JPWO2017179108A1 - Method for producing lower olefin - Google Patents

Abstract

The present invention includes a contact step in which a raw material containing at least one selected from the group consisting of methanol and dimethyl ether and a zeolite-containing shaped catalyst are brought into contact in a reactor, and the raw material is the methanol relative to the total amount of the raw material. And the zeolite in the zeolite-containing shaped catalyst contains at least one selected from the group consisting of dimethyl ether and the zeolite-containing molded catalyst satisfies the following (1) to (4):
(1) The zeolite is an intermediate pore size zeolite (2) The zeolite is substantially free of protons (3) The zeolite contains silver (4) Silica alumina molar ratio of the zeolite (SiO ₂ / Al ₂ O ₃ molar ratio) is 800 or more and 2000 or less.

Description

  The present invention relates to a method for producing a lower olefin.

  In recent years, among the methods for producing lower olefins such as ethylene and propylene, a method for producing propylene from methanol and / or dimethyl ether has attracted attention (for example, see Patent Document 1). A method for producing propylene from ethylene and methanol has also been proposed (see, for example, Patent Document 3). As a catalyst used in these methods, a zeolite catalyst has been proposed, and specifically, two types of SAPO-34 type and ZSM-5 type have been proposed.

  For example, Patent Document 1 discloses a catalyst for converting methanol into a lower olefin, and a method for producing and using the catalyst. In that disclosure, a SAPO-34 type zeolite catalyst is a special catalyst.

  Patent Document 2 discloses a continuous process for selectively converting an oxygenate feedstock to propylene in a reactor including a moving bed reactor. Specifically, the raw material is composed of bifunctional catalyst particles containing molecular sieves and having the ability to convert at least a portion of oxygenate into C3 olefins and the ability to interconvert C2 and C4 olefins into C3 olefins. A process for conversion to propylene is disclosed. It is also disclosed that a zeolite having a structure corresponding to ZSM-5 and a structure corresponding to SAPO-34 is used as the bifunctional catalyst.

  Further, Patent Document 3 provides a new process in which propylene is produced using ethylene and methanol and / or dimethyl ether as raw materials, and the amount of unreacted ethylene recycled is small, and the equipment and utility costs are low. Is disclosed. The catalyst used in the examples described in the patent document is H-ZSM-5 type zeolite having a silica alumina molar ratio of 1100.

  Furthermore, Patent Document 4 discloses a method for improving the yield of propylene, taking out a high-value-added aromatic compound, and obtaining high-quality gasoline not containing the aromatic compound. In the method described in this patent document, dimethyl ether is reacted on a catalyst in a reactor to obtain a reaction mixture containing lower olefins and gasoline hydrocarbons, and this is mixed with a C5 olefin mixture and a C5 or higher gasoline in a first separator. The mixture is separated into a mixture and an aqueous phase, a gasoline mixture of C5 or higher is fed to the second separator, most of the aromatic compounds contained in the mixture are separated and recovered, and at least a part of the residue is recycled as a recycled stream. It is a method characterized by recirculating. The catalyst used is preferably the ZSM-5 type.

  Furthermore, Patent Document 5 discloses an intermediate pore size zeolite-containing catalyst which contains substantially no proton and contains silver. The patent document discloses a process for producing ethylene and propylene from hydrocarbons containing C4 to C12 olefins.

JP 2008-544941 A JP 2008-504273 A JP 2008-106056 A US Published Patent No. 2009/0124841 International Publication No. 2000/10948

  However, there are at least the following problems when industrially producing lower olefins from methanol and / or dimethyl ether using the above-described conventional zeolite catalyst.

  First, the SAPO-34 type zeolite catalyst has a remarkable activity deterioration due to coking due to its small pore diameter. Therefore, in order to produce lower olefins in a circulating fluidized bed system, a large amount of catalyst circulation is required. In addition, since the catalytic activity is significantly deteriorated by coking, the resulting olefins cannot be recycled to obtain further lower olefins. These features must be considered disadvantageous for industrial implementation.

  On the other hand, in the method for producing a lower olefin using methanol and / or dimethyl ether as a raw material using a ZSM-5 type zeolite catalyst, if the activity is too high and the activity is too high, an aromatic which is a by-product The selectivity of the compound increases and the selectivity of propylene decreases. At the same time, catalyst deterioration due to coking is also a problem. Here, the spent catalyst whose activity is deteriorated by coking can be regenerated by burning the coke with air. However, the water vapor generated in the regeneration promotes dealumination of the zeolite skeleton, and thus causes catalyst activity deterioration that cannot be recovered by the regeneration. Further, the deterioration due to dealumination becomes more remarkable as the amount of coke increases.

  On the other hand, if the activity is too low, a large amount of catalyst is required to completely convert methanol and / or dimethyl ether. Therefore, when a lower olefin is produced using a ZSM-5 type zeolite catalyst, the activity is controlled by pre-treating an unused catalyst (a catalyst that has not been subjected to the contacting step after preparation) for the purpose of activity control. It is necessary to optimize.

  However, when the ZSM-5 type zeolite catalyst is pretreated and its activity is optimized, the appropriate range of the activity is very narrow, so that the catalyst activity optimization by the known pretreatment is optimized. Then, the reproducibility of the activity adjusted to an appropriate range is poor. Therefore, for industrial implementation, it is necessary to find a method capable of easily and reproducibly optimizing the yield and activity by pretreatment of the catalyst.

  Then, an object of this invention is to provide the manufacturing method of a lower olefin which can obtain a high yield of lower olefin stably over a long period of time.

  As a result of intensive studies in order to solve the above-described problems of the prior art, the present inventors have obtained a raw material containing at least one selected from the group consisting of a desired range of methanol and dimethyl ether, and a predetermined zeolite catalyst. It has been found that by using a method for producing a lower olefin having a contacting step in a reactor, a high yield of lower olefin can be obtained stably over a long period of time, and the present invention has been completed. It was.

That is, the present invention is as follows.
[1]
Having a contact step of bringing a raw material containing at least one selected from the group consisting of methanol and dimethyl ether into contact with a zeolite-containing shaped catalyst in a reactor;
The raw material contains 10% by mass or more of at least one selected from the group consisting of the methanol and dimethyl ether with respect to the total amount of the raw material,
The zeolite in the zeolite-containing shaped catalyst satisfies the following (1) to (4):
(1) The zeolite is an intermediate pore size zeolite (2) The zeolite is substantially free of protons (3) The zeolite contains silver (4) Silica alumina molar ratio of the zeolite (SiO ₂ / Al ₂ O ₃ molar ratio) is 800 or more and 2000 or less.
[2]
The method for producing a lower olefin according to [1], wherein the zeolite in the zeolite-containing shaped catalyst further contains an alkali metal.
[3]
The method for producing a lower olefin according to [1] or [2], wherein the zeolite-containing shaped catalyst is heat-treated at 500 ° C. or higher in the presence of water vapor and oxygen.
[4]
The method for producing a lower olefin according to any one of [1] to [3], wherein a silver cation occupancy ratio relative to a cation site of zeolite in the zeolite-containing shaped catalyst is 10% or more and 70% or less.
[5]
The method for producing a lower olefin according to any one of [1] to [4], wherein the zeolite-containing shaped catalyst further contains silica.
[6]
The method for producing a lower olefin according to any one of [1] to [5], wherein the reactor is a fluidized bed type reactor or a fixed bed type reactor.
[7]
The said raw material is a manufacturing method of the lower olefin in any one of [1]-[6] which further contains olefins.

