JP2008081437A - Manufacturing method of propylene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing propylene by causing a raw material gas, containing a 4C or higher olefin and methanol and/or dimethyl ether, to be brought into contact with a catalyst. <P>SOLUTION: A catalyst comprising zeolite having a cage type structure is used as a catalytic active component. Preferably, a catalyst comprising zeolite having a structure represented by a code, prescribed by the International Zeolite Association (IZA), CHA, DDR, EAB, ERI, FAU, LEV, OFF or MWW, more preferably MWW, is used as the zeolite catalyst having the cage type structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing propylene from a raw material gas containing an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether.

As a method for producing propylene, conventionally, steam cracking of naphtha and fluid catalytic cracking of vacuum gas oil have been generally performed. In recent years, metathesis reaction using ethylene and 2-butene as raw materials, methanol and / or dimethyl ether are used. MTO (methanol to olefin) process as a raw material is also attracting attention. On the other hand, a method of producing a lower olefin using an olefin having 4 or more carbon atoms and an oxygen-containing compound such as methanol as raw materials is also known (Patent Document 1).
US 2003/0181777

Patent Document 1 describes that in the catalytic catalytic cracking reaction of olefins having 4 or more carbon atoms in order to obtain ethylene and propylene, the production of high boiling hydrocarbons such as aromatic compounds can be suppressed by coexisting oxygen-containing compounds. In claim 4, zeolite having a pore size index of 14 to 29 is claimed as a catalyst, and in claim 5, zeolite of MTT type is claimed. However, each of the examples is an example of an MTT catalyst, and there is no description regarding the target ethylene and propylene production capacity, and it is difficult to say that the production technology is sufficient as a propylene production method.
For these reasons, development of a technique for producing propylene more efficiently than the current method has been desired.

  An object of the present invention is to provide a method for efficiently producing propylene by bringing a raw material gas containing an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether into contact with a catalyst.

  As a result of intensive studies to solve the above problems, the present inventors have found that propylene can be efficiently produced by using a zeolite having a specific structure as a catalytically active component. It came.

  That is, the first gist of the present invention is to contact a raw material mixed gas containing an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether in the presence of a catalyst containing a cage type structure zeolite as a catalytic active component. In the production method of propylene.

  The second gist of the present invention is that, in the above method, the cage type structure zeolite comprises MWW, CHA, DDR, EAB, ERI, FAU, LEV, and OFF in accordance with a code defined by International Zeolite Association (IZA). The present invention resides in a method for producing propylene, which is one or more selected from the group.

  The third gist of the present invention resides in a method for producing propylene, characterized in that, in the above method, the cage type structure zeolite is MWW.

  The fourth gist of the present invention is that in the above method, the amount of the olefin having 4 or more carbon atoms fed to the reactor is the sum of the number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether. The propylene production method is characterized in that the molar ratio is 0.1 or more and 10 or less.

  The fifth gist of the present invention resides in a method for producing propylene, wherein the gas temperature at the reactor inlet is 300 ° C. or higher and 700 ° C. or lower in the above method.

  The sixth gist of the present invention resides in a method for producing propylene, characterized in that, in the above method, the reactor is a fixed bed reactor.

  According to a seventh aspect of the present invention, in the above method, a method for producing propylene, wherein at least a part of hydrocarbons having 4 or more carbon atoms contained in the reactor outlet gas is recycled to the reactor inlet, Exist.

According to the present invention, propylene can be produced in a high yield by using a olefin having 4 or more carbon atoms and methanol and / or dimethyl ether as raw materials and using a zeolite having a specific structure as a catalyst.
In addition, according to the present invention, since the by-product of the aromatic compound is suppressed, effects such as reduction in the catalyst deterioration rate and simplification of the purification process are also achieved, and the production efficiency of propylene is greatly increased.

  Below, the typical aspect for implementing this invention is demonstrated concretely, However, This invention is not limited to the following aspects, unless the summary is exceeded.

