WO2021066410A1 - Catalyst for ammoxidation of propylene, method for preparing same, and method for ammoxidation of propylene using same - Google Patents

Abstract

The present invention relates to a catalyst for ammoxidation of propylene, a method for preparing same, and a method for ammoxidation of propylene using same. Specifically, provided in one embodiment of the present invention is a catalyst having a structure in which a metal oxide is impregnated in a silica carrier, and having a narrow particle size distribution and excellent abrasion resistance.

Description

Catalyst for ammoxidation of propylene, production method thereof, and ammoxidation method of propylene using the same

Cross-reference with related application(s)

This application is for Korean Patent Application No. 10-2019-0121172 filed on September 30, 2019, Korean Patent Application No. 10-2019-0134089 filed on October 25, 2019, and Korean Patent Application No. 10-2020 filed on September 24, 2020. It claims the benefit of the priority based on No. -0123874, and all contents disclosed in the literature of the Korean patent application are included as part of this specification.

The present invention relates to a catalyst for ammoxidation of propylene, a method for preparing the same, and a method for ammoxidation of propylene using the same.

The ammoxidation process of propylene is based on a reduction reaction of reacting ammonia and propylene and a mechanism of reoxidation by oxygen, the conversion rate of the reactant (i.e., propylene), and the selectivity of the reaction product (i.e., acrylonitrile). And catalysts of various compositions to increase the yield have been studied.

Specifically, since the Mo (molybdenum)-Bi (bismuth) oxide catalyst was presented, catalysts to which metals having various oxidation states were added have been studied in order to increase the catalytic activity and stability. As a result, depending on the type or amount of metal added, the yield of acrylonitrile is improved compared to the initial study.

However, despite the diversification of the catalyst composition, studies on its structure and physical properties were insufficient, and thus the conversion rate of the reactant (i.e., propylene) and the selectivity of the reaction product (i.e., acrylonitrile) were remarkable during the ammoxidation of propylene. There was a limit to the height of it.

Specifically, it is common to obtain a catalyst having a secondary particle structure in which metal oxide particles and silica particles are aggregated by co-precipitation of a metal precursor having a desired composition and a nano silica sol, followed by spray drying and firing.

According to this, secondary particles having a wide particle size distribution are obtained, and thus a classification process is required as a post-treatment. Moreover, the catalyst having the secondary particle structure is vulnerable to friction, and may be deteriorated or damaged during the ammoxidation reaction of propylene in the fluidized bed reactor, and there is a disadvantage in that the catalyst must be continuously supplied.

The present invention provides a catalyst for ammoxidation of propylene having a uniform particle size distribution while being able to participate in the reaction as well as the outer surface portion (i.e., the surface of the catalyst) and the inner surface (pores) thereof. To prepare acrylonitrile in higher yield.

Specifically, in one embodiment of the present invention, a catalyst for ammoxidation of propylene having a structure in which a metal oxide of a specific composition is supported on a silica carrier and having a uniform particle size distribution in the supported state is provided.

The catalyst of one embodiment may exhibit high catalytic efficiency and reactivity due to a large effective surface area capable of participating in the reaction, and may exhibit a small fine powder content and a uniform particle size distribution without a classification process.

Therefore, by using the catalyst of one embodiment, it is possible to prepare acrylonitrile with higher selectivity and yield while converting propylene at a higher ratio.

1 schematically shows a catalyst prepared using coprecipitation and spray drying.

2 schematically shows a catalyst according to the embodiment.

In the present invention, various transformations can be applied and various embodiments may be provided, and specific embodiments will be illustrated and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, terms including ordinal numbers such as first and second to be used hereinafter may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Hereinafter, "particle diameter Dv" means a particle diameter at the v% point of the cumulative volume distribution according to the particle diameter. That is, D50 is the particle diameter at 50% of the cumulative volume distribution according to the particle diameter, D90 is the particle diameter at 90% of the cumulative volume distribution according to the particle diameter, and D10 is at 10% of the cumulative volume distribution according to the particle diameter. It is the particle size.

Hereinafter, a catalyst for ammoxidation of propylene according to the embodiment will be described in detail with reference to the drawings.

Catalyst for ammoxidation of propylene

In one embodiment of the present invention, a metal oxide represented by the following Formula 1 is supported on a silica carrier; In a state in which the metal oxide is supported on a silica carrier, a D50 particle diameter of 30 to 300 μm, and a D10 particle diameter, a D50 particle diameter, and a D90 particle diameter satisfying the relationship of the following formula 1, provides a catalyst for ammoxidation of propylene. :

[Equation 1]

[Formula 1]

In Formula 1,

A is one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba,

B is one or more elements of Li, Na, K, Rb, and Cs,

C is one or more elements of Cr, W, B, Al, Ca, and V, and

Wherein a to e, and x are the fractions of atoms or groups, respectively, a is 0.1 to 5, b is 0.1 to 5, c is 0.01 to 10, d is 0.01 to 2, and e is 0 to 10 , x is 24 to 48.

A generally known catalyst for ammoxidation of propylene is prepared through coprecipitation and spray drying, and is provided in a secondary particle structure in which metal oxide nanoparticles and silica nanoparticles are aggregated (FIG. 1).

