KR20200051474A - Zinc ferrite-based catalysts and method of preparing the same - Google Patents

Abstract

A method for preparing a zinc ferrite-based catalyst according to an embodiment of the present application includes the steps of: obtaining a precipitate by making a metal precursor solution containing a zinc precursor, a ferrite precursor, and water touch contact with a basic solution; filtering, drying and firing the precipitate to obtain a solid sample; and preparing a catalyst by coating a composition containing the solid sample and a side reaction inhibitor on a carrier. According to the present invention, it is possible to obtain butadiene in high yield.

Description

Zinc ferrite catalyst and method for manufacturing the same {ZINC FERRITE-BASED CATALYSTS AND METHOD OF PREPARING THE SAME}

This application claims the benefit of the filing date of Korean Patent Application No. 10-2018-0134410 filed with the Korean Intellectual Property Office on November 5, 2018, the entire contents of which are incorporated herein.

The present application relates to a zinc ferrite-based catalyst and a method for manufacturing the same.

In the petrochemical market, the oxidative dehydrogenation reaction of butene to produce butadiene, which is gradually increasing in demand, is a reaction in which butene and oxygen react to produce butadiene and water. In addition, it is possible to lower the reaction temperature.

The oxidative dehydrogenation reaction of normal-butene (1-butene, trans-2-butene, cis-2-butene) is a reaction in which normal-butene and oxygen react to produce butadiene and water. However, in the oxidative dehydrogenation reaction, since oxygen is used as a reactant, many side reactions such as a complete oxidation reaction are expected, so it is the most important core technology to suppress such side reactions as much as possible and to develop a catalyst having a high selectivity of butadiene. Catalysts used in the oxidative dehydrogenation reaction of butenes known to date include ferrite-based catalysts, tin-based catalysts, and bismuth molybdate-based catalysts.

Among them, the ferrite-based catalyst has different activity as a catalyst depending on the type of metal constituting the divalent cation site of the spinel structure. Among them, zinc ferrite, magnesium ferrite, and manganese ferrite have good activity for the oxidative dehydrogenation reaction of butene. It has been reported that zinc ferrite has a higher selectivity of butadiene than ferrite catalysts of other metals [F.-Y. Qiu, L.-T. Weng, E. Sham, P. Ruiz, B. Delmon, Appl. Catal., Vol. 51, p. 235 (1989)].

The use of zinc ferrite-based catalysts in the oxidative dehydrogenation reaction of butene has been reported, and in order to increase the reaction activity and life of the zinc ferrite catalyst for the oxidative dehydrogenation reaction, pretreatment such as treatment with additives to the catalyst and It is known that butadiene can be obtained in the long term with higher yield through post-treatment.

However, in the oxidative dehydrogenation reaction of butene, an increase in side reaction materials such as CO _x becomes a problem, which decreases the efficiency of the process and increases the cost. Therefore, there is an urgent need to research and develop a method to minimize side reactions even when a Fe ₂ O ₃ crystal structure is present.

United States Patent Publication No. 2013-0209351

This application is intended to provide a zinc ferrite-based catalyst and a method for producing the butadiene with high yield by increasing the conversion of butene and increasing the selectivity of butadiene.

One embodiment of the present application,

A step of obtaining a precipitate by contacting a metal precursor solution containing a zinc precursor, a ferrite precursor, and water with a basic aqueous solution;

Filtering the precipitate, followed by drying and firing to obtain a solid sample; And

Comprising the step of preparing a catalyst by coating the composition containing the solid sample and the side reaction inhibitor on a carrier,

The side reaction inhibitor provides a method for producing a zinc ferrite-based catalyst comprising one or more of Cs, Ti, Zr, V, Nb, W, Cu, Ag, Cd, and Sb.

In addition, another exemplary embodiment of the present application provides a zinc ferrite-based catalyst prepared according to the method for preparing the zinc ferrite-based catalyst.

In addition, another embodiment of the present application,

Preparing the zinc ferrite catalyst; And

Preparing butadiene by using the zinc ferrite catalyst in an oxidative dehydrogenation reaction of butene

It provides a method for producing butadiene containing.

