JP2016124831A - Apparatus for producing olefin, dehydrogenation catalyst, and method for producing acid-base catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing an olefin, in which the production efficiency of the olefin such as butadiene is improved.SOLUTION: An apparatus 100 for producing the olefin includes: a first reactor 110 in which a dehydrogenation catalyst for accelerating a dehydrogenation reaction is housed so that ethanol is converted by the dehydrogenation catalyst to produce acetaldehyde; and a second reactor 130 in which an acid-base catalyst for accelerating a condensation reaction, a dehydration reaction and a hydrogenation reaction is housed so that, when the acetaldehyde and ethanol produced in the first reactor 110 are introduced thereinto, the acetaldehyde and ethanol are converted by the acid-base catalyst to produce the olefin.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an olefin production apparatus that produces olefin using ethanol as a starting material, a dehydrogenation catalyst that can be used in the olefin production apparatus, and a method for producing an acid-base catalyst.

  Of the olefins, butadiene (1,3-butadiene) is used as a raw material for synthetic rubbers such as styrene / butadiene rubber and nitrile / butadiene rubber, and synthetic resins such as ABS resin (Acrylonitrile Butadiene Styrene copolymer). High production volume. Conventionally, butadiene has been produced by cracking (catalytic cracking) of petroleum naphtha.

  On the other hand, in recent years, a technique for producing ethanol from lignocellulosic biomass has been developed, and a technique for producing butadiene using ethanol as a starting material has attracted attention. As such a technology, a catalyst for promoting the conversion reaction from ethanol to butadiene is accommodated in one reactor, and ethanol is introduced into the reactor, thereby promoting the conversion reaction from ethanol to butadiene by the catalyst. The technique to make is disclosed (for example, patent document 1).

As a catalyst for promoting the conversion reaction from ethanol to butadiene, Patent Document 1 discloses a mixture of a metal oxide of Groups 4 to 13 of the periodic table, MgO (magnesium oxide), and SiO ₂ (silicon dioxide). It is disclosed. Examples of the method for adjusting the catalyst include a kneading method, an impregnation method, a vapor deposition method, and a supported complex decomposition method.

International Publication No. 2013/125389

  In the above-described technology for producing olefins