This is because, instead of evenly distributed inside and outside of the metal oxide particles, a portion that can participate in the ammoxidation reaction of propylene is limited to the outer surface portion (i.e., the surface of the secondary particles), and provides a small surface area. The amount of ammonia desorbed from the catalyst surface during ammoxidation reaction is large.

On the other hand, the catalyst of the embodiment may be prepared by an impregnation method, and thus may be provided in a structure in which a metal oxide is supported on a silica carrier (FIG. 2).

For example, a silica carrier may be immersed in a metal precursor solution prepared to satisfy a stoichiometric molar ratio of a desired metal oxide, and the metal precursor solution may be impregnated in the silica carrier.

Thereafter, when the solvent (i.e., water) is removed through the drying process, the metal precursor remains on the pore walls of the silica carrier, and the metal precursor is oxidized in the firing process to form a film that continuously coats the pore walls of the silica carrier. have.

The catalyst of one embodiment thus prepared may have less fine powder content and superior durability than a catalyst prepared with the same composition through co-precipitation and spray drying, even if the classification process is not performed as a post-treatment after manufacture.

In addition, the catalyst of one embodiment is a catalyst by controlling the metal oxide composition to further include not only Mo and Bi known to increase the activity of the ammoxidation reaction, but also a metal forming an active point of an appropriate level for the ammoxidation reaction of propylene. It can further increase the activity.

Particularly, in the catalyst of one embodiment, the portion that can participate in the ammoxidation reaction of propylene by evenly supporting the metal oxide in the inner pores of the silica carrier is not only the outer surface portion (i.e., the surface of the catalyst) but also the inner surface (pore ), there is an advantage.

Further, the catalyst of the embodiment may be implemented in a structure in which a metal oxide is supported on a silica carrier by using an impregnation method, has a small fine powder content and a uniform particle size distribution without a classification process.

Moreover, the metal oxide exhibits excellent abrasion resistance due to the structure supported on the silica carrier and the uniform particle size distribution, so that acrylonitrile in a higher yield without additional supply of a catalyst during the ammoxidation reaction of propylene in the fluidized bed reactor. Can be manufactured.

Hereinafter, the catalyst of the embodiment will be described in more detail,

Catalyst structure

The catalyst of the embodiment may include a silica carrier including second pores; An inner coating layer that continuously coats the walls of the second pores and includes a metal oxide represented by Chemical Formula 1; And first pores located inside the second pores and occupying an empty space excluding the inner coating layer.

Specifically, the catalyst of the embodiment may have an egg-shell structure.

To this end, the silica carrier may include a non-porous core portion; And a porous shell portion positioned on the surface of the non-porous core and including second pores.

More specifically, the porous shell includes a concave portion and a convex portion of a surface, and the concave portion has the second pores open to the surface of the porous shell. It may be formed.

Accordingly, the catalyst of the embodiment may include a coating layer that continuously coats the concave portions and the convex portions of the porous shell and includes a metal oxide represented by Chemical Formula 1; And first pores occupying an empty space excluding the coating layer in the concave portion of the silica carrier.

Uniformity of D50 particle size and particle size distribution of catalyst

The catalyst of the embodiment may have a uniform particle size distribution compared to D50 and a small fine powder content in a state in which a metal oxide is supported on a silica support.

Specifically, the catalyst of the embodiment may have a D50 particle diameter of 30 to 200 µm, and a ratio of the [difference between the D90 particle diameter and the D10 particle diameter] to the D50 particle diameter is less than 2.0, and may exhibit a narrow particle size distribution.

More specifically, the catalyst of one embodiment has a lower limit of D50 particle size of 30 µm or more, 35 µm or more, 40 µm or more, or 45 µm or more, and an upper limit of 300 µm or less, 280 µm or less, 260 µm or less, 240 It can be made into µm or less, 220 µm or less, or 200 µm or less.

In addition, the catalyst of one embodiment has a ratio of [difference between D90 particle diameter and D10 particle diameter] to D50 particle diameter to be less than 2.0, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, or 1.5 or less, thereby providing a narrow particle size distribution. Can be indicated.

In other words, the uniformity of the particle size distribution represented by the catalyst of the embodiment may be supported by the fact that the D10 particle diameter and the D90 particle diameter relative to the D50 particle size satisfy the relationship of the following Equation 1, specifically the following Equation 1-1:

[Equation 1]

[Equation 1-1]

Catalyst wear loss

Particle wear refers to a phenomenon in which solid particles are decomposed through mechanical and chemical processes. Particle wear is classified into two types: abrasion and fragmentation, and both types may occur together.

Particularly, in the fluidized bed process, catalyst particles may be worn and finely divided, and there is a need to make-up the catalyst by an amount that has been continuously worn, which may affect the economics of the entire process.

The ASTM9797-00 method is known as a standard for measuring the wear of particles. This is, after filling 50 g of catalyst (W0) in a vertical inner tube having an inner diameter of 35 mm and a height of 710 mm, and then _{flowing N 2} gas at 10 L/min, and after 5 hours, the amount of catalyst collected in the fine filter (W ) Is measured, and abrasion resistance (attrition loss) is measured using the following equation.

