JP2016026864A - Catalyst for synthesis of ethyl acetate, device of producing ethyl acetate and method for producing ethyl acetate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for synthesis of ethyl acetate which makes it possible to produce ethyl acetate from a mixed gas of hydrogen and carbon monoxide.SOLUTION: A catalyst for synthesis of ethyl acetate is for synthesizing ethyl acetate from a mixed gas of hydrogen and carbon monoxide. The catalyst is a mixture of catalyst particles α comprising rhodium and catalyst particles β comprising copper. A volume ratio expressed by [particle group of the mixed catalyst particles β]/[ particle group of the mixed catalyst particles α] is preferably at least 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a catalyst for synthesizing ethyl acetate, an apparatus for producing ethyl acetate, and a method for producing ethyl acetate.

Ethyl acetate is used as a solvent for paints such as lacquer, as an extraction solvent in a laboratory, or as a developing solvent for chromatographic methods.
As a method for producing ethyl acetate, for example, a method in which ethylene and acetic acid are reacted in a gas-phase circulation using a metal salt solid catalyst has been proposed (for example, Patent Document 1). In addition, a method of reacting ethanol and acetic acid in the presence of a solid acidic catalyst has been proposed (for example, Patent Document 2).

Japanese Patent No. 3330404 Japanese Patent No. 4724341

By the way, in recent years, technology for producing bioethanol, for example, from woody and herbaceous biomass (also referred to as cellulosic biomass) such as waste wood and unused parts of crops such as rice straw that do not compete with food and feed has been developed. ing.
On the other hand, there is a method in which cellulosic biomass is converted into a mixed gas containing hydrogen and carbon monoxide, and then oxygenated products such as ethanol, acetaldehyde, and acetic acid are synthesized from the mixed gas. According to this method, not only woody and herbaceous biomass but also various biomass such as animal biomass derived from animal carcasses and feces, raw garbage, waste paper, and waste fiber can be used as a raw material. Furthermore, since a mixed gas of hydrogen and carbon monoxide can be obtained from resources other than petroleum such as natural gas and coal, a method of synthesizing ethanol and the like from the mixed gas has been studied as a technology to escape from dependence on petroleum. ing.
As for ethyl acetate, a technique capable of being produced from a mixed gas of hydrogen and carbon monoxide is required. In view of the above circumstances, an object of the present invention is to provide a catalyst for ethyl acetate synthesis that can produce ethyl acetate from a mixed gas of hydrogen and carbon monoxide.

The catalyst for synthesizing ethyl acetate of the present invention is a catalyst for synthesizing ethyl acetate from a mixed gas containing hydrogen and carbon monoxide, and contains catalyst particles α containing rhodium and copper. It is a mixture with catalyst particles β.
The volume ratio represented by [particle group of catalyst particles β to be mixed] / [particle group of catalyst particles α to be mixed] is preferably 1 or more.

  The ethyl acetate production apparatus of the present invention comprises a reaction tube filled with the catalyst for synthesizing ethyl acetate of the present invention, a supply means for supplying the mixed gas into the reaction tube, and a product from the reaction tube. And a discharging means for discharging.

The ethyl acetate production method of the present invention is characterized in that ethyl acetate is obtained by contacting a mixed gas containing hydrogen and carbon monoxide with the catalyst for synthesizing ethyl acetate of the present invention.
It is preferable to bring the mixed gas into contact with the catalyst for synthesizing ethyl acetate under conditions of a temperature of 260 to 280 ° C. and a pressure of 2 to 3 MPa.

  In this article, oxygenates include alcohols such as methanol, ethanol, and propanol, carboxylic acids such as acetic acid, aldehydes such as acetaldehyde, esters such as methyl formate, ethyl formate, methyl acetate, and ethyl acetate, carbon atoms, hydrogen atoms, and oxygen atoms. Means a molecule consisting of Among oxygenates, compounds having 2 carbon atoms (for example, acetic acid, ethanol, acetaldehyde, etc.) are referred to as C2 oxygenates.

  According to the catalyst for synthesizing ethyl acetate of the present invention, ethyl acetate can be produced from a mixed gas of hydrogen and carbon monoxide.

It is a schematic diagram of the manufacturing apparatus of ethyl acetate concerning one Embodiment of this invention.

(Catalyst for ethyl acetate synthesis)
The catalyst for synthesizing ethyl acetate of the present invention (hereinafter sometimes referred to as a synthesis catalyst) is a mixture of catalyst particles α containing rhodium and catalyst particles β containing copper. By using a mixture of the catalyst particles α and the catalyst particles β as a synthesis catalyst, ethyl acetate can be produced from a mixed gas containing hydrogen and carbon monoxide (hereinafter sometimes simply referred to as a mixed gas).

<Catalyst particles α>
The catalyst particles α contain rhodium. Rhodium is a hydrogenation active metal (the hydrogenation active metal used for the catalyst particles α is sometimes referred to as a hydrogenation active metal α). As the catalyst particles α, those having high CO conversion and high ethyl acetate production efficiency are preferable. By using such catalyst particles α, the production efficiency of ethyl acetate can be further improved.

In this paper, “CO conversion” is the percentage of the number of moles of CO consumed in the synthesis of oxygenates in the number of moles of CO in the mixed gas.
Further, “selectivity” is the percentage of the number of moles of CO consumed in the mixed gas occupied by the number of moles of C converted to a specific oxygenate. For example, according to the following formula (i), the selectivity for ethanol as an alcohol is 100 mol%. On the other hand, according to the following formula (ii), the selectivity for ethanol as a C2 oxygenate is 50 mol%, and the selectivity for acetaldehyde as a C2 oxygenate is also 50 mol%. In addition, in the formulas (i) and (ii), the selectivity for the C2 oxygenate is 100 mol%.