The zinc ferrite-based catalyst according to an exemplary embodiment of the present application may be prepared by coating a composition comprising a zinc ferrite-based catalyst and a side reaction inhibitor on a carrier, thereby reducing the crystal structure of α-Fe ₂ O _{3 in the} catalyst. Accordingly, the activity of the catalyst can be increased.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can obtain butadiene with a high yield while using a small amount of steam.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can control the activity per unit volume of the catalyst, thereby lowering the temperature inside the catalyst layer to stably operate the reactor.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can reduce the amount of wastewater generated so that the manufacturing method can increase the efficiency of the process.

1 is a cross-sectional view of a reactor used for the oxidative dehydrogenation reaction of butene according to an exemplary embodiment of the present application.

Hereinafter, the present application will be described in more detail.

In this specification, 'yield (%)' is defined as a value obtained by dividing the number of moles of 1,3-butadiene as a product of an oxidative dehydrogenation reaction by the number of moles of butene as a raw material. For example, the yield can be expressed by the following equation.

Yield (%) = [(Number of moles of 1,3-butadiene produced) / (Number of moles of butene supplied)] × 100

In the present specification, 'conversion rate (%)' refers to a rate of conversion of a reactant to a product. For example, the conversion rate of butene may be defined by the following equation.

Conversion rate (%) = [(mole number of butene reacted) / (mole number of butene supplied)] × 100

In the present specification, 'selectivity (%)' is defined as a value obtained by dividing the amount of change in butadiene (BD) by the amount of change in butene (BE). For example, the selectivity can be expressed by the following equation.

Selectivity (%) = [(molar number of 1,3-butadiene or COx generated) / (molar number of butene reacted)] × 100

In the present specification, 'butadiene' means 1,3-butadiene.

As described above, it is known that the activity of a ferrite-based catalyst having a spinel structure (AFe ₂ O ₄ ) is good as a catalyst for the process of producing 1,3-butadiene through an oxidative dehydrogenation reaction of butene. have.

On the other hand, in the case of a ferrite-based catalyst, it is known that the reactivity to 2-butene, especially trans-2-butene, shows better results than the bismuth-molybdenum catalyst (Mo-Bi catalyst). have. Therefore, even if the Mo-Bi catalyst is applied to the oxidative dehydrogenation reaction of 2-butene, the same effect as in the present application, that is, the result such as the conversion of butene or the selectivity of butadiene is not obtained.

At this time, the ZnFe ₂ O ₄ catalyst used in the oxidative dehydrogenation reaction of butene is generally prepared by a co-precipitation method. The coprecipitation method is prepared through precipitation, stirring, aging and washing, drying, and calcination processes, and it is very important to uniformly precipitate zinc (Zn) and ferrite (Fe).

The problem is that α-Fe ₂ O ₃ phase is formed in the process of synthesis of a zinc ferrite catalyst using a conventional coprecipitation method. The α-Fe ₂ O ₃ phase shows a low butadiene selectivity in the oxidative dehydrogenation reaction of butene, while a high butadiene selectivity in the ZnFe ₂ O ₄ phase.

In addition, the zinc ferrite-based catalyst theoretically forms a spinel structure having the formula of ZnFe ₂ O ₄ , and additional functions may be added to the catalyst by using a method of adding a metal other than Zn and Fe. However, when a metal is additionally added to the zinc ferrite catalyst, a phenomenon in which an intrinsic crystal structure of the zinc ferrite catalyst changes occurs, which may lead to a decrease in catalyst performance.

Accordingly, the present inventors conducted a study on a method for preparing a zinc ferrite-based catalyst capable of increasing activity by controlling the production of α-Fe ₂ O ₃ phase to improve butadiene selectivity, and completed the present invention.

A method of manufacturing a zinc ferrite-based catalyst according to an exemplary embodiment of the present application includes: obtaining a precipitate by contacting a metal precursor solution containing a zinc precursor, a ferrite precursor, and water with a basic aqueous solution; Filtering the precipitate, followed by drying and firing to obtain a solid sample; And coating the composition containing the solid sample and the side reaction inhibitor on a carrier to prepare a catalyst, wherein the side reaction inhibitor is one of Cs, Ti, Zr, V, Nb, W, Cu, Ag, Cd, and Sb. Contains more than species.

In one embodiment of the present application, the solid sample may include a zinc ferrite-based catalyst represented by Formula 1 below.