Abrasion resistance (attrition loss) (%) = (W0)/W X 100

The catalyst of one embodiment has a wear resistance (attrition loss) measured according to the ASTM9797-00 method of 9% or less, 8.7% or less, 8.4% or less, 8.2% or less, or 8% or less, and the loss amount It is very small and can be excellent in abrasion resistance.

Therefore, compared to the catalyst of the secondary particle structure prepared through coprecipitation and spray drying, the catalyst of the embodiment exhibits excellent abrasion resistance, and even without additional supply of a catalyst during the ammoxidation reaction of propylene in the fluidized bed reactor, a higher yield It is possible to prepare acrylonitrile.

Composition of metal oxides

On the other hand, even if it has the same structure as the catalyst of the embodiment, if the type and content of the components constituting the metal oxide do not satisfy the above formula (1), the active sites of the catalyst having insufficient or excessively high density for ammoxidation of propylene are formed. Can be.

Accordingly, it is necessary to satisfy the type and content of the metal oxide to satisfy the formula (1).

In particular, when the metal oxide is represented by the following Formula 1-1, the effect of increasing the conversion rate by increasing the rate of movement of the lattice oxygen of molybdenum of Fe, and the formation of a complex oxide with molybdenum of Co to increase the partial oxidation reaction characteristics of propylene. As a synergistic effect of the effect, and the effect of increasing AN selectivity by dispersing the active point of the complex oxide containing molybdenum of K, the activity in the ammoxidation reaction of propylene may be higher:

[Formula 1-1]

In Formula 1-1, a to d, and x are each an atom or a fraction of an atomic group, a is 0.1 to 5, specifically 0.1 to 2.0, b is 0.1 to 5, specifically 0.5 to 3.0 , c is 0.01 to 10, specifically 1 to 10, d is 0.01 to 2, specifically 0.01 to 1.0, x may be 24 to 48, specifically 28 to 45.

Metal oxide: weight ratio of silica carrier

The catalyst of one embodiment is a weight ratio of 10:90 to 15:95, specifically 20:80 to 50:50, such as 15:85 to 35:65 of the metal oxide and the silica support (metal oxide: silica support) Can be included as.

Within this range, the catalyst of the embodiment may have high selectivity of acrylonitrile with high activity.

Method for producing a catalyst for ammoxidation of propylene

In another embodiment of the present invention, a method of preparing the catalyst of the above-described embodiment is provided using an impregnation method.

As briefly described above, the catalyst of one embodiment may be prepared through a series of processes in which a metal precursor solution is supported on the silica carrier using an impregnation method, dried and then calcined.

More specifically, as a method of preparing the catalyst of the embodiment,

Additives that are citric acid, oxalic acid, or mixtures thereof; And preparing a first precursor solution including a Mo precursor,

Bi precursor, Fe precursor, A precursor (A = one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba), and B precursor (B = one or more of Li, Na, K, Rb, and Cs Element) preparing a second precursor solution,

Mixing the first and second precursor solutions so that the molar ratio of the metal satisfies the stoichiometric molar ratio of Formula 1 below,

Supporting the mixture of the first and second precursor solutions on a silica carrier,

Drying the silica carrier on which the mixture of the first and second precursor solutions is supported, and

There is provided a method comprising the step of firing the dried material:

[Formula 1]

In Formula 1,

A is one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba,

B is one or more elements of Li, Na, K, Rb, and Cs,

C is one or more elements of Cr, W, B, Al, Ca, and V, and

Wherein a to e, and x are the fractions of atoms or groups, a is 0.1 to 5, b is 0.1 to 5, c is 0.01 to 10, d is 0.01 to 2, and e is 0 to 10, x is 24 to 48.

Manufacturing process of the first precursor solution

The step of preparing the first precursor solution may be a step of dissolving water, a Mo precursor, and an additive at 20 to 80° C. to prepare an aqueous solution containing water, a Mo precursor, and an additive.

In the step of preparing the first precursor solution, an additive including citric acid, oxalic acid, or a mixture thereof is used.

The additive functions as a strength control agent in the catalyst manufacturing process using coprecipitation and spray drying, but in one embodiment, the additive functions to make the first precursor solution transparent.

When the additive is added, the weight ratio of the molybdenum precursor and the additive may satisfy 1:0.1 to 1:1, specifically 1:0.2 to 1:0.7, and the solubility of the molybdenum precursor increases within this range. It can be, but is not limited thereto.

Manufacturing process of the second precursor solution

Excluding the Mo precursor included in the first precursor solution, a second precursor solution including the remaining metal precursors may be prepared.

Specifically, the step of preparing the second precursor solution includes essentially a Bi precursor, an Fe precursor, an A precursor, and a B precursor in water at 20 to 50° C., and optionally, a C precursor (Cr, W, B , Al, Ca, and V may be to prepare a second precursor solution further comprising one or more elements).

More specifically, in the step of preparing the second precursor solution, the type of metal precursor other than the Mo precursor may be selected in consideration of the composition of the metal oxide in the final catalyst.

For example, in consideration of the metal oxide composition satisfying Formula 1-1, a second precursor solution including water, a Bi precursor, an Fe precursor, a Co precursor, and a K precursor may be prepared.

Processes of preparing the first and second precursor solutions are each independent, and the order of preparation is not limited.