4H ₂ + 2CO → CH ₃ CH ₂ OH + H ₂ O (i)
7H ₂ + 4CO → C ₂ H ₅ OH + CH ₃ CHO + 2H ₂ O (ii)

The catalyst particles α may contain a hydrogenation active metal α other than rhodium. As the hydrogenation active metal α other than rhodium, any metal conventionally known as a metal capable of synthesizing oxygenates from a mixed gas may be used. For example, alkali metals such as lithium and sodium; Elements belonging to Group 7 of the periodic table; ruthenium, elements belonging to Group 8 of the periodic table; cobalt, elements belonging to Group 9 of the periodic table; nickel, palladium, elements belonging to Group 10 of the periodic table, etc. Can be mentioned.
Hydrogenation active metals α other than rhodium may be used singly or in combination of two or more. As hydrogenation active metals α other than rhodium, from the viewpoint of further increasing the CO conversion rate and further increasing the production efficiency of ethyl acetate, a combination of manganese and lithium, a combination of ruthenium, rhenium and sodium, an alkali, etc. A combination of a metal and another hydrogenation active metal α is preferred.

In addition to rhodium, the catalyst particles α may contain a promoter metal (the promoter metal used for the catalyst particle α may be referred to as promoter metal α).
Examples of the co-active metal α include one or more selected from titanium, vanadium, chromium, boron, magnesium, lanthanoids, and elements belonging to Group 13 of the periodic table. Among these, titanium, magnesium, and vanadium are preferable. Titanium is more preferable. When the catalyst particles α contain these co-active metals α, the CO conversion rate can be further increased and the production efficiency of ethyl acetate can be further increased.
Hereinafter, the hydrogenation active metal α and the auxiliary metal α may be collectively referred to as the catalyst metal α.

 As the catalyst particles α, for example, those containing rhodium, manganese and alkali metal are preferable, and those containing rhodium, manganese, alkali metal and promoter metal α are more preferable.

 The catalyst particles α may be an aggregate of the catalyst metal α or a supported catalyst in which the catalyst metal α is supported on a carrier, and among these, a supported catalyst is preferable. By using the supported catalyst, the contact efficiency between the catalytic metal α and the mixed gas is increased, and the CO conversion rate can be further increased.

As the carrier, a carrier conventionally used for a catalyst can be used. For example, a porous carrier is preferable.
The material of the porous carrier is not particularly limited, and examples thereof include silica, zirconia, titania, magnesia, alumina, activated carbon, zeolite, etc. Among them, various products having different specific surface areas and pore diameters can be procured on the market. Therefore, silica is preferable.

The size of the porous carrier is not particularly limited. For example, a porous carrier made of silica preferably has a particle size of 0.5 to 5000 μm. The particle size of the porous carrier is adjusted by sieving.
In addition, the porous carrier preferably has a narrowest particle size distribution.

The total pore volume (total pore volume) in the porous carrier is not particularly limited, but is preferably 0.01 to 1.0 mL / g, more preferably 0.1 to 0.8 mL / g, 0 More preferably, it is 3 to 0.7 mL / g. When the total pore volume is less than the above lower limit, the specific surface area of the porous carrier becomes too small, and when the catalyst metal α is supported, the dispersibility may be lowered, and the CO conversion rate may be lowered. If the total pore volume exceeds the above upper limit value, the pore diameter becomes too small and it becomes difficult to put the catalyst metal α into the support when the catalyst metal α is supported, and as a result, the surface area of the support is fully utilized. Otherwise, the mixed gas is difficult to diffuse, and as a result, the catalytic metal α and the mixed gas cannot be sufficiently contacted, and the CO conversion rate and the ethyl acetate production efficiency may be lowered.
The total pore volume is a value measured by a water titration method. The water titration method is a method in which water molecules are adsorbed on the surface of a porous carrier and the pore distribution is measured from the condensation of the molecules.

Although the average pore diameter of the porous carrier is not particularly limited, for example, 0.01 to 20 nm is preferable, and 0.1 to 8 nm is more preferable. If the average pore diameter is less than the above lower limit, it becomes difficult to put the catalyst metal α into the support when the catalyst metal α is supported. As a result, the surface area of the support cannot be fully utilized or the mixed gas diffuses. As a result, the catalytic metal α and the mixed gas cannot be sufficiently brought into contact with each other, and the CO conversion rate and the ethyl acetate production efficiency may be lowered. If the average pore diameter exceeds the above upper limit, the specific surface area of the support becomes too small, and when the catalyst metal α is supported, the dispersibility may be lowered, and the CO conversion rate may be lowered.
The average pore diameter is a value measured by the following method. When the average pore diameter is 0.1 nm or more and less than 10 nm, it is calculated from the total pore volume and the BET specific surface area. When the average pore diameter is 10 nm or more, it is measured by a mercury porosimetry porosimeter.
Here, the total pore volume is a value measured by a water titration method, and the BET specific surface area is a value calculated from the amount of adsorption and the pressure at that time using nitrogen as an adsorption gas.
In the mercury intrusion method, mercury is pressurized and pressed into the pores of the porous carrier, and the average pore diameter is calculated from the pressure and the amount of mercury inserted.