[Formula 1]

ZnFe _a O _x

In Chemical Formula 1,

a is 1.5 to 2.8,

x can be determined by the oxidation number of the cation.

In Chemical Formula 1, a may be 1.6 to 2.5, and preferably 1.8 to 2.2.

In one embodiment of the present application, based on the total weight of the metal precursor solution, the content of the zinc precursor may be 0.1 wt% to 5 wt%, and may be 0.1 wt% to 3 wt%. In addition, based on the total weight of the metal precursor solution, the content of the ferrite precursor may be 1 wt% to 10 wt%, and may be 1 wt% to 7 wt%. When the content of the zinc precursor and the ferrite precursor satisfies the above-described range, it is easy to synthesize a zinc ferrite-based catalyst when forming a precipitate by coprecipitation.

In an exemplary embodiment of the present application, the zinc precursor and the ferrite precursor are each independently selected from the group consisting of nitrate, ammonium salt, sulfate, and chloride, or one or more types, or Hydrates thereof. Specifically, it is preferably nitrate or chloride, or a hydrate thereof.

In one embodiment of the present application, the zinc precursor may be zinc chloride (ZnCl ₂ ). In this case, the formation of a zinc ferrite catalyst is excellent.

In one embodiment of the present application, the ferrite precursor may be ferric chloride hydrate (FeCl ₃ · 6H ₂ O). In this case, the formation of a zinc ferrite catalyst is excellent.

In one embodiment of the present application, the water may use pure water (DI water). The temperature of the DI water may be greater than 0 ° C and less than 40 ° C. Preferably, it may be greater than 0 ° C and less than or equal to 30 ° C. More preferably, it may be 5 ° C or more and 25 ° C or less. When the temperature of the pure water satisfies the above range, the production amount of the catalyst by the precipitation method is increased, and the content of the active catalyst is adjusted to ultimately improve the selectivity and yield of butadiene according to the oxidative dehydrogenation reaction.

In one embodiment of the present application, the pH of the basic aqueous solution may be 7 to 10. Preferably, the pH may be 7.5 to 9. When the above range is satisfied, there is an effect of stably generating a zinc ferrite catalyst.

In one embodiment of the present application, the basic aqueous solution may be at least one selected from the group consisting of potassium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, aqueous sodium hydroxide solution, aqueous sodium carbonate solution and aqueous ammonia. Preferably, the basic aqueous solution may be ammonia water. In this case, during the preparation of the zinc ferrite-based catalyst, it is easy to precipitate, and there is an effect of improving the formation of catalyst particles.

In one embodiment of the present application, the concentration of the basic aqueous solution may be 5% to 40% by weight, and 8% to 30% by weight.

In an exemplary embodiment of the present application, the step of obtaining the precipitate may further include agitating the metal precursor solution after contacting the basic aqueous solution. By further comprising the stirring step, precipitation of metal precursors is facilitated, and catalyst particle formation is advantageous. The stirring step may be performed at room temperature, and the stirring method may be used without limitation as long as it is a method of mixing a liquid phase and a liquid phase. In addition, the stirring time of the stirring step may be 30 minutes to 3 hours, and may be 1 hour to 2 hours.

In one embodiment of the present application, the step of filtering the precipitate is not particularly limited as long as it is a filtration method commonly used in the art. For example, it may be vacuum filtration. Specifically, it may be a method of filtering under reduced pressure using a vacuum pump, and in this case, there is an effect of washing and separating moisture from the catalyst. Another example could be using filter-press equipment. It may be a method of passing the distilled water after accumulating the coprecipitation solution in a filter cloth.

In an exemplary embodiment of the present application, the precipitate may be further filtered and washed before firing. By further including the washing step, it is possible to remove unnecessary ions (ions) remaining in the precipitate.

In an exemplary embodiment of the present application, the drying step may be performed after filtration and washing after filtering the precipitate. The step of drying the precipitate is not particularly limited as long as it is a drying method commonly used in the art. For example, a dryer can be used and an oven can be used. The drying step may be dried at 80 ℃ to 150 ℃.

