KR100926800B1 - Catalysts for the dimethyl ether synthesis from methanol, preparing method of the same, and synthesis method of the dimethyl ether - Google Patents

Abstract

The present invention relates to a catalyst for synthesizing dimethyl ether by dehydration of methanol, a method for preparing the same, and a method for preparing dimethyl ether. More specifically, by containing a predetermined amount of aluminum phosphate binder, effectively improving the life of the catalyst, The present invention relates to a catalyst for synthesizing dimethyl ether by dehydration of methanol capable of obtaining diethyl ether in high yield while maintaining high catalytic activity, a method for preparing the same, and a method for preparing dimethyl ether.

Methanol, diethyl ether, aluminum phosphate

Description

Catalyst for synthesis of dimethyl ether by dehydration of methanol, preparation method thereof and preparation method of dimethyl ether {Catalysts for the dimethyl ether synthesis from methanol, preparing method of the same, and synthesis method of the dimethyl ether}

The present invention relates to a catalyst for synthesizing dimethyl ether by dehydration of methanol containing an aluminum phosphate binder, a method for preparing the same, and a method for preparing dimethyl ether in order to effectively improve the life of the catalyst and to obtain a high yield of diethyl ether. It is about.

Dimethylether is widely used as aerosol propellant and basic raw material of chemical industry, and has similar physical properties to LPG and contains oxygen, which can be widely used as clean diesel fuel. Development is needed.

The industrial production method of dimethyl ether can be divided into two types.

The first method is to prepare dimethyl ether directly from synthesis gas (CO + H ₂ ), as shown in Scheme 1 below. Methanol synthesis catalyst and dehydration catalyst are mixed and CuO / ZnO / Al _{2 is used.} O ₃ is mainly used, and as a dehydration catalyst, a solid acid catalyst such as zeolite is used.

3CO + 3H ₂ → CH ₃ OCH _{3 +} CO ₂

The second method is a method of synthesizing by dehydrating methanol as shown in the following scheme 2.

2CH ₃ OH → CH ₃ OCH ₃ + H ₂ O

The reaction for preparing dimethyl ether by dehydration of methanol according to Scheme 2 is performed at a temperature of 250 to 450 ° C., and a solid acid catalyst is usually used.

As the solid acid catalyst used in the production of dimethyl ether, gamma-alumina (JP-A-1984-16845), silica-alumina (JP-A-1984-42333) and the like are generally used. However, gamma-alumina or silica alumina is a hydrophilic material, and water can be easily adsorbed on the surface, thereby decreasing the active point and lowering catalytic activity. Therefore, when water is included in methanol used as a raw material in the production process of dimethyl ether, there is a problem in that the activity of the solid acid catalyst is significantly reduced. Thus, in the current dimethyl ether production process, the content of water in methanol as a raw material is lowered to several hundred ppm or less. However, methanol produced as a synthesis gas is a by-product and contains 10 to 20% by volume of water. Strict removal of water is required.

DME conversion reaction in methanol produces one molecule of water per two molecules of reaction methanol. When the water molecule is in contact with the zeolite catalyst at high temperature and high pressure like the DME conversion reaction, it becomes hydrothermal condition and the aluminum in the zeolite skeleton It escapes from this backbone and eventually removes the acidic properties of the zeolite, causing permanent catalyst deactivation. Particularly, when using hydrous methanol, such a phenomenon is intensified, and thus a technique for preventing dealumination in the zeolite skeleton is urgently needed.

In addition, a large amount of water generated by the dehydration reaction is included in the process of recovering and reusing unreacted methanol in the dimethyl ether production process, and thus, water removal using the distillation process is required. Therefore, in order to reduce energy consumption in the distillation process and improve economics over the existing process, the development of a new catalyst that is not easily deactivated by water is urgently needed.

Meanwhile, the reaction for converting methanol into dimethyl ether is performed by an acid catalyst, and thus, the activity and selectivity of the catalyst may vary depending on the acid point strength of the acid catalyst due to the generation of dimethyl ether corresponding to the intermediate formation step up to the hydrocarbon. For example, under a catalyst having a strong acid point, methanol is further reacted with hydrocarbons through the formation of dimethyl ether, and as a result, hydrocarbons are produced as by-products and catalysts are easily deactivated by coke formation. On the other hand, if the acid strength is too weak or the acid density is too low, there is a problem in that the conversion to dimethyl ether is insufficient because of low activity of the catalyst.

When hydrophobic zeolites such as USY, Mordenite, ZSM, Beta, etc. are used for methanol dehydration, they show stronger activity at lower temperatures than gamma-alumina, but they are too strong to produce dimethyl ether from methanol. Side reactions result in hydrocarbons and coke to lower selectivity. In addition, according to the results of the previous studies of the present inventors, ordinary H-USY, H-ZSM-5, H-Beta zeolite has a strong acid point, there is a problem to generate hydrocarbon by-products such as methane, ethane, propane. Hydrocarbons produced as a by-product are low molecular weight alkanes and are of low value as products, but also form coke to deactivate the catalyst.

As a result recently published by the researchers, a patent application method for preparing dimethyl ether using crude methanol containing 5 to 50 mol% of water in raw methanol to suppress hydrocarbon generation in hydrophobic zeolites has been filed. [Korean Patent Registration 10-0454091].

The present invention aims to solve the problem that the catalyst is easily deactivated by dealumination when synthesizing dimethyl ether by methanol dehydration.

In addition, an object of the present invention is to solve the problem that hydrocarbon by-products are generated due to excessively high catalytic activity.

The present invention provides a metal cation selected from (a) 1 part by weight of a hydrogen (H) or ammonium (NH ₄ ) type hydrophobic zeolite, (b) 0.05-10 parts by weight of an aluminum phosphate binder, and (c) an alkali metal and an alkaline earth metal. The above problems are solved by providing a catalyst for dimethyl ether synthesis by dehydration of methanol comprising 0.001 to 0.1 parts by weight of a precursor of.

