane gas at a reaction temperature of 700 ° C. and normal pressure.
/ Min, and the methane was subjected to aromatization reaction. In the reaction product, hydrogen, carbon monoxide, carbon dioxide, hydrocarbons having 2 to 5 carbon atoms, benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, dimethylnaphthalene, etc. are present in addition to unreacted methane. I was Table 1 shows the results 200 minutes after the start of the reaction. Similarly, Ga (2%) / H prepared in Example 1
Using a ZSM-5 catalyst and a Zn (3%) / HZSM-5 catalyst, a methane aromatization reaction was carried out in the same manner as in Example 2. Table 1 shows the reaction results 200 minutes after the start of the reaction.
Shown in

Comparative Example 1 As a comparative example of Example 2, HZSM-5 not supporting a metal was used.
Using a catalyst, a methane aromatization reaction was carried out in the same manner as in Example 2. Table 1 shows the results 200 minutes after the start of the reaction.

[0030]

[Table 1]

Note: The following definitions are common to Tables 1-4. Co
(2%) indicates a catalyst in which 2% of cobalt is supported on HZSM-5. Conversion: methane conversion HC selectivity: hydrocarbon selectivity HC distribution: hydrocarbon distribution C ₆ H ₆ : benzene C ₁₀ H ₈ : naphthalene

Example 3 A method for preparing a catalyst in which molybdenum is supported on HZSM-5:
0.66 g 10 ml of ammonium paramolybdate
Of distilled water, and 12 g of powder of HZSM-5 (silica / alumina ratio = 12) (surface area: 800 m ² / g, pore diameter = 7 °) was added, and the mixture was evaporated to dryness using a rotary vacuum evaporator with sufficient stirring. By solidification, an HZSM-5 carrier of ammonium paramolybdate was obtained. After filling this into a quartz reaction tube (1.2φ, length 30 cm, V-shaped type), it was heated at 400 ° C. under a pure oxygen gas flow (40 ml / min, 1 atm).
Mo (3%) / HZSM
-5 was obtained.

Method for preparing a catalyst in which cobalt, gallium, zinc and chromium are further supported on Mo (3%) / HZSM-5 catalyst: 0.072 g of cobalt nitrate is dissolved in 3 ml of distilled water, and the Mo prepared above is dissolved. (3%) / HZSM-
After adding 1.5 g of 5 catalyst, the mixture was similarly evaporated to dryness and calcined to obtain Mo (3%) / Co (1%) / HZSM-5.
A catalyst was prepared. Similarly, Mo (3%) / Ga
(1.5%) / HZSM-5 catalyst, Mo (3%) / Zn
(1%) / HZSM-5 catalyst and Mo (3%) / Cr
(3%) / HZSM-5 catalyst was prepared.

Example 4 Using a catalyst prepared in Example 3 and further supporting cobalt, gallium, zinc and chromium on the Mo (3%) / HZSM-5 catalyst, the aromatic methane was produced in the same manner as in Example 2. The reaction was carried out. Table 2 shows the results 200 minutes after the start of the reaction. Comparative Example 2 As a comparative example of Example 4, Mo / H supporting 6% of Mo was used.
An aromatization reaction of methane was carried out in the same manner as in Example 2 using a ZSM-5 catalyst. Table 2 shows the results 200 minutes after the start of the reaction.

[0035]

[Table 2]

Example 5 Preparation of a catalyst in which lanthanum, neodymium, samarium, and yttrium are further supported on a Mo (3%) / HZSM-5 catalyst: 0.11 g of lanthanum nitrate is dissolved in 2 ml of distilled water. Mo (3%) / HZSM prepared in Step 3.
After adding 1.2 g of -5 catalyst, the mixture was similarly evaporated to dryness and calcined to obtain Mo (3%) / La (3%) / HZSM-
Five catalysts were prepared. Similarly, Mo (3%) / Nd
(3%) / HZSM-5 catalyst, Mo (3%) / Sm (3
%) / HZSM-5 catalyst and Mo (3%) / Y (3%)
/ HZSM-5 catalyst was prepared.

Example 6 Aromatic methane was prepared in the same manner as in Example 2 except that the catalyst prepared in Example 5 and further supporting lanthanum, neodymium, samarium, and yttrium on the Mo (3%) / HZSM-5 catalyst was used. The reaction was carried out. Table 3 shows the results 200 minutes after the start of the reaction.

[0038]

[Table 3]

Example 7 Preparation and reaction of a catalyst in which heteropolyacid is supported on HZSM-5: PMoW (1.5%) prepared using 12-phosphomolybdenum tungstic acid as a raw material and supported on HZSM-5
Table 4 shows the results of the methane aromatization test performed using the -HZSM-5 catalyst. Similarly, PMoV (3%)-HZSM using 12-phosphomolybdenum vanadate as a raw material
-5 catalyst was prepared, and the results of the methane aromatization test are shown in Table 4 in the same manner.

[0040]

[Table 4]

[0041]

The catalyst of the present invention exhibits extremely excellent conversion and selectivity as a catalyst for an aromatization reaction. Further, by the aromatization method using the catalyst of the present invention, high value-added aromatic hydrocarbons such as benzene, toluene, xylene and naphthalene and hydrogen are produced from lower hydrocarbons such as methane with high activity and high yield. It is possible to

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Claims (6)

[Claims] 1. A catalyst for aromatizing lower hydrocarbons comprising a metallosilicate and at least one metal selected from the group consisting of metals consisting of zinc, gallium and cobalt and compounds of these metals. 2. At least one selected from molybdenum and a compound thereof, and at least one selected from the group consisting of metals consisting of zinc, gallium, cobalt, chromium, lanthanum, neodymium, samarium and yttrium, and compounds of these metals And a metallosilicate for the aromatization of lower hydrocarbons. 3. A catalyst for aromatizing lower hydrocarbons comprising a heteropolyacid containing at least one metal selected from molybdenum, tungsten and vanadium and a metallosilicate. 4. A method comprising subjecting a lower hydrocarbon to a catalytic reaction at a high temperature in the presence of a catalyst comprising a metallosilicate with at least one selected from the group consisting of metals consisting of zinc, gallium and cobalt and compounds of these metals. A method for producing an aromatic compound mainly composed of an aromatic hydrocarbon and hydrogen. 5. At least one selected from molybdenum and its compounds, and at least one selected from the group consisting of metals consisting of zinc, gallium, cobalt, chromium, lanthanum, neodymium, samarium and yttrium, and compounds of these metals A method for producing an aromatic compound and hydrogen containing an aromatic hydrocarbon as a main component, wherein a lower hydrocarbon is contacted at a high temperature in the presence of a catalyst composed of an aromatic compound and a metallosilicate. 6. A lower hydrocarbon is contacted at a high temperature in the presence of a lower hydrocarbon aromatization catalyst comprising a heteropolyacid containing at least one metal selected from molybdenum, tungsten and vanadium and a metallosilicate. A method for producing an aromatic compound containing an aromatic hydrocarbon as a main component and hydrogen.