KR20210118543A - Method for preraring butadiene - Google Patents

Abstract

The present invention relates to a method for preparing butadiene. The method includes the steps of: (S10) supplying a mixed gas stream including butene, steam, oxygen (O_2) and an inert diluent gas to a first reactor; (S20) passing the mixed gas stream through a catalyst layer in which a catalyst including at least one selected from the group consisting of ferrite-based catalysts and MoBi-based metal oxide catalysts is packed, in the first reactor, to obtain a reaction product stream including butadiene produced from oxidative dehydrogenation; and (S30) supplying the reaction product stream to a second reactor and passing it through a catalyst layer in which a MnCe-based metal oxide catalyst is packed, in the second reactor, to remove oxygen compounds contained in the reaction product stream, wherein the first reactor is operated at a temperature of 250-550℃, and the second reactor is operated at a temperature of 150-350℃. According to the present invention, it is possible to reduce unreacted oxygen and oxygen compounds upon the preparation of butadiene through oxidative dehydrogenation.

Description

Butadiene manufacturing method {METHOD FOR PRERARING BUTADIENE}

The present invention relates to a method for producing butadiene, and more particularly, to a method for producing butadiene through an oxidative dehydrogenation reaction.

Butadiene (BD) is an important raw material for making plastic, nylon, polybutadiene, maleic anhydride and styrene butadiene rubber, etc. in the petrochemical market. Its demand is gradually increasing.

Methods for producing the butadiene include a naphtha cracking method, a direct dehydrogenation method, and an oxidative dehydrogenation method.

Conventionally, in order to prepare the butadiene, it has been prepared together with ethylene and propylene using a naphtha pyrolysis method. However, when butadiene is produced by the naphtha pyrolysis method, there is a problem in that the selectivity of butadiene is low and energy loss due to high temperature operation is large.

In comparison, the oxidative dehydrogenation method can produce butadiene with high selectivity without depending on the naphtha pyrolysis method, and can save energy by operating at a low temperature compared to the naphtha pyrolysis method. In addition, there is an advantage in that butadiene can be prepared by a thermodynamically advantageous reaction compared to the direct dehydrogenation method.

However, when butadiene is produced through the oxidative dehydrogenation method, although activity and selectivity are high, a method for further reducing unreacted oxygen and oxygen compounds emitted as by-products is required for a safe and efficient process.

WO 2013-136434 A

The problem to be solved in the present invention relates to a method of reducing unreacted oxygen and oxygen compounds during butadiene production through an oxidative dehydrogenation method in order to solve the problems mentioned in the technology that is the background of the present invention.

That is, an object of the present invention is to provide a safe and efficient method for producing butadiene by improving the selectivity of butadiene by producing butadiene through an oxidative dehydrogenation method, and reducing unreacted oxygen and oxygen compounds, which are by-products.

According to an embodiment of the present invention for solving the above problems, the present invention provides _{a step of supplying a mixed gas stream including butene, steam, oxygen (O 2} ) and an inert diluent gas to the first reactor (S10); The mixed gas stream is passed through a catalyst bed filled with a catalyst containing at least one selected from the group consisting of a ferritic catalyst and a MoBi-based metal oxide catalyst in the first reactor, and a reaction product stream containing butadiene by oxidative dehydrogenation reaction manufacturing a (S20); and supplying the reaction product stream to a second reactor, passing through a catalyst bed filled with a MnCe-based metal oxide catalyst in the second reactor, to remove oxygen compounds contained in the reaction product stream (S30), The operating temperature of the first reactor is 250 to 550° C., and the operating temperature of the second reactor is 150 to 350° C. It provides a method for producing butadiene.

According to the butadiene production method of the present invention, a reaction product with high butadiene selectivity is prepared by an oxidative dehydrogenation method in the first reactor, and the content of unreacted oxygen and oxygen compounds as a by-product in the reaction product is reduced in the second reactor. , while producing butadiene with high selectivity, it is possible to provide a safe and efficient method for producing butadiene.

1 is a process flow diagram of a butadiene manufacturing method according to an embodiment of the present invention.
2 is a process flow diagram of a butadiene manufacturing method according to a comparative example.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the term 'stream' may mean a flow of a fluid in a process, and may also mean a fluid itself flowing in a pipe. Specifically, the 'stream' may mean both the fluid itself and the flow of the fluid flowing within a pipe connecting each device. In addition, the fluid may refer to gas and liquid.