Moreover, this invention solves the said subject by providing the manufacturing method of the catalyst for dimethyl ether synthesis by the dehydration reaction of the said methanol.

Moreover, this invention solves the said subject by providing the manufacturing method of the dimethyl ether using the said catalyst.

The catalyst for dimethyl ether synthesis by the dehydration reaction of methanol according to the present invention contains an aluminum phosphate binder, thereby increasing the hydrothermal stability of the catalyst.

In addition, the present invention has the effect of effectively improving the life of the catalyst by preventing the dealumination of the catalyst and the generation of by-products.

In addition, the present invention maintains high catalytic activity and does not produce byproducts such as lower hydrocarbons, so that diethyl ether can be obtained with high yield.

The present invention relates to a catalyst for dimethyl ether synthesis by dehydration of methanol, which can effectively improve the life of the catalyst and obtain a high yield of diethyl ether, a method for preparing the same, and a method for producing dimethyl ether.

In the reaction using zeolite as a solid acid catalyst, catalyst inactivation occurs mainly due to two causes. Firstly, deactivation may occur as coke produced by the strong acid point in the zeolite pores fills the pores or blocks the pores. In this case, the solution can be solved by masking the strong acid point by the use of a base ion such as an appropriate alkali metal and alkaline earth metal. The second is a reaction in which water is contained or produced at high temperature, that is, in hydrothermal conditions, water attacked aluminum in the zeolite skeleton to dealumination, thereby permanently losing the acidity of the zeolite, resulting in deactivation. In particular, in the synthesis of dimethyl ether by the dehydration reaction of methanol, the formation of methanol containing water is inevitable, and the development of a catalyst for improving the deactivation of the catalyst due to the water is urgently needed. In such a case, the dealumination can be prevented effectively by containing a phosphorus (P) component.

Accordingly, the catalyst for synthesizing dimethyl ether by dehydration of methanol according to the present invention includes (a) hydrogen (H) or ammonium (NH ₄ ) type hydrophobic zeolites, (b) aluminum phosphate binders, and (c) alkali metals. And alkaline earth metals are impregnated with a metal cation having the greatest technical characteristics.

Referring to the present invention in more detail as follows.

The present invention relates to (a) 1 part by weight of a hydrogen (H) or ammonium (NH ₄ ) type hydrophobic zeolite, (b) 0.05 to 10 parts by weight of an aluminum phosphate binder, and (c) a cation selected from an alkali metal and an alkaline earth metal. It provides a catalyst for dimethyl ether synthesis by dehydration of methanol comprising 0.001 to 0.1 parts by weight of the precursor.

The hydrophobic zeolite is generally used in the art, and is not particularly limited. More specifically, the hydrophobic zeolite may have a SiO ₂ / Al ₂ O ₃ molar ratio in the range of 20 to 300. At this time, when the SiO ₂ / Al ₂ O ₃ molar ratio is in the range of 50 to 200, it can be applied more preferably, and when the SiO ₂ / Al ₂ O ₃ molar ratio is in the range of 50 to 100, it can be more preferably applied. . For example, when the SiO ₂ / Al ₂ O ₃ molar ratio is less than 20, the acid density of the zeolite is too high, so it is easy to form coke, and the amount of aluminum is high so that the hydrothermal stability is low, and the hydrophilic property is higher, and the water content is higher than methanol. There are in this case the reaction one drop the conversion problem, when the SiO ₂ / Al ₂ O ₃ molar ratio exceeds 300 decreases the number of zeolite acid site, that is, the number of active sites of the methanol conversion reaction because it may cause small falling active matter the SiO ₂ / Hydrophobic zeolites such as USY, mordenite, ZSM, beta, and ferrierite having an Al ₂ O ₃ molar ratio range are preferred.

Commonly used zeolites include Na-type zeolites with Na ⁺ ion exchange (e.g., Na-ZSM-5, Na-Beta, Na-Mordenite, etc.) and H-type zeolites with H ⁺ ion exchange (e.g., H-ZSM -5, H-Beta, H-Mordenite, etc.). However, according to studies of the team does not efficient in this reaction include Na-type zeolites do not have a little acid sites, H ⁺ is ion-exchanged H-type zeolite there is a problem to produce a hydrocarbon by-products owing to the too strong acid sites.

Thus, the present invention contains 0.001 to 0.1 parts by weight of a precursor of a cation selected from alkali metals and alkaline earth metals with respect to 1 part by weight of hydrogen (H) type or ammonium (NH ₄ ) type hydrophobic zeolite to provide an optimal acid point for dimethyl ether production. The strength of the strong acid point was properly adjusted to retain. At this time, the precursor of the cation may be used more preferably, when contained in 0.005 to 0.05 parts by weight, more preferably used when contained in 0.005 to 0.03 parts by weight. In other words, hydrogen (H) type or ammonium (NH ₄ ) type hydrophobic zeolites having a strong acid point are impregnated with salts such as sodium, magnesium, or potassium, and thus Na-H type, Mg-H type, KH type, or Na- type. The strength of the strong acid point is controlled by making NH ₄ type, Mg-NH ₄ type or K-NH ₄ type zeolite. The equivalent ratio of the cation according to the precursor addition of the metal cation selected from the alkali metal and the alkaline earth metal is in the range of 10 to 90 equivalent% based on the hydrogen cation (H ⁺ ) of the hydrophobic zeolite in consideration of the formation of by-products and the activity of the catalyst. Good to be included.

  Phosphorus (P) component not only has an effect of increasing the hydrothermal stability of the zeolite, but also plays an additional role of weakening the strong acid point of the zeolite. In the case of using a catalyst formed by using the conventional alumina as a binder, even though phosphoric acid is treated to add phosphorus (P), phosphoric acid is difficult to interact by ion exchange with aluminum sites in the zeolite pores. This is because phosphoric acid binds to alumina used as a binder before zeolite alumina.

