KR20250020196A - Catalyst for oxidative dehydrogenation and method of preparing same - Google Patents

Abstract

The present invention provides a catalyst for oxidative dehydrogenation reaction and a method for producing the same.

Description

Catalyst for oxidative dehydrogenation reaction and method of preparing same {CATALYST FOR OXIDATIVE DEHYDROGENATION AND METHOD OF PREPARING SAME}

The present application relates to a catalyst for oxidative dehydrogenation reaction and a method for producing the same.

There are several methods for producing butadiene as an intermediate for many petrochemical products, including naphtha cracking, direct dehydrogenation of butene, and oxidative dehydrogenation of butene. Among these, the naphtha cracking process has the problems of high reaction temperature, high energy consumption, separate equipment requirement, and generation of unnecessary products.

In addition, the direct dehydrogenation reaction of butene is an endothermic reaction with a very large heat of reaction, and requires high temperature and low pressure conditions for high yield butadiene production. It is also thermodynamically unfavorable, and therefore, there were some aspects that made it unsuitable for use as a commercialization process.

Meanwhile, the oxidative dehydrogenation reaction of butene is a reaction in which butene and oxygen react to produce butadiene and water. Unlike the direct dehydrogenation reaction of butene, it is an exothermic reaction, so butadiene can be obtained at a relatively low temperature. In addition, it is thermodynamically advantageous because water is produced as a product. Due to these advantages, there are some parts that are suitable for use as a commercialization process. Among them, ferrite-based catalysts are used to increase the activity of the oxidative dehydrogenation reaction of butene.

However, the oxidative dehydrogenation reaction of butene using a ferrite-based catalyst is an exothermic reaction, generating a large amount of heavy and CO _x components as byproducts, which increases the operating cost to remove them.

In addition, during the reaction process, there was a problem of deactivation due to carbon deposition on the ferrite series catalyst, which shortened the life of the catalyst.

Therefore, research on ferrite-based catalysts is needed to minimize the generation of by-products and catalytic carbon deposition.

Republic of Korea Patent Publication No. 10-2013-0046458

The present application seeks to provide a catalyst for oxidative dehydrogenation reaction and a method for producing the same to minimize the generation of by-products and catalytic carbon deposition during the process of producing butadiene.

An embodiment of the present application provides a method for preparing a catalyst for an oxidative dehydrogenation reaction, comprising: a step of preparing a precursor aqueous solution containing an iron (Fe) precursor and a zinc (Zn) precursor; a step of coprecipitating the precursor aqueous solution and a basic aqueous solution to prepare a solution containing a metal oxide; a step of filtering the solution to obtain a slurry of the metal oxide; a step of drying the slurry; a step of first calcining the slurry to obtain a solid sample represented by the following chemical formula 1; and a step of coating the solid sample, the cerium precursor, and the manganese precursor on a carrier to prepare a catalyst.

[Chemical Formula 1]

Zn _1-a1 Fe ₂ O ₄

In the above chemical formula 1,

0 ≤ a1 < 0.001.

Another embodiment of the present application provides a catalyst for oxidative dehydrogenation reaction, comprising: a carrier; and a coating layer provided on the carrier, wherein the coating layer includes a compound represented by the following chemical formula 2.

[Chemical formula 2]

Mn _a2 Ce _b ZnFe ₂ O ₄

In the above chemical formula 2,

0.002 < a2 < 0.1,

0.001 < b < 0.02.

A catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention can minimize the generation of by-products and catalyst carbon deposition during the process of manufacturing butadiene.

A catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention can increase the yield of butadiene.

A catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention can reduce process costs for producing butadiene.

A method for producing a catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention enables the production of a catalyst for oxidative dehydrogenation reaction having excellent performance.

Figure 1 is a diagram showing the manufacturing sequence of a catalyst for oxidative dehydrogenation reaction of Examples 1 and 2 and Comparative Example 3.
Figure 2 is a diagram showing the manufacturing sequence of a catalyst for oxidative dehydrogenation reaction of Comparative Example 1.
Figure 3 is a diagram showing the manufacturing sequence of a catalyst for the oxidative dehydrogenation reaction of Comparative Example 2.
Figure 4 is a diagram showing the TPO profiles of Examples 1 and 2 and Comparative Examples 1 and 3.

Below, the present specification is described in more detail.

In this specification, when it is said that a certain member is located 'on' another member, this includes not only cases where a certain member is in contact with another member, but also cases where another member exists between the two members.