Hereinafter, the present invention will be described in more detail with reference to FIG. 1 to help the understanding of the present invention.

According to the present invention, there is provided a method for producing butadiene. The butadiene production method includes the steps of supplying a mixed gas stream including butene, steam, oxygen (O ₂ ) and an inert diluent gas to the first reactor 100 ( S10 ); The mixed gas stream is passed through a catalyst bed filled with a catalyst including at least one selected from the group consisting of a ferritic catalyst and a MoBi-based metal oxide catalyst in the first reactor 100, and includes butadiene by oxidative dehydrogenation reaction preparing a reaction product stream (S20); and supplying the reaction product stream to the second reactor 200, passing the catalyst bed filled with the MnCe-based metal oxide catalyst in the second reactor 200, to remove oxygen compounds contained in the reaction product stream ( S30), wherein the operating temperature of the first reactor 100 may be 250 to 550° C., and the operating temperature of the second reactor 200 may be 150 to 350° C.

According to an embodiment of the present invention, in step S10, the mixed gas stream may include butene, steam, oxygen, and an inert diluent gas.

The mixed gas stream may include, for example, a C4 mixture containing a high content of butene, and steam generated by vaporizing air and water. For example, the mixed gas stream may be supplied to the first reactor 100 in a state in which the C4 mixture, air, and steam are mixed. As another example, the mixed gas stream may be supplied to the first reactor 100 as respective streams of the C4 mixture stream, the air stream and the steam stream.

In the mixed gas stream, the C4 mixture is intended to provide butenes used as reactants, for example 1-butene, 2-butene, C4 raffinate-1, C4 raffinate-2 and C4 raffinate-3. can be selected from the group consisting of

In addition, the air may supply nitrogen (N ₂ ) serving as an inert diluent gas while supplying oxygen.

In addition, an inert hydrocarbon gas may be supplied instead of nitrogen as the inert diluent gas. The inert hydrocarbon gas may not be involved in the oxidative dehydrogenation of butene in the process and may be easily condensed compared to nitrogen. For example, the inert hydrocarbon gas may include at least one selected from the group consisting of butane and pentane.

In addition, the steam may control the heat of reaction generated during the oxidative dehydrogenation reaction and improve the selectivity of butadiene.

According to an embodiment of the present invention, the molar ratio of butene, steam, oxygen and inert diluent gas may be 1:3 to 10:0.5 to 1.5:2 to 10. Butadiene can be produced with high selectivity by supplying a mixed gas stream including butene, steam, oxygen, and an inert diluent gas to the first reactor 100 in a molar ratio within the above range to perform an oxidative dehydrogenation reaction.

The butene and oxygen may act as reactants for producing butadiene by performing an oxidative dehydrogenation reaction with each other in step S20 to be described later. Specifically, there is a problem in that, by oxidative dehydrogenation of the butene and oxygen, a desired butadiene is produced with high selectivity and, at the same time, unreacted oxygen and an oxygen compound are generated as a by-product.

The oxygen compound generated as a by-product in the oxidative dehydrogenation reaction may include, for example, acetaldehyde. Since the acetaldehyde can act as a serious fouling agent, in an environment in which the acetaldehyde is present, driving stability is lowered, and economically due to a short period of stop for fouling removal. There is a problem with loss.

Therefore, in the present invention, butadiene is produced with high selectivity by oxidative dehydrogenation reaction of butene and oxygen, but unreacted oxygen is selectively removed together with acetaldehyde, which causes the above problems, thereby improving the yield, safety and efficiency of the process at the same time An object of the present invention is to provide a method for producing butadiene that can be improved.

According to an embodiment of the present invention, in the mixed gas stream supplied to the first reactor 100, butene, oxygen and nitrogen are precisely controlled and supplied using a mass flow rate controller, and steam is supplied with water by an HPLC pump. After injection, it can be vaporized and injected.

The temperature of the inlet for supplying the mixed gas stream to the first reactor 100 may be maintained at 150 to 300° C., and the mixed gas stream supplied through the inlet passes through the heat exchange layer and then the catalyst layer in step S20 to be described later. It can undergo oxidative dehydrogenation while passing.