Therefore, in the present invention, to treat the zeolite with phosphoric acid in order to simultaneously show the effect of increasing the hydrothermal stability and weakening the strong acid point of the zeolite, the zeolite powder was first treated with phosphoric acid, preventing the treated phosphoric acid from courageously binding with the binder. In order to introduce an aluminum phosphate binder having a low affinity for phosphoric acid in order to achieve the present invention, there is the biggest technical feature in completing the present invention. The aluminum phosphate binder not only acts as a binder in shaping the catalyst, but also acts as a source of phosphorus (P) by itself, so that the thermal stability of the aluminum phosphate binder when the aluminum phosphate binder is used without treating the phosphor with a zeolite catalyst Augmentation effect was obtained.

The aluminum phosphate binder is generally used in the art, and is not particularly limited. Specifically, in consideration of the hydrothermal stabilization effect of zeolite and the economical efficiency due to the loss of phosphorus, the P / Al molar ratio is in the range of 0.7 to 2. More preferably, it can be used.

The catalyst for dimethyl ether synthesis according to the present invention may include the aluminum phosphate binder in the range of 0.05 to 10 parts by weight based on 1 part by weight of the hydrophobic zeolite. More preferably, it is preferable to use an aluminum phosphate binder in the range of 0.1 to 5 parts by weight, and even more preferably, to use an aluminum phosphate binder in the range of 0.15 to 1 part by weight. In this case, when the content of the aluminum phosphate binder is too small, there may be a problem in that the physical strength is weak when the catalyst is molded and easily broken. When the content of the aluminum phosphate binder exceeds 10 parts by weight of the zeolite as a catalyst component, Since a low content may cause a problem of lowering catalytic activity, it is preferable to use an aluminum phosphate binder in the above content range.

In addition, the catalyst for synthesizing dimethyl ether according to the present invention is impregnated with 0.01 to 0.2 parts by weight of phosphorus (P) precursor with respect to 1 part by weight of hydrophobic zeolite, and the phosphorus (P) component may be further ion exchanged. In the case where the phosphorus (P) is supported too much, it may be a problem to inhibit the pore of zeolite to inhibit the catalytic activity, so it is preferable to ion exchange the phosphorus in the molar range. The phosphorus precursor is generally used in the art, and is not particularly limited. Specifically, phosphoric acid or phosphate may be used.

On the other hand, the aluminum phosphate binder may further include 0.01 to 1 parts by weight of the inorganic binder, based on 1 part by weight of the hydrophobic zeolite in consideration of the physical strength of the catalyst. The inorganic binder is generally used in the art and is not particularly stable. For example, a single inorganic binder or two or more inorganic binders selected from silica, kaolin, silica-alumina, zirconia, titania, and alumina may be used. have. When such an inorganic binder is added too much, the relative content of phosphorus (P) present in the catalyst for synthesizing dimethyl ether according to the present invention may be reduced, so it is preferable to maintain a 0.01 to 1 part by weight content range.

Thus, when the catalyst of the present invention is applied to the dehydration reaction of methanol, dimethyl ether can be obtained in much higher yield than the conventional dimethyl ether production process without any deactivation of the catalyst and without generating any hydrocarbon by-products. In addition, the catalyst of the present invention has the effect of ensuring a much longer life than the existing catalyst.

The method for preparing a catalyst for preparing dimethyl ether as described above may be prepared by applying a method generally used in the art, but is not particularly limited, and more specifically, by adding water to the aluminum precursor and the phosphorus precursor In the first step of preparing an aluminum phosphate slurry, the aluminum phosphate slurry, hydrogen (H) or ammonium (NH ₄ ) -type hydrophobic zeolite fine particles and deionized water are mixed and molded, dried, in a temperature range of 400 ~ 700 ℃ It may be prepared by a manufacturing method comprising the two steps of firing a molded product and the three steps of mixing the molded product with a metal cation precursor of an alkali metal or alkaline earth metal, and drying, and firing in a temperature range of 400 ~ 700 ℃. have.

The production method of the catalyst for preparing dimethyl ether is a production method in which the phosphorus (P) component is not additionally added. The present invention further includes adding a phosphorus (P) component to further increase the hydrothermal stability of the hydrophobic zeolite. It can also be prepared by the following two kinds of production methods.

The first method further includes adding a phosphorus (P) component to prepare an aluminum phosphate slurry by adding water to the aluminum precursor and the phosphorus precursor, hydrogen (H) type or ammonium (NH ₄ ) type. After impregnating the hydrophobic zeolite fine particles in an aqueous solution of phosphoric acid or phosphate, dried, and calcined at a temperature range of 400 ~ 700 ℃ to produce a hydrophobic zeolite fine particles impregnated with phosphorus, the hydrophobic zeolite fine particles impregnated with, After mixing by molding the aluminum phosphate slurry and deionized water, and then dried, and then calcined at a temperature range of 400 ~ 700 ℃ to prepare a molding and drying by mixing the precursor of a metal cation of alkali metal or alkaline earth metal And, by the manufacturing method comprising three steps of firing in the temperature range of 400 ~ 700 ℃ It can be.

The second method further includes adding a phosphorus (P) component to prepare an aluminum phosphate slurry by adding water to the aluminum precursor and the phosphorus precursor, hydrogen (H) type or ammonium (NH ₄ ) type. After mixing and molding hydrophobic zeolite fine particles, the aluminum phosphate slurry and deionized water, drying, firing at a temperature range of 400 ~ 700 ℃ to prepare a molding, after impregnating the molding in an aqueous solution of phosphoric acid or phosphate , Drying, firing at a temperature in the range of 400 to 700 ° C. to form a phosphorus-impregnated molding, and mixing and drying the molding and a precursor of a cation of an alkali metal or alkaline earth metal, and drying in a temperature range of 400 to 700 ° C. It may be prepared by a manufacturing method comprising three steps of firing at.

In the two kinds of manufacturing method further comprising the step of adding the phosphorus (P) component, the aqueous solution of phosphoric acid or phosphate is 0.01 to 0.2 parts by weight of phosphoric acid or phosphate relative to 1 part by weight of hydrophobic zeolite than It can be used preferably.