In this specification, when a part is said to 'include' a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless otherwise specifically stated.

In this specification, 'p to q' means 'p or more and q or less'.

<Method for producing a catalyst for oxidative dehydrogenation reaction>

One embodiment of the present invention provides a method for producing a catalyst for oxidative dehydrogenation reaction, characterized by coating a coating solution containing a compound represented by the chemical formula 1, a cerium precursor, and a manganese precursor on a carrier. To this end, the method for producing a catalyst for oxidative dehydrogenation reaction according to the present invention produces a catalyst using a co-precipitation method.

The solid sample represented by the above chemical formula 1 may refer to a solid sample containing a compound represented by the above chemical formula 1. That is, the present invention is characterized in that after preparing a solid sample containing a compound represented by the above chemical formula 1, a carrier is coated with a coating solution containing the solid sample, a cerium precursor, and a manganese precursor. Due to the above characteristic, even if the cerium precursor and the manganese precursor are added, the desired catalytic performance can be achieved without causing a structural change in the compound represented by the above chemical formula 1.

The method for preparing a catalyst for dehydrogenation reaction according to the present invention may include a step of preparing an aqueous precursor solution containing an iron (Fe) precursor and a zinc (Zn) precursor. Specifically, the method for preparing a catalyst for dehydrogenation reaction according to the present invention may include a step of preparing an aqueous precursor solution by dissolving an iron (Fe) precursor and a zinc (Zn) precursor in water.

At this time, in one embodiment of the present invention, the content of iron (Fe) included in the precursor aqueous solution may be 0.005 parts by weight to 20 parts by weight, preferably 0.01 parts by weight to 10 parts by weight, based on 100 parts by weight of the precursor aqueous solution.

In addition, in one embodiment of the present invention, the content of zinc (Zn) included in the precursor aqueous solution may be 0.005 parts by weight to 20 parts by weight, preferably 0.01 parts by weight to 10 parts by weight, based on 100 parts by weight of the precursor aqueous solution.

When the above content is satisfied, it is possible to manufacture a catalyst including a compound represented by the chemical formula 1 in a coating layer, thereby effectively performing the function of a catalyst for oxidative dehydrogenation reaction while reducing by-products.

In one embodiment of the present invention, the iron (Fe) precursor may be an ammonium salt, nitrate, carbonate, chloride, sulfate, hydroxide, organic acid salt, oxide or a mixture thereof of iron element. Specifically, the iron (Fe) precursor may be an iron chloride, but is not limited thereto.

In one embodiment of the present invention, the zinc (Zn) precursor may be an ammonium salt, nitrate, carbonate, chloride, sulfate, hydroxide, organic acid salt, oxide or a mixture thereof of the zinc element. Specifically, the zinc (Zn) precursor may be a chloride of lead, but is not limited thereto.

The method for producing a catalyst for dehydrogenation reaction according to the present invention may include a step of producing a solution containing a metal oxide by co-precipitating the precursor aqueous solution and the basic aqueous solution.

In one embodiment of the present invention, the step of preparing a solution containing a metal oxide by co-precipitating the precursor solution and the basic aqueous solution may include the step of adding the basic aqueous solution dropwise so that the pH of the precursor solution becomes 7 to 10; and the step of stirring the precursor solution and the basic aqueous solution. For this purpose, a co-precipitation tank may be used, but other devices or equipment may be used as long as the above step can be performed, and the form thereof may not be limited.

In one embodiment of the present application, the step of adding the basic aqueous solution dropwise may be done at a rate of 7 g/min to 11 g/min, preferably 8 g/min to 10 g/min. When the above rate is satisfied, the content of the active ingredient can be easily controlled within a certain range, thereby producing an excellent catalyst.

In one embodiment of the present invention, the basic aqueous solution may be 5 to 40 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the solution in which the metal precursor aqueous solution and the basic aqueous solution are mixed. When the above content is satisfied, there is an effect in which it is easier to manufacture a spinel-phase catalyst.

In one embodiment of the present invention, the basic aqueous solution may be ammonia water, but is not limited thereto, and a weakly basic substance capable of adjusting the pH of the precursor aqueous solution to 7 to 10 may be used.

In one embodiment of the present application, when the basic aqueous solution is ammonia water, it may contain 20 to 40 wt% of ammonia based on the ammonia water. When the above range is satisfied, an excellent oxidative dehydrogenation reaction catalyst can be produced while reducing the emission of pollutants.