  According to the method for producing a lower olefin of the present invention, a high-yield lower olefin can be produced stably over a long period of time.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be variously modified without departing from the gist thereof.

[Production method of lower olefin]
The method for producing a lower olefin according to this embodiment comprises a raw material containing at least one selected from the group consisting of methanol and dimethyl ether, and a zeolite-containing shaped catalyst (hereinafter also simply referred to as “catalyst”) in the reactor. A contacting step. Moreover, the raw material contains 10% by mass or more of at least one selected from the group consisting of the methanol and dimethyl ether with respect to the total amount (100% by mass) of the raw material. Furthermore, the zeolite in the zeolite-containing shaped catalyst satisfies the following (1) to (4):
(1) The zeolite is an intermediate pore size zeolite (2) The zeolite is substantially free of protons (3) The zeolite contains silver (4) Silica alumina molar ratio of the zeolite (SiO ₂ / Al ₂ O ₃ molar ratio) is 800 or more and 2000 or less.
Here, in this specification, the lower olefin refers to an olefin having 2 to 5 carbon atoms (hereinafter, the carbon number may be abbreviated as “C”). A preferred lower olefin is propylene.

[Contact process]
The contact step of this embodiment is a step of bringing the raw material and the zeolite-containing shaped catalyst into contact in the reactor. In the contacting step, the raw material may further contain olefins. Furthermore, in the contacting step, the raw material preferably further includes at least a part of olefins produced by the method for producing a lower olefin of the present embodiment from the viewpoint of obtaining a higher yield of lower olefin.

<Raw material>
The raw material of this embodiment contains at least one selected from the group consisting of at least methanol and dimethyl ether, and may further contain olefins. The raw material contains 10% by mass or more and preferably 25% by mass or more of at least one selected from the group consisting of methanol and dimethyl ether with respect to the total amount (100% by mass) of the raw material. The total amount of methanol and dimethyl ether contained in the raw material is 100% by mass or less. When olefins are included, the total amount is preferably 90% by mass or less.

  In this specification, “total amount of raw materials” includes the masses of methanol and dimethyl ether and olefins, and other compounds are included in the raw materials, but are not included in the total amount of raw materials. Therefore, when not containing olefins, naturally, the raw material contains 100% by mass of at least one selected from the group consisting of methanol and dimethyl ether.

  The olefins of the present embodiment are preferably olefins having 2 to 8 carbon atoms, and more preferably olefins having 2 to 6 carbon atoms. These olefins are preferably supplied as raw materials mixed with methanol and dimethyl ether. Further, the desired lower olefins are separated and recovered from the product components obtained by contacting with the zeolite catalyst of the present embodiment by a conventionally known distillation purification process, and a part or all of the other olefins are recycled. You can also. In addition, in addition to a linear, branched, and cyclic olefin, "olefins" as used in this specification also contains cycloparaffin, and may contain dienes and alkynes. In the present embodiment, by recycling at least a part of the generated olefins, the target lower olefin in the present embodiment tends to be efficiently obtained.

  In the reaction product, in addition to the lower olefin, olefins having 6 or more carbon atoms and a small amount of aromatic hydrocarbon are present. Here, the desired lower olefin is separated and recovered from the reaction product, and the olefins having 2 to 8 carbon atoms contained in the residue are recycled to the reactor to further improve the yield of the desired lower olefin. It tends to be able to be made.

  Moreover, since methanol and / or dimethyl ether are used as raw materials, water vapor derived from the desorbed water coexists in the reaction field. In general, it is known that zeolites contained in conventional catalysts are deteriorated by dealumination with high-temperature steam. However, in the catalyst of this embodiment, deterioration of zeolite occurs even in the presence of steam. Hateful. Therefore, in the contact step of the present embodiment, the catalyst of the present embodiment can be used without separating water vapor.

  The desired lower olefin is separated and recovered, and the recycle ratio of the residue (mass ratio to be recycled as a raw material) is preferably 10% by mass or more and 95% by mass or less, more preferably, relative to the total amount of the raw material (100% by mass). It is 15 mass% or more and 90 mass% or less.

  In addition, aromatic hydrocarbons can be recovered from the residue not used for recycling. Furthermore, when supplying a raw material to a reactor, you may mix dilution gas. Examples of the dilution gas include inert gases such as hydrogen, methane, water vapor, and nitrogen, but are preferably other than hydrogen. This is because hydrogen tends to suppress the coking deterioration of the catalyst, but causes a hydrogenation reaction of produced propylene and the like, and propylene purity (propylene concentration in C3 fraction [mol%]: propylene / (propylene + propane)) This is because a decrease of × 100) is caused. In the industrial production of lower olefins, it is important that the propylene purity is high. In the present embodiment, even if hydrogen is not used, the coking deterioration of the catalyst is small and stable operation is possible.

<Zeolite-containing molded catalyst>
(Intermediate pore size zeolite)
The zeolite-containing shaped catalyst of the present embodiment contains zeolite as a main catalyst component. The zeolite is an intermediate pore size zeolite. The medium pore diameter zeolite refers to a zeolite having a pore diameter of 5.0 to 6.5 mm. Further, the term “medium pore diameter zeolite” means “the pore diameter range is small pore diameter zeolite represented by A-type zeolite, and large pore diameter represented by mordenite, X-type or Y-type zeolite. “Zeolite in the middle of the pore diameter of zeolite” means a zeolite having a so-called oxygen 10-membered ring in its crystal structure.

  The intermediate pore size zeolite is not limited to the following, but examples include ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-21, ZSM-23, ZSM-35, and ZSM-38 types. Zeolite may be mentioned. Among these, ZSM-5 type zeolite is preferable. The structure type of zeolite can be confirmed by comparison with a known zeolite diffraction pattern using a powder X-ray analyzer.

(Proton content)
The zeolite in the zeolite-containing shaped catalyst of the present embodiment is substantially free of protons. The fact that it does not substantially contain protons is 0.02 mmol or less per gram of zeolite, as determined by the liquid phase ion exchange / filter droplet method described in the examples below. Means that. Preferably, the zeolite has a proton amount of 0.01 mmol or less per gram of the zeolite.

  The liquid phase ion exchange / filter droplet method is known as Intrazeolite Chemistry, “ACS Symp. Ser.”, 218, P369-382 (1983), The Chemical Society of Japan, [3], P. 521-527 (1989). The proton amount in this embodiment using this method is measured as follows. The zeolite-containing shaped catalyst calcined in air is subjected to ion exchange treatment using an aqueous NaCl solution, and then the catalyst is recovered by filtration and a filtrate is obtained. The recovered catalyst is washed with pure water, and the entire amount of the resulting washing solution is collected and mixed with the above filtrate. The amount of protons in the obtained mixed solution is obtained by neutralization titration, and the value converted to the mass of zeolite contained in the catalyst is taken as the amount of protons in the zeolite. The amount of proton is measured by the method described in the examples described later.