In the above catalyst production method of the present invention, the aluminum precursor and the phosphorus precursor of the aluminum phosphate binder is not particularly limited to those commonly used in the art, more specifically, as the aluminum precursor, boehmite, aluminum hydroxide, chloride A single precursor selected from aluminum, aluminum sulfate, aluminum nitrate, and aluminum alkoxide or two or more kinds of precursors may be used. Examples of the phosphorus precursor include phosphoric acid (H ₃ PO ₄ ), phosphorous acid (H ₃ PO ₃ ), and ammonium hydrogen phosphate ( Single precursor or two selected from (NH ₄ ) ₂ HPO ₄ , or NH ₄ H ₂ PO ₄ ), sodium hydrogen phosphate ((Na ₂ HPO ₄ , or NaH ₂ PO ₄ ) and sodium phosphate (Na ₃ PO ₄ ) In addition, the above precursor may be used The aluminum precursor and the phosphorus precursor may be in the form of solid particles, a slurry, or a solution.

Hydrophobic zeolites used in the catalyst preparation according to the present invention are generally applied in the art, and are not particularly limited, but more specifically, USY and mordenite having a molar ratio of SiO ₂ / Al ₂ O _{3 in} the range of 20 to 300 ( Mordenite), ZSM system, Beta, etc. can be used. At this time, when the SiO ₂ / Al ₂ O ₃ molar ratio is in the range of 50 to 200, it can be applied more preferably, and when the SiO ₂ / Al ₂ O ₃ molar ratio is in the range of 50 to 100, it can be more preferably applied. . The hydrophobic zeolite can be in powder form or any other form and can be supported using conventional impregnation methods.

In addition, the prepared aluminum phosphate binder is preferably in consideration of the hydrothermal stabilization effect of the zeolite and economics due to the loss of phosphorus component, P / Al molar ratio of 0.7 to 2. In the aluminum phosphate binder, the solid content may be 0.05 to 10 parts by weight with respect to 1 part by weight of the zeolite. When the weight part is less than 0.05 parts by weight, the zeolite content ratio may be too high, resulting in a problem that the physical strength of the molded product is lowered. In the case of exceeding 10 parts by weight, the amount of zeolite may be relatively small, resulting in a decrease in the acid point of the catalyst, thereby lowering the catalytic activity.

On the other hand, in addition to the aluminum phosphate binder, an inorganic oxide binder that does not have a strong binding force with a phosphorus compound may be additionally used.The inorganic binder may be a single inorganic binder or two selected from silica, kaolin, silica-alumina, zirconia, titania, and alumina. The above inorganic binder can be used. It is preferable to contain these content in 0.01-1 weight part with respect to 1 weight part of hydrophobic zeolites. When the inorganic binder is included too much, the physical strength of the calcined catalyst after molding is reduced and the amount of phosphorus supplied to the zeolite is decreased, thereby reducing the zeolite hydrothermal stabilization efficiency.

The zeolite or the zeolite treated with phosphorus is kneaded with an aluminum phosphate slurry or a slurry in which an aluminum phosphate and an inorganic oxide binder are mixed, and then a catalyst is formed. At this time, as an organic binder or pore-forming agent, a single organic binder selected from methylcellulose, polyvinyl alcohol, polyethylene glycol, and hydroxymethylcellulose, or Two or more organic binders may be used, and their content is preferably 0.01 to 0.2 parts by weight based on 1 part by weight of hydrophobic zeolite in consideration of the physical strength of the calcined catalyst after molding.

In addition, in the step of adding to the phosphorus (P) component, the precursors of phosphorus include phosphoric acid (H ₃ PO ₄ ), phosphorous acid (H ₃ PO ₃ ), and ammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ , Or phosphate salts such as NH ₄ H ₂ PO ₄ ). Phosphorus can be dried by mixing a hydrophobic zeolite with an aqueous solution of a phosphorus compound and heating it at 70-100 ° C., at which time it can be stirred during heating to evenly disperse phosphorus in the hydrophobic zeolite. The dried phosphorus-containing hydrophobic zeolite can be calcined in air at a temperature of 400-700 ° C. before molding. At this time, in the case where too much of the compound containing phosphorus, phosphorus can block the hydrophobic zeolite pores, rather it can reduce the catalytic activity.

The molding method is not particularly limited to methods commonly known in the art, but may be molded by, for example, extrusion, spray drying or pelletizing. In particular, as a catalyst for preparing dimethyl ether from methanol in a fixed bed reactor, a catalyst molded by an extrusion method may be more preferably used. It can also be shaped into granules, extrudates, tablets, spheres or pellets, depending on the purpose of the catalyst.

Drying and calcining of the extruded catalyst are carried out by methods generally known in the art, and then dried at room temperature (20 ° C.) to 100 ° C. and then calcined for 1 to 48 hours at 400 to 700 ° C. in air. can do. At this time, when the firing temperature is less than 400 ℃, it is insufficient to burn the organic material in the catalyst or to obtain the catalyst strength, and if it exceeds 700 ℃, the structure of the hydrophobic zeolite may be broken, and the structure of the binder is changed to increase the catalyst strength. It is recommended to maintain the firing range as it may drop. The calcining process is an essential process for the sufficient impregnation of the cationic salt and the establishment of the hydrophobic zeolite structure, and it is possible to prepare the catalyst of the present invention only when the above temperature range is maintained.

As a precursor of a cation selected from alkali metals and alkaline earth metals contained in order to control the strength of the strong acid point of the hydrophobic zeolite of the formed catalyst, it is added as a salt or hydroxide of a specific cation such as chloride, nitrate, sulfate, carbonate, etc. As a method for inclusion in the hydrophobic zeolite, a conventional impregnation method or an ion exchange method can be used.