In this specification, the 'pH' is a numerical value indicating the degree of acidity or alkalinity of water, and specifically means an index of hydrogen ion concentration. When the pH value is 7 at 25℃, it is defined as neutral, when the pH value is less than 7, it is acidic, and when the pH value is more than 7, it is defined as alkaline.

In one embodiment of the present invention, the step of drying the slurry can be performed at a temperature of 60° C. to 130° C., preferably 80° C. to 120° C. In addition, the step of drying the slurry can be performed for 20 hours to 36 hours, preferably 22 hours to 26 hours, but the time conditions can be changed depending on the content of the slurry.

The method for producing a catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention may include a step of first calcining the slurry to obtain a solid sample. That is, the step of drying the slurry and then calcining the dried slurry may be included. In the present specification, the step of calcining the dried slurry is defined as first calcination in order to distinguish it from the step of calcining a carrier coated with a coating solution described later.

In one embodiment of the present invention, the step of first calcining the slurry to obtain a solid sample can be performed at 700° C. or lower, preferably 680° C. or lower. In addition, the step of first calcining the slurry to obtain a solid sample can be performed for 4 to 12 hours, preferably 5 to 10 hours, but the time conditions can be changed depending on the content of the slurry.

At this time, the solid sample may include a compound represented by the chemical formula 1. More specifically, the solid sample may be composed of a compound represented by the chemical formula 1.

A method for producing a catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention may include a step of producing a catalyst by coating the solid sample, the cerium precursor, and the manganese precursor on a carrier.

In one embodiment of the present invention, the step of manufacturing a catalyst by coating a carrier with the solid sample, the cerium precursor, and the manganese precursor may include the step of pulverizing the solid sample to manufacture a powder; the step of manufacturing a coating solution including the powder, the cerium precursor, and the manganese precursor; the step of coating the carrier with the coating solution; and the step of secondary calcining the carrier.

That is, the solid sample containing the compound represented by the chemical formula 1 is manufactured into a powder, and then a cerium precursor and a manganese precursor are added to manufacture a coating solution. Due to the above characteristic, even if the cerium precursor and the manganese precursor are added, no structural change occurs in the compound represented by the chemical formula 1, so that the coke generation amount can be reduced and the yield of the product due to the oxidative dehydrogenation reaction can be increased without impairing the function of the catalyst.

The present invention manufactures a catalyst for oxidative dehydrogenation reaction including a carrier and a coating layer provided on the carrier by coating a coating liquid on the carrier and then calcining the carrier. At this time, in order to distinguish the step of coating the coating liquid and then calcining it from the first calcination step of calcining a dried slurry, the step of calcining the carrier coated with a solid sample is defined as the second calcination step.

In one embodiment of the present invention, the step of preparing a coating solution including the powder, a cerium precursor and a manganese precursor may include a step of adding the powder to a solution including the cerium precursor and the manganese precursor.

In one embodiment of the present invention, the solution containing the cerium precursor and the manganese precursor may contain 0.001 part by weight to 0.02 part by weight of the cerium, preferably 0.001 part by weight to 0.01 part by weight.

In one embodiment of the present invention, the solution containing the cerium precursor and the manganese precursor may contain 0.002 part by weight to 0.1 part by weight of the manganese, preferably 0.002 part by weight to 0.04 part by weight.

In one embodiment of the present invention, the cerium precursor may be an ammonium salt, nitrate, carbonate, chloride, sulfate, hydroxide, organic acid salt, oxide or a mixture thereof of the element cerium. Specifically, the cerium precursor may be a nitrate or hydroxide of cerium, but is not limited thereto.

In one embodiment of the present invention, the manganese precursor may be an ammonium salt, nitrate, carbonate, chloride, sulfate, hydroxide, organic acid salt, oxide or a mixture thereof of the manganese element. Specifically, the manganese precursor may be a chloride of manganese, but is not limited thereto.

In one embodiment of the present invention, the step of secondary calcining the silica carrier can be performed at 700° C. or lower, preferably 680° C. or lower. In addition, the step of secondary calcining the silica carrier can be performed for 4 to 12 hours, preferably 5 to 10 hours.

In one embodiment of the present invention, the carrier may be a silica (SiO ₂ ) carrier or an alumina/silica carrier, and preferably an alumina/silica carrier.

<Catalyst for oxidative dehydrogenation reaction>

One embodiment of the present invention provides a catalyst for oxidative dehydrogenation reaction, characterized in that a coating layer coated on a carrier includes a compound represented by the chemical formula 2.