  Ammonium ion type and polyvalent metal cation type zeolite generate protons by heat treatment. Therefore, prior to the measurement of the proton amount by the above method, the zeolite-containing shaped catalyst is calcined.

(Including silver)
The zeolite in the zeolite-containing shaped catalyst of the present embodiment contains silver. By containing silver is meant that the zeolite contains silver in the state of a cation (silver ion) corresponding to silver. Examples of the method of containing silver in the zeolite include a method of containing a zeolite containing no silver or a zeolite-containing shaped catalyst by a known ion exchange method. When silver is contained in the zeolite by an ion exchange method, it is preferable to use a silver salt. Examples of the silver salt include silver nitrate, silver acetate, and silver sulfate.

  The amount of silver contained in the zeolite as a cation is not particularly limited. However, as will be described later, since the silica alumina molar ratio of the zeolite of the present embodiment is 800 or more and 2000 or less, the preferable content is determined from the ion exchange capacity and the zeolite content in the zeolite-containing shaped catalyst. Determined. Therefore, the amount of silver can be indicated by the occupancy ratio of silver cations to the cation sites of zeolite. That is, the occupancy ratio of the silver cation to the cation site of the zeolite is preferably 10% or more and 70% or less, more preferably 10% or more and 50% or less, and further preferably 10% or more and 30% or less. When the occupancy is 10% or more, the activity of the reaction tends to be sufficient, and when the occupancy is 70% or less, the ion exchange rate becomes too high. Tends to be suppressed from becoming too high.

  The silver content in the zeolite or zeolite-containing shaped catalyst can be quantified by a known method, for example, X-ray fluorescence analysis. On the other hand, the occupancy ratio of the silver cation to the cation site can be quantified by ion-exchanging the zeolite-containing shaped catalyst with a sodium nitrate solution and measuring the amount of silver ions in the filtrate. The silver at the cation site can be distinguished from other silver. Silver that does not exist at the cation site is not eluted by the ion exchange. Further, the occupancy ratio of the silver cation to the cation site referred to in the present embodiment is the silica-alumina ratio of the zeolite determined by the analysis method described in the examples described later, and the aluminum content (mmol / g) calculated therefrom. It is indicated by the ratio of the amount of silver (mmol / g) present at the cation site relative to. Note that the silver content in the catalyst does not change before and after the steaming process of the present embodiment described later.

  Since the zeolite of the present embodiment is substantially free of protons as described above, the remaining cation sites exchanged with silver cations are cations of at least one metal selected from alkali metals and alkaline earth metals. Ion exchange at. That is, the zeolite contains a cation of at least one metal selected from alkali metals and alkaline earth metals. The metal cation is preferably a cation of at least one metal selected from alkali metals, more preferably a cation of at least one metal selected from the group consisting of sodium and potassium. That is, the zeolite in the zeolite-containing shaped catalyst of the present embodiment is a zeolite containing both silver and at least one metal selected from alkali metals and alkaline earth metals. In addition, like silver, “containing further alkali metal” means containing in a corresponding cation state, for example, ion exchange with 0.1 N nitric acid to induce alkali metal ions in the filtrate. By measuring by coupled plasma emission spectroscopy (ICP-AES), the alkali metal present at the cation site can be quantified. In addition, the alkali metal which does not exist in a cation site does not elute by the said ion exchange. The occupancy ratio of the alkali metal cation to the cation site of the zeolite is determined by the balance between the silver cation occupancy ratio and the proton acid amount described above, preferably 30% to 90%, more preferably 50% to 90%. % Or less, more preferably 70% or more and 90% or less.

  For example, when the zeolite of this embodiment is prepared in a silver / sodium cation exchange type, if an alkali component is present at a portion that is not a cation site in the zeolite, a part of silver cannot be supported as a silver cation. When forming the zeolite, it is preferable to convert the zeolite into a proton type. Therefore, the zeolite in the zeolite-containing shaped catalyst formed as a proton type zeolite is first exchanged with sodium type (preferably using an aqueous solution of sodium nitrate) and converted into sodium type (non-proton type), and then the silver cation. Is preferably exchanged (preferably using an aqueous silver nitrate solution). In addition, by controlling the content of the alkali metal component in the components other than zeolite constituting the zeolite-containing shaped body catalyst, the zeolite may be ion-exchanged in advance and then processed and prepared as a shaped body catalyst. Is possible.

(Silica alumina molar ratio)
The silica alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio) of the zeolite of this embodiment is 800 or more and 2000 or less. When the silica-alumina molar ratio is less than 800, the selectivity for lower olefins containing propylene is reduced, and the deterioration of the zeolite-containing shaped catalyst due to coking associated with the conversion reaction is accelerated. For example, in the case where the manufacturing method of the present embodiment is implemented by the fixed-bed 2 tower swing method, the switching frequency becomes faster, so the regeneration frequency increases. Accordingly, the progress of reproduction deterioration is accelerated. On the other hand, if the silica-alumina molar ratio exceeds 2000, a problem in catalyst preparation occurs. In order to maintain the catalytic activity of the high silica alumina molar ratio zeolite-containing shaped catalyst, it is necessary to increase the silver cation occupancy of the zeolite when preparing the same silver content. However, when the zeolite of the present embodiment is prepared into an aprotic silver exchange type by ion exchange, an attempt to increase the silver cation occupancy gradually deteriorates the exchange efficiency. In order to avoid this, it is necessary to increase the metal concentration in the exchange liquid. However, if the silica alumina molar ratio of the zeolite exceeds 2000, both ion exchange with alkali metal and ion exchange with silver are difficult to proceed. In the case of industrially carrying out the production method of the embodiment, it takes a long time to prepare the catalyst, and it is necessary to increase the number of ion exchanges. In addition, there is a problem that an excessive amount of chemical solution is required and the amount of waste liquid generated is excessive.

  The silica-alumina molar ratio of zeolite in the zeolite-containing shaped catalyst of the present embodiment is preferably 800 or more and 1500 or less, more preferably 900 or more and 1200 or less. The silica-alumina molar ratio of zeolite can be determined by a known method, for example, by completely dissolving in an alkali aqueous solution or hydrofluoric acid aqueous solution, and analyzing the obtained solution by plasma emission spectroscopy. Specifically, it is measured by the method described in the examples described later.

  As the zeolite of the present embodiment, for example, a metalloaluminosilicate in which a part of aluminum atoms constituting the zeolite skeleton is substituted with an element such as Ga, Fe, B, Cr, etc., all the aluminum atoms constituting the zeolite skeleton are as described above. Metallosilicates substituted with various elements can also be used. In that case, the silica-alumina molar ratio is calculated after converting the content of the above-mentioned elements in the metalloaluminosilicate or metallosilicate to the number of moles of alumina.