Supporting process of the first and second precursor solution mixture in a carrier

After mixing the first and second precursor solutions, they may be supported on a silica carrier.

Here, the silica carrier including the aforementioned second pores is added to the mixture of the first and second precursor solutions, so that the mixture of the first and second precursor solutions is supported in the first pores in the silica support. I can.

Specifically, the D50 size of the silica carrier on which the metal oxide is not supported may be 20 to 400 μm.

More specifically, the silica carrier on which the metal oxide is not supported has a D50 size of 20 to 400 μm; It may include second pores having a diameter of 10 to 200 nm.

More specifically, the D50 of the silica carrier itself without metal oxide has a lower limit of 20 µm or more, 25 µm or more, 30 µm or more, 35 µm or more, 40 µm or more, or 43 µm or more, and the upper limit is It may be 400 µm or less, 350 µm or less, 300 µm or less, 270 µm or less, 230 µm or less, or 200 µm or less.

In addition, the second pores contained in the silica carrier itself not carrying the metal oxide have a diameter of 10 nm or more, 15 nm or more, or 20 nm or more, and 200 nm or less, 100 nm or less, 50 nm or less, 40 It can be made into nm or less, or 30 nm or less.

Drying process of the carrier carrying the first and second precursor solution mixtures

Drying the silica carrier on which the mixture of the first and second precursor solutions is supported may include first vacuum drying the silica carrier on which the mixture of the first and second precursor solutions is supported at 120 to 160 mbar, and The first vacuum-dried material may be secondarily vacuum-dried at 30 to 50 mbar to obtain a silica carrier on which a mixture of the first and second precursor solutions is supported.

Specifically, the first vacuum drying is performed at 60 to 80° C. for 1 to 2 hours, and the second vacuum drying is performed at 80 to 100° C. for 15 to 45 minutes, whereby the solvent (ie, water) is removed. , Only the first and second precursors may remain on the walls of the first pores.

The material on which the secondary vacuum drying has been completed can be fired immediately, but by tertiary drying at normal pressure, even the solvent (ie, water) remaining after the secondary vacuum drying can be effectively removed.

Specifically, the third drying may be performed at 100 to 120 °C for 20 to 30 hours.

However, this is only an example, and the solvent (ie, water) is removed, and there is no particular limitation as long as it is a drying condition capable of obtaining a carrier on which the first and second precursors are supported.

Final firing process

Finally, the dried material, that is, the carrier on which the first and second precursors are supported, is calcined for 2 to 5 hours in a temperature range of 500 to 700° C. to finally obtain a catalyst.

However, the drying and firing conditions are only examples, and a condition capable of sufficiently removing the solvent from the internal pores of the carrier and oxidizing the metal precursor is sufficient.

Propylene ammoxidation method

In another embodiment of the present invention, there is provided a method for ammoxidation of propylene, comprising reacting propylene and ammonia in the presence of the catalyst of the above-described embodiment in a reactor.

The catalyst of the embodiment has high activity and stability at high temperature, and is used for ammoxidation reaction of propylene to increase the conversion rate of propylene, selectivity and yield of acrylonitrile.

For matters other than the catalyst of the embodiment, it is possible to refer to matters generally known in the art, and a detailed description thereof will be omitted.

Hereinafter, embodiments of the present invention will be described in more detail in the following examples. However, the following examples are merely illustrative of embodiments of the invention, and the contents of the present invention are not limited by the following examples.

Example 1

(1) Manufacturing process of precursor solution

10.592 g of Mo precursor ((NH ₄ ) ₆ ·Mo ₇ O ₂₄ ) and 0.1 g of citric acid were added and mixed in distilled water at 60° C. to prepare a Mo precursor solution.

Independently, in distilled water at room temperature _{, 1.819 g of Bi precursor (Fe(NO 3} ) ₃ 5H ₂ O), 9.488 g of Co precursor (Co(NO ₃ ) ₂ ·6H ₂ O), 2.990 g of Fe precursor (Fe (NO ₃ ) ₂ ·9H ₂ O), and 0.354 g of K precursor (KNO ₃ ) were added, and 1.46 g of nitric acid (HNO ₃ ) was added and then mixed, and Bi, Fe, Co, and K precursors were mixed. The solution was prepared.

The Mo precursor solution; And the Bi, Fe, Co, and K precursor mixture solution was mixed to complete a precursor mixture solution of Mo, Bi, Fe, Co, and K.

In the precursor mixture solution, the total amount of distilled water is 36.59 g.

(2) Supporting process of precursor solution in silica carrier (using impregnation method)

_{Silica (SiO 2} , D60-60A, AGC-Si) particles having a D50 particle diameter of 55 μm and an internal pore size of 24.4 nm were used as a carrier.

The silica carrier was added to the precursor mixture solution of Mo, Bi, Fe, Co, and K, and sequentially stirred at room temperature and 80° C. for 2 hours, respectively, and the Mo, Bi, Fe , Ni, Co, and K precursor mixture solution was sufficiently supported.

(3) Drying and sintering process of the silica carrier loaded with the precursor solution

Thereafter, the silica carrier on which the precursor mixture solution of Bi, Fe, Co, and K is supported is recovered and introduced into a rotary vacuum dryer, followed by primary vacuum drying for 1 hour and 40 minutes under a pressure of 140 mbar and a temperature of 70° C. Then, a second vacuum drying was performed for 30 minutes under a pressure of 40 mbar and a temperature of 90°C.