In one embodiment of the present application, the step of calcining the precipitate may be heated at a rate of 1 ° C / min at 80 ° C, and maintained at 600 ° C to 800 ° C for 5 to 10 hours. The calcination step, specifically, 600 ℃ to 700 ℃, may be specifically baked at 600 ℃ to 650 ℃. The calcining step may be specifically 5 to 8 hours, and more specifically 5 to 6 hours.

The firing method may be a heat treatment method commonly used in the art.

In one embodiment of the present application, the step of calcining the precipitate may be performed by injecting 1 L / min of air into the kiln.

According to an exemplary embodiment of the present application, coating the composition containing the solid sample and the side reaction inhibitor on a carrier to prepare a catalyst, wherein the side reaction inhibitor is Cs, Ti, Zr, V, Nb, W, Cu , Ag, Cd and Sb.

In the step of preparing a catalyst by coating the composition containing the solid sample and the side reaction inhibitor on a carrier, the content of the side reaction inhibitor may be 0.005% to 1.8% by weight, and 0.008% by weight based on the total weight of the solid sample. It may be from 0.1 to 0.1% by weight, it may be from 0.008% by weight to 0.012% by weight. When the content of the side reaction inhibitor is less than 0.005% by weight, an increase in the effect of adding the side reaction inhibitor may be insignificant, and when the side reaction inhibitor is added in excess, side reactions such as COx increase during oxidative dehydrogenation of butene may proceed. Is undesirable. In particular, in the butadiene manufacturing process, when considering butadiene selectivity, butadiene yield, COx selectivity, etc., it is most preferable that the content of the side reaction inhibitor is 0.008 wt% to 0.012 wt%.

In an exemplary embodiment of the present application, the step of preparing the catalyst by supporting the solid sample on a carrier, prepares a slurry including the solid sample, a side reaction inhibitor, and water, and then coats the slurry on a carrier It can be performed in a way. At this time, the solid content of the solid sample included in the slurry may be 1% to 30% by weight.

In one embodiment of the present application, the side reaction inhibitor may be made of a metal material, and the type is not particularly limited, but Cs, Ti, Zr, V, Nb, W, Cu, Ag, Cd, and Sb 1 Species. In addition, the side reaction inhibitor may be an oxide containing one or more of Cs, Ti, Zr, V, Nb, W, Cu, Ag, Cd and Sb.

In general, the process in which iron oxide is reduced by hydrogen consists of several steps. At this time, when the reduction proceeds at a low temperature, the mobility of oxygen may be increased. The iron oxide reduction process can be applied to the zinc ferrite-based catalyst. In this regard, as a result of Temperature Programmed Reduction (TPR) to check the reduction characteristics of the catalyst and Temperature Programmed Reduction / Oxidation (TPRO) analysis to confirm the behavior of oxygen in the catalyst, the catalyst with the side reaction inhibitor is reduced by one step And it was confirmed that the re-oxidation is made, which may mean that oxygen is relatively rich in the catalyst lattice. Therefore, it can be seen that side reactions are suppressed by the oxidation and reduction properties of oxygen.

In an exemplary embodiment of the present application, in the step of coating the solid sample and the side reaction inhibitor on the carrier, the size and shape of the carrier may vary depending on the size of the reactor to be used for the reaction, and is not particularly limited, but has a diameter. It may be a spherical or cylindrical 2mm to 20mm.

The step of coating the solid sample and side reaction inhibitor on the carrier is to perform a process in which the solid sample and side reaction inhibitor enter the pores of the carrier, so that the solid sample and side reaction inhibitor adhere to the surface area of the carrier. In addition, it may mean that it is present in the pores of the carrier.

In addition, by controlling the amount of the zinc ferrite catalyst component per unit volume through the coating step, it is possible to control the oxidative dehydrogenation reaction rate of butene, thereby enabling effective reaction heat control.

The coating step may be carried by mixing the porous carrier with the slurry and then drying while stirring, or allowing the slurry to be impregnated as much as the pore volume of the carrier and then dried to be supported. The drying method is not particularly limited, but a rotary evaporator may be used. In addition, the previous process can be repeated several times to increase the content of the solid sample.

In one embodiment of the present application, the carrier may have a pore structure. The carrier having a pore structure is not particularly limited, but the pulverized solid sample may have pores of a size that can enter the pores of the carrier.

Further, according to an exemplary embodiment of the present application, the pore structure of the carrier may have a pore size of 10 µm to 300 µm, and a porosity relative to the total volume of the carrier may be 10% to 50%.