<Binder>
The zeolite-containing shaped catalyst of the present embodiment comprises a porous refractory inorganic oxide such as alumina, silica, silica / alumina, zirconia, titania, diatomaceous earth, clay, etc. as a binder or a diluent for molding (matrix) (hereinafter, both Are also referred to as “binders etc.”), and a mixture obtained by mixing with the above zeolite is molded, and the obtained molded body is used as a catalyst. From the viewpoint of catalyst strength and catalyst performance, alumina and silica are preferable, and silica is more preferable from the viewpoint of not forming unnecessary acid sites on the catalyst.

  The raw material of silica is not limited to the following, but examples include colloidal silica, water glass (sodium silicate), and fumed silica force. Among these, colloidal silica is preferable, and NH4 stable with low Na content. A type of colloidal silica is more preferred.

  When performing the contact process of this embodiment in a fixed bed, it is preferable to shape | mold a zeolite and a binder by a well-known method, for example, extrusion molding and tableting.

  When performing the contact process of this embodiment in a fluidized bed, it is preferable to form into a fine spherical shape suitable for a fluidized bed by a spray drying method. As described above, a silica binder or the like is preferable from the viewpoint of catalyst performance. When colloidal shear force is used as a binder or the like, the particle size of the shear force is preferably smaller, more preferably 4.0 nm or more and 20 nm or less, and still more preferably 4.0 nm or more and 15 nm or less. By using a colloidal shear force having a small particle diameter, the wear resistance of the zeolite-containing shaped catalyst containing silica for fluidized bed tends to be improved. Here, the particle size of the siri force can be measured by a dynamic light scattering particle size distribution measuring apparatus. When a binder or the like is used, the content thereof is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 70% by mass with respect to the total amount (100% by mass) of zeolite and the binder. % Or less.

  When colloidal silica is selected as the silica raw material, at least one water-soluble compound selected from the group consisting of nitrate, acetate, carbonate, sulfate and chloride is added to the spray-dried raw material mixture. Preferably it is present. The “water-soluble compound” as used herein is a compound having a solubility of 1 g or more in 100 g of water at 25 ° C. As the water-soluble compound, each ammonium salt is preferable, and ammonium nitrate is more preferable.

  A plurality of these water-soluble compounds can be used simultaneously. The presence of these water-soluble compounds in the spray-dried raw material mixture tends to provide a zeolite-containing shaped catalyst having excellent wear resistance and a dense structure with few voids inside. Suitable for catalytic use in bed reaction.

  The zeolite-containing shaped body catalyst of the present embodiment is heated at 500 ° C. or higher in the presence of water vapor as a pretreatment prior to being subjected to the contact step for the purpose of improving propylene yield and resistance to coking deterioration. It is preferable that it is treated (hereinafter also referred to as “steaming treatment”), and more preferably, the steaming treatment is performed at a temperature of 500 ° C. or more and 900 ° C. or less and a water vapor partial pressure of 0.01 atm or more. The steaming process here is performed in the presence of nitrogen, air, and a mixed gas thereof as a sweep gas in order to control the partial pressure of water vapor. The steaming treatment is preferably performed in the presence of oxygen, more preferably at least 0.1 mol% or more. When the steaming process is performed in the presence of oxygen, a catalyst having a desired activity can be obtained with good reproducibility. However, when the steaming process is performed in the presence of oxygen, the catalyst is present at the cation site of the zeolite. It is speculated that this is because silver can exist stably.

  In general, the above-mentioned steaming treatment can be used as a method for controlling the activity of zeolite and a zeolite-containing shaped catalyst. However, in the case where a conventional H-type zeolite catalyst is used, it is difficult to prepare an optimum catalyst for the reaction of the present embodiment having a narrow range of suitable performance using the treatment method. On the other hand, the zeolite-containing shaped catalyst of the present embodiment can be easily and reproducibly prepared with a desired performance suitable for the production method of the lower olefin of the present embodiment by silver loading and steaming treatment. can do.

  The zeolite-containing shaped body catalyst of the present embodiment may cause coking deterioration when used in a conversion reaction for a long period of time, but in that case, it is usually 400 ° C. or higher in air or a mixed gas composed of oxygen and an inert gas. By burning and removing the coke on the catalyst at a temperature of 700 ° C. or lower, the catalyst having undergone coking deterioration can be regenerated (hereinafter, this process is also referred to as “regeneration process”). As described above, the zeolite-containing shaped body catalyst of the present embodiment is less likely to cause dealumination due to the regeneration treatment, which is a problem with ordinary H-type zeolite catalysts, even during such regeneration treatment.

  The reproduction process can be performed by a known method. In the fixed bed, for example, the reaction and the regeneration can be alternately performed as a two-column swing system. In the fluidized bed system, a method of regenerating and returning the catalyst extracted from the reactor, or a method of regenerating while recirculating a part of the catalyst between the reactor and the regenerator by using a regenerator together can be employed. The amount of coke deposited on the catalyst can be determined from the mass change before and after regeneration of the extracted catalyst, such as thermogravimetry.

In the contacting step of the present embodiment, the zeolite-containing molded body catalyst is filled in the reactor, and the raw material catalytic conversion reaction is performed. The reaction temperature is preferably 400 ° C. or higher and 600 ° C. or lower, more preferably 450 ° C. or higher and 580 ° C. or lower. The reaction operation pressure is preferably 0.01 MPaG or more and 1.0 MPaG or less, more preferably 0.05 MPaG or more and 0.5 MPaG or less. To the mass of the catalyst, the weight hourly space velocity of the raw material (WHSV) is preferably not more than 0.1 hr ^-1 or more 100 hr ^-1, more preferably less ^{1hr -1} or 10 hr ^-1.

<Reactor>
As the reactor of this embodiment, any of a fixed bed type, a moving bed type, a fluidized bed type, and an air flow type reactor can be used, but a fluidized bed type or a fixed bed type is preferable, and the reaction activity In view of facilitating temperature control, a fluidized bed type is more preferable. Here, the formation reaction of dimethyl ether by dehydration reaction from methanol is an exothermic reaction of 23 kJ / mol. Therefore, when the reaction is carried out in a fixed bed, the temperature control of the catalyst layer tends to be relatively difficult when the reaction is attempted in one stage from the raw material methanol.
2CH ₃ OH → CH ₃ OCH ₃ + H ₂ O (23 kJ / mol)

  Therefore, with two reactors, dimethyl ether is synthesized in the first reactor, and a lower olefin is produced in the second reactor. It is also possible to synthesize dimethyl ether and produce a lower olefin with the lower catalyst. At this time, the zeolite-containing shaped catalyst of this embodiment may be used also in the dimethyl ether synthesis reaction, and a conventionally known alumina catalyst or the like may be used as a catalyst for dimethyl ether synthesis by a conventionally known method.