The precursor of the cation selected from the alkali metal and the alkaline earth metal may be contained in 0.001 to 0.1 parts by weight, wherein the content of the cation is in the range of 10 to 90 equivalent% relative to the hydrogen cation (H ⁺ ) of the hydrophobic zeolite It may be included as. If the amount of cation contained is less than 10 equivalent%, the amount of cation is not sufficient to neutralize the strong acid point of the hydrophobic zeolite, and the remaining strong acid point may generate byproduct hydrocarbons. It is preferable to maintain the above range because the base ions replace not only the strong acid point but also the weak acid point of the hydrophobic zeolite, thereby lowering the activity of the catalyst.

On the other hand, the method for producing dimethyl ether by dehydrating methanol on the catalyst according to the invention as follows.

The catalyst is charged to the reactor, followed by pretreatment of the catalyst prior to the methanol dehydration reaction, which consists of flowing an inert gas such as nitrogen at a temperature of 20-100 mL / g-catalyst / min at a temperature of 100-350 ° C. Methanol is flowed into the reactor on the pretreated catalyst. At this time, the reaction temperature is maintained at 150 ~ 350 ℃, if the reaction temperature is less than 150 ℃, the conversion rate is low because the reaction rate is not enough, if the conversion temperature is higher than 350 ℃ thermodynamically disadvantageous to the production of dimethyl ether There is a problem of being lowered. The reaction pressure is maintained at 1 to 100 atm, but if it exceeds 100 atm, it is not suitable due to problems in the reaction operation. In addition, it is preferable that the liquid hourly space velocity (LHSV) proceeds with the methanol dehydration reaction in the range of 0.05-100 h ^{−1 on} the basis of methanol. If the liquid space velocity is less than 0.05 h ^{−1, the} reaction productivity is too low, and if it exceeds 100 h ⁻¹ , there is a problem that the conversion rate is lowered because the contact time with the catalyst is shortened. As the reactor, a fixed bed reactor, a fluidized bed reactor, or a reactor in the form of a slurry in a liquid phase may be used, and any of these may be used to obtain the same effect.

The catalyst according to the present invention can maintain a high catalytic activity for a long time with little deactivation by dealuminization of the hydrophobic zeolite catalyst during dehydration of methanol containing water, thereby making it possible to manufacture dimethyl ether efficiently. The methanol containing water may have a water content of 5 to 50 mol%.

In addition, the catalyst according to the present invention is a part of the hydrogen cation of the hydrogen (H) type or ammonium (NH ₄ ) type hydrophobic zeolite is appropriately substituted with a specific cation selected from alkali metals and alkaline earth metals to remove the strong acid point to suppress side reactions to the hydrocarbon and The formation of coke can be suppressed as much as possible, thereby greatly improving the selectivity of dimethyl ether.

As described above, in the present invention, by using hydrophobic zeolite whose hydrothermal stability is increased and the strength of the strong acid point is used as a catalyst, the durability of the catalyst is increased during the methanol dehydration reaction, and dimethyl ether is increased without generating hydrocarbon by-products. It could be produced in yield.

If the present invention will be described in detail based on the following examples, the present invention is not limited to the examples.

Example 1

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed. After molding, an extruder having a diameter of 2 mm was used. The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0103 parts of potassium nitrate (KNO _3, FW 101) dissolved in 0.72 parts of deionized water per 1 part by weight of hydrophobic zeolite, and then sufficiently dried at 120 ° C. for 12 hours, followed by air It heated to 500 degreeC by 3 degree-C / min heating rate in the inside, hold | maintained at this temperature for 5 hours, and manufactured the catalyst.

The catalyst was crushed-classified to a size of about 1 mm, 1 g of which was charged to a fixed bed reactor.

In this state, at a reactor temperature of 300 ° C. and a reactor pressure of 10 atm, methanol containing 20 mol% of water was passed through the catalyst layer at a space velocity of LHSV 10 h ⁻¹ . Shown in

Example 2

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and the solution was mixed with 23.3 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed. After molding, an extruder having a diameter of 2 mm was used. The molded sample was calcined at 500 ° C. for 5 hours.

To 1 part by weight of the hydrophobic zeolite, 0.0159 parts by weight of sodium nitrate (NaNO _3, FW 85) was impregnated into a solution dissolved in 0.72 parts by weight of deionized water, which was then sufficiently dried at 120 ° C. for 12 hours, and then dried in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 3

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed. After molding, an extruder having a diameter of 2 mm was used. The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0252 parts of calcium nitrate (Ca (NO ₃ ) _2, FW 236) dissolved in 0.72 parts of deionized water per 1 part by weight of hydrophobic zeolite _{, and} then sufficiently dried at 120 ° C. for 12 hours. After heating in air at 3 ℃ / min temperature increase rate to 500 ℃ and maintained at this temperature for 5 hours to prepare a catalyst.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 4

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.74 parts by weight of sample A, 0.1 parts by weight of silica, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and deaeration 0.1 parts by weight of deionized water was mixed. At this time, the hydrophobic zeolite and the organic binder were mixed well first, and then a slurry made by mixing sample A, silica and water was kneaded and then molded using an extruder having a diameter of 2 mm. The molded sample was dried at 120 ° C. and calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0075 parts by weight of sodium nitrate (NaNO _3, FW 85) dissolved in 0.72 parts by weight of deionized water per 1 part by weight of hydrophobic zeolite _{, and} then sufficiently dried at 120 ° C. for 12 hours, followed by 3 The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 5

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.1 parts by weight of kaolin, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water was mixed. At this time, the hydrophobic zeolite and the organic binder was mixed well first, and then a slurry made by mixing Sample A, kaolin and water was kneaded and molded using an extruder having a diameter of 2 mm. The molded sample was dried at 120 ° C. and calcined at 500 ° C. for 5 hours.

The molded article was impregnated into a solution in which 0.0089 parts by weight of potassium nitrate (KNO _3, FW 101) was dissolved in 0.72 parts by weight of deionized water, based on 1 part by weight of hydrophobic zeolite _{, and} then sufficiently dried at 120 ° C. for 12 hours, followed by drying in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 6

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.073 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight) and 1 part by weight of deionized water were mixed well. It was dried sufficiently at 120 ° C. for 12 hours. The sample was ground well with a mortar and then heated in air to 500 ° C. at a rate of 3 ° C./min and maintained at this temperature for 5 hours (Sample A).