For the method of measuring the pore size on the surface of the carrier, a commonly used technique may be used, and although not particularly limited, a mercury porosimeter may be used.

Further, according to an exemplary embodiment of the present application, the pore structure of the carrier may cause the carrier to have a specific surface area of 0.005 m ² / g to 0.5 m ² / g.

The specific surface area of the carrier is related to the supporting properties of the solid sample and the performance as a catalyst, and when the specific surface area is less than 0.005 m ² / g, it is difficult to expect a desired reaction performance because it cannot sufficiently provide the surface where the reaction occurs, 0.5 When it is larger than m ² / g, it is difficult to make the pore size of the carrier large, so it is difficult to carry a solid sample, and it is also difficult for the reactant to enter the pores or the product to escape out of the pores, so it may not function as a catalyst. The surface area of the carrier can typically be the BET surface area by N ₂ adsorption.

In one embodiment of the present application, the carrier may include one or more of alumina, silica, alumina / silica, silicon carbide, titania, and zirconia. More specifically, alumina / silica may be included, which has a pore structure in which the zinc ferrite-based catalyst component can be stably supported on a carrier, and has a small acidic site that causes side reactions, and thus does not react with the zinc ferrite-based catalyst component. Chemical stability.

In one embodiment of the present application, the step of firing the carrier on which the slurry is supported may be carried out at 500 ° C to 800 ° C after drying under reduced pressure or drying in an oven. Baking may mean that the zinc ferrite catalyst component supported on the porous carrier forms an active phase. When fired at a temperature lower than 500 ° C, the supported ferrite component does not form an active phase, and thus, the activity for the butene oxidation dehydrogenation reaction is lowered. When fired at a temperature higher than 800 ° C, the surface area of the supported ferrite component is Excessively reduced, the activity for the butene oxidative dehydrogenation reaction may be deteriorated, and the ferrite component and the carrier may react to form another crystalline phase, resulting in poor selectivity. Specifically, it can be carried out at 600 ° C to 700 ° C.

In addition, another exemplary embodiment of the present application provides a zinc ferrite-based catalyst prepared according to the above-described method for preparing a zinc ferrite-based catalyst.

In addition, an exemplary embodiment of the present application, preparing the zinc ferrite-based catalyst; And using the zinc ferrite-based catalyst for an oxidative dehydrogenation reaction of butene to produce butadiene.

In one embodiment of the present application, the step of preparing the butadiene comprises a reaction temperature of 400 ° C. to 600 ° C. for a raw material comprising C4 oil, steam, oxygen (O ₂ ) and nitrogen (N ₂ ), Under pressure conditions of 0.0bar to 10bar, it may be to react under the conditions of GHSV (Gas Hourly Space Velocity) 50h ^-1 to 400h ^-1 .

The C4 oil may mean useful C4 raffinate-1, 2, 3 after separating useful compounds from the C4 mixture produced by naphtha cracking, and refers to C4 species obtained through ethylene dimerization. It may be.

In one embodiment of the present application, the C4 oil is n-butane (n-butane), trans-2-butene (trans-2-butene), cis-2-butene (cis-2-butene), and 1 It may be a mixture of 1 or 2 or more selected from the group consisting of -butene.

In one embodiment of the present application, the steam (steam) or nitrogen (N ₂ ) in the oxidative dehydrogenation reaction, while reducing the risk of explosion of the reactants, while preventing the coking of the catalyst (coking) and removal of the reaction heat It is a dilution gas injected for the purpose.

In one embodiment of the present application, the oxygen (O ₂ ) reacts with a C4 fraction as an oxidant to cause a dehydrogenation reaction.

In one embodiment of the present application, the oxidative dehydrogenation reaction may be prepared according to Scheme 1 or Scheme 2 below.

[Scheme 1]

C ₄ H ₈ + 1/2 O ₂ → C ₄ H ₆ + H ₂ O

[Scheme 2]

C ₄ H ₁₀ + O ₂ → C ₄ H ₆ + 2H ₂ O

Butadiene is produced by removing hydrogen from butane or butene through the oxidative dehydrogenation reaction. Meanwhile, in the oxidative dehydrogenation reaction, a side reaction product including carbon monoxide (CO) or carbon dioxide (CO ₂ ) may be generated in addition to the main reaction as in Reaction Scheme 1 or 2. The side reaction product may include a process that is separated and discharged outside the system so that continuous accumulation does not occur in the process.