  As described above, as disclosed in the present specification, the zeolite-containing molded body catalyst of the present embodiment achieves a high propylene (olefin) yield, and also deteriorates due to coking and deterioration during regeneration processing in which coke is burned. Since propagating is difficult, propylene can be stably produced over a long period of time even if a fixed bed reactor is used. In addition, when using a fluidized bed reactor, the frequency of the catalyst circulation regeneration treatment may be low, and it is difficult to cause deterioration over time, so that the catalyst makeup amount is small. Further, according to the method disclosed in the present specification, a catalyst controlled to an optimum activity having the performance can be easily prepared with good reproducibility. These features are extremely advantageous when the present embodiment is industrially implemented.

  Hereinafter, the present embodiment will be described in more detail with specific examples and comparative examples. However, the present embodiment is not limited to the following examples and comparative examples unless the gist of the present embodiment is exceeded. . Analytical methods for obtaining various physical properties and evaluations performed in Examples and Comparative Examples described below are as follows.

(Physical Property 1) Proton Amount by Liquid Phase Ion Exchange / Filtered Drop Drop Method 2.5g of zeolite-containing shaped catalyst, which was separated in a mortar and calcined in air at a temperature of 400 to 600 ° C, was added to 3.4 mol / liter NaCl. Ion exchange was performed in 25 mL of an aqueous solution for 10 minutes under ice cooling. After the obtained mixture was filtered, the zeolite was washed with 50 mL of pure water, and the entire amount of the filtrate containing water used for washing was recovered. This filtrate (including water used for washing) was neutralized and titrated with a 0.1N NaOH aqueous solution, and the proton content was determined from the neutralization point. This was determined from the zeolite content in the zeolite-containing shaped catalyst, based on the zeolite mass. Converted into a proton amount.

(Physical Property 2) Silica Alumina Ratio 0.2 g of zeolite was added to 50 g of 5N NaOH aqueous solution. This was transferred to a stainless steel micro cylinder with a Teflon (registered trademark) inner tube, and the micro cylinder was sealed. The zeolite was completely dissolved by holding in an oil bath for 15 to 70 hours. The obtained zeolite solution was diluted with ion-exchanged water, the silicon and aluminum concentrations in the diluted solution were measured with a plasma emission spectrometer (ICP apparatus), and the silica-alumina molar ratio of the zeolite was calculated from the results. The ICP device and its measurement conditions are shown below.
Apparatus: JOBIN YVON (JY138 ULTRACE) manufactured by Rigaku Denki Co., Ltd. Silicon measurement wavelength: 251.60 nm
Aluminum measurement wavelength: 396.152 nm
Plasma power: 1.0 kW
Nebulizer gas: 0.28 L / min
Sheath gas: 0.3 to 0.8 L / min
Coolant gas: 13L / min

(Evaluation 1) Methanol and / or dimethyl ether conversion rate and yield of each component The conversion rate (conversion rate based on methanol and / or dimethyl ether) was calculated by the following formula.
Conversion = {(Methanol in raw material + dimethyl ether) − (Methanol in outlet product gas + dimethyl ether) × 100} / (Methanol in raw material + dimethyl ether) (mass%)
Moreover, the yield of each component was made into the density | concentration (mass%) of the hydrocarbon reference | standard remove | excluding the moisture content in a product.

(Evaluation 2) PY Purity Propylene purity (shown as “PY purity” in the table) is the propylene concentration [mol%] in the product C3 fraction (propylene and propane), and is calculated from the following formula. Asked.
Propylene purity [mol%] = propylene [mol] / (propylene [mol] + propane [mol]) × 100

[Example 1] Fluidized bed reaction (Step 1: Preparation of catalyst raw material mixture)
While stirring 882 g of colloidal Siri force (34% by mass of Siri force content), 18 g of 61% by mass nitric acid aqueous solution (manufactured by Wako Pure Chemicals, special grade reagent) was added to pH = 1, and ammonium nitrate (Japanese 100 g (manufactured by Kojun Pure Chemical Co., Ltd., special grade reagent) was further added. While stirring this silica solution, NH4 type MFI-1000 zeolite manufactured by Zeolist (trade name “ZD05020”, the silica alumina molar ratio of the zeolite was 980 when it was completely dissolved and measured by ICP) Finally, 1034 g of water was added to adjust the solid content of the catalyst raw material to 30% by mass, and the mixture was further stirred at 25 ° C. for 1 hour to obtain a catalyst raw material mixture.

(Process 2: Spray drying process)
The obtained catalyst raw material mixture was spray-dried using a spray dryer (model OC-16 manufactured by Okawara Chemical Industries Co., Ltd.) to obtain a dried product. The atomization was performed using a disk atomizer at a hot air inlet temperature of 230 ° C. and an outlet temperature of 130 ° C.

(Process 3: Firing process)
The obtained dried product was calcined in a muffle furnace at 700 ° C. for 1 hour in an air atmosphere to obtain a zeolite-containing shaped catalyst (containing 50% by mass of silica binder, average particle size 55 μm).

(Process 4: Acid exchange process)
The obtained zeolite-containing shaped catalyst was dispersed in a 1N nitric acid aqueous solution (10 cc / g-zeolite shaped product) and subjected to ion exchange treatment at room temperature for 1 hour. Next, filtration, washing with water, and drying were performed to prepare an H exchange type ZSM-5 / SiO ₂ shaped body catalyst (formed body catalyst A).

(Process 5: Ion exchange process)
The obtained molded catalyst A was dispersed in a 1N sodium nitrate aqueous solution (10 cc / g-zeolite molded product), and the ion exchange treatment for 1 hour at room temperature was repeated three times. Next, filtration, washing with water and drying were performed to prepare a Na exchange type ZSM-5 / SiO ₂ shaped body catalyst. This was dispersed in a 0.00054N silver nitrate aqueous solution (10 cc / g-zeolite compact) and subjected to ion exchange treatment at room temperature for 2 hours. Subsequently, the molded body catalyst B was prepared by filtering, washing with water and drying. The silver content of the compact catalyst B measured by fluorescent X-ray analysis was 0.0465% by mass. Separately, the silver content determined by the ion exchange method almost coincided with 0.047% by mass. Moreover, from the silica alumina ratio 980 of the raw material zeolite, the silver cation occupation ratio with respect to the zeolite cation site was 25.7%.

(Process 6: Steaming process)
40 g of the obtained molded catalyst B was packed into a stainless fluidized bed reactor having an inner diameter of 23.9 mmφ and a catalyst support and a SUS wire mesh (mesh opening 10 μm) as a gas supply unit, and the temperature was 650. Steaming treatment was performed for 24 hours under the conditions of ° C, pressure 0.2 MPaG, steam flow rate 9.6 g / hr, and air 530 NCCM (steam concentration 27.3 mol%, oxygen concentration 15.3 mol%). The amount of protons in the shaped catalyst B after the steaming treatment was determined by liquid phase ion exchange / filter droplet method, and it was 0.0012 mmol / g-zeolite.