11.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 21.3 parts by weight of deionized water, and then the solution was mixed with 20.5 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). To the solution mixed with 12.2 parts by weight of deionized water was added with vigorous stirring. At this time, an exothermic reaction occurred and stirring was further performed for 3 hours after mixing of the solution. The resulting viscous aluminum phosphate gel was used as a binder (Sample B).

0.755 weight part of sample B, 0.053 weight part of organic binders (methylcellulose, 4000cps), and 0.1 weight part of deionized water were mixed with respect to 1 weight part of said sample A. At this time, the sample A and the organic binder was mixed well first, and then the sample B and water were mixed to knead and molded using an extruder having a diameter of 2 mm. The molded sample was sufficiently dried at 120 ° C., and then heated to 500 ° C. at a rate of 3 ° C./min in air, and baked at 500 ° C. for 5 hours.

The molded article was impregnated into a solution in which 0.0089 parts by weight of potassium nitrate (KNO _3, FW 101) was dissolved in 0.71 parts by weight of deionized water based on 1 part by weight of hydrophobic zeolite _{, and} then sufficiently dried at 120 ° C. for 12 hours, followed by 3 ° C. in air. The catalyst was prepared by heating to 500 ° C./min at a rate of temperature increase and holding at this temperature for 5 hours to calcinate.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 7

11.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 21.3 parts by weight of deionized water, and the solution was mixed with 20.5 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 12.2 parts by weight of deionized water (Sample A).

0.77 parts by weight of sample A, 0.05 parts by weight of methyl cellulose (methylcellulose, 4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed with 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50 molar ratio) zeolite. After the molding using a 2mm diameter extruder (extruder). The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.073 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight) and 1 part by weight of deionized water based on 1 part by weight of hydrophobic zeolite, and then dried sufficiently at 120 ° C. for 12 hours, followed by 3 ° C. in air. It calcined by heating to 500 ° C. at a rate of temperature increase / min.

The phosphorus-containing molded body was impregnated into a solution in which 0.014 parts by weight of calcium nitrate (KNO _3, FW 101) was dissolved in 0.8 parts by weight of deionized water based on 1 part by weight of hydrophobic zeolite _{, and} then dried sufficiently at 120 ° C. for 12 hours. After heating, it was heated to 500 ° C. at a rate of temperature increase of 3 ° C./min in air, and maintained at this temperature for 5 hours to be calcined to prepare a catalyst.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 8

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and the solution was mixed with 23.3 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-beta (SiO ₂ / Al ₂ O ₃ = 60 molar ratio) zeolite, after mixing 0.74 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water, Molding was performed using an extruder with a diameter of 2 mm. The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0114 parts of sodium nitrate (NaNO _3, FW 85) dissolved in 0.72 parts of deionized water per 1 part by weight of hydrophobic zeolite _{, and} then sufficiently dried at 120 ° C. for about 12 hours, and then in air. A catalyst was prepared by heating to 500 ° C. at a temperature increase rate of 3 ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 9

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 4 parts by weight of Sample A, methyl cellulose (methyl cellulose, 4000 cps) and 0.15 parts by weight of an organic binder were mixed, followed by 2 diameters. Molding was performed using an extruder in mm. The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0103 parts of potassium nitrate (KNO _3, FW 101) dissolved in 0.72 parts of deionized water based on 1 part by weight of hydrophobic zeolite, and then sufficiently dried at 120 ° C. for 12 hours, followed by air It heated to 500 degreeC by 3 degree-C / min heating rate in the inside, hold | maintained at this temperature for 5 hours, and manufactured the catalyst.

The catalyst was crushed-classified to a size of about 1 mm, 1 g of which was charged to a fixed bed reactor.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Example 10

Experiment in the same manner as in Example 1, the catalyst was prepared using H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 240 molar ratio) zeolite.

Example 11

The experiment was carried out in the same manner as in Example 1, but the catalyst was prepared using NH ₄ -ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite.

Comparative Example 1

33.2 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ), 78.9 parts by weight of deionized water and 20.0 parts by weight of nitric acid (HNO ₃ , 6% by weight) were vigorously stirred in a solution mixed with A viscous boehmite gel was prepared (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 1.32 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed. It was. At this time, the hydrophobic zeolite and the organic binder were mixed well first, and then the solution prepared by mixing the sample A and water was mixed to form a dough, which was molded using an extruder having a diameter of 2 mm. The molded sample was dried at 120 ° C. and calcined at 500 ° C. for 5 hours.

The molded article was impregnated into a solution in which 0.0089 parts by weight of potassium nitrate (KNO _3, FW 101) was dissolved in 0.72 parts by weight of deionized water with respect to 1 part by weight of hydrophobic zeolite _, which was then sufficiently dried at 120 ° C. for 12 hours, and then dried in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Comparative Example 2

33.2 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ), 78.9 parts by weight of deionized water and 20.0 parts by weight of nitric acid (HNO ₃ , 6% by weight) were vigorously stirred in a solution mixed with A viscous boehmite gel was prepared (Sample A).

0.61 part by weight of sample A, 0.1 part by weight of silica, 0.05 part by weight of methyl cellulose (methylcellulose, 4000 cps) as an organic binder, and 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite 0.1 parts by weight of deionized water was mixed. At this time, the hydrophobic zeolite and the organic binder were mixed well first, and then a solution made by mixing sample A, silica and water was kneaded, and molded using an extruder having a diameter of 2 mm. The molded sample was dried at 120 ° C. and calcined at 500 ° C. for 5 hours.

The molded article was impregnated into a solution in which 0.0089 parts by weight of potassium nitrate (KNO _3, FW 101) was dissolved in 0.72 parts by weight of deionized water with respect to 1 part by weight of hydrophobic zeolite _, which was then sufficiently dried at 120 ° C. for 12 hours, and then dried in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Comparative Example 3

33.2 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ), 78.9 parts by weight of deionized water and 20.0 parts by weight of nitric acid (HNO ₃ , 6% by weight) were vigorously stirred in a solution mixed with A viscous boehmite gel was prepared (Sample A).