[catalyst]
In the present invention, a catalyst containing a cage type zeolite as a catalytic active component is used as the catalyst.
In general, zeolites have a structure in which channels of approximately the same size as the pore diameter are connected in a tunnel or three-dimensionally, and a cage type structure with a cage space larger than the pore diameter inside the structure. There are zeolites. The former type is a code having a structure defined by International Zeolite Association (IZA), and includes MFI, BEA, MTT, and TON. On the other hand, in the present invention, the latter cage type structure zeolite is used.

  Among them, as a preferable material in the present invention, specifically, a zeolite specified by International Zeolite Association (IZA) and expressed by MWW, CHA, DDR, EAB, ERI, FAU, LEV, OFF can be mentioned. More preferably, it is a zeolite having an MWW structure. These may be used alone or in combination of two or more.

  Cage-type zeolites have large cage-like cavities (cages) in the zeolite, which increases the diffusion rate, effectively contributes to the reaction by the active sites present in the cavities, and is usually somewhat bulky. Advantages such as easy formation of a transition state of a reaction that becomes a structure are conceivable, reaction results can be improved, and high propylene production activity can be obtained.

  Among them, the zeolite having the MWW structure has a 10-membered ring channel structure similar to that of the MFI-type zeolite, but is different from the MFI-type zeolite having no cage structure, and is larger than the 10-membered ring channel inside the pore. By having a large cage of rugby ball type, it is advantageous in diffusion and formation of a transition state, and becomes a catalyst excellent in selectivity and durability.

The cage type zeolite is preferably a crystalline aluminosilicate, and usually the SiO ₂ / Al ₂ O ₃ molar ratio is 20 or more, preferably 25 or more, more preferably 50 or more, and still more preferably 90 or more. 5000 or less, preferably 1000 or less, and more preferably 500 or less.

  Further, a part or all of Al constituting this may be substituted with atoms of Group 2 to Group 14 of the periodic table, and further, the ion exchange site may be H-type. It may be obtained by salt exchange. The substituted atom is preferably one or more of B, Ti, V, Fe, Zn, Ga, Ge, Zr, Sn and the like.

The BET specific surface area of the zeolite is usually 200 m ² / g or more, preferably 250 m ² / g or more, more preferably 300 m ² / g or more, and usually 2000 m ² / g or less, preferably 1500 m ² / g or less, more Preferably it is 1000 m < ² > / g or less. The pore volume is usually 0.1 cc / g or more, preferably 0.2 cc / g or more, and usually 3 cc / g or less, preferably 2 cc / g or less.

  Specific examples of the crystalline aluminosilicates include those having a CHA structure such as Chabazite and SSZ-13, those having a DDR structure such as Sigmar 1, those having an EAB structure such as Bellbergite, and ERI such as Elionite. Those having a structure, those having a FAU structure such as USY, those having a LEV structure such as Levine, those having an OFF structure such as offretite, those having an MWW structure such as MCM22, SSZ25, ITQ1, ERB1, and PSH3. , Preferably having an MWW structure, particularly preferably MCM-22.

Other These zeolites respective commercial products may be used after synthesized by the known methods described in ^{"Verified Syntheses Of Zeolitic Materials" (} 2 nd Revised Edition 2001 Elsevirr) etc. IZA issuance above. For example, a CHA-structured zeolite was synthesized by a known method described in US Pat. No. 4,544,538, and a DDR-structured zeolite was prepared by Stud. Surf. Sci. Catal. , 37, 57-64 (1988), a zeolite having a FAB structure is described in J. Org. Chem. Soc. (A). , 1470-1475 (1970), ERI-structured zeolite is synthesized by a known method described in JP-A-11-179158, and FAU-structured zeolite is Zeolites, 15, 90, (1995), a LEV-structured zeolite is synthesized by a known method described in Microporous Materials, 11, 269-273 (1997), and an OFF-structured zeolite is Cryst. Res. Technol. , 31, K29-31 (1996), a zeolite having an MWW structure is described in J. Org. Phys. Chem. B, 102, 44-51 (1998) synthesized by a known method can be used.