The material that has been completed until the second vacuum drying is recovered and put into an oven, and after 3 times drying for 24 hours under normal pressure and 110 ℃ temperature conditions, while maintaining the temperature of 580 ℃ in the box sintering furnace in an air atmosphere 　3 hours During heat treatment, the catalyst of Example 1 was finally obtained.

(4) Process of ammoxidation of flophyllene

In a tubular reactor having an inner diameter of 3/8 inch (inch), 0.05 g of quartz wool was charged for activation of the catalyst, and 0.2 g of the catalyst of Example 1 was charged into the reactor.

As described above, the internal pressure of the reactor filled with the quartz fiber and the catalyst was maintained at atmospheric pressure (1 atm), and the internal temperature of the reactor was raised at a temperature increase rate of 10 °C/min, while nitrogen and ammonia gas were flowed as a pretreatment process. Accordingly, after the temperature inside the reactor reached 400° C., which is the temperature at which the ammoxidation reaction is possible, it was maintained in an atmosphere of reducing gas for 15 minutes to allow sufficient pretreatment.

In the reactor where the pretreatment was completed, air was supplied together with propylene and ammonia as reactants, and the ammoxidation process of propylene was performed. At this time, the supply amount of the reactants was configured to be a propylene:ammonia:air = 0.8:1.2:8 volume ratio, while the total weight hourly space velocity (WHSV) of propylene, ammonia, and air was 1.54 h ^-1. .

After completion of the ammoxidation reaction, the product was recovered and analyzed using various equipment to confirm whether acrylonitrile was well produced.

The analysis method, analysis result, etc. will be described in detail in the experimental examples described later.

Examples 2 to 7

(1) catalyst manufacturing process (using the impregnation method)

A precursor solution was prepared according to the composition shown in Table 1 below, and the silica carriers shown in Table 2 were used, but the rest were the same as in Example 1 to prepare each of the catalysts of Examples 2 to 7.

(2) Process of ammoxidation of flophyllene

In addition, instead of the catalyst of Example 1, each catalyst of Examples 2 to 7 was used to perform the ammoxidation process of flophyllene, and the product was recovered, and analysis was performed in the same manner as in Example 1.

Comparative Example 1

(1) Catalyst manufacturing process (using spray drying after coprecipitation)

First, 10.592 g of Mo precursor ((NH ₄ ) ₆ Mo ₇ O ₂₄ ) and 3.18 g of citric acid were added and mixed in distilled water at 60° C. to prepare a Mo precursor solution.

Independently, in distilled water at room temperature, 1.819 g of Bi precursor (Fe(NO ₃ ) _3· 5H ₂ O), 9.488 g of Co precursor (Co(NO ₃ ) ₂ ·6H ₂ O), 2.900 g of Fe precursor ( Fe(NO ₃ ) ₂ ·9H ₂ O), and 0.354 g of K precursor (KNO ₃ ) were added, and 0.83 g of nitric acid (HNO ₃ ) was added and then mixed, and Bi, Fe, Co, and K precursors A mixed solution was prepared.

The Mo precursor solution; And the Bi, Fe, Co, and K precursor mixed solution was mixed, silica sol silica sol 22.53 g (LUDOX AS 40, solid content: 40%) was added and stirred, and then a disk-type spray dryer was used. It was spray-dried at 120°C (inlet) and 230°C (outlet).

The powder thus obtained was fired at 580° C. for 3 hours, and finally obtained as the catalyst of Comparative Example 1.

(3) Ammoxidation process of flophyllene

The catalyst of Comparative Example 1 was used instead of the catalyst of Example 1, and the ammoxidation process of flophyllene was performed in the same manner as in Example 1.

After completion of the ammoxidation reaction of Comparative Example 1, the product was recovered and analyzed in the same manner as in Example 1.

Comparative Examples 2 to 4

(1) catalyst manufacturing process (using the impregnation method)

A precursor solution was prepared according to the composition shown in Table 1 below, and the silica carriers shown in Table 2 were used, but the rest of the catalysts of Comparative Examples 2 to 4 were prepared in the same manner as in Example 1.

(2) Process of ammoxidation of flophyllene

In addition, after performing the ammoxidation process of flophyllene using each catalyst of Comparative Examples 2 to 4 instead of the catalyst of Example 1, the product was recovered, and analysis was performed in the same manner as in Example 1.

Comparative Example 5

(1) catalyst manufacturing process (using the impregnation method)

First, 10.592 g of Mo precursor ((NH ₄ ) ₆ ·Mo ₇ O ₂₄ ) and 0.53 g of citric acid were added and mixed in distilled water at 60° C. to prepare a Mo precursor solution.