The reactor used for the oxidative dehydrogenation reaction is shown in FIG. 1. After fixing the zinc ferrite catalyst prepared by the method according to an exemplary embodiment of the present application to a straight-type molten salt type reactor, and installing the reactor in an electric furnace to circulate molten salt to maintain a constant temperature outside the catalyst layer. , It is possible to allow the reaction to proceed while the reactant continuously passes through the catalyst layer in the reactor.

The temperature of the molten salt for advancing the oxidative dehydrogenation reaction may be 250 ° C to 550 ° C, specifically 280 ° C to 500 ° C, more specifically 300 ° C to 450 ° C, and the amount of reactant injected The amount of catalyst can be set so that the gas hourly space velocity (GHSV) is 50 h ^-1 to 500 h ^-1 based on butene.

As described above, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application may reduce the α-Fe ₂ O ₃ crystal structure in the catalyst by preparing a side reaction inhibitor on a carrier carrying the zinc ferrite-based catalyst, , Accordingly, the activity of the catalyst can be increased.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can obtain butadiene with a high yield while using a small amount of steam.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can control the activity per unit volume of the catalyst, thereby lowering the temperature inside the catalyst layer to stably operate the reactor.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can reduce the amount of wastewater generated so that the manufacturing method can increase the efficiency of the process.

Hereinafter, examples will be described in detail to specifically describe the present application. However, the embodiments according to the present application may be modified in various other forms, and the scope of the present application is not interpreted to be limited to the embodiments described below. The embodiments of the present application are provided to more fully describe the present application to those skilled in the art.

< Example >

< Experimental Example  1>

In order to examine the activity of the catalyst according to the addition time of the side reaction inhibitor according to an exemplary embodiment of the present application, the following experiment was conducted.

A zinc ferrite-based catalyst was prepared, and an experiment was conducted in which Zr as a side reaction inhibitor was added to the catalyst at different time points at 1.6% by weight as follows.

One) Experimental Example  1-1

Zinc chloride (ZnCl ₂₎ to 0.122 mol and 0.243 mol of ferric chloride (FeCl ₃ -6H ₂ O) was dissolved in water to prepare a metal precursor solution 12.778 mol. At this time, the molar ratio of metal components contained in the aqueous metal precursor solution is Fe: Zn = 2: 1.

Next, after preparing a co-precipitation tank (pH 7 to 9) in which ammonia water was prepared, a metal precursor aqueous solution was deposited with ammonia water having a concentration of 9% to 10% by weight to coprecipitate iron and zinc. After completion of co-precipitation, the co-precipitation solution was stirred for 1 hour to achieve a sufficient process, and after stopping the stirring, the precipitate was allowed to stand for 1 hour at room temperature so that the precipitates settled and aged.

The stirred and aged coprecipitation solution was filtered using a Filter-press equipment, and the coprecipitate was put in a calcination furnace and heat-treated at 650 ° C for 5 hours to prepare a zinc ferrite catalyst.

The prepared zinc ferrite catalyst was pulverized / classified to a size of 0 to 400 µm, preferably 0 to 100 µm, using a grinding equipment. An appropriate amount of H ₂ O was supplied and dissolved in the pulverized catalyst powder. The carrier was introduced into the filter distiller, and the dissolved slurry was introduced into the filter distiller to perform coating.

2) Experimental Example  1-2

In Experimental Example 1-1, during the coprecipitation process, ZrO ₂ was added in the same manner as in Experimental Example 1-1, except that 1.6% by weight of ZrO ₂ was added based on the weight sum of the zinc precursor and the ferrite precursor.

3) Experimental Example  1-3

A zinc ferrite catalyst was prepared as in Experimental Example 1-1.

The carrier was introduced into the filter distiller, and the slurry in which ZrO ₂ was dissolved in water was introduced into the filter distiller to perform coating and firing processes on the carrier. At this time, the content of ZrO ₂ was 1.6% by weight based on the total weight of the carrier. Thereafter, H ₂ O was supplied to the pulverized zinc ferrite catalyst powder to further coat the dissolved slurry on a carrier.