According to an embodiment of the present invention, in step S20, the mixed gas stream supplied to the first reactor 100 passes through the catalyst bed in the first reactor 100, and butene and oxygen in the mixed gas stream are oxidatively dehydrogenated. The reaction may be a step of preparing a reaction product including butadiene.

The catalyst layer in the first reactor 100 may be filled with a catalyst including at least one selected from the group consisting of a ferritic catalyst and a MoBi-based metal oxide catalyst.

According to an embodiment of the present invention, the ferritic catalyst may include ferrite and a carrier. Specifically, the ferritic catalyst may be in a form in which ferrite in powder form is supported on a carrier. At this time, the size and shape of the carrier may vary depending on the size of the reactor to be used for the reaction and are not particularly limited, but may be spherical or cylindrical with a diameter of 2 mm to 20 mm, and the pore structure of the carrier Specifically, the pore size may be 1 um to 300 um, and the porosity may be 10% to 90%.

The carrier may be, for example, any one selected from the group consisting of alumina, silica, alumina/silica, silicon carbide, titania, and zirconia. Specifically, alumina/silica may be included, which has a pore structure in which a ferrite solid sample can be stably supported on a carrier and has high thermal conductivity, so that a target reaction can be achieved even with a small amount of catalyst. controllable and chemical stability.

The ferrite may be represented by the following general formula (1).

[General formula 1]

Zn ₁ Fe _a M _b O _x

In Formula 1, a is 2 to 2.8, b is 0 to 0.2, M is Be, Mg, Ca, Sr, Ba, Al, Cr, Co, Mn, Cu, Ni, La, Ce, Mo, Bi , P and Si, and x may be determined by the oxidation number of the cation. In this case, the content of the solid sample may be 1 to 30 parts by weight based on 100 parts by weight of the total ferritic catalyst. When the oxidative dehydrogenation reaction of butene and oxygen is performed using the ferritic catalyst as described above, the conversion rate, the selectivity of butadiene and the yield can be improved with excellent activity.

According to an embodiment of the present invention, the MoBi-based metal oxide catalyst may be represented by the following general formula (2).

[General Formula 2]

Mo _a Bi _b Co _c (M1) _d (M4) _e O _x

In the general formula 2, M1 is selected from group 1 metal elements, M4 is selected from 4th period transition metal elements excluding cobalt, a is 9 to 25, b is 0.5 to 2, c is 1 to 10, d is 0.01 to 1, e is 0.5 to 5, and x may be determined by the oxidation number of the cation. When the oxidative dehydrogenation reaction of butene and oxygen is performed using the MoBi-based metal oxide catalyst as described above, the conversion rate, the selectivity and the yield of butadiene can be improved with excellent activity.

According to an embodiment of the present invention, the operating temperature of the first reactor 100 may be 250 to 550 ℃. For example, the operating temperature of the first reactor 100 may be 300 to 500 °C, 300 to 400 °C, 360 to 375 °C, or 376 to 390 °C. The oxidative dehydrogenation reaction of butene and oxygen can be efficiently carried out within the above temperature range.

According to an embodiment of the present invention, the reaction product stream containing butadiene produced by the oxidative dehydrogenation reaction while the mixed gas stream passes through the catalyst bed in the first reactor 100 includes butadiene, an oxygen compound, and unreacted oxygen. There may be, and the oxygen compound may include acetaldehyde as described above.

According to an embodiment of the present invention, in step S30, the reaction product stream generated in step S20 is supplied to the second reactor 200, and is included in the reaction product stream while passing through the catalyst bed in the second reactor 200. It may be a step of removing the oxygen compound and unreacted oxygen.

The catalyst layer in the second reactor 200 may be filled with an MnCe-based metal oxide catalyst. For example, the MnCe-based metal oxide catalyst may collectively mean a metal oxide including manganese (Mn) and cerium (Ce). Preferably, the MnCe-based metal oxide catalyst may be represented by the following general formula (3).

[General Formula 3]

Mn _a Ce _1-a O _x

In Formula 3, a is 0.4 to 0.8, and x may be determined by the oxidation number of the cation.

Acetaldehyde can be selectively removed from the reaction product stream by using the MnCe-based metal oxide catalyst as described above. Specifically, in step S30, the reaction product stream may be selectively removed by oxidatively decomposing acetaldehyde in the reaction product stream while passing through the catalyst bed filled with the MnCe-based metal oxide catalyst.