(Process 7: Contact process)
25.5 g of the compacted catalyst B after the steaming treatment was charged into a stainless steel fluidized bed reactor having an inner diameter of 23.9 mmφ and provided with a SUS wire mesh (mesh opening 10 μm) as a catalyst support gas feeder, Methanol conversion reaction was carried out under conditions of a temperature of 550 ° C., a pressure of 0.14 MPaG, and a methanol flow rate of 25.0 g / hr (LV 2.2 cm / sec, contact time 2.95 sec). Immediately after starting the raw material supply, the reaction product was directly introduced into the gas chromatograph (TCD, FID detector) from the reactor outlet, and the composition was analyzed. The analysis by gas chromatography was performed under the following conditions.

(Gas chromatograph analysis conditions)
Equipment: Product name “GC-17A” manufactured by Shimadzu Corporation
Column: Custom capillary column manufactured by SUPELCO, USA, trade name “SPB-1” (inner diameter 0.25 mm, length 60 m, film thickness 3.0 μm)
Sample gas volume: 1mL (sampling line kept at 200-300 ° C)
Temperature rising program: held at 40 ° C. for 12 minutes, then heated up to 200 ° C. at 5 ° C./min, and then held at 200 ° C. for 22 minutes.
Split ratio: 200: 1
Carrier gas (nitrogen) flow rate: 120 mL / min FID detector: air supply pressure 50 kPa (about 500 mL / min), hydrogen supply pressure 60 kPa (about 50 mL / min)
Measurement method: A TCD detector and an FID detector are connected in series, hydrogen and hydrocarbons having 1 and 2 carbon atoms are detected by a TCD detector, and hydrocarbons having 3 or more carbon atoms are detected by an FID detector. Ten minutes after the start of analysis, the detection output was switched from TCD to FID. The reaction was continued for 100 hours while appropriately analyzing the reaction product. Table 1 shows the analysis results at each time (in Example 1, 4 hours, 25 hours, 50 hours, and 100 hours).

[Comparative Example 1]
In step 5, the compact catalyst B is not prepared. In step 6, the compact catalyst B is replaced with the compact catalyst A to perform a steaming process. In step 7, the compact catalyst B after the steaming process is performed. The same procedure as in Example 1 was conducted except that the methanol conversion reaction was carried out in place of the shaped catalyst A after the steaming treatment. The results are shown in Table 1.

[Comparative Example 2]
In the process 6, it implemented similarly to the comparative example 1 except having changed the 24-hour steaming process into the 48-hour steaming process. Three hours after the start of the methanol conversion reaction, the gas at the outlet of the reactor was analyzed and evaluated. As a result, dimethyl ether was detected, and it was found that the methanol dehydration reaction was not completed. Therefore, the reaction evaluation was stopped. The results are shown in Table 1.

[Comparative Example 3]
In Step 1, except that NH4 type MFI-1000 zeolite was replaced with trade name “MFI-240” (ZSM-5 type zeolite having a nominal silica alumina ratio of 240) manufactured by Clariant Catalyst Co., Ltd. The same operation as in Comparative Example 1 was performed. That is, as a result of performing Steps 2 to 4, a compact catalyst C was obtained, and Steps 6 and 7 were performed using the compact catalyst C. The results are shown in Table 1.

  From Example 1 and Comparative Examples 1 to 3, the production method using the zeolite-containing shaped catalyst of this embodiment has a lower aromatic yield than the production method using the H-ZSM-5 type catalyst, and propylene. It was found that the yield of low-grade olefins and the like was high, and that extremely high resistance to coking deterioration was exhibited. Moreover, when H-ZSM-5 zeolite was used as the catalyst, it was at least found that selecting the silica alumina molar ratio was important for improving the propylene yield. However, even when H-ZSM5 having a silica-alumina molar ratio of 980 is employed and subjected to a steaming treatment, the olefin yield and deterioration resistance obtained by the production method using the zeolite-containing shaped catalyst of this embodiment It did not reach the performance. When it was attempted to compensate for this difference in the results of the steaming treatment conditions, it became clear that the activity was greatly reduced, and it was at least found that it was difficult to control the activity under the steaming treatment conditions for the H-ZSM-5 type catalyst.

[Example 2] Fixed bed reaction Next, a method for controlling catalyst activity related to the effects of the present embodiment was examined by a fixed bed reaction using methanol as a raw material.

(Step 1: Ion exchange step)
A compact catalyst containing ZSM5 type zeolite having a silica alumina molar ratio of 1040 (determined by ICP method after completely dissolving the zeolite-containing compact catalyst) (containing 30% by mass of SiO ₂ binder, 1. 6 mmφ * 5 to 10 mmL H-type zeolite-containing shaped catalyst of JGC Universal Co., Ltd. is dispersed in a 1N sodium nitrate aqueous solution (10 cc / g-zeolite shaped product) and subjected to ion exchange treatment for 1 hour at room temperature. Repeated times. Next, filtration, washing with water and drying were performed to prepare a Na-type zeolite compact catalyst. This was dispersed in a 0.0020N silver nitrate aqueous solution (10 cc / g-zeolite compact) and subjected to ion exchange treatment at room temperature for 2 hours. Subsequently, the compact catalyst D was prepared by filtration, washing with water and drying. The silver content of the compact catalyst D measured by fluorescent X-ray analysis was 0.084% by mass. Moreover, the silver cation occupation rate with respect to the zeolite cation site of silver was 34.8%.

(Process 2: Steaming process)
The obtained compact catalyst D was filled in a quartz glass reactor having an inner diameter of 27.2 mmφ with 10 g, under conditions of a temperature of 650 ° C., a steam flow rate of 31.8 g / hr, a nitrogen flow rate of 73 NCCM, and air of 103 NCCM (steam The steaming treatment was performed for 36 hours at a concentration of 80 mol% and an oxygen concentration of 2.5 mol%. The proton content of the shaped catalyst D after the steaming treatment was 0.0014 mmol / g-zeolite.

(Process 3: Contact process)
8.6 g of shaped catalyst D after the steaming treatment is filled into a 15 mm inner diameter stainless steel fixed bed reaction tube (cross-sectional area 1.6 cm ² ) with a thermometer sheath tube, temperature 550 ° C., pressure 0.14 MPaG The methanol conversion reaction was carried out under the conditions of a methanol flow rate of 12.3 g / hr and nitrogen of 36 NCCM (contact time 1.76 sec, WHSV 1.44 hr ⁻¹ ). Since the reaction temperature profile changes with time, the reaction temperature profile was appropriately adjusted with an external electric furnace so that the maximum catalyst layer temperature was 550 ° C. The reaction product was introduced directly into the gas chromatography (TCD, FID detector) from the reactor outlet from the start of the raw material supply, and the composition was analyzed in a timely manner. The reaction was continued until dimethyl ether was confirmed in the reactor outlet product gas. At 35 hours, dimethyl ether was detected. The results are shown in Table 2.