Independently, 1.091 g of Bi precursor (Fe(NO ₃ ) ₃ ·5H ₂ O), 4.365 g of Co precursor (Co(NO ₃ ) ₂ ·6H ₂ O), 3.636 g of Fe precursor ( Fe(NO ₃ ) ₂ ·9H ₂ O), 2.908 g of Ni precursor (Ni(NO ₃ ) ₂ ·6H ₂ O), 0.045 g of K precursor (KNO ₃ ), 1.954 g of Ce precursor (Ce(NO ₃ ) ₃ · 6H ₂ O), 2.564 g of Mg precursor (Mg(NO ₃ ) ₂ · 6H ₂ O), and 0.037 g of Rb precursor (RbNO ₃ ) were added, and 0.74 g of nitric acid (HNO ₃ ) was added. Then, the mixture was mixed to prepare a mixed solution of Bi, Co, Fe, Ni, K, Ce, Mg, and Rb precursors.

The Mo precursor solution; And the Bi, Co, Fe, Ni, K, Ce, Mg, and Rb precursor mixture solution was mixed to complete a precursor mixture solution of Mo, Bi, Fe, Co, and K.

In the precursor mixture solution, the total amount of distilled water is 18.45 g.

(2) Process of ammoxidation of flophyllene

In addition, after performing the ammoxidation process of flophyllene using the catalyst of Comparative Example 5 instead of the catalyst of Example 1, the product was recovered, and analysis was performed in the same manner as in Example 1.

In Table 1, Mo is (NH ₄ ) ₆ Mo ₇ O ₂₄ , Bi is Bi(NO ₃ ) ₃ ·5H ₂ O, Co is Co(NO ₃ ) ₂ ·6H ₂ O, and Fe is Fe( NO ₃ ) ₂ ·9H ₂ O, and K is KNO ₃ . Also, the omitted unit is g.

Meanwhile, Comparative Example 5 in which a number of substances were added to the dissimilar metal precursor solution was omitted from Table 1 for convenience.

Experimental Example 1: Catalyst Analysis

According to the following analysis method, each catalyst of Examples and Comparative Examples was analyzed, and the results are shown in Table 3:

Measurement of D10, D50 and D90 : Dv can be measured using a laser diffraction method. Specifically, each catalyst of Examples and Comparative Examples was introduced into a particle size measuring device (Microtrac, Blue wave) using a laser diffraction method, and the particle size distribution was calculated by measuring the difference in the diffraction pattern according to the particle size when the particles pass through the laser beam. do. In the measuring device, by calculating the particle diameter at the point where it becomes 10%, 50% and 90% of the cumulative volume distribution according to the particle diameter, the values of D10, D50 and D90 are obtained, and the particle size distribution ((D90-D10)/ The value of D50) can also be output.

Abrasion resistance : Based on ASTM9797-00 method, after filling 50g of catalyst (W0) into a vertical inner tube with an inner diameter of 35mm and a height of 710mm, N2 gas flowed at 10L/min, and then collected in a fine filter after 5 hours. The amount of catalyst (W) was measured, and abrasion resistance was measured using the following equation.

Wear resistance (%) = (W-W0)/W

The catalyst of the comparative example is prepared through coprecipitation and spray drying, and exhibits a wide particle size distribution such that a classification process is inevitable as a post-treatment. Specifically, in the catalyst of the comparative example, the value of (D90-D10)/D50 is 2 or more.

On the other hand, the catalyst of the embodiment exhibits a uniform particle size distribution without a separate classification process as it is prepared through a series of processes in which a metal precursor solution is supported on a silica carrier and then a solvent is removed and then calcined. Specifically, the catalyst of Examples has a value of (D90-D10)/D50 of 1.5 or less, specifically 1.0 or less.

According to Table 3, in the relationship with the catalyst of Comparative Example 1 through co-precipitation and spray drying, the impregnation method used to prepare the catalysts of Examples 1 to 7 was used to prepare a catalyst having excellent wear resistance in a uniform particle size. It can be seen that this is an advantageous method.

Here, the catalyst of Comparative Example 1, as a result of being prepared through coprecipitation and spray drying, exhibits a wide particle size distribution such that post-treatment (eg, classification process) is inevitable. On the other hand, since the catalysts of Examples 1 to 7 were prepared through the impregnation method, they exhibited uniform particle size distribution without a separate classification process.

On the other hand, the catalysts of Comparative Examples 2 and 3, despite being prepared through the impregnation method, the D50 particle diameter does not satisfy the range (ie, 30 to 200 μm) specified in the above embodiment, and the particle size distribution and abrasion resistance are compared. It is inferior to Example 1.

Specifically, in the case of Comparative Example 2, as a carrier having an excessively small D50 particle diameter was used, the active ingredient was insufficiently impregnated in the carrier having such a small particle diameter, so that the D50 particle diameter of the final catalyst was the lower limit of the range specified in the above embodiment. It is inferred that the particle size distribution and wear resistance became inferior.

In addition, in the case of Comparative Example 3, as a carrier having an excessively large D50 particle diameter was used, the active ingredient was unevenly impregnated into the carrier having such a large particle diameter, so that the D50 particle diameter of the final catalyst was the upper limit of the range specified in the above embodiment Exceeded, and it is inferred that the particle size distribution and wear resistance became inferior.

In contrast, the catalysts of Comparative Examples 4 and 5 were prepared through the impregnation method, and although the D50 particle diameter satisfies the range (ie, 30 to 200 μm) specified in the above embodiment, due to the effect of the active metal , Particle size distribution and abrasion resistance are equivalent to or inferior to Comparative Example 1.