Although the specific surface area of a porous support | carrier is not specifically limited, For example, 1-1000 m < ² > / g is preferable, 300-800 m < ² > / g is more preferable, 400-700 m < ² > / g is more preferable. When the specific surface area is less than the above lower limit, the specific surface area of the support becomes too small, and when the catalyst metal α is supported, the dispersibility may be lowered, and the CO conversion rate may be lowered. If the specific surface area exceeds the above upper limit, the pore diameter becomes too small, and when the catalytic metal α is supported, it becomes difficult to put the catalytic metal α into the inside of the support, and as a result, the surface area of the support cannot be fully utilized. Or the mixed gas becomes difficult to diffuse, and as a result, the catalytic metal α and the mixed gas cannot be sufficiently contacted, and the CO conversion rate and the ethyl acetate production efficiency may be lowered.
The specific surface area is a BET specific surface area measured by a BET gas adsorption method using nitrogen as an adsorption gas.

  When the catalyst particle α is a supported catalyst, the average particle diameter of the particle group (catalyst particle group α) of the catalyst particle α is determined in consideration of the type of the carrier and the like, and is preferably 0.5 to 5000 μm, for example. If the average particle diameter of the catalyst particle group α is less than the lower limit, the pressure loss may increase and the mixed gas may not easily flow. There is a possibility that the contact efficiency between the catalyst particle α and the catalyst particle α is lowered. As the catalyst particles α, the catalyst particles having a small particle diameter are made into secondary particles by applying pressure in the presence of a binder, or the catalyst particles having a large particle diameter are pulverized to obtain an appropriate particle diameter. It may be adjusted to.

 The supported state of the catalyst metal α in the supported catalyst is not particularly limited. For example, a powdered metal may be supported on the porous carrier, or may be supported on the porous carrier in the form of a metal element. In particular, a state of being supported on a porous carrier in the form of a metal element is preferable. If it is in a state of being supported on the porous carrier in the form of a metal element, the contact area with the mixed gas is increased, and the CO conversion rate can be further increased.

 The supported amount of the hydrogenation active metal α in the supported catalyst is determined in consideration of the type of the hydrogenation active metal α, the type of the porous carrier, and the like. For example, if the porous carrier is silica, the porous carrier 100 0.05-30 mass parts is preferable with respect to mass parts, and 1-10 mass parts is more preferable. If the amount is less than the lower limit, the amount of the hydrogenation active metal α may be too small and the CO conversion rate may decrease. If the amount exceeds the upper limit, the hydrogenation active metal α cannot be uniformly and highly dispersed. There is a risk that the conversion rate decreases.

 The amount of the promoter metal α supported in the supported catalyst is determined in consideration of the type of promoter metal α, the type of hydrogenation active metal α, and the like. 20 mass parts is preferable and 0.1-10 mass parts is more preferable. If the amount is less than the lower limit, the amount of the auxiliary metal α supported is too small, and the effect of using the auxiliary metal α is hardly exhibited. If the value exceeds the upper limit, the surface of the porous carrier is excessively coated with the promoter metal α, and the CO conversion rate and ethyl acetate production efficiency may be reduced.

 The amount of the catalyst metal α supported is determined in consideration of the composition of the catalyst metal α, the material of the porous carrier, and the like. For example, 0.05 to 30 parts by mass with respect to 100 parts by mass of the porous carrier is preferable. 1-10 mass parts is more preferable. If the amount is less than the above lower limit value, the amount of catalyst metal α supported is too small and the CO conversion rate may be reduced. If the amount exceeds the upper limit value, the catalyst metal α cannot be uniformly and highly dispersed. The production efficiency of ethyl acetate may be reduced.

The catalyst particle α is a supported catalyst, and the catalyst containing rhodium, manganese, alkali metal, and promoter metal α is preferably a composition represented by the following formula (I).
aA ・ bB ・ cC ・ dD (I)
(I) In the formula, A represents rhodium, B represents manganese, C represents an alkali metal, D represents a promoter metal α, a, b, c, and d represent mole fractions, and a + b + c + d = 1.
In formula (I), a is preferably 0.053 to 0.98. If the amount is less than the above lower limit, the rhodium content is too small and the CO conversion rate may not be sufficiently increased. If the amount exceeds the upper limit, the content of other metals is too small. There is a possibility that the CO conversion rate cannot be sufficiently increased.
In the formula (I), b is preferably 0.0006 to 0.67. If the amount is less than the above lower limit, the content of manganese is too small and the CO conversion rate may not be sufficiently increased. If the amount exceeds the upper limit, the content of other metals is too small. There is a possibility that the CO conversion rate cannot be sufficiently increased.
In the formula (I), c is preferably 0.00056 to 0.51. If it is less than the above lower limit value, the alkali metal content is too small and the CO conversion rate may not be sufficiently increased, and if it exceeds the above upper limit value, the content of other metals becomes too small. The CO conversion rate may not be sufficiently increased.
In the formula (I), d is preferably 0.0026 to 0.94. If the amount is less than the above lower limit value, the content of the co-active metal α may be too small and the CO conversion rate may not be sufficiently increased. If the amount exceeds the upper limit value, the content of other metals decreases. Therefore, the CO conversion rate may not be sufficiently increased.

In the synthesis catalyst, the content of the catalyst particle α is determined in consideration of the ability of the catalyst particle α and the like, and is appropriately determined in the range of 9 to 91% by mass, for example.
The type of catalyst particles α in the synthesis catalyst may be one type or two or more types.

The catalyst particles α are produced according to a conventionally known method for producing a metal catalyst. Examples of the method for producing the catalyst particles α include an impregnation method, an immersion method, an ion exchange method, a coprecipitation method, a kneading method, and the like. Among these, the impregnation method is preferable. By using the impregnation method, the catalyst obtained is more uniformly dispersed in the catalyst metal α, the contact efficiency with the mixed gas is further increased, and the CO conversion rate is further increased.
The raw material compound of the catalyst metal α used for the catalyst production includes inorganic salts such as oxides, chlorides, nitrates and carbonates, organic salts such as oxalates, acetylacetonate salts, dimethylglyoxime salts, and ethylenediamineacetate salts. Or what is normally used when manufacturing a metal catalyst, such as a chelate compound, a carbonyl compound, a cyclopentadienyl compound, an ammine complex, an alkoxide compound, an alkyl compound, is mentioned.