These aluminosilicates can control the amount of Al contained by controlling the amount of Al during synthesis. In addition, a part of Al and B atoms constituting the aluminosilicate may be removed and removed by steaming, acid treatment or the like to have a high silica alumina ratio. Of these, SiO ₂ / Al ₂ The O ₃ molar ratio is 20 or more, preferably 25 or more, more preferably 50 or more, and is 5000 or less, preferably 1000 or less, more preferably 500 or less.

  The zeolite catalyst may be used in the reaction as it is, or may be used in the reaction by granulating and forming it using a substance or a binder inert to the reaction. Examples of the substance or binder inert to the reaction include alumina or alumina sol, silica, silica gel, silicate, quartz, and a mixture thereof. Among these, silicate is preferable in that a strong molded body can be obtained as an industrial catalyst. Mixing with these substances is effective for reducing the cost of the entire catalyst and acting as a heat sink for heat shielding during catalyst regeneration. It is also effective for increasing the density of the catalyst and increasing the catalyst strength. .

  The particle size of the catalyst varies depending on the conditions during the synthesis, but is usually 0.01 μm to 500 μm, preferably 0.1 to 10 μm as an average particle size. If the particle size of the catalyst is too large, the surface area showing catalytic activity will be small, and if it is too small, the handleability will be inferior, which is not preferable in either case. This average particle diameter can be determined by laser diffraction measurement. However, since the laser diffraction method cannot measure 0.1 μm or less, when the result measured by the laser diffraction method is 0.1 μm or less, the value obtained by a scanning electron microscope (SEM) is the average particle size referred to in the present invention. The diameter.

[Reaction raw materials]
Next, the olefin having 4 or more carbon atoms, methanol, and dimethyl ether used as reaction raw materials in the present invention will be described.

<Olefin>
The olefin having 4 or more carbon atoms used as a raw material for the reaction is not particularly limited. For example, FT (Fischer) using raw materials such as those produced by catalytic cracking or steam cracking from petroleum feedstock (C4 raffinate-1, C4 raffinate-2, etc.), or hydrogen / CO mixed gas obtained by coal gasification Tropsch) obtained by synthesis, obtained by oligomerization reaction including ethylene dimerization, obtained by dehydrogenation or oxidative dehydrogenation of paraffin having 4 or more carbon atoms, obtained by MTO reaction 4 or more, particularly 4 to 10 carbon atoms, obtained by various known methods such as those obtained by dehydration reaction of alcohol, those obtained by hydrogenation reaction of diene compounds having 4 or more carbon atoms, etc. Olefin can be used arbitrarily. At this time, olefins having 4 or more carbon atoms resulting from each production method are used. It may be used as it states that the compounds of mixed arbitrarily to be used was purified olefins.

<Methanol, dimethyl ether>
The origin of production of methanol and / or dimethyl ether used as a raw material for the reaction is not particularly limited. For example, obtained by hydrogenation reaction of coal and natural gas, and by-product hydrogen / CO mixed gas in the steel industry, obtained by reforming reaction of plant-derived alcohols, obtained by fermentation method And those obtained from organic materials such as recycled plastic and municipal waste. At this time, a state in which compounds other than methanol and dimethyl ether resulting from each production method are arbitrarily mixed may be used as it is, or a purified one may be used.

[Reaction operations and conditions]
Hereinafter, the operation and conditions of the propylene production reaction of the present invention using the above-described catalyst and reaction raw materials will be described.

<Reactor>
The reaction mode in the production method of the present invention is not particularly limited as long as the olefin having 4 or more carbon atoms and the methanol and / or dimethyl ether feedstock are in a gas phase in the reaction zone, and is not limited to a fluidized bed reactor, moving bed reactor, or stationary. A known gas phase reaction process using a bed reactor can be applied. In the case of a fixed bed reactor, it is particularly advantageous in terms of equipment costs including incidental equipment, catalyst costs, and operation management.
Further, it can be carried out in any form of batch, semi-continuous or continuous, but is preferably carried out continuously, and the method may be a method using a single reactor, or in series or in parallel. A method using a plurality of arranged reactors may also be used.