4) Experimental Example  1-4

A zinc ferrite catalyst was prepared as in Experimental Example 1-1.

The crushed zinc ferrite catalyst powder and ZrO ₂ were dissolved by supplying an appropriate amount of H ₂ O. At this time, the content of ZrO ₂ was 1.6% by weight based on the total weight of the zinc ferrite catalyst powder. The carrier was introduced into the filter distiller, and the dissolved slurry was introduced into the filter distiller to perform coating.

5) Experimental Example  1-5: Butadiene production

As a reactor, a zinc ferrite catalyst prepared in Experimental Examples 1-2 to 1-4 was fixed to a catalyst tube volume of 150 cc in a metal tubular reactor having a diameter of 1.8 cm, 40% by weight of cis-2-butene as a reactant, and trans-2-butene 60 A weight% 2-butene mixture and oxygen were used and nitrogen and steam were introduced. The reactant ratio was set at a molar ratio of oxygen / butene 1, steam / butene 8 and nitrogen / butene 1, and steam was vaporized in a vaporizer at 340 ° C. to enter the reactor together with the reactants.

The amount of the butene mixture was controlled to 0.625 cc / min using a mass flow regulator for liquid, the oxygen and nitrogen were controlled using a mass flow regulator for gas, and the amount of steam was controlled using a liquid pump. The gas hourly space velocity (GHSV) of the reactor was set to 133h ^-1 and reacted under normal temperature (pressure gauge 0) under the temperature conditions shown in Table 1 below.

After the reaction, gas chromatography (GC) analysis was performed on the product to calculate butene conversion, butadiene selectivity, butadiene yield (Y), and COx selectivity. After connecting, it was measured by moving from the top of the reactor to the bottom at a constant speed and scanning.

< GC  Analysis conditions>

① Column: HP-1 (L: 30m, ID: 0.32mm, film: 1.05m)

② Injection volume: 1µl

③ Inlet Temp .: 280 ℃, Pressure: 36.3psi, Total flow: 33.5ml / min, Split flow: 30ml / min, spilt ratio: 20.5: 1

④ Column flow: 1.2ml / min

⑤ Oven temp .: 50 ℃-> 0 ℃ (6min), 0 ℃ (maintain 15min), 0 ℃-> 250 ℃ raising and maintaining (40min)

⑥ Detector temp .: 280 ℃, H2: 35ml / min, Air: 300ml / min, He: 20ml / min

⑦ GC Model: Agilent 6890

[Table 1]

As in the above results, in the case of Experimental Example 1-4, which is prepared by coating a composition containing a zinc ferrite catalyst and a side reaction inhibitor on a carrier, butene conversion and butadiene are selected in comparison with Experimental Example 1-2 and Experimental Example 1-3. It can be seen that the degree increases.

< Experimental Example  2>

In order to examine the activity of the catalyst according to the content of the side reaction inhibitor according to an exemplary embodiment of the present application, the following experiment was conducted.

A zinc ferrite-based catalyst was prepared, and experiments were conducted in which Zr as a side reaction inhibitor was added to the catalyst in different contents as follows.

One) Experimental Example  2-1

A zinc ferrite catalyst was prepared as in Experimental Example 1-1.

The crushed zinc ferrite catalyst powder and ZrO ₂ were dissolved by supplying an appropriate amount of H ₂ O. At this time, the content of ZrO ₂ was 0.01% by weight based on the total weight of the zinc ferrite catalyst powder. The carrier was introduced into the filter distiller, and the dissolved slurry was introduced into the filter distiller to perform coating.

2) Experimental Example  2-2

In Experimental Example 2-1, the content of the ZrO ₂ was performed in the same manner as in Experimental Example 2-1, except that the content of the zinc ferrite catalyst powder was adjusted to 0.015% by weight.

3) Experimental Example  2-3: Butadiene production

As a reactor, a zinc ferrite catalyst prepared in Experimental Example 1-1, Experimental Example 2-1, and Experimental Example 2 was fixed to a metal tubular reactor having a diameter of 1.8 cm with a catalyst layer volume of 150 cc, and cis-2-butene 40 weight as a reactant %, Trans-2-butene 60% by weight of 2-butene mixture and oxygen were used and nitrogen and steam were introduced. The reactant ratio was set at a molar ratio of oxygen / butene 1, steam / butene 8 and nitrogen / butene 1, and steam was vaporized in a vaporizer at 340 ° C. to enter the reactor together with the reactants.