[Example 3] Fixed bed reaction (verification of effect of silver loading)
A molded body catalyst was produced in the same manner as in Example 2 except that the 0.0020N silver nitrate aqueous solution (10 cc / g-zeolite molded body) was replaced with a 0.0015N silver nitrate aqueous solution (10 cc / g-zeolite molded body) in Step 1. E was prepared. In step 2, the formed body catalyst E is replaced with the formed body catalyst D, and a steaming process is performed. In step 3, the formed body catalyst D after the steaming process is replaced with the formed body catalyst E after the steaming process. The methanol conversion reaction was performed. The results are shown in Table 2. The silver content of the compact catalyst E before the steaming treatment as measured by fluorescent X-ray analysis was 0.057% by mass, and the silver cation occupancy with respect to the zeolite cation site was 23.6%. Moreover, the amount of protons in the shaped catalyst E after the steaming treatment in Step 2 was 0.0015 mmol / g-zeolite. Further, in Step 3, dimethyl ether was detected at 52 hours. The results are shown in Table 2.

[Comparative Example 4]
Next, as a comparison with Examples 2 and 3, in a conventional H-type zeolite-containing shaped catalyst, a method for performing a control method by pretreatment of catalytic activity, which is a problem of the present embodiment, by steaming treatment, methanol Was studied by a fixed bed reaction.

In Step 2, a compact catalyst containing ZSM-5 type zeolite with a molar ratio of silica alumina before the exchange of sodium and silver was 1,040 (containing 30% by mass of SiO ₂ binder, 1.6 mmφ * 5) A methanol conversion reaction was carried out in the same manner as in Example 2 except that the catalyst was changed to an H-type zeolite-containing molded catalyst (molded catalyst F) manufactured by JGC Universal Co., Ltd. Further, the methanol conversion reaction was similarly performed for the compact catalyst F in which the steaming treatment conditions in Step 2 were changed from 36 hours to 12 hours and 72 hours, respectively. The results are shown in Table 3. In the molded body catalyst having a steaming time of 72 hours, the reaction was stopped because dimethyl ether was detected by sampling 4 hours after the start of the reaction.

[Comparative Example 5]
In Step 2, the compact catalyst D is an H-type zeolite-containing compact catalyst containing ZSM-5 type zeolite having a silica-alumina molar ratio of 42 (containing 50% by mass of SiO ₂ binder, compression molding, 6-20 mesh crush classification) Article) A methanol conversion reaction was carried out in the same manner as in Example 2 except that (molded catalyst G) was used. The results are shown in Table 3.

  From Example 2, Example 3, Comparative Example 4 and Comparative Example 5, the zeolite-containing shaped body catalyst in this embodiment can control the amount of silver supported by changing the concentration of the liquid to be treated for ion exchange treatment. It has been found that at least it is possible to carry out very delicate activity control required as a catalyst used in this embodiment for producing a lower olefin from methanol and / or dimethyl ether. On the other hand, when using an H-ZSM-5 type zeolite-containing shaped catalyst as a catalyst, it was at least found that it is important to select the silica-alumina molar ratio. However, even when H-ZSM-5 type zeolite having a silica alumina molar ratio of 1000 is adopted and further subjected to the steaming treatment, it does not reach the deterioration resistance performance of the zeolite-containing shaped catalyst of this embodiment. It is at least known that the activity is greatly reduced when the steaming treatment conditions are supplemented, and the very delicate activity control required as a catalyst used in this embodiment for producing a lower olefin from methanol and / or dimethyl ether is obtained. At least, it has been found that it is difficult to optimize with pretreatment conditions.

[Example 4] Fixed bed reaction / regeneration cycle test (evaluation of catalyst permanent deterioration)
The catalyst E used in the fixed bed reaction evaluation in Example 3 was collected and baked in a muffle furnace at 580 ° C. for 5 hours to remove and regenerate the coke adhered to the catalyst. Using the catalyst after calcination regeneration, methanol conversion reaction was carried out in the same manner as in Step 3: Contacting Step of Example 3. The presence or absence of catalyst activity deterioration was confirmed by evaluating the reaction results while repeating this reaction and regeneration treatment. In the 4th and 5th cycles, the time until dimethyl ether was confirmed in the product gas at the outlet of the reactor (maintenance time for complete conversion of methanol) was 54 and 53 hours, respectively, and the catalytic activity and coking deterioration behavior were not changed. It was. From this, it was found that the catalyst used here had no activity deterioration due to regeneration treatment (deterioration due to dealumination). The results are shown in Table 4.

[Example 5] Influence of catalyst pretreatment method For the purpose of confirming the reproducibility of the catalyst of this embodiment, verification equivalent to Example 3 was further performed twice. First, catalyst E was prepared in the same manner as in Example 3. Next, a part of the obtained catalyst E was steamed by the same method as in step 2 of Example 2 to obtain catalyst E-2S. Separately, a part of the catalyst E was steamed by the same method as in step 2 of Example 2 to obtain catalyst E-3S. The proton amount of catalyst E-2S and the proton amount of E-3S were 0.0013 and 0.0015 mmol / g-zeolite, respectively. Using the catalysts E-2S and E-3S, the contacting step was performed in the same manner as in Step 3 of Example 2. The results are shown in Table 5 together with the results of Example 3.

[Example 6] Influence of catalyst pretreatment method For the purpose of confirming the influence of oxygen coexistence in the steaming treatment step, the catalyst E obtained in Example 3 was treated under the following steaming treatment conditions. .

(Process 2: Steaming process)
10 g of a molded glass catalyst E was charged into a quartz glass reactor having an inner diameter of 27.2 mmφ, under conditions of normal pressure, temperature 650 ° C., steam flow rate 31.8 g / hr, nitrogen flow rate 176 NCCM (steam concentration 80 mol%, nitrogen concentration 20 mol%), the steaming treatment was performed for 36 hours to obtain catalyst E-4S. In addition, under the same conditions as catalyst E-4S, the other molded article catalyst E was steamed to obtain catalyst E-5S. The proton amount of catalyst E-4S and the proton amount of E-5S were 0.0014, 0,0012 mmol / g-zeolite. Using the catalysts E-4S and E-5S, the contacting step was performed in the same manner as in Step 3 of Example 2. The results are shown in Table 5.

  From Examples 3 and 5 and Example 6, it can be seen that at least the preferred catalyst performance can be prepared with better reproducibility by performing the steaming treatment of the catalyst of the present embodiment in the presence of oxygen.

[Comparative Example 7]
A catalyst H was prepared by compression molding SAPO-34 having a Si / Al / P molar ratio of 2 / 12.6 / 9.9. The catalyst H was crushed and classified into an 8-20 mesh catalyst, and 8.56 g of the catalyst was packed into a 15 mm inner diameter stainless steel fixed bed reaction tube (cross-sectional area 1.6 cm ² ) provided with a thermometer sheath tube. The reaction was carried out under conditions.
Raw material supply rate: Methanol 6.2 g / hr, nitrogen 18 NCCM
Reaction pressure: 0.14 MPa / G
Reaction temperature: 420 ° C. WHSV: 0.72 hr ⁻¹
The results are shown in Table 6.