According to an embodiment of the present invention, step S30 may be performed under a condition in which oxygen is present. Specifically, acetaldehyde contained in the reaction product stream is oxidized while passing through the catalyst layer filled with the MnCe-based metal oxide catalyst while consuming unreacted oxygen contained in the reaction product stream. It can be decomposed into carbon monoxide, carbon dioxide and water. . Through this, there is an effect of reducing fouling by removing unreacted oxygen, improving process safety, and at the same time, removing acetaldehyde to further prevent generation of fouling, thereby improving driving stability.

According to an embodiment of the present invention, the operating temperature of the second reactor 200 may be 150 to 350 ℃. For example, the operating temperature of the second reactor 200 may be 155 to 330 °C, 160 to 300 °C, 150 to 210 °C, 170 to 210 °C, 190 to 310 °C, or 240 to 310 °C. It is possible to increase the efficiency of selectively removing acetaldehyde within the above temperature range.

According to an embodiment of the present invention, steps S10 to S30 may be continuously performed.

According to an embodiment of the present invention, the first reactor 100 and the second reactor 200 in the butadiene production method may use, for example, a straight-line molten salt oxidation reactor.

For example, in step S20, the catalyst layer of the molten salt oxidation reactor is filled with a catalyst comprising at least one selected from the group consisting of a ferritic catalyst and a MoBi-based metal oxide catalyst, and the molten salt oxidation reactor is installed in an electric furnace Thus, after maintaining a constant temperature outside the catalyst layer by circulating the molten salt, the reaction may proceed while the mixed gas stream continuously passes through the catalyst layer.

In addition, in the step S30, the catalyst layer of the molten salt oxidation reactor is filled with a MnCe-based metal oxide catalyst, and the molten salt oxidation reactor is installed in an electric furnace to circulate the molten salt to keep the temperature outside the catalyst layer constant. After the reaction is maintained, the reaction product stream may be allowed to proceed continuously while passing through the catalyst bed.

According to an embodiment of the present invention, the operating temperature of the first reactor 100 may be 360 to 375 °C, and the operating temperature of the second reactor 200 may be 150 to 210 °C. More specifically, the operating temperature of the second reactor 200 may be 170 to 210 ℃. In this way, by controlling the operating temperature of the first reactor 100 and the second reactor 200, the conversion rate, the selectivity of butadiene, and the yield are improved, and acetaldehyde, a by-product in the reaction product, is effectively removed in a safe and efficient way. butadiene can be prepared.

According to an embodiment of the present invention, the operating temperature of the first reactor 100 may be 376 to 390°C, and the operating temperature of the second reactor 200 may be 190 to 310°C. More specifically, the operating temperature of the second reactor 200 may be 240 to 310 ℃. In this way, by controlling the operating temperature of the first reactor 100 and the second reactor 200, the conversion rate, the selectivity of butadiene, and the yield are improved, and acetaldehyde, a by-product in the reaction product, is effectively removed in a safe and efficient way. butadiene can be prepared.

According to an embodiment of the present invention, after step S30, the step of separating butadiene from the reaction product (S40) may be further included.

In step S40, the reaction product stream in which the content of acetaldehyde and unreacted oxygen has been lowered through step S30 is supplied to the separation and purification unit 300, and the reaction product through the separation and purification process in the separation and purification unit 300 It may be a step of separating butadiene from

Specifically, the separation and purification unit 300 receives the reaction product stream discharged from the second reactor 200, and unreacted butene, heavy by-products (Heavies), off-gas and butadiene from the reaction product. each can be separated.

At this time, unreacted butene separated in the separation and purification unit 300 may be re-supplied to the first reactor 100 and reused as butene in the mixed gas stream. For example, unreacted butene separated in the separation and purification unit 300 may be mixed with the C4 mixture stream supplied to the first reactor 100 and supplied to the first reactor 100 .

The separation and purification unit 300 is composed of devices necessary for high-purity separation of butadiene from the reaction product, and may be generally performed through a separation and purification process.