In one embodiment of the present invention, a2 of the chemical formula 2 may be 0.002 < a2 < 0.1, preferably 0.002 < a2 < 0.04. That is, the addition of a small amount of manganese (Mn) as a promoter is a characteristic of the catalyst for oxidative dehydrogenation reaction of the present invention, and due to the characteristic, the function of the catalyst for oxidative dehydrogenation reaction can be effectively performed while reducing the amount of by-products and coke generated.

In one embodiment of the present invention, b in the chemical formula 2 may be 0.001 < b < 0.02, preferably 0.001 < b < 0.01. That is, cerium is a substance having an effect on the coke generation content, and when the content is satisfied, it can effectively perform the function of a catalyst for oxidative dehydrogenation reaction while reducing byproducts and coke generation content.

In one embodiment of the present invention, the compound represented by the chemical formula 2 can be represented by the following chemical formula 3.

[Chemical Formula 3]

Mn _a3 Ce _0.002 ZnFe ₂ O ₄

In the above chemical formula 3,

0.002 < a3 < 0.1.

More specifically, the catalyst for oxidative dehydrogenation reaction according to one embodiment of the present invention may have a form in which the coating layer includes ZnFe ₂ O ₄ , CeO _2, MnO, Mn ₃ O ₄ and CeMnO.

According to one embodiment of the present invention, a catalyst for oxidative dehydrogenation reaction is characterized in that it is manufactured by using a coating solution in which a structure of a zinc ferrite-based material (catalyst) is pre-sintered and a cerium precursor and a manganese precursor are added to the zinc ferrite-based material. That is, since the cerium precursor and the manganese precursor do not affect the structure of the zinc ferrite-based material, it is characterized in that the amount of coke generated can be reduced and the yield of products resulting from the oxidative dehydrogenation reaction can be increased without impairing the function of the catalyst.

In one embodiment of the present invention, the catalyst for oxidative dehydrogenation reaction may contain cerium in an amount of 0.05 to 2.5 parts by weight, preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of the catalyst for oxidative dehydrogenation reaction.

In one embodiment of the present invention, the catalyst for oxidative dehydrogenation reaction may contain manganese in an amount of 0.05 to 2.5 parts by weight, preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of the catalyst for oxidative dehydrogenation reaction. When the above content is satisfied, the phenomenon of coke being deposited on the catalyst for oxidative dehydrogenation reaction may be prevented while not reducing the activity of the catalyst.

In one embodiment of the present invention, the compound represented by the chemical formula 2 has a spinel structure, and the crystal size of the compound represented by the chemical formula 2 may be 110 nm or more, preferably 113 nm or more. In addition, the crystal size of the compound represented by the chemical formula 2 may be 120 nm or less.

In one embodiment of the present invention, the catalyst for oxidative dehydrogenation reaction can be used in the oxidative dehydrogenation reaction of butene. That is, it can be used in the oxidative dehydrogenation reaction of butene to produce butadiene from butene.

Accordingly, the catalyst for oxidative dehydrogenation reaction according to the present invention can minimize the occurrence of by-products and the catalytic carbon deposition phenomenon during the process of producing butadiene due to the above characteristics. In addition, it has the advantage of increasing the yield of butadiene and reducing the process cost of producing butadiene.

In one embodiment of the present invention, the coating layer may further include cerium oxide (CeO ₂ ). The cerium oxide (CeO ₂ ) in the coating layer is added after the compound represented by the chemical formula 1 is formed, as described below, and does not affect the content and crystal size of α-Fe ₂ O ₃ of the compound represented by the chemical formula 1.

When cerium is added, the phenomenon of coke deposition on the catalyst for oxidative dehydrogenation reaction can be prevented.

The description of the method for producing a catalyst for oxidative dehydrogenation reaction according to the present invention can also be applied to the catalyst for oxidative dehydrogenation reaction according to the present invention. The opposite is also true.

One embodiment of the present invention provides a method for oxidative dehydrogenation of butene using an oxidative dehydrogenation catalyst according to the present invention. That is, the oxidative dehydrogenation catalyst according to the present invention may be a catalyst used in a process of producing butadiene through an oxidative dehydrogenation reaction of butene as described above.

In one embodiment of the present invention, the oxidative dehydrogenation reaction of butene can be carried out using a fixed bed reactor, a moving bed reactor, or a fluidized bed reactor.