  In addition, when packing the above-mentioned catalyst into the fluidized bed reactor, in order to keep the temperature distribution of the catalyst layer small, particulates inert to the reaction such as quartz sand, alumina, silica, silica-alumina, etc. are mixed with the catalyst. And may be filled. In this case, there is no particular limitation on the amount of granular material inactive to the reaction such as quartz sand. In addition, it is preferable that this granular material is a particle size comparable as a catalyst from the surface of uniform mixing property with a catalyst.

  Further, the reaction substrate (reaction raw material) may be divided and supplied to the reactor for the purpose of dispersing heat generated by the reaction.

The catalyst used in the present invention has less coking than the conventional catalyst and the rate of catalyst deterioration is slow, but when performing continuous operation for one year or longer, it is necessary to regenerate the catalyst during operation.
For example, when selecting a fixed bed reactor, it is desirable to install at least two reactors and operate while switching between reaction and regeneration. As the form of the fixed bed reactor, a multitubular reactor or an adiabatic reactor is selected.
On the other hand, when selecting a fluidized bed reactor, it is preferable to carry out the reaction while continuously feeding the catalyst to the regeneration tank and continuously returning the catalyst regenerated in the regeneration tank to the reactor.

  Here, examples of the regeneration operation of the catalyst include those that regenerate the catalyst introduced from the reactor by treating it with nitrogen gas containing oxygen or water vapor.

<Feed concentration ratio of olefin and methanol and / or dimethyl ether>
The amount of the olefin having 4 or more carbon atoms fed to the reactor is usually 0.1 or more, preferably in a molar ratio with respect to the total number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether It is 0.2 or more, usually 10 or less, preferably 5 or less.
That is, when the supply molar amount of olefins having 4 or more carbon atoms is M _c4 , the supply molar amount of methanol is M _m , and the supply molar amount of dimethyl ether is M _dm , M _c4 is 0.1 of (M _m + 2M _dm ). It is preferably 10 to 10 times, particularly preferably 0.2 to 5 times. If the supply concentration ratio is too low or too high, the reaction is slow, which is not preferable.

That is, the present invention is characterized in that the reaction rate is remarkably increased by supplying an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether in an appropriate concentration ratio.
When the olefin having 4 or more carbon atoms and methanol and / or dimethyl ether are supplied to the reactor, they may be supplied separately, or may be supplied after mixing a part or all of them in advance.

<Substrate concentration>
There is no particular limitation on the total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol and dimethyl ether in all feed components fed to the reactor, but the sum of olefins having 4 or more carbon atoms, methanol and dimethyl ether is 90 mol% or less is preferable in a supply component. More preferably, it is 20 mol% or more and 70 mol% or less. If the substrate concentration is too high, aromatic compounds and paraffins are prominently produced and the propylene selectivity tends to decrease. On the other hand, if the substrate concentration is too low, the reaction rate becomes slow, so a large amount of catalyst is required, and the cost for purifying the reactor, the product, and the reaction equipment increases, which is not economical.
Therefore, it is preferable to dilute the reaction substrate with a diluent described below as necessary so as to obtain such a preferable substrate concentration.

<Diluent>
In the reactor, in addition to olefins having 4 or more carbon atoms and methanol and / or dimethyl ether, helium, argon, nitrogen, carbon monoxide, carbon dioxide, hydrogen, water, paraffins, methane and other hydrocarbons, aromatics Gases that are inert to the reaction, such as group compounds and mixtures thereof, can be present, and among these, water (water vapor) is preferably present together.
As such a diluent, impurities contained in the reaction raw material may be used as they are, or a separately prepared diluent may be mixed with the reaction raw material and used.
The diluent may be mixed with the reaction raw material before entering the reactor, or may be supplied to the reactor separately from the reaction raw material.

<Space velocity>
The space velocity mentioned here is a flow rate of olefin having 4 or more carbon atoms and methanol and / or dimethyl ether as reaction raw materials per weight of the catalyst (catalytic active component), and the weight of the catalyst is the granulation of the catalyst. -It is the weight of the inactive component used for molding and the catalytically active component which does not contain a binder. The flow rate is the total flow rate (weight / hour) of an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether.