The amount of the butene mixture was controlled to 0.625 cc / min using a mass flow regulator for liquid, the oxygen and nitrogen were controlled using a mass flow regulator for gas, and the amount of steam was controlled using a liquid pump. The gas hourly space velocity (GHSV) of the reactor was set to 133h ^-1 and reacted under normal temperature (pressure gauge 0) under the temperature conditions shown in Table 1 below.

After the reaction, gas chromatography (GC) analysis was performed on the product to calculate butene conversion, butadiene selectivity, butadiene yield (Y), and COx selectivity. After connecting, it was measured by moving from the top of the reactor to the bottom at a constant speed and scanning. The GC analysis conditions are the same as those of Experimental Example 1-5 described above.

[Table 2]

As in the above results, in the case of Experimental Examples 2-1 and 2-3, which is an exemplary embodiment of the present application, it was confirmed that the butadiene selectivity, butadiene yield, and the like increased compared to Experimental Example 1-1 without adding a side reaction inhibitor. Can be. In particular, in the butadiene manufacturing process, when considering butadiene selectivity, butadiene yield, COx selectivity, etc., it can be seen that the content of the side reaction inhibitor is most preferably 0.008 wt% to 0.012 wt%.

As described above, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application is prepared by coating a composition comprising a zinc ferrite-based catalyst and a side reaction inhibitor on a carrier, thereby reducing the α-Fe ₂ O ₃ crystal structure in the catalyst It is possible to increase the activity of the catalyst.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can obtain butadiene with a high yield while using a small amount of steam.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can control the activity per unit volume of the catalyst, thereby lowering the temperature inside the catalyst layer to stably operate the reactor.

In addition, the zinc ferrite-based catalyst according to an exemplary embodiment of the present application can reduce the amount of wastewater generated so that the manufacturing method can increase the efficiency of the process.

Claims (10)

A step of obtaining a precipitate by contacting a metal precursor solution containing a zinc precursor, a ferrite precursor, and water with a basic aqueous solution;
Filtering the precipitate, followed by drying and firing to obtain a solid sample; And
Comprising the step of preparing a catalyst by coating the composition containing the solid sample and the side reaction inhibitor on a carrier,
The side reaction inhibitor is Cs, Ti, Zr, V, Nb, W, Cu, Ag, Cd and Sb method for producing a zinc ferrite-based catalyst comprising at least one. The method of claim 1, wherein the solid sample comprises a zinc ferrite-based catalyst represented by Formula 1 below:
[Formula 1]
ZnFe _a O _x
In Chemical Formula 1,
a is 1.5 to 2.8,
x can be determined by the oxidation number of the cation. The method according to claim 1, wherein the zinc precursor and the ferrite precursor are each independently selected from the group consisting of nitrate (nitrate), ammonium salt (ammonium salt), sulfate (sulfate) and chloride (chloride), or a hydrate thereof Method for producing phosphorus zinc ferrite catalyst. The method of claim 1, wherein the zinc precursor is zinc chloride (ZnCl ₂ ). The method of claim 1, wherein the ferrite precursor is ferric chloride hydrate (FeCl ₃ · 6H ₂ O). The method of claim 1, wherein the basic aqueous solution is at least one selected from the group consisting of potassium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, sodium hydroxide aqueous solution, sodium carbonate aqueous solution and ammonia water. The method of claim 1, wherein the carrier comprises at least one of alumina, silica, alumina / silica, silicon carbide, titania, and zirconia. The method according to claim 1, In the step of preparing a catalyst by coating the composition containing the solid sample and the side reaction inhibitor on a carrier,
The method for producing a zinc ferrite catalyst based on the total weight of the solid sample, the content of the side reaction inhibitor is 0.005% to 1.8% by weight. A zinc ferrite-based catalyst prepared according to any one of claims 1 to 8. Preparing a zinc ferrite catalyst of claim 9; And
Preparing butadiene by using the zinc ferrite catalyst in an oxidative dehydrogenation reaction of butene
Method for producing butadiene containing.

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