In one embodiment of the present invention, the butene used in the oxidative dehydrogenation reaction of butene may be 1-butene or 2-butene.

In one embodiment of the present invention, the reaction raw material used in the oxidative dehydrogenation reaction of butene may include butene, steam, oxygen and nitrogen.

In one embodiment of the present invention, the reaction temperature of the oxidative dehydrogenation reaction of butene may be 250°C to 500°C, preferably 350°C to 460°C, and the reaction pressure may be 0 bar to 10 bar. The reaction pressure is a measured pressure, and 0 bar means normal pressure. Satisfying the reaction temperature is preferable for optimizing the activation of the catalyst, and when the reaction pressure is satisfied, the selectivity of butadiene can be increased. However, the reaction temperature and reaction pressure can be controlled by the size of the reactor, the composition of the reaction raw material, etc.

In one embodiment of the present invention, the method for producing butadiene is not particularly limited and can be applied as a method commonly used in this technical field, except for using the oxidative dehydrogenation catalyst of the present invention.

Hereinafter, in order to specifically explain the present application, examples will be given and described in detail. However, the examples according to the present application may be modified in various different forms, and the scope of the present application is not construed as being limited to the examples described below. The examples of the present application are provided to more completely explain the present application to a person having average knowledge in the art.

<Production of catalyst>

1) Example 1

The molar ratio of metals ( _ZnCl2 ) and ferric chloride ( _FeCl2 ) in 2,000.00 g of pure water (DI water) : Fe) = 1: 2 was satisfied, and the metal precursor aqueous solution was prepared by dissolving it. Then, the ammonia aqueous solution was added dropwise so that the pH of the metal precursor aqueous solution became 7, and the solution was stirred for 1 hour to cause coprecipitation, thereby preparing a coprecipitate.

Thereafter, the precipitate was washed with distilled water, dried at 120°C for 24 hours, and then heated to 650°C at a heating rate of 1°C/min in an air atmosphere. The elevated temperature of 650°C was maintained for 6 hours (first calcination) to produce a zinc-iron oxide solid sample having a spinel structure. The structure of the zinc-iron oxide solid sample was ZnFe ₂ O ₄ .

Next, the solid sample was pulverized to prepare a powder, and the powder, cerium nitrate (Ce(NO ₃ ) ₃ 6H ₂ O) and manganese chloride (MnCl ₂ 4H ₂ O) were added to deionized water (DI water) to prepare a coating solution. An alumina/silica carrier (SA5218, manufacturer: Saint Gobain) was added to the coating solution to prepare a coating catalyst.

The above coating catalyst was calcined at 650°C for 6 hours (secondary calcination) to produce a catalyst for the oxidative dehydrogenation reaction of Example 1.

At this time, the catalyst for the oxidative dehydrogenation reaction of Example 1 contained 0.1 wt% of cerium and 0.05 wt% of manganese based on the catalyst for the oxidative dehydrogenation reaction.

2) Example 2

In Example 1, a catalyst for oxidative dehydrogenation reaction was prepared by adding the powder and cerium nitrate (Ce(NO ₃ ) ₃ 6H ₂ O) and manganese chloride (MnCl ₂ 4H ₂ O) to deionized water to prepare a coating solution so that the catalyst for oxidative dehydrogenation reaction contained 0.1 wt% of manganese based on the catalyst for oxidative dehydrogenation reaction, and a catalyst for oxidative dehydrogenation reaction of Example 2 was prepared in the same manner as in Example 1.

That is, the catalyst for the oxidative dehydrogenation reaction of Example 2 contained 0.1 wt% of cerium and 0.1 wt% of manganese based on the catalyst for the oxidative dehydrogenation reaction.

The process for preparing a catalyst for the oxidative dehydrogenation reaction of Examples 1 and 2 is shown in Fig. 1.

3) Comparative Example 1

In Example 1, a solid sample was pulverized to prepare a powder, and the powder and cerium nitrate (Ce(NO ₃ ) ₃ 6H ₂ O) were added to pure water (DI water) to contain 0.1 wt% of cerium based on the oxidative dehydrogenation reaction catalyst, thereby preparing a coating solution, with the exception that a catalyst for oxidative dehydrogenation reaction of Comparative Example 1 was prepared in the same manner as in Example 1.

The process for manufacturing a catalyst for the oxidative dehydrogenation reaction of Comparative Example 1 is shown in Fig. 2.