0.66 parts by weight of sample A, 0.1 parts by weight of kaolin, 0.05 parts by weight of methyl cellulose (methylcellulose, 4000 cps) as an organic binder, and 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite 0.1 parts by weight of deionized water was mixed. At this time, the hydrophobic zeolite and the organic binder were mixed well first, and then a solution prepared by mixing Sample A, kaolin, and water was kneaded and then molded using an extruder having a diameter of 2 mm. The molded sample was dried at 120 ° C. and calcined at 500 ° C. for 5 hours.

The molded article was impregnated into a solution in which 0.0089 parts by weight of potassium nitrate (KNO _3, FW 101) was dissolved in 0.72 parts by weight of deionized water with respect to 1 part by weight of hydrophobic zeolite _, which was then sufficiently dried at 120 ° C. for 12 hours, and then dried in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Comparative Example 4

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.1 parts by weight of kaolin, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water was mixed. At this time, the hydrophobic zeolite and the organic binder were mixed well first, and then a slurry made by mixing Sample A, kaolin and water was kneaded and molded using an extruder having a diameter of 2 mm. The molded sample was sufficiently dried at 120 ° C. for 12 hours, and then heated to 500 ° C. at a rate of 3 ° C./min in air, and then calcined by holding at this temperature for 5 hours to prepare a catalyst.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Comparative Example 5

12.5 parts by weight of boehmite (Catapal B, Vista, AlO (OH), 75% by weight Al ₂ O ₃ ) was mixed with 23.0 parts by weight of deionized water, and then the solution was mixed with 25.4 parts by weight of phosphoric acid (H ₃ PO ₄ , 85% by weight). A viscous aluminum phosphate gel was prepared by vigorously stirring the solution with 13.2 parts by weight of deionized water (Sample A).

To 1 part by weight of H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 80 molar ratio) zeolite, 0.74 parts by weight of Sample A, 0.05 parts by weight of methylcellulose (4000 cps) as an organic binder, and 0.1 parts by weight of deionized water were mixed. After molding, an extruder having a diameter of 2 mm was used. The molded sample was calcined at 500 ° C. for 5 hours.

The molded article was impregnated with a solution of 0.0342 parts of potassium nitrate (KNO _3, FW 101) dissolved in 0.72 parts of deionized water per 1 part by weight of hydrophobic zeolite _, which was then sufficiently dried at 120 ° C. for 12 hours, and then dried in air. The catalyst was prepared by heating to 500 ° C. at a temperature increase rate of ° C./min, and holding at this temperature for 5 hours to bake.

In addition, methanol dehydration was carried out in the same manner as in Example 1, and the obtained reaction results are shown in Table 1 below.

Experimental Example 1

In order to compare the hydrothermal stability of the catalysts prepared in Examples 1 to 8 and Comparative Examples 1 to 5, the prepared catalyst was mounted on a quartz tube containing a heating furnace, and then heated at a temperature of 5 ° C./min while flowing 100 wt% water vapor. The catalyst was hydrothermally heated to 700 ° C. at 5 ° C. and maintained at this temperature for 5 hours. The methanol dehydration reaction was carried out in the same manner as in Example 1, but the reaction temperature was 300 ° C., and the obtained reaction results are shown in Table 1 below.

Table 1 below shows the results of methanol dehydration reaction under the same conditions using methanol as a raw material using the catalysts prepared in Examples 1 to 8 and Comparative Examples 1 to 5, respectively.

As shown in Table 1, in the methanol dehydration reaction using the catalyst according to the embodiment of the present invention, the production yield of dimethyl ether was very high, close to the thermodynamic parallel yield, and no hydrocarbon by-products were produced. Even after hydrothermal treatment as in Experimental Example 1, the catalytic activity did not drop significantly, and the yield of dimethyl ether nearly parallel was shown at 300 ° C., and there was no detection of byproduct hydrocarbons.

As shown in Examples 1 to 5, the catalyst formed by hydrophobic zeolite with aluminum phosphate was found to have increased hydrothermal stability, so that the catalytic activity was maintained even after hydrothermal treatment at 700 ° C. under 100% water vapor. In particular, as shown in Examples 6 and 7, even if phosphoric acid was treated before or after forming the hydrophobic zeolite into aluminum phosphate, the hydrothermal stability of the catalyst was increased, and thus the catalytic activity was maintained as in Examples 1 to 5. there was. In addition, when the aluminum phosphate binder P / Al molar ratio ranges from 0.7 to 2 as in Examples 3 to 7, the extra phosphorus component may stabilize the acid point by interacting with aluminum in the hydrophobic zeolite, thereby providing a hydrothermal stabilization effect.

As shown in Comparative Examples 1 to 3, boehmite, silica, and kaolin, which do not contain phosphorus instead of aluminum phosphate binder, have excellent catalytic activity and selectivity for dimethyl ether before hydrothermal treatment, but catalytic activity after hydrothermal treatment is significantly decreased. have.

In addition, in the case of the catalyst prepared by mixing the aluminum phosphate binder and H-ZSM-5 without impregnating an alkali metal or alkaline earth metal salt (Comparative Example 4), the production yield of dimethyl ether was as low as 36%. And 62% hydrocarbons were produced as by-products, indicating very low selectivity. On the other hand, in the case of the catalyst prepared by impregnating a sodium salt corresponding to 100% of the hydrophobic zeolite hydrogen cation (Comparative Example 5), the reaction yield was very low as the production yield of dimethyl ether was 3.2%. This is because most of the hydrogen ions (H ⁺ ) serving as hydrophobic zeolite acid sites are ion-exchanged by sodium ions, and most of the acid sites are lost, so that the activity is hardly exhibited.