An example of a method for producing the catalyst particles α by the impregnation method will be described. First, a raw material compound of catalytic metal α containing rhodium is dissolved in a solvent such as water, methanol, ethanol, tetrahydrofuran, dioxane, hexane, benzene, toluene, and the carrier is immersed in the obtained solution (impregnation solution). The impregnating liquid is adhered to the carrier. When a porous material is used as the carrier, the impregnating solution is sufficiently permeated into the pores of the carrier, and then the solvent is evaporated to form a catalyst.
As a method of impregnating the carrier with the impregnating solution, a method in which a solution in which all raw material compounds are dissolved is impregnated in the carrier (simultaneous method), a solution in which each raw material compound is separately dissolved is prepared, and each solution is sequentially added to the carrier. And the like (sequential method) and the like. Among these, the sequential method is preferable. The catalyst obtained by the sequential process can further increase the CO conversion and the ethyl acetate production efficiency.

  As a sequential method, for example, a primary support in which a porous carrier is impregnated with a solution (primary impregnation liquid) containing an auxiliary metal α (primary impregnation step) and dried to support the auxiliary metal α on the porous carrier. A method of obtaining a support (primary support process), then impregnating the primary support with a solution containing a hydrogenation active metal α (secondary impregnation liquid) (secondary impregnation process) and drying it (secondary support process) Is mentioned. In this way, by supporting the auxiliary active metal α on the porous carrier and then supporting the hydrogenation active metal α on the porous carrier, the catalyst particles α are those in which the catalytic metal α is more highly dispersed, The CO conversion rate can be further increased, and the production efficiency of ethyl acetate can be further increased.

Examples of the primary supporting step include a method of drying a porous carrier impregnated with the primary impregnating liquid (primary drying operation), and heating and firing it at an arbitrary temperature (primary baking operation).
The drying method in the primary drying operation is not particularly limited, and examples thereof include a method of heating the porous carrier impregnated with the primary impregnation liquid at an arbitrary temperature. The heating temperature in primary drying operation should just be the temperature which can evaporate the solvent of a primary impregnation liquid, and will be 80-120 degreeC, if a solvent is water. The heating temperature in the primary firing operation is, for example, 300 to 600 ° C. By performing the primary firing operation, components that do not contribute to the catalytic reaction among the components contained in the raw material compound of the auxiliary active metal α are sufficiently volatilized, and the catalytic activity can be further enhanced.

Examples of the secondary supporting step include a method of drying the primary support impregnated with the secondary impregnating liquid (secondary drying operation), and further heating and baking at an arbitrary temperature (secondary baking operation).
The drying method in the secondary drying operation is not particularly limited, and examples thereof include a method of heating the primary carrier impregnated with the secondary impregnation liquid at an arbitrary temperature. The heating temperature in secondary drying operation should just be the temperature which can evaporate the solvent of a secondary impregnation liquid, and will be 80-120 degreeC, if a solvent is water. The heating temperature in the secondary firing operation is, for example, 300 to 600 ° C. By performing the secondary firing operation, components that do not contribute to the catalytic reaction among the components contained in the raw material compound of the hydrogenation active metal α are sufficiently volatilized, and the catalytic activity can be further enhanced.

The obtained catalyst particles α are subjected to a reduction treatment and activated.
As a method for the reduction treatment, a method in which a reducing gas is brought into contact with the catalyst particles α at 200 to 600 ° C. is preferable.
For example, the heating time in the reduction treatment is preferably 1 to 10 hours, and more preferably 2 to 5 hours.

<Catalyst particles β>
The catalyst particles β contain copper.
The catalyst particles β may contain a metal other than copper. As metals other than copper, those which convert aldehydes and carboxylic acids into ethanol and / or ethyl acetate are preferable, for example, iron, rhodium-iron, rhodium-molybdenum, palladium, palladium-iron, palladium-molybdenum, iridium-iron. Rhodium-iridium-iron, iridium-molybdenum, rhenium-zinc, platinum, nickel, cobalt, ruthenium, rhodium oxide, palladium oxide, platinum oxide, ruthenium oxide and the like. Hereinafter, the copper contained in the catalyst particles β and the other metals may be collectively referred to as catalyst metal β.
Among them, as the catalytic metal β, copper alone or a combination of copper and a transition metal other than copper (in this paper, the transition metal includes an element belonging to Group 12) is preferable, and copper, copper-zinc, copper-chromium or copper -Zinc-chromium is preferred.
The catalyst particles β are preferably those that can convert not only aldehydes and carboxylic acids but also esters other than ethyl acetate into ethanol and / or ethyl acetate.
By using such catalyst particles β, by-products such as aldehyde and carboxylic acid are reduced, the process of isolating ethyl acetate is simplified, and the production efficiency can be further improved.

The catalyst particles β may be aggregates of catalyst metals β, or may be supported catalysts in which the catalyst metal β is supported on a carrier, and among these, supported catalysts are preferable. By using a supported catalyst, aldehyde and carboxylic acid can be more efficiently converted to ethanol and / or ethyl acetate.
The catalyst particle β carrier is the same as the catalyst particle α carrier.