4) Comparative Example 2

In Example 1, a catalyst for an oxidative dehydrogenation reaction was prepared by dissolving a manganese precursor solution containing manganese chloride (MnCl ₂ 4H ₂ O) containing 0.1 wt% (0.005 mol%) of manganese (Mn) based on the catalyst for an oxidative dehydrogenation reaction into 2000.00 g of pure water, simultaneously adding zinc chloride (ZnCl ₂ ) and ferric chloride (FeCl ₂ ), to prepare a metal precursor aqueous solution. At this time, the metal molar ratio of zinc chloride (ZnCl ₂ ) and ferric chloride (FeCl ₂ ) (Zn : Fe) was 0.995: 2.

Next, an ammonia aqueous solution was added dropwise so that the pH of the metal precursor aqueous solution became 7, and the solution was stirred for 1 hour to cause coprecipitation, thereby preparing a coprecipitate.

Thereafter, the precipitate was washed with distilled water, dried at 120°C for 24 hours, and then heated to 650°C at a heating rate of 1°C/min in an air atmosphere. The elevated temperature of 650°C was maintained for 6 hours (first calcination) to produce a zinc-iron-manganese oxide solid sample having a spinel structure.

Next, the solid sample was pulverized to prepare a powder, and the powder and cerium nitrate (Ce(NO ₃ ) ₃ 6H ₂ O) were added to deionized water (DI water) to prepare a coating solution. An alumina/silica carrier (SA5218, manufacturer: Saint Gobain) was added to the coating solution to prepare a coating catalyst.

The above coating catalyst was calcined at 650°C for 6 hours (secondary calcination) to prepare a catalyst for the oxidative dehydrogenation reaction of Comparative Example 2.

That is, compared to Example 1, manganese chloride (MnCl ₂ ) was added when preparing the metal precursor aqueous solution rather than when preparing the coating solution, thereby producing a catalyst for the oxidative dehydrogenation reaction of Comparative Example 2.

At this time, the catalyst for oxidative dehydrogenation reaction of Comparative Example 2 contained 0.1 wt% of cerium and 0.1 wt% of manganese based on the catalyst for oxidative dehydrogenation reaction.

The process for manufacturing a catalyst for the oxidative dehydrogenation reaction of Comparative Example 2 is shown in Fig. 3.

5) Comparative Example 3

In Example 1, a catalyst for oxidative dehydrogenation reaction was prepared by adding the powder and cerium nitrate (Ce(NO ₃ ) ₃ 6H ₂ O) and manganese chloride ((MnCl ₂ 4H ₂ O) to deionized water (DI water) to prepare a coating solution so that the catalyst for oxidative dehydrogenation reaction contained 0.2 wt% of manganese based on the catalyst for oxidative dehydrogenation reaction, and a catalyst for oxidative dehydrogenation reaction of Comparative Example 3 was prepared in the same manner as in Example 1.

That is, the catalyst for the oxidative dehydrogenation reaction of Comparative Example 3 contained 0.1 wt% of cerium and 0.2 wt% of manganese based on the catalyst for the oxidative dehydrogenation reaction.

That is, Comparative Example 3 follows the manufacturing order of Examples 1 and 2 as shown in Fig. 1, but means a case in which manganese is added in a larger amount than in Examples 1 and 2.

This is summarized in Table 1 below.

Solid sample Ce content (wt%) Mn content (wt%) Chemical formula Example 1 ZnFe ₂ O ₄ 0.1 0.05 Mn _0.002 Ce _0.002 ZnFe ₂ O ₄ Example 2 ZnFe ₂ O ₄ 0.1 0.1 Mn _0.005 Ce _0.002 ZnFe ₂ O ₄ Comparative Example 1 ZnFe ₂ O ₄ 0.1 - Ce _0.002 ZnFe ₂ O ₄ Comparative Example 2 Mn _0.005 Zn _0.995 Fe ₂ O ₄ 0.1 0.1 Mn _0.005 Ce _0.002 Zn _0.995 Fe ₂ O ₄ Comparative Example 3 ZnFe ₂ O ₄ 0.1 0.2 Mn _0.009 Ce _0.002 ZnFe ₂ O ₄

In the above Table 1, the chemical formulas refer to compounds included in the coating layers of the catalysts of Examples 1 and 2 and Comparative Examples 1 to 3.