According to an embodiment of the present invention, in the butadiene manufacturing method, if necessary, a distillation column (not shown), a condenser (not shown), a reboiler (not shown), a valve (not shown), a pump (not shown), a separator ( Devices such as (not shown) and a mixer (not shown) may be additionally installed.

As mentioned above, the butadiene manufacturing method according to the present invention has been shown in the description and drawings, but the descriptions and drawings above describe and show only the essential components for understanding the present invention, and the processes shown in the description and drawings and In addition to the apparatus, processes and apparatus not separately described and not shown may be appropriately applied and used for carrying out the butadiene production method according to the present invention.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is clear to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

manufacturing example

Preparation Example 1

(Production of zinc ferrite catalyst)

_{Zn(NO 3} ) _2· 6H ₂ O 9.64 g and Fe(NO ₃ ) _3· 9H ₂ O 29.09 g were added to 50 ml of distilled water at room temperature and dissolved while stirring to prepare a precursor aqueous solution A. An aqueous ammonia solution (Sigma-Aldrich, Ammonium hydroxide solution ACS reagent) was added to the prepared precursor aqueous solution A and precipitated until pH 9 was reached. Then, after further stirring for 1 hour, the precipitate (solid sample) obtained after separating the precipitate in a vacuum filter was dried at 200° C. for 24 hours. The dried solid sample was again dispersed in the aqueous solution and then ball milled to prepare a slurry, and the solid content of the prepared slurry was adjusted to 15 wt%. A spherical porous silica alumina (SA5205, Saint Gobain, Inc.) with a diameter of 3 mm and the prepared slurry were added, supported using a rotary evaporator, and heat-treated at 650° C. for 5 hours in an air atmosphere to obtain zinc ferrite component. A catalyst supported by 15 wt% was prepared.

Preparation 2

(Preparation of the first MnCe-based metal oxide catalyst)

In 50 ml of distilled water _{, 4.18 g of Mn(NO 3} ) _2· 4H ₂ O and 7.24 g of Ce(NO ₃ ) _3· 6H ₂ O were added and dissolved while stirring to prepare a precursor aqueous solution B. After adding 6.4 g of citric acid to the prepared precursor aqueous solution B, the mixture was stirred at 85° C. for 1 hour. Then, after raising the temperature to 95° C., 4.14 g of ethylene glycol was added and stirred for 3 hours to prepare a slurry. The prepared slurry was heated on a hot plate without a washing process, and the solvent was removed to recover a sample. The recovered sample was dried at 110° C. for 12 hours and then calcined at 500° C. for 6 hours. The calcined sample was pulverized into particles having an average size of 150 to 300 mesh (50 to 100 μm) using a standard sieve to prepare a first MnCe-based metal oxide catalyst of _{Mn 0.5} Ce _0.5 O _{x .}

Preparation 3

(Preparation of the second MnCe-based metal oxide catalyst)

A second MnCe-based metal oxide catalyst was prepared in the same manner as in Preparation Example 2, except that in Preparation Example 2, the calcination temperature was controlled to 600°C instead of 500°C.

Example

Example 1

Butadiene was prepared as in the process flow diagram shown in FIG. 1 below. Specifically, the mixed gas stream is supplied to the first reactor 100 , and the reaction product stream discharged from the first reactor 100 is supplied to the second reactor 200 , and discharged from the second reactor 200 . The reaction product was supplied to a separation and purification unit 300 to separate butadiene to obtain it.

At this time, a molten salt oxidation reactor having an outer diameter of 1/2 inch was used as the first reactor 100 and the second reactor 200 , and the first reactor 100 was heated (or removed) by using molten salt. The temperature was controlled to 370 °C, and the temperature of the second reactor 200 was controlled to 160 °C.

In addition, the mixed gas stream was supplied to the first reactor 100 at a flow rate of 47.85 cc/min by controlling the molar ratio of butene, steam, oxygen and nitrogen to 1:5:0.75:2.82.

In addition, the catalyst layer of the first reactor 100 was filled with 20 ml of the zinc ferrite catalyst prepared in Preparation Example 1 as a catalyst.

In addition, 0.1 g of the first MnCe-based metal oxide catalyst prepared in Preparation Example 2 was filled in the catalyst layer of the second reactor 200 as a catalyst.

Example 2

In Example 1, it was carried out in the same manner as in Example 1, except that the temperature of the second reactor 200 was controlled to 180 ℃.