  The SAPO-34 catalyst system showed high selectivity with respect to lower olefins, but had low activity and required a large amount of catalyst. Moreover, the activity deterioration was remarkable, and dimethyl ether and methanol were detected at the time of sampling for only 5.83 hours. Therefore, this catalyst is extremely disadvantageous for industrial implementation.

[Example 7] Fixed bed reaction using dimethyl ether raw material In a fixed bed evaluation experiment using methanol as a raw material, heat generation during dehydration reaction to dimethyl ether is large, and it is difficult to maintain a uniform catalyst layer temperature. Therefore, the evaluation reaction was conducted by supplying dimethyl ether and water.

The steamed shaped molded catalyst E4.56 g used in Example 3 was charged into a 15 mm inner diameter stainless steel fixed bed reaction tube (cross-sectional area 1.6 cm ² ) provided with a thermometer sheath tube, and the temperature was 550 ° C., Dimethyl ether conversion reaction was carried out under the conditions of a pressure of 0.10 MPaG, a dimethyl ether flow rate of 8.2 g / hr, and steam of 3.2 g / hr (LV 3.16 cm / sec, contact time 1.3 sec). In addition, the change of reaction temperature profile was suppressed and it adjusted with the external electric furnace suitably so that the catalyst layer average temperature might be set to 550 degreeC. The reaction product was directly introduced into the gas chromatography (TCD, FID detector) from the reactor outlet from the start of the raw material supply, and the composition was analyzed. The reaction continued for 24 hours, but no unreacted dimethyl ether was detected. The results are shown in Table 7.

  From the results of this Example, it was found that the yield of olefins such as propylene was further improved when the catalyst of the present embodiment could be reacted at a relatively isothermal temperature in the dimethyl ether raw material system.

[Comparative Examples 8 and 9]
In Comparative Examples 8 and 9, the compacted catalyst E after the steaming treatment was subjected to the compacted catalyst F after the 36-hour steaming treatment used in Comparative Example 4 and the 36-hour steaming treatment used in the Comparative Example 5, respectively. A dimethyl ether conversion reaction was carried out in the same manner as in Example 7 except that the molded product catalyst G was used. The reaction continued for 24 hours, but no unreacted dimethyl ether was detected in any case. The results are shown in Table 7.

  From Example 7 and Comparative Examples 8 and 9, when dimethyl ether, which is a single-molecule dehydration reaction product, is used as a raw material for a methanol raw material fixed bed reaction, the catalyst layer temperature is stabilized and a reaction at a relatively isothermal temperature is possible. became. Even under such conditions, it has been at least found that the zeolite-containing shaped catalyst of the present embodiment is superior in yield of olefins such as propylene.

[Example 8] Fixed bed reaction with dimethyl ether / olefin raw material As an alternative to the methanol raw material, dimethyl ether and water were supplied, and as a mixed system with the olefin raw material, a fixed bed evaluation reaction was performed by supplying 1-butene gas.

The steamed shaped catalyst E7.7 g used in Example 3 was charged into a stainless steel fixed-bed reaction tube (cross-sectional area 1.6 cm ² ) having an inner diameter of 15 mm with a thermometer sheath tube, and the temperature was 550 ° C. Butene / dimethyl ether conversion at pressure 0.10 MPaG, dimethyl ether flow rate 8.2 g / hr, 1-butene flow rate 22.8 g / hr, steam 3.2 g / hr, (LV 5.29 cm / sec, contact time 1.3 sec) Reaction was performed. In addition, it adjusted with the external electric furnace suitably so that the catalyst layer average temperature might be set to 550 degreeC. The reaction product was directly introduced into the gas chromatography (TCD, FID detector) from the reactor outlet from the start of the raw material supply, and the composition was analyzed. The reaction continued for 24 hours, but no unreacted dimethyl ether was detected. The results are shown in Table 8.

[Comparative Example 10]
The conditions in the above fixed bed reaction were as follows: 5.35 g of catalyst E was charged into a 15 mm inner diameter stainless steel fixed bed reaction tube (cross-sectional area 1.6 cm ² ) provided with a thermometer sheath tube, temperature 550 ° C., pressure 0.10 MPaG, A butene conversion reaction was carried out in the same manner as in Example 8, except that the flow rate of 1-butene was 22.8 g / hr and nitrogen was 92.6 SCCM / min (LV 3.68 cm / sec, contact time 1.3 sec). In Example 8 and Comparative Example 10, when it is assumed that dimethyl ether is dehydrated to produce ethylene, the olefin concentration in the supply gas is equal to 62.1 mol%. The results are shown in Table 8.

  From the results of Example 8 and Comparative Example 10, this embodiment has higher yields of ethylene and propylene among lower olefins by simultaneously supplying dimethyl ether (that is, methanol) as compared to a butene-only raw material system. That is, it has been at least found that C4 and C5 olefins can be recycled.

  In the method for producing a lower olefin according to the present invention, when the zeolite-containing shaped body catalyst of the present embodiment is used, a high propylene (lower olefin) yield is achieved, and deterioration due to coking and deterioration during coke combustion regeneration are unlikely to occur. Therefore, even if a fixed bed reactor is used, it becomes possible to produce propylene stably over a long period of time. In addition, when using a fluidized bed reactor, the circulation rate of the zeolite catalyst is low, and it is difficult to cause deterioration over time, so that the catalyst make-up amount is small. At the same time, the catalyst using methanol and / or dimethyl ether as a raw material is required to have very delicate activity control, but the zeolite-containing shaped body catalyst of the present embodiment can prepare a catalyst having a desired activity by a simple method. Is also possible. These facts are extremely advantageous when the present embodiment is industrially implemented.

Claims (7)

Having a contact step of bringing a raw material containing at least one selected from the group consisting of methanol and dimethyl ether into contact with a zeolite-containing shaped catalyst in a reactor;
The raw material contains 10% by mass or more of at least one selected from the group consisting of the methanol and dimethyl ether with respect to the total amount of the raw material,
The zeolite in the zeolite-containing shaped catalyst satisfies the following (1) to (4):
(1) The zeolite is an intermediate pore size zeolite (2) The zeolite is substantially free of protons (3) The zeolite contains silver (4) Silica alumina molar ratio of the zeolite (SiO ₂ / Al ₂ O ₃ molar ratio) is 800 or more and 2000 or less.   The method for producing a lower olefin according to claim 1, wherein the zeolite in the zeolite-containing shaped catalyst further contains an alkali metal.   The method for producing a lower olefin according to claim 1 or 2, wherein the zeolite-containing shaped catalyst is heat-treated at 500 ° C or higher in the presence of water vapor and oxygen.   The manufacturing method of the lower olefin of any one of Claims 1-3 whose silver cation occupation rate with respect to the cation site of the zeolite in the said zeolite containing molded object catalyst is 10% or more and 70% or less.   The said zeolite containing molded object catalyst is a manufacturing method of the lower olefin of any one of Claims 1-4 which further contains a silica.   The method for producing a lower olefin according to any one of claims 1 to 5, wherein the reactor is a fluidized bed type or a fixed bed type reactor.   The said raw material is a manufacturing method of the lower olefin of any one of Claims 1-6 which further contains olefins.