<Experimental Example 1 - Evaluation of the sedimentation reduction rate of coke>

The catalysts for the oxidative dehydrogenation reaction of Examples 1 and 2 and Comparative Examples 1 to 3 were each filled into a metal tubular reactor with a diameter of 3.5 cm to a fixed catalyst volume of 10 cc, and then a reaction raw material stream was introduced into the metal tubular reactor at a gas hourly space velocity (GHSV) of 1,500 hr ^-1 , while the oxidative dehydrogenation reaction was performed at a reaction temperature of 400° C. and a reaction pressure of 1 bar for 14 hours. 2-butene, steam, oxygen, and nitrogen were used as the reaction raw materials. At this time, the components of the reaction raw materials were adjusted to satisfy OBR = 0.2, SBR = 8, and NBR = 1.

For reference, in Experimental Example 1, the coke generation was accelerated by increasing the space velocity in an experiment related to coke generation.

After the reaction was completed, the coke deposition reduction rate was measured.

The results are shown in Table 2 below.

<Experimental Example 2 - Catalyst Performance Evaluation>

The catalysts for the oxidative dehydrogenation reaction of Examples 1 and 2 and Comparative Examples 1 to 3 were each filled into a metal tubular reactor with a diameter of 3.5 cm to a fixed catalyst volume of 150 cc, and then a reaction raw material stream was introduced into the metal tubular reactor at a gas hourly space velocity (GHSV) of 100 hr ^-1 , and the oxidative dehydrogenation reaction was performed at a reaction temperature at which the oxygen conversion rate was 99% or higher and a reaction pressure of 1 bar. 2-butene, steam, oxygen, and nitrogen were used as the reaction raw materials. At this time, the components of the reaction raw materials were adjusted to satisfy OBR = 0.1, SBR = 8, and NBR = 1.

After the reaction was completed, the conversion, selectivity, and yield of the catalyst were measured.

The results are shown in Table 2 below.

In the above experimental example 2, OBR, SBR and NBR have the following meanings, respectively.

* OBR = Oxygen/2-butene ratio

* SBR = Steam/2-butene ratio

* NBR = Nitrogen/2-butene ratio

catalyst X_BE (%) S_BD (%) Y_BD (%) Coke content (wt%) Coke sedimentation reduction rate (%) Example 1 85.54 87.20 74.59 0.0120 - 28.6 Example 2 88.74 87.50 77.65 0.0065 - 61.3 Comparative Example 1 86.50 86.70 75.00 0.0168 - Comparative Example 2 83.48 87.18 72.78 0.0254 + 51.2 Comparative Example 3 84.50 86.58 73.16 0.0196 + 16.7

In Table 2 above, X_BE represents the conversion of butene, and S_BD and Y_BD represent the selectivity and yield of butadiene, respectively.

Each value was calculated using the following formula.

* X_BE (%) = [number of moles of 2-butene reacted/number of moles of reactant supplied] Х 100(%)

* S_BD (%) = [number of moles of butadiene produced/number of moles of 2-butene reacted] Х 100(%)

* Y_BD (%) = X_BE (%) Х S_BD (%) / 100(%)

In addition, in the above Table 2, the coke deposition reduction rate was calculated by using the following formula for the coke contents of the examples and comparative examples through TGA analysis, and then calculating the % reduction when the coke content of comparative example 1 was set to 100.

* Coke content (wt%) = [(Weight of catalyst before TGA analysis - Weight of catalyst after TGA analysis) / Weight of catalyst before TGA analysis] × 100 (%)

From the results in Table 2 above, it was confirmed that the catalyst for oxidative dehydrogenation reaction according to the present invention has high butadiene selectivity and yield, and superior performance in terms of coke generation compared to the comparative example. In addition, it was confirmed that the butadiene selectivity and yield of Example 2 were also superior to the comparative example.

Specifically, from the results of Examples 1 and 2, it was confirmed that when manganese was added in the coating solution stage, a synergistic effect with cerium occurred, significantly reducing coke generation. In the case of Comparative Example 1, since manganese was not added, a synergistic effect with cerium could not be confirmed.

In addition, it was confirmed that Comparative Example 2, in which manganese was added to the metal precursor solution in the co-precipitation step rather than the step of preparing the coating solution, showed a decrease in butadiene selectivity and yield and a significant increase in coke generation. This is interpreted to be because the manganese added in the co-precipitation step changes the structure of ZnFe ₂ O ₄ , which causes problems such as a decrease in active sites and an increase in by-products.