 The supported amount of the catalyst metal β in the supported catalyst is determined in consideration of the type of the catalyst metal β and the like, for example, 1 to 50 parts by weight is preferable with respect to 100 parts by weight of the porous carrier, and 3 to 25 parts by weight More preferably, 4-20 mass parts is further more preferable, and 5-15 mass parts is especially preferable. If the amount is less than the above lower limit value, the amount of catalyst metal β supported is too small and the activity may be reduced. If the amount exceeds the upper limit value, the surface of the porous carrier is excessively coated with the catalyst metal β, and the activity is low. May decrease.

As the catalyst particles β, copper alone or a catalyst in which copper and a transition metal other than copper are supported on a carrier (hereinafter sometimes referred to as a copper-based supported catalyst) is preferable.
As the copper-based supported catalyst, those represented by the following formula (II) are preferable.
eE · fF ··· (II)
(II) In the formula, E represents copper, F represents a transition metal other than copper, e and f represent molar fractions, and e + f = 1.
(II) In the formula, F is preferably zinc or chromium. F may be used individually by 1 type and may be used in combination of 2 or more type.
In formula (II), e is preferably 0.5 to 0.9. If it is less than the above lower limit value, the copper content is too small, and the efficiency of converting aldehydes and carboxylic acids to ethanol and / or ethyl acetate may be reduced. If the amount is too small, the efficiency of converting esters other than aldehyde, carboxylic acid, and ethyl acetate into ethanol and / or ethyl acetate may be reduced.
(II) f in the formula is preferably 0.1 to 0.5. If it is less than the above lower limit, the content of F is too small, and the efficiency of converting esters other than aldehyde, carboxylic acid, and ethyl acetate into ethanol and / or ethyl acetate may be reduced. When it exists, there exists a possibility that the content of copper may decrease too much and the efficiency which converts an aldehyde and carboxylic acid into ethanol and / or ethyl acetate may fall.

  As a suitable combination of the catalyst particle α and the catalyst particle β in the present invention, a combination of the catalyst particle α containing rhodium and not containing copper and the catalyst particle β containing copper and not containing rhodium is preferable.

The average particle diameter of the particle group (catalyst particle group β) of the catalyst particles β is the same as the average particle diameter of the catalyst particle group α.
The average particle diameter of the catalyst particle group β may be the same as or different from the average particle diameter of the catalyst particle group α. However, from the viewpoint of preventing the catalyst particles α and the catalyst particles β from being classified, the ratio represented by [average particle diameter of the catalyst particle group α] / [average particle diameter of the catalyst particle group β] is 0. 5 to 2 is preferable.
The specific gravity of the catalyst particles β and the specific gravity of the catalyst particles α may be the same or different. However, from the viewpoint of preventing separation of the catalyst particles α and the catalyst particles β, the ratio represented by [specific gravity of the catalyst particles α] / [specific gravity of the catalyst particles β] is preferably 0.5 to 2.

In the synthetic catalyst, the content of the catalyst particles β is determined in consideration of the ability of the catalyst particles β and the like, for example, appropriately determined in the range of 9 to 91% by mass.
The type of catalyst particles β in the synthesis catalyst may be one type or two or more types.

  The mass ratio represented by catalyst particle β / catalyst particle α (hereinafter referred to as β / α mass ratio) is, for example, preferably 1 or more, more preferably more than 1, more preferably more than 1 or less, and more preferably 2.5 to 5 Is particularly preferred. If the β / α mass ratio is less than the above lower limit value, the CO conversion rate may be lowered at an early stage, or the aldehyde or carboxylic acid content may increase and the cost may be increased for separating them. If the value exceeds the upper limit, the production amount of ethyl acetate per unit mass of the synthesis catalyst is decreased, and the production efficiency may be reduced.

The volume ratio represented by [volume of catalyst particle group β to be mixed] / [volume of catalyst particle group α to be mixed] (hereinafter, β / α volume ratio) is, for example, preferably 1 or more and more than 1 More preferably, more than 1 and less than 6 is more preferable, and 2 to 5 is particularly preferable. If the β / α volume ratio is less than the above lower limit value, the CO conversion rate may decrease at an early stage, or the aldehyde or carboxylic acid content may increase and the cost may increase due to separation of these. If the value exceeds the upper limit, the production amount of ethyl acetate per unit mass of the synthesis catalyst is decreased, and the production efficiency may be reduced.
[Volume of catalyst particle group β to be mixed] and [Volume of catalyst particle group α to be mixed] are apparent volumes before mixing.

Examples of the method for producing the catalyst particles β include the same method as the method for producing the catalyst particles α.
The obtained catalyst particles β are subjected to a reduction treatment and activated.
As a method for the reduction treatment, a method in which a reducing gas is brought into contact with the catalyst particles β at 200 to 600 ° C. is preferable.
For example, the heating time in the reduction treatment is preferably 1 to 10 hours, and more preferably 2 to 5 hours.

<Other catalyst particles>
The synthetic catalyst may include catalyst particles other than the catalyst particles α and the catalyst particles β. However, from the viewpoint of controlling a secondary reaction and preventing a decrease in production efficiency of ethyl acetate, the synthetic catalyst is substantially The catalyst particles α and the catalyst particles β are preferably included. “Substantially consisting of catalyst particles α and catalyst particles β” means that the catalyst particles α and the catalyst particles α and the catalyst particles β are not included at all or do not affect the effect of the present invention. It means that catalyst particles other than the catalyst particle β are included.

  The method for producing a synthetic catalyst is to mix catalyst particles α and catalyst particles β. The mixing method of the catalyst particles α and the catalyst particles β is not particularly limited, and examples thereof include a method of mixing the catalyst particle group α and the catalyst particle group β with a powder mixing device or the like.