Example 3

In Example 1, it was carried out in the same manner as in Example 1, except that the temperature of the second reactor 200 was controlled to 200 °C.

Example 4

In Example 1, the temperature of the first reactor 100 is controlled to 380° C., and in the catalyst layer of the second reactor 200, the second MnCe-based metal oxide catalyst prepared in Preparation Example 3 instead of the first MnCe-based metal oxide catalyst is used as a catalyst. It was carried out in the same manner as in Example 1, except that the MnCe-based metal oxide catalyst was charged and the temperature of the second reactor 200 was controlled to 200°C.

Example 5

In Example 4, it was carried out in the same manner as in Example 4, except that the temperature of the second reactor 200 was controlled to 250°C.

Example 6

In Example 4, it was carried out in the same manner as in Example 4, except that the temperature of the second reactor 200 was controlled to 300°C.

comparative example

Comparative Example 1

Butadiene was prepared as in the process flow diagram shown in FIG. 2 below. Specifically, the mixed gas stream was supplied to the first reactor 100 , and the reaction product stream discharged from the first reactor 100 was supplied to the separation and purification unit 300 to separate butadiene and obtain it.

At this time, a molten salt oxidation reactor having an outer diameter of 1/2 inch was used as the first reactor 100, and the temperature of the first reactor 100 was controlled to 370° C. by heating (or removing heat) using molten salt. .

In addition, the mixed gas stream was supplied to the first reactor 100 at a flow rate of 47.85 cc/min by controlling the molar ratio of butene, steam, oxygen and nitrogen to 1:5:0.75:2.82.

In addition, the catalyst layer of the first reactor 100 was filled with 20 ml of the zinc ferrite catalyst prepared in Preparation Example 1 as a catalyst.

Comparative Example 2

In Example 1, it was carried out in the same manner as in Example 1, except that the temperature of the second reactor 200 was controlled to 125 °C.

Comparative Example 3

In Example 1, it was carried out in the same manner as in Example 1, except that the temperature of the second reactor 200 was controlled to 140 ℃.

Experimental example

In Examples 1 to 6 and Comparative Examples 2 to 3, thermal conductivity of the reaction product discharged from the second reactor 200, however, in Comparative Example 1, the reaction product discharged from the first reactor 100 The analysis was performed using a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID). GC was measured by connecting to the rear end of the first reactor 100 in Comparative Example 1, and the second reactor 200 in Examples 1 to 8 and Comparative Examples 2 to 3 via an on-line connection. Then, the conversion rate and selectivity were calculated by the following method and shown in Table 1 below. In this case, COx means carbon monoxide (CO) or carbon dioxide (CO ₂ ) in the reaction product.

1) Oxygen conversion rate (%) = (1 - number of moles of oxygen after reaction / number of moles of initial oxygen) x 100

2) Butene conversion (%) = (1 - number of moles of butene after reaction / number of moles of initial butene) x 100

3) Butadiene selectivity (%) = (number of moles of butadiene/(number of moles of butene in the initial stage - moles of butene after reaction)) x 100

4) COx selectivity (%) = ((CO and CO ₂ moles/4)/(initial number of moles of butene - moles of butene after reaction)) x 100

5) Acetaldehyde selectivity (%) = ((Mole number of acetaldehyde/4)/(Mole number of initial butene - mole number of butene after reaction)) x 100

Conversion rate (%) Selectivity (%) Oxygen butene butadiene COx acetaldehyde Example 1 99.9 75.0 88.4 10.9 0.14 Example 2 99.9 75.4 88.6 10.8 0.09 Example 3 99.9 77.6 88.8 10.6 0.02 Example 4 87.2 76.8 91.0 8.6 0.14 Example 5 90.1 73.9 89.9 9.6 0.11 Example 6 99.9 76.0 88.3 11.4 0.02 Comparative Example 1 97.2 76.1 89.1 10.3 0.22 Comparative Example 2 98.0 74.5 88.6 10.7 0.23 Comparative Example 3 98.7 74.4 88.4 11.0 0.21

Referring to Table 1, a reaction product stream is prepared by oxidatively dehydrogenating the mixed gas stream in the first reactor 100 in the method according to the present invention, and the reaction product is supplied to the second reactor 200 to produce a reaction product It can be seen that acetaldehyde in the stream is selectively removed. Specifically, it was confirmed that 35% or more, up to 90% or more were removed compared to Comparative Example 1, which did not go through the second reactor 200, and there was little change in the selectivity of butadiene and COx.