The space velocity is usually about 0.01 hour- ¹ or more, preferably about 0.05 hour- ¹ or more, more preferably about 0.1 hour- ¹ or more, usually about 500 hour- ¹ or less, preferably about 200 hours- ¹ or less. If the space velocity is too high, the conversion of the raw material olefin and methanol and / or dimethyl ether is low, and sufficient propylene selectivity cannot be obtained. On the other hand, if the space velocity is too low, the amount of catalyst necessary to obtain a certain production amount increases, the reactor becomes too large, and undesirable by-products such as aromatic compounds and paraffin are produced, and propylene selection is performed. This is not preferable because the rate decreases.

  Further, as the reaction is continued, the catalyst causes coking in the reactor and the reaction activity decreases. In this case, a preliminary reactor is prepared, the raw material supply is switched, a switching operation of a plurality of reactors is performed, and a catalyst can be generated. In addition, by removing the catalyst from the reactor and oxidizing the coke accumulated in the oxygen-containing atmosphere, for example, all or a part thereof can be removed to regenerate the catalyst. The catalyst regenerated in this way is reintroduced into the reactor again. However, from the viewpoint of extracting and reintroducing the catalyst, it is easier to operate a process using a plurality of fixed bed reactors, or a process using a moving bed reactor or a fluidized bed reactor. Become.

<Reaction temperature>
The lower limit of the reaction temperature is usually about 200 ° C. or higher, preferably 250 ° C. or higher, more preferably 300 ° C. or higher. The upper limit of the reaction temperature is usually 750 ° C. or lower, preferably 700 ° C. or lower. If the reaction temperature is too low, the reaction rate tends to be low, a large amount of unreacted raw material tends to remain, and the yield of propylene also decreases. On the other hand, if the reaction temperature is too high, it is difficult to obtain a stable activity of the catalyst, and the yield of propylene is significantly reduced. Here, the reaction temperature refers to the temperature at the inlet of the catalyst layer.

<Reaction pressure>
The upper limit of the reaction pressure is usually 5 MPa (absolute pressure, the same applies hereinafter) or less, preferably 2 MPa or less, more preferably 1 MPa or less, and particularly preferably 0.7 MPa or less. The lower limit of the reaction pressure is not particularly limited, but is usually 0.1 kPa or more, preferably 7 kPa or more, more preferably 50 kPa or more. If the reaction pressure is too high, the amount of undesired by-products such as paraffins and aromatic compounds increases, and the yield of propylene tends to decrease. If the reaction pressure is too low, the reaction rate tends to be slow.

<Reaction product>
As the reactor outlet gas (reactor effluent), a mixed gas containing reaction product propylene, unreacted raw materials, by-products and a diluent is obtained. The propylene concentration in the mixed gas is usually 5 to 95% by weight.
The unreacted raw material is usually an olefin having 4 or more carbon atoms. Depending on the reaction conditions, methanol and / or dimethyl ether are included, but it is preferable to carry out the reaction under such reaction conditions that the conversion of methanol and / or dimethyl ether is 100%. Thereby, separation of the reaction product and the unreacted raw material becomes easy.
By-products include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water.

<Product separation>
The mixed gas containing propylene, unreacted raw materials, by-products and diluent as reaction product outlet gas is introduced into a known separation / purification facility, and is collected and purified according to each component. What is necessary is just to process recycling and discharge.
One aspect of this separation / purification method includes a step of cooling and compressing the gas at the outlet of the reactor to remove most of the condensed moisture, and a hydrocarbon fluid containing a portion of moisture after removing the moisture. A method including a step of drying the olefin and paraffin by distillation using a molecular sieve or the like and then purifying each olefin and paraffin by distillation is applied. In the above method, the compressed hydrocarbon fluid may be supplied to one distillation column. However, a multistage compressor is installed to roughly separate hydrocarbons that are easily condensed and hydrocarbons that are difficult to condense, and separate them. Distillation may be performed by supplying to the distillation column.