(Ethyl acetate production equipment)
The ethyl acetate production apparatus of the present invention (hereinafter sometimes simply referred to as production apparatus) includes a reaction tube filled with a synthesis catalyst, a supply means for supplying a mixed gas into the reaction tube, and a product discharged from the reaction tube. And a discharging means.

  An example of the manufacturing apparatus of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing a manufacturing apparatus 10 according to an embodiment of the present invention. The production apparatus 10 includes a reaction tube 1 filled with a synthesis catalyst to form a reaction bed 2, a supply tube 3 connected to the reaction tube 1, a discharge tube 4 connected to the reaction tube 1, and a reaction tube 1. And a pressure control unit 6 provided in the discharge pipe 4.

The reaction bed 2 may be filled with only the synthesis catalyst, or may be filled with the synthesis catalyst and the diluent. The diluent is for preventing excessive heat generation of the synthetic catalyst during the production of ethyl acetate, and examples thereof include the same carriers as those used for the catalyst particles α, quartz sand, alumina balls, and the like.
When the reaction bed 2 is filled with a diluent, the mass ratio represented by the diluent / synthetic catalyst is determined in consideration of the type and specific gravity, and is preferably 0.5 to 5, for example.
However, in the present invention, since the catalyst particle β plays a role as a diluent with respect to the catalyst particle α, it is preferable that the reaction bed 2 is filled with only the synthetic catalyst. If no diluent is used, the production amount of ethyl acetate per unit volume of the reaction bed 2 can be increased, and the production apparatus 10 can be made compact.

The reaction tube 1 is preferably made of a material that is inert to the mixed gas and the synthesized oxygenate, and preferably has a shape capable of withstanding heating at about 100 to 500 ° C. or pressurization at about 10 MPa. An example of the reaction tube 1 is a substantially cylindrical member made of stainless steel.
The supply pipe 3 is a supply means for supplying the mixed gas into the reaction tube 1 and includes, for example, a pipe made of stainless steel or the like.
The discharge pipe 4 is a discharge means for discharging the synthesis gas (product) containing ethyl acetate synthesized in the reaction bed 2 and includes, for example, a pipe made of stainless steel or the like.
The temperature control part 5 should just be what can make the reaction bed 2 in the reaction tube 1 arbitrary temperature, for example, an electric furnace etc. are mentioned.
The pressure control part 6 should just be what can make the pressure in the reaction tube 1 arbitrary pressure, for example, a well-known pressure valve etc. are mentioned.
The manufacturing apparatus 10 may include a known device such as a gas flow rate control unit that adjusts a gas flow rate such as mass flow.

(Method for producing ethyl acetate)
In the method for producing ethyl acetate of the present invention, a mixed gas is brought into contact with a synthesis catalyst. An example of the manufacturing method of ethyl acetate of this invention is demonstrated using the manufacturing apparatus of FIG.
First, the inside of the reaction tube 1 is set to an arbitrary temperature and an arbitrary pressure, and the mixed gas 20 is caused to flow into the reaction tube 1 from the supply tube 3.

The mixed gas 20 is not particularly limited as long as it contains hydrogen and carbon monoxide. For example, the mixed gas 20 may be prepared from natural gas or coal, biomass gas obtained by gasifying biomass, or the like. It may also be one obtained by gasifying organic waste such as waste plastic, waste paper, and waste clothing (hereinafter sometimes referred to as recycle gas). Biomass gas and recycle gas are obtained by a conventionally known method, for example, heating pulverized biomass or organic waste in the presence of water vapor (for example, 800 to 1000 ° C.).
When biomass gas or recycle gas is used as the mixed gas 20, before supplying the mixed gas 20 into the reaction tube 1, for the purpose of removing impurities such as tar, sulfur, nitrogen, chlorine and moisture, The mixed gas 20 may be subjected to gas purification treatment. As the gas purification treatment, for example, various methods known in the technical field such as a wet method and a dry method can be adopted. Examples of wet methods include sodium hydroxide method, ammonia absorption method, lime / gypsum method, magnesium hydroxide method, and dry methods include activated carbon adsorption method such as pressure swing adsorption (PSA) method, electron beam method, etc. Is mentioned.

The mixed gas 20 is mainly composed of hydrogen and carbon monoxide, that is, the total of hydrogen and carbon monoxide in the mixed gas 20 is preferably 50% by volume or more, and 80% by volume or more. More preferably, it is more preferable that it is 90 volume% or more, and 100 volume% may be sufficient. The greater the content of hydrogen and carbon monoxide, the higher the production efficiency of ethyl acetate.
The volume ratio represented by hydrogen / carbon monoxide in the mixed gas 20 (hereinafter sometimes referred to as H ₂ / CO ratio) is preferably 1/5 to 5/1, and more preferably 1/2 to 3/1. 1/1 to 2.5 / 1 is more preferable. If it is in the said range, it will become a stoichiometrically appropriate range by reaction by which the oxygenated product in a catalytic reaction is produced | generated, and the further improvement of the production efficiency of ethyl acetate can be aimed at.
The mixed gas 20 may contain methane, ethane, ethylene, nitrogen, carbon dioxide, water, etc. in addition to hydrogen and carbon monoxide.

 The temperature (reaction temperature) for bringing the mixed gas 20 and the catalyst into contact, that is, the temperature in the reaction tube 1 is preferably, for example, 260 to 280 ° C. If it is more than the said lower limit, the speed | rate of a catalytic reaction can fully be raised and ethyl acetate can be manufactured more efficiently. If it is below the upper limit, the ethyl acetate synthesis reaction can be used as the main reaction to further improve the ethyl acetate production efficiency.