Experimental Example 2

The long lifespans of some catalysts prepared in Examples and Comparative Examples were measured-compared as attributes. Long-term life was measured by methanol dehydration in the same manner as in Example 1, but the reaction temperature was performed under more severe experimental conditions, such as LHSV of 20 h ^-1 at 300 ° C, and the catalyst life was lowered by 50% of methanol conversion. It refers to the time it takes to, the obtained reaction results are shown in Table 2 below.

division Catalyst (SiO ₂ / Al ₂ O ₃ Molar ratio) Binder (P / Al molar ratio, content (part by weight) ¹ ) Impregnation amount of cation (equivalent%) ² and phosphorus content (part by weight) ¹ Catalyst Life (Hour) ³ Example 1 K-H-ZSM-5 (80) Aluminum phosphate (1.20, 0.25) K (30) 1,179 Example 6 K-P-H-ZSM-5 (80) Aluminum phosphate (1.05, 0.25) K (26), P (0.015) 1,254 Comparative Example 1 K-H-ZSM-5 (80) Bohemite (0.25) K (26) 754 1) Based on 1 part by weight of hydrophobic zeolite 2) Based on cation (H ⁺ ) of hydrophobic zeolite 3) According to Experiment 2

Table 2 shows the results of performing long-life experiments in the harsh conditions under some conditions of the catalysts prepared in Examples 1 and 6 and Comparative Example 1. The catalyst life of the catalyst of Example 6 prepared by using the aluminum phosphate binder in the hydrophobic zeolite treated with the catalyst or phosphoric acid of Example 1 prepared by using the aluminum phosphate binder in the hydrophobic zeolite was compared using the boehmite binder. It was relatively longer than the catalyst of 1. This is because when the methanol containing water is used as a reactant or when the conversion rate of methanol is high, that is, water is produced by the yield of dimethyl ether as shown in Scheme 2, hydrothermal conditions are formed, and the methanol conversion reaction temperature is 250 to 350. Considering that the reaction pressure is usually 10 atm, the hydrophobic zeolite catalyst is deactivated due to dealumination.

Claims (15)

(a) 1 part by weight of hydrogen (H) or ammonium (NH ₄ ) type hydrophobic zeolite, (b) 0.05 to 10 parts by weight of an aluminum phosphate binder, and (c) 0.001 to 0.1 parts by weight of a precursor of a metal cation selected from alkali metals and alkaline earth metals Catalyst for synthesizing dimethyl ether by dehydration of methanol, comprising a. [Claim 2] The catalyst for synthesizing dimethyl ether according to claim 1, wherein (d) phosphorus precursor is contained in an amount of 0.01 to 0.2 parts by weight based on 1 part by weight of the hydrophobic zeolite. The catalyst for synthesizing dimethyl ether according to claim 1, wherein (a) the hydrophobic zeolite has a SiO ₂ / Al ₂ O ₃ molar ratio in the range of 20 to 300. The catalyst for dimethyl ether synthesis according to claim 1, wherein the (b) aluminum phosphate binder has a P / Al molar ratio in the range of 0.7 to 2. The method of claim 1, wherein (b) the aluminum phosphate binder, one, two or more inorganic binders selected from silica, kaolin, silica-alumina, zirconia, titania and alumina, based on 1 part by weight of the hydrophobic zeolite, Catalyst for synthesizing dimethyl ether, characterized in that contained in 0.01 to 1 part by weight. Adding water to the aluminum precursor and the phosphorus precursor to prepare an aluminum phosphate slurry; A step of preparing a molded product by mixing the aluminum phosphate slurry, hydrogen (H) or ammonium (NH ₄ ) type hydrophobic zeolite fine particles and deionized water, followed by drying and baking in a temperature range of 400 to 700 ° C .; And Three steps of mixing the molded product with a precursor of a metal cation selected from alkali metals and alkaline earth metals, drying, firing at a temperature range of 400 ~ 700 ℃ Method for producing a catalyst for dimethyl ether synthesis by dehydration of methanol, characterized in that consisting of. 7. The method of claim 6, wherein the hydrophobic zeolite fine particles used in the second step are hydrophobic zeolite fine particles impregnated with an aqueous solution of phosphoric acid or phosphate. The method of claim 6, wherein the molded article prepared in step 2 further comprises the step of impregnating an aqueous solution of phosphoric acid or phosphate, drying and firing at a temperature range of 400 ~ 700 ℃ to produce a phosphorus-impregnated molding. Method for producing a catalyst for dimethyl ether synthesis, characterized in that. The method of claim 7 or 8, wherein the aqueous solution of phosphoric acid or phosphate is prepared so that the phosphoric acid or phosphate is contained in a concentration of 0.01 to 0.2 parts by weight with respect to 1 part by weight of hydrophobic zeolite. Way. The catalyst for dimethyl ether synthesis according to claim 6, wherein the aluminum phosphate slurry further comprises a single inorganic binder selected from silica, kaolin, silica-alumina, zirconia, titania, and alumina, or two or more inorganic binders. Manufacturing method. The method for preparing a catalyst for synthesizing dimethyl ether according to claim 10, wherein the inorganic binder is added in an amount of 0.01 to 1 part by weight based on 1 part by weight of the hydrophobic zeolite. 7. The method of claim 6, wherein a single organic binder or two or more organic binders selected from methyl cellulose, polyvinyl alcohol, polyethylene glycol, and hydroxy methyl cellulose are additionally added to the first or second stage. Method for producing a catalyst for synthesizing dimethyl ether. The method for preparing a catalyst for synthesizing dimethyl ether according to claim 12, wherein the organic binder is added in an amount of 0.01 to 0.2 parts by weight based on 1 part by weight of the hydrophobic zeolite. Dehydration of methanol is carried out under the catalyst of any one of claims 1 to 5, wherein the dehydration of methanol is carried out at a reaction temperature of 150 to 350 ° C., a reaction pressure of 1 to 100 atmospheres, and a liquid hourly space velocity (LHSV) of 0.05 to 5. Method for producing dimethyl ether, characterized in that carried out under the conditions of 100 h ^-1 range. 15. The process for producing dimethyl ether according to claim 14, wherein the methanol contains 5 to 50 mol% water.