In the case of Comparative Example 4, it is inferred that due to the influence of a metal oxide containing only Mo and Bi as active metals, the active ingredient is insufficiently impregnated into the carrier, resulting in inferior particle size distribution and wear resistance of the final catalyst.

In addition, in the case of Comparative Example 5, as the active metals included not only Mo and Bi, but also a plurality of active metals (i.e., Ce, Fe, Ni, Co, Mg, K, and Rb), the active ingredient was non-uniformly in the carrier. It is inferred that the particle size distribution and abrasion resistance remained at the same level as Comparative Example 1.

Experimental Example 2: Analysis of ammoxidation product of propylene

Using FID (Flame Ionization Detector and TCD (thermal conductivity detector) equipped chromatography (Gas chromatography, manufacturer: Agilent instrument name: HP 6890 N), each ammoxidation product of Examples and Comparative Examples was analyzed.

Specifically, as FID, products such as ethylene (ehthlene), hydrogen cyanide, acetaldehyde, acetonitrile, and acetonitrile were analyzed, and as TCD _{, NH 3} , O ₂ , Gas products such as CO and CO ₂ and unreacted propylene were analyzed to determine the number of moles of propylene reacted and the number of moles of ammoxidation products in Examples and Comparative Examples, respectively.

By substituting the number of moles of propylene supplied in addition to the analysis results according to the following 1, 2, and 3, the conversion of propylene, the selectivity and yield of acrylonitrile, a product of the ammoxidation reaction of propylene, were calculated, and the calculated value was calculated. It is described in Table 4.

[Equation 1]

[Equation 2]

[Equation 3]

The catalyst of Comparative Example 1 was prepared through coprecipitation and spray drying, and as a result, the internal pores were hardly included, so that the portion capable of participating in the reaction was limited to the outer surface portion.

Moreover, since the catalyst of Comparative Example 1 has a non-uniform particle size distribution, the catalyst efficiency and reactivity are low when the catalyst is applied to the ammoxidation process of propylene without classifying the catalyst. In addition, since the catalyst of Comparative Example 1 has a secondary particle structure that is vulnerable to friction, it may be deteriorated or damaged during the ammoxidation reaction of propylene in the fluidized bed reactor. Accordingly, the conversion rate of propylene and the yield of acrylonitrile are inevitably lowered unless additional catalysts are continuously supplied during the reaction.

In fact, according to Table 2, it was confirmed that the conversion of propylene was 25% and the yield of acrylonitrile was only 9% when the reaction using the catalyst of Comparative Example 1 without additional supply of the catalyst during the reaction.

On the other hand, the catalysts of Comparative Examples 2 to 5 have a particle size distribution and abrasion resistance equal to or inferior to Comparative Example 1, but have a larger effective surface area capable of participating in the reaction than Comparative Example 1 due to the structure manufactured by the impregnation method. The conversion of propylene and the yield of acrylonitrile can be improved compared to Comparative Example 1.

However, the catalysts of Comparative Examples 2 and 3 do not satisfy the D50 particle diameter and particle size distribution (ie, D50 particle diameter: 30 to 200 μm, particle size distribution: (D90-D10)/D50 < 2.0) specified in the above embodiment. The conversion rate of propylene and the yield of acrylonitrile are low compared to Examples 1 to 7.

In addition, the catalyst of Comparative Example 4 does not satisfy the particle size distribution (i.e., particle size distribution: (D90-D10)/D50 < 2.0) specified in the above embodiment, and contains only Mo and Bi as active metals. Under the influence of, the conversion rate of propylene and the yield of acrylonitrile are inferior to those of Examples 1 to 7.

The catalyst of Comparative Example 5 does not satisfy the particle size distribution (i.e., particle size distribution: (D90-D10)/D50 < 2.0) specified in the above embodiment, and as active metals, not only Mo and Bi, but also Ce, Fe, and Ni , Co, Mg, K, and Rb due to the influence of the formation of excessively dense active sites, the conversion of propylene and the yield of acrylonitrile are inferior to those of Examples 1 to 7.

On the other hand, the catalysts of Examples 1 to 7 not only have a larger effective surface area capable of participating in the reaction than Comparative Example 1 due to the structure prepared by the impregnation method, but also the D50 particle size and particle size distribution (i.e., D50 particle diameter: 30 to 200 μm, particle size distribution: (D90-D10)/D50 < 2.0), and the metal oxide composition satisfies the above formula (1), significantly improving the conversion rate of propylene and the yield of acrylonitrile It is evaluated as one.

With reference to the catalysts of Examples 1 to 7 as described above, the conversion of propylene and the yield of acrylonitrile were further adjusted by adjusting the D50 particle size and particle size distribution, and the metal oxide composition of the catalyst within the ranges specified in the above embodiment. It will also be possible to improve.