  Components other than propylene (olefin, paraffin, etc.), especially part or all of hydrocarbons with 4 or more carbon atoms, are recycled by mixing with the reaction raw materials after being separated and purified as described above, or by directly supplying them to the reactor. It is preferable to do this. In addition, among the by-products, components inactive to the reaction can be reused as a diluent.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
[Catalyst preparation]
Preparation Example 1 (MWW type)
70 wt% NaAlO ₂ 0.06 g, 1M NaOH aqueous solution 9 ml were dissolved in 31.5 g of demineralized water and stirred. When it became a transparent aqueous solution, 2 g of hexamethyleneimine and 3 g of silica (manufactured by Nippon Aerosil Co., Ltd .: Aerosil 200) were added as templates and stirring was continued for 2 hours. The obtained slurry was put in a 100 ml autoclave and synthesized while rotating at 160 ° C. for 4 days. After cooling the autoclave, the contents were filtered, washed with water, and dried at 120 ° C. Then, it baked at 550 degreeC for 6 hours under air stream, and the containing template was removed.

  2.0 g of this calcined sample was suspended in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. The liquid after the treatment was separated into solid components by suction filtration, sufficiently washed with water, then suspended again in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. After the treatment, the solid component was separated by suction filtration, sufficiently washed with water, and then dried at 100 ° C. for 24 hours. After drying, calcination was performed at 500 ° C. for 4 hours under air flow to obtain an H-type aluminosilicate (referred to as “catalyst A”).

This catalyst A was confirmed by XRD (X-ray diffraction) to have a zeolite structure of MWW type. When the composition of the catalyst A was quantified by chemical analysis, it was SiO ₂ / Al ₂ O ₃ = 140 (molar ratio).

Preparation Example 2 (MWW type)
70 wt% NaAlO ₂ 0.8 g and NaOH 1.4 g were dissolved in 162 g of demineralized water and stirred. When it became a transparent aqueous solution, 9.9 g of hexamethyleneimine and 12 g of silica (manufactured by Nippon Aerosil Co., Ltd .: Aerosil 200) were added and stirring was continued for 2 hours. The resulting slurry was divided into two 100 ml autoclaves and tumbled at 150 ° C. for 7 days. After cooling the autoclave, the contents were filtered, washed with water, and dried at 120 ° C. Then, it baked at 550 degreeC for 6 hours under air stream, and the containing template was removed.

  2.0 g of this calcined sample was suspended in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. The liquid after the treatment was separated into solid components by suction filtration, sufficiently washed with water, then suspended again in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. After the treatment, the solid component was separated by suction filtration, sufficiently washed with water, and then dried at 100 ° C. for 24 hours. The dried catalyst was calcined at 500 ° C. for 4 hours under air flow to obtain an H-type aluminosilicate (referred to as “catalyst B”).

This catalyst B was confirmed by XRD (X-ray diffraction) to have a zeolite structure of MWW type. When the composition of the catalyst B was quantified by chemical analysis, it was SiO ₂ / Al ₂ O ₃ = 31 (molar ratio).

Preparation Example 3 (MWW type)
2.4 g of NaOH was dissolved in 51.3 g of demineralized water, and 20.8 g of hexamethyleneimine was added and stirred. To this, 0.12 g of 70 wt% NaAlO ₂ was added, and when it became a transparent aqueous solution, 12.4 g of boric acid was added and stirred for 30 minutes. To this, 9 g of silica (Nippon Aerosil Co., Ltd .: Aerosil 200) was added and stirring was continued for 2 hours. The resulting slurry was divided into two 100 ml autoclaves and tumbled at 175 ° C. for 7 days. After cooling the autoclave, the contents were filtered, washed with water, and dried at 120 ° C. Then, it baked at 550 degreeC for 6 hours under air stream, and the containing template was removed.

  2.0 g of this calcined sample was suspended in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. The liquid after the treatment was separated into solid components by suction filtration, sufficiently washed with water, then suspended again in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. After the treatment, the solid component was separated by suction filtration, sufficiently washed with water, and then dried at 100 ° C. for 24 hours. The dried catalyst was calcined at 500 ° C. for 4 hours under air flow to obtain an H-type boroaluminosilicate (referred to as “catalyst C”).