Comparative Example 3 is the same as the Example in that manganese is added in the manufacturing stage of the coating solution, but manganese was added in excessive amounts. It was confirmed that the yield of butadiene decreased while coke generation increased. This is interpreted as being because if the manganese content is too high, the active site of ZnFe ₂ O ₄ is covered, and manganese oxide is formed in excessive amounts, causing many side reactions.

In addition, FIG. 4 shows the TPO profiles of Examples 1 and 2 and Comparative Examples 1 and 3, and it can be confirmed that Examples 1 and 2 have large oxygen storage capacities, and in particular, it can be confirmed that Example 2 has the largest oxygen storage capacity. A large oxygen storage capacity means that less coke is generated.

As shown in the results of FIG. 4, it was confirmed that Comparative Example 1, in which manganese was not added, and Comparative Example 3, which was manufactured in the same manufacturing order as the examples but with excessive manganese addition, generated a larger amount of coke than the catalyst for oxidative dehydrogenation according to the present invention because the oxygen storage capacity was smaller than that of the catalyst for oxidative dehydrogenation according to the present invention.

That is, from the results of FIG. 4, it was confirmed that the catalyst for oxidative dehydrogenation reaction according to the present invention had excellent performance in terms of coke generation, and it was confirmed that Example 2 was particularly excellent in terms of coke generation.

Claims (10)

A step of preparing a precursor solution containing an iron (Fe) precursor and a zinc (Zn) precursor;
A step of preparing a solution containing a metal oxide by co-precipitating the precursor aqueous solution and the basic aqueous solution;
A step of filtering the above solution to obtain a slurry of the metal oxide;
A step of drying the above slurry;
A step of first calcining the above slurry to obtain a solid sample represented by the following chemical formula 1; and
A method for producing a catalyst for oxidative dehydrogenation reaction, comprising the step of coating the above solid sample, a cerium precursor and a manganese precursor on a carrier to produce a catalyst:
[Chemical Formula 1]
Zn _1-a1 Fe ₂ O ₄
In the above chemical formula 1,
0 ≤ a1 < 0.001. In the first paragraph,
A method for producing a catalyst for oxidative dehydrogenation reaction, wherein the content of iron (Fe) contained in the precursor aqueous solution is 0.005 parts by weight to 20 parts by weight based on 100 parts by weight of the precursor aqueous solution. In the first paragraph,
A method for producing a catalyst for oxidative dehydrogenation reaction, wherein the content of zinc (Zn) contained in the precursor aqueous solution is 0.005 parts by weight to 20 parts by weight based on 100 parts by weight of the precursor aqueous solution. In the first paragraph,
The step of preparing a solution containing a metal oxide by co-precipitating the above precursor aqueous solution and the basic aqueous solution
A step of adding the basic aqueous solution dropwise so that the pH of the precursor aqueous solution becomes 7 to 10; and
A method for producing a catalyst for oxidative dehydrogenation reaction, comprising the step of stirring the above precursor aqueous solution and the above basic aqueous solution. In the first paragraph,
A method for producing a catalyst for oxidative dehydrogenation reaction, wherein the step of drying the above slurry is performed at a temperature of 60°C to 130°C. In the first paragraph,
A method for producing a catalyst for oxidative dehydrogenation reaction, wherein the step of first calcining the above slurry to obtain a solid sample is performed at 700°C or lower. In the first paragraph,
The step of manufacturing a catalyst by coating the above solid sample, cerium precursor and manganese precursor on a carrier
A step of grinding the above solid sample to produce a powder;
A step of preparing a coating solution including the above powder, a cerium precursor and a manganese precursor;
A step of coating the carrier with the coating solution; and
A method for producing a catalyst for oxidative dehydrogenation reaction, comprising a step of secondary calcination of the above-mentioned carrier. In Article 7,
A method for producing a catalyst for oxidative dehydrogenation reaction, wherein the step of secondary calcination of the above-mentioned carrier is performed at 700°C or lower. carrier; and
Including a coating layer provided on the above carrier,
The above coating layer is a catalyst for oxidative dehydrogenation reaction comprising a compound represented by the following chemical formula 2:
[Chemical formula 2]
Mn _a2 Ce _b ZnFe ₂ O ₄
In the above chemical formula 2,
0.002 < a2 < 0.1,
0.001 < b < 0.02. In Article 9,
The compound represented by the above chemical formula 2 has a spinel structure,
A catalyst for oxidative dehydrogenation reaction, wherein the crystal size of the compound represented by the chemical formula 2 above is 110 nm or more.