Claims (18)

1. The metal oxide represented by the following formula (1) is a catalyst supported on a silica carrier,

   The catalyst,

   The D50 particle diameter is 30 to 300 μm,

   The D10 particle size, the D50 particle size, and the D90 particle size satisfy the relationship of Formula 1 below,

   Catalyst for ammoxidation of propylene:

   [Equation 1]

   

   [Formula 1]

   

   In Formula 1,

   A is one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba,

   B is one or more elements of Li, Na, K, Rb, and Cs,

   C is one or more elements of Cr, W, B, Al, Ca, and V, and

   Wherein a to e, and x are the fractions of atoms or groups, respectively, a is 0.1 to 5, b is 0.1 to 5, c is 0.01 to 10, d is 0.01 to 2, and e is 0 to 10 , x is 24 to 48.
2. The method of claim 1,

   The catalyst,

   A silica carrier including second pores;

   An inner coating layer that continuously coats the walls of the second pores and includes a metal oxide represented by Chemical Formula 1; And

   Including; first pores located inside the second pores and occupying an empty space excluding the inner coating layer

   Catalyst for ammoxidation of propylene.
3. The method of claim 1,

   The catalyst,

   The D50 particle diameter is 45 to 200 ㎛,

   Catalyst for ammoxidation of propylene.
4. The method of claim 1,

   The catalyst,

   The D10 particle size, D50 particle size, and D90 particle size satisfy the relationship of the following formula 1-1,

   Catalyst for ammoxidation of propylene:

   [Equation 1-1]

   
5. The method of claim 1,

   The metal oxide,

   It is represented by the following formula 1-1,

   Catalyst for ammoxidation of propylene:

   [Formula 1-1]

   

   In Formula 1-1, each definition of a to d and x is the same as in claim 1.
6. The method of claim 1,

   The weight ratio of the metal oxide and the silica carrier is 15:85 to 35:65,

   Catalyst for ammoxidation of propylene.
7. The method of claim 1,

   The catalyst,

   According to ASTM9797-00, after 50g of catalyst (W0) was filled in a vertical inner tube with an inner diameter of 35 mm and a height of 710 mm, N ₂ gas was flowed at 10 L/min, and then the catalyst collected in the fine filter after 5 hours. By measuring the amount (W) of, the attrition loss calculated using the following equation is 9% or less,

   Catalyst for ammoxidation of propylene:

   Wear loss (%) = (W-W0)/W
8. Additives that are citric acid, oxalic acid, or mixtures thereof; And preparing a first precursor solution including a Mo precursor,

   Bi precursor, Fe precursor, A precursor (A = one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba), and B precursor (B = one or more of Li, Na, K, Rb, and Cs Element) preparing a second precursor solution,

   Mixing the first and second precursor solutions so that the molar ratio of the metal satisfies the stoichiometric molar ratio of Formula 1 below,

   Supporting the mixture of the first and second precursor solutions on a silica carrier,

   Drying the silica carrier on which the mixture of the first and second precursor solutions is supported, and

   Comprising the step of firing the dried material,

   Method for producing a catalyst for ammoxidation of propylene:

   [Formula 1]

   

   In Formula 1,

   A is one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba,

   B is one or more elements of Li, Na, K, Rb, and Cs,

   C is one or more elements of Cr, W, B, Al, Ca, and V, and

   Wherein a to e, and x are the fractions of atoms or groups, a is 0.1 to 5, b is 0.1 to 5, c is 0.01 to 10, d is 0.01 to 2, and e is 0 to 10, x is 24 to 48.
9. The method of claim 8,

   In the step of preparing the first precursor solution,

   The weight ratio of the Mo precursor and the additive is to satisfy 1:0.1 to 1:1,

   Method for producing a catalyst for ammoxidation of propylene.
10. The method of claim 8,

    In the step of preparing the second precursor solution,

    To prepare a second precursor solution further comprising a C precursor (at least one element of Cr, W, B, Al, Ca, and V),

    Method for producing a catalyst for ammoxidation of propylene.
11. The method of claim 8,

    In the step of preparing the second precursor solution,

    To prepare a second precursor solution comprising a Bi precursor, a Fe precursor, a Co precursor, and a K precursor,

    Method for producing a catalyst for ammoxidation of propylene.
12. The method of claim 8,

    Drying the silica carrier on which the mixture of the first and second precursor solutions is supported,

    First vacuum drying the silica carrier on which the mixture of the first and second precursor solutions is supported at 120 to 160 mbar, and

    Including the step of obtaining a silica carrier on which the mixture of the first and second precursor solutions is supported by secondary vacuum drying the first vacuum-dried material at 30 to 50 mbar,

    Method for producing a catalyst for ammoxidation of propylene.
13. The method of claim 12,

    The primary vacuum drying,

    That is carried out at 60 to 80 °C,

    Method for producing a catalyst for ammoxidation of propylene.
14. The method of claim 12,

    The second vacuum drying,

    That is carried out at 80 to 100 °C,

    Method for producing a catalyst for ammoxidation of propylene.
15. The method of claim 12,

    The second vacuum-dried material is thirdly dried at normal pressure; which further comprises,

    Method for producing a catalyst for ammoxidation of propylene.
16. The method of claim 15,

    The third drying,

    That is carried out at 100 to 120 °C,

    Method for producing a catalyst for ammoxidation of propylene.
17. The method of claim 8,

    The step of firing the dried material,

    Which is carried out at 500 to 700 °C,

    Method for producing a catalyst for ammoxidation of propylene.
18. In the reactor, comprising the step of reacting propylene and ammonia in the presence of the catalyst of claim 1,

    Method for ammoxidation of propylene.

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