In addition, when the operating temperature of the first reactor is 370° C., when the operating temperature of the second reactor is 180 to 200° C., the acetaldehyde removal effect is excellent, and in particular, when the operating temperature of the second reactor is 200° C. The acetaldehyde removal effect was the best.

In addition, when using the second MnCe-based metal oxide catalyst compared to the first MnCe-based metal oxide catalyst, when the first reactor 100 is operated at a temperature of 380° C., the operating temperature of the second reactor 200 is 250 to 300° C. It was confirmed that the acetaldehyde removal effect was improved by operating at a rather high level, and in particular, when the operating temperature of the second reactor was 300° C., the acetaldehyde removal effect was the most excellent.

In addition, in Comparative Examples 2 and 3, butadiene was prepared using the first reactor 100 and the second reactor 200 as in the present invention, but the operating temperature of the second reactor 200 was out of the range according to the present invention , it can be confirmed that the removal effect of acetaldehyde did not appear.

100: first reactor
200: second reactor
300: separation and purification unit

Claims (12)

supplying a mixed gas stream including butene, steam, oxygen (O ₂ ) and an inert diluent gas to the first reactor (S10);
The mixed gas stream is passed through a catalyst bed filled with a catalyst containing at least one selected from the group consisting of a ferritic catalyst and a MoBi-based metal oxide catalyst in the first reactor, and a reaction product stream containing butadiene by oxidative dehydrogenation reaction manufacturing a (S20); and
Supplying the reaction product stream to the second reactor, passing through the catalyst bed filled with the MnCe-based metal oxide catalyst in the second reactor, removing oxygen compounds contained in the reaction product stream (S30),
The operating temperature of the first reactor is 250 to 550 ℃,
The operating temperature of the second reactor is a butadiene production method of 150 to 350 ℃. According to claim 1,
The mixed gas stream has a molar ratio of butene, steam, oxygen and an inert diluent gas of 1:3 to 10:0.5 to 1.5:2 to 10. According to claim 1,
The operating temperature of the first reactor is 360 to 375 ℃,
The operating temperature of the second reactor is a butadiene production method of 150 to 210 ℃. 4. The method of claim 3,
The operating temperature of the second reactor is 170 to 210 ℃ butadiene production method. According to claim 1,
The operating temperature of the first reactor is 376 to 390 ℃,
The operating temperature of the second reactor is 190 to 310 ℃ butadiene production method. 6. The method of claim 5,
The operating temperature of the second reactor is a butadiene production method of 240 to 310 ℃. According to claim 1,
The ferritic catalyst is a method for producing butadiene that satisfies the following general formula 1:
[General formula 1]
Zn ₁ Fe _a M _b O _x
In Formula 1, a is 2 to 2.8, b is 0 to 0.2, M is Be, Mg, Ca, Sr, Ba, Al, Cr, Co, Mn, Cu, Ni, La, Ce, Mo, Bi , P and Si, where x is determined by the oxidation number of the cation. According to claim 1,
The MoBi-based metal oxide catalyst is a butadiene production method that satisfies the following general formula 2:
[General Formula 2]
Mo _a Bi _b Co _c (M1) _d (M4) _e O _x
In the general formula 2, M1 is selected from group 1 metal elements, M4 is selected from 4th period transition metal elements excluding cobalt, a is 9 to 25, b is 0.5 to 2, c is 1 to 10, d is 0.01 to 1, e is 0.5 to 5, and x is determined by the oxidation number of the cation. According to claim 1,
The MnCe-based metal oxide catalyst is a butadiene production method represented by the following general formula 3:
[General Formula 3]
Mn _a Ce _1-a O _x
In Formula 3, a is 0.4 to 0.8, and x is determined by the oxidation number of the cation. According to claim 1,
The step S30 is a method for producing butadiene that is performed under conditions in which oxygen is present. According to claim 1,
In the step S30, the butadiene production method in which unreacted oxygen contained in the reaction product stream is removed. According to claim 1,
The method for producing butadiene, wherein the oxygen compound includes acetaldehyde.

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