 The pressure (reaction pressure) when bringing the mixed gas 20 and the catalyst into contact, that is, the pressure in the reaction tube 1 is preferably, for example, 2 to 3 MPa. If it is more than the said lower limit, the speed | rate of a catalytic reaction can fully be raised and ethyl acetate can be manufactured more efficiently. If it is below the upper limit, the ethyl acetate synthesis reaction can be used as the main reaction to further improve the ethyl acetate production efficiency.

  The inflowing mixed gas 20 comes into contact with the catalyst particles α in the reaction bed 2, and, for example, a part thereof is ethyl acetate, aldehyde, or carboxylic acid by a catalytic reaction represented by the following formulas (1) to (4). It becomes an oxygenate containing by-products such as alcohol. Among the by-products, aldehydes such as acetaldehyde are quickly converted to alcohol by the catalyst particles β (formula (5) below), and the reaction of formula (4) (formation of ethyl acetate) is promoted.

2H ₂ + 2CO → CH ₃ COOH (1)
3H ₂ + 2CO → CH ₃ CHO + H ₂ O (2)
4H ₂ + 2CO → CH ₃ CH ₂ OH + H ₂ O (3)
CH ₃ COOH + CH ₃ CH ₂ OH → CH ₃ COOCH ₂ CH ₃ + H ₂ O (4)
H ₂ + CH ₃ CHO → CH ₃ CH ₂ OH (5)

Then, the synthesis gas 22 containing ethyl acetate is discharged from the discharge pipe 4. The synthesis gas 22 is not particularly limited as long as it contains ethyl acetate. For example, the synthesis gas 22 may contain oxygenated substances other than ethyl acetate, hydrocarbons such as methane, and the like.
In the synthesis gas 22, the selectivity for ethyl acetate is preferably 10 mol% or more, and more preferably 15 mol% or more. If the selectivity of ethyl acetate is not less than the above lower limit, the process of removing compounds other than ethyl acetate can be simplified.

  As for the supply speed of the mixed gas 20, for example, the space velocity of the mixed gas in the reaction bed 2 (a value obtained by dividing the supply amount of gas per unit time by the total amount of catalyst (in terms of volume)) is preferably 10 To 50,000 L / L-catalyst / h, more preferably 100 to 10000 L / L-catalyst / h, still more preferably 500 to 5000 L / L-catalyst / h, and particularly preferably 500 to 1200 L / L-catalyst / h. Is done. The space velocity is appropriately adjusted in consideration of the reaction pressure, the reaction temperature, and the composition of the mixed gas that is a raw material.

 If necessary, the synthesis gas 22 discharged from the discharge pipe 4 may be treated with a gas-liquid separator or the like to separate ethyl acetate from the unreacted mixed gas 20 and by-products.

  In the present embodiment, the mixed gas is brought into contact with the reaction bed 2 of the fixed bed. However, for example, the synthesis catalyst may be in a form other than the fixed bed, such as a fluidized bed or a moving bed, and the mixed gas may be brought into contact therewith. .

  In the present invention, by-products in the synthesis gas 22 may be separated for each component by distillation or the like. Ethyl acetate may be synthesized based on a conventional method using the separated ethanol and acetic acid.

  Since the synthesis catalyst of the present invention is a mixture of catalyst particles α containing rhodium and catalyst particles β containing copper, by using this, a mixed gas containing hydrogen and carbon monoxide is used to produce ethyl acetate. Can be manufactured.

 EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

(Production Example 1) Production of Catalyst Particles α 61 mL of an aqueous solution containing 1.23 g of titanium lactate ammonium salt (Ti (OH) ₂ [OCH (CH ₃ ) COO ⁻ ] ₂ (NH ₄ ⁺ ) ₂ ) It was dropped and impregnated on 100 g of 2 mm spherical silica gel (specific surface area: 430 m ² / g, average pore diameter: 5.7 nm, total pore volume: 0.61 mL / g). This was dried at 110 ° C. for 3 hours and further calcined at 450 ° C. for 3 hours to obtain a primary support. 7.68 g of rhodium chloride trihydrate (RhCl ₃ .3H ₂ O), 0.48 g of lithium chloride monohydrate (LiCl · H ₂ O), manganese chloride tetrahydrate (MnCl ₂ .4H ₂ O) ) 61 mL of an aqueous solution containing 4.33 g was dropped onto the primary support, impregnated, dried at 110 ° C. for 3 hours, and further calcined at 400 ° C. for 3 hours to obtain catalyst particles α. The obtained catalyst particle α contains rhodium, manganese, lithium and titanium as the catalyst metal α, and the rhodium loading rate = 3 mass% / SiO ₂ , Rh: Mn: Li: Ti = 1.00: 0.750: It was 0.275: 0.143 (molar ratio).

(Production Example 2) Production of catalyst particles β Copper nitrate trihydrate (Cu (NO ₃ ) ₂ .3H ₂ O) 19.0 g and zinc nitrate hexahydrate (Zn (NO ₃ ) ₃ .6H ₂ O ) 95 mL of an aqueous solution containing 22.7 g was added dropwise to 100 g of spherical silica gel having a particle size of 1 to 2 mm (specific surface area: 315 m ² / g, average pore diameter: 10 nm, total pore volume: 0.95 mL / g). And impregnated. This was dried at 110 ° C. for 3 hours and further calcined at 400 ° C. for 3 hours to obtain catalyst particles β. The obtained catalyst particles β contained copper and zinc as the catalyst metal β, and had a copper loading ratio = 5 mass% / SiO ₂ and Cu: Zn = 1.00: 0.97 (molar ratio).