This catalyst C was confirmed by XRD to have a zeolite structure of MWW type. When the composition of the catalyst C was quantified by chemical analysis, it was SiO ₂ / Al ₂ O ₃ = 276 (molar ratio) and SiO ₂ / B ₂ O ₃ = 91 (molar ratio).

Preparation Example 4 (MFI type)
70 wt% NaAlO ₂ 0.22 g and NaOH 0.16 g were dissolved in 26 g of demineralized water and stirred. When it became a transparent aqueous solution, 10.2 g of 40 wt% tetrapropylammonium hydroxide aqueous solution and 6 g of silica sol (Nissan Chemical Co., Ltd .: Snowtech 40) were added and stirring was continued for 2 hours. The obtained slurry was placed in a 2100 ml autoclave and synthesized while rotating at 160 ° C. for 2 days. After cooling the autoclave, the contents were filtered, washed with water, and dried at 120 ° C. Then, it baked at 550 degreeC for 6 hours under air stream, and the containing template was removed.

2.0 g of this calcined sample was suspended in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. The liquid after the treatment was separated into solid components by suction filtration, sufficiently washed with water, then suspended again in 40 ml of 1M aqueous ammonium nitrate solution and stirred at 80 ° C. for 2 hours. After the treatment, the solid component was separated by suction filtration, sufficiently washed with water, and then dried at 100 ° C. for 24 hours. The dried catalyst was calcined at 500 ° C. for 4 hours under air flow to obtain an H-type aluminosilicate (referred to as “catalyst D”).
This catalyst D was confirmed by XRD to have a zeolite structure of MFI type. When the composition of the catalyst D was quantified by chemical analysis, it was SiO ₂ / Al ₂ O ₃ = 50 (molar ratio).

[Propylene production]
The production examples and comparative examples of propylene using the catalysts A to D are shown below.

<Example 1>
Propylene was produced using Catalyst A.
A normal pressure fixed bed flow reactor was used for the reaction, and a mixture of 50 mg of the catalyst A and 0.5 g of quartz sand was packed in a quartz reaction tube having an inner diameter of 6 mm. The reactor was fed with 15 mol% isobutene, 15 mol% methanol, and 70 mol% nitrogen through an evaporator. 70 minutes after the start of the reaction, the product was analyzed by gas chromatography. Table 1 shows reaction conditions and reaction results.
The conversion of isobutene was 68.3%, and the propylene selectivity based on carbon was 55.7 mol%.

<Examples 2-3>
The reaction was carried out under the same reaction conditions as in Example 1 except that Catalyst B (Example 2) or Catalyst C (Example 3) was used as the catalyst. Table 1 shows reaction conditions and reaction results.

<Comparative Example 1>
The reaction was conducted under the same reaction conditions as in Example 1 except that catalyst D was used as the catalyst. Table 1 shows reaction conditions and reaction results.
Compared with Examples 1-3, there were many aromatic compounds and the selectivity of propylene was low.

Claims (7)

  A method for producing propylene, comprising bringing a raw material mixed gas containing an olefin having 4 or more carbon atoms and methanol and / or dimethyl ether into contact in the presence of a catalyst containing a cage-type zeolite as a catalytic active component.   The cage type zeolite is one or more selected from the group consisting of MWW, CHA, DDR, EAB, ERI, FAU, LEV, and OFF in accordance with the code defined by International Zeolite Association (IZA). The method for producing propylene according to claim 1.   The method for producing propylene according to claim 2, wherein the zeolite having a cage type structure is MWW.   The amount of olefin having 4 or more carbon atoms supplied to the reactor is 0.1 to 10 in terms of molar ratio with respect to the sum of the number of moles of methanol supplied to the reactor and twice the number of moles of dimethyl ether. The method for producing propylene according to any one of claims 1 to 3, wherein:   The method for producing propylene according to any one of claims 1 to 4, wherein a gas temperature at the reactor inlet is 300 ° C or higher and 700 ° C or lower.   6. The method for producing propylene according to claim 1, wherein the reactor is a fixed bed reactor.   The method for producing propylene according to any one of claims 1 to 6, wherein at least a part of hydrocarbons having 4 or more carbon atoms contained in the reactor outlet gas is recycled to the reactor inlet.