(Test Example 1)
6.4 g of the catalyst particles α obtained in Production Example 1 and 13.5 g of the catalyst particles β obtained in Production Example 2 were mixed to produce a synthetic catalyst ([particle group of catalyst particles β to be mixed] / The volume ratio represented by [particle group of the catalyst particles α to be mixed] was 3). This was filled into a stainless steel cylindrical reaction tube having an inner diameter of 10.2 mm and a length of 108 cm to form a reaction bed, and an ethyl acetate production apparatus similar to the ethyl acetate production apparatus 10 of FIG. 1 was obtained.
While reducing gas (hydrogen concentration 30% by volume, nitrogen concentration 70% by volume) was passed through the reaction bed at 750 L / L-catalyst / h at normal pressure, it was heated at 320 ° C. for 2 hours to reduce the catalyst. .
Next, ethyl acetate was produced by the following procedure.
After the reaction bed temperature is lowered to 240 ° C., a mixed gas (hydrogen concentration 60 vol%, carbon monoxide concentration 30 vol%, nitrogen concentration 10 vol%) is circulated at a space velocity of 1500 L / L-catalyst / h, and the reaction pressure Was increased to 2.0 MPa. Thereafter, the reaction temperature was raised to 268 ° C. at a rate of 1 ° C./1 minute, and the time when the temperature was stabilized was regarded as the reaction start time. Two hours after the start of the reaction, the synthesis gas was recovered and analyzed by gas chromatography. From the obtained data, the CO conversion rate (mol%) and the product selectivity (mol%) were calculated. These results are shown in Table 1.

(Test Examples 2 to 6)
Except that the reaction pressure and reaction temperature were changed to the values shown in Table 1, respectively, ethyl acetate was produced in the same manner as in Test Example 1, and the CO conversion rate and the product selectivity were determined. It is shown in 1.

(Test Example 7)
19.3 g of the catalyst particles α obtained in Production Example 1 and 40.7 g of the catalyst particles β obtained in Production Example 2 were mixed to produce a synthetic catalyst ([particle group of the catalyst particles β to be mixed] / The volume ratio represented by [particle group of the catalyst particles α to be mixed] was 3). This was filled into a stainless steel cylindrical reaction tube having an inner diameter of 16.55 mm and a length of 103 cm to form a reaction bed, and an ethyl acetate production apparatus similar to the ethyl acetate production apparatus 10 of FIG. 1 was obtained.
While reducing gas (hydrogen concentration 30 vol%, nitrogen concentration 70 vol%) was passed through the reaction bed at 350 L / L-catalyst / h at normal pressure, it was heated at 295 ° C. for 2 hours to reduce the catalyst. .
Next, ethyl acetate was produced by the following procedure.
After the reaction bed temperature is lowered to 240 ° C., a mixed gas (hydrogen concentration 60 vol%, carbon monoxide concentration 30 vol%, nitrogen concentration 10 vol%) is circulated at a space velocity of 700 L / L-catalyst / h, and the reaction pressure Was increased to 2.0 MPa. Thereafter, the reaction temperature was raised to 261 ° C. at a rate of 1 ° C./1 minute, and the time when the temperature was stabilized was regarded as the reaction start time. Two hours after the start of the reaction, the synthesis gas was recovered and analyzed by gas chromatography. From the obtained data, the CO conversion rate (mol%) and the product selectivity (mol%) were calculated. These results are shown in Table 1.

As shown in Table 1, in Test Examples 1 to 7, the ethyl acetate selectivity was 5.1 to 50.7 mol%. From this result, it was found that by applying the present invention, ethyl acetate can be synthesized from a mixed gas containing hydrogen and carbon monoxide.
In comparison between Test Examples 1 to 7, Test Examples 1 to 4 having a reaction temperature of 260 to 280 ° C. and a reaction pressure of 2 to 3 MPa have a reaction temperature of 260 to 280 ° C. and a reaction pressure of 1 MPa. Compared with Test Examples 5-6, the selectivity of ethyl acetate was high. From this result, it was found that the production efficiency of ethyl acetate can be further increased by setting the reaction temperature to 260 to 280 ° C. and the reaction pressure to 2 to 3 MPa.
Furthermore, in Test Example 7 in which the reaction gas flow rate was a space velocity of 700 L / L-catalyst / h, the ethyl acetate selectivity was more than 50 mol%. From this result, it was found that the selectivity of ethyl acetate becomes very high by adjusting the flow rate of the reaction gas.

DESCRIPTION OF SYMBOLS 1 Reaction tube 2 Reaction bed 3 Supply tube 4 Discharge tube 5 Temperature control part 6 Pressure control part 10 Manufacturing apparatus 20 Mixed gas 22 Syngas

Claims (5)

A catalyst for ethyl acetate synthesis that synthesizes ethyl acetate from a mixed gas containing hydrogen and carbon monoxide,
A catalyst for synthesizing ethyl acetate, which is a mixture of catalyst particles α containing rhodium and catalyst particles β containing copper.   2. The ethyl acetate according to claim 1, wherein a volume ratio represented by [particle group of catalyst particles β to be mixed] / [particle group of catalyst particles α to be mixed] is 1 or more. Catalyst for synthesis.   A reaction tube filled with the catalyst for synthesizing ethyl acetate according to claim 1, a supply unit that supplies the mixed gas into the reaction tube, and a discharge unit that discharges a product from the reaction tube. An ethyl acetate production apparatus characterized by the above.   A method for producing ethyl acetate, wherein the catalyst for synthesizing ethyl acetate according to claim 1 or 2 is brought into contact with a mixed gas containing hydrogen and carbon monoxide to obtain ethyl acetate.   5. The method for producing ethyl acetate according to claim 4, wherein the mixed gas is brought into contact with the catalyst for synthesizing ethyl acetate under the conditions of a temperature of 260 to 280 ° C. and a pressure of 2 to 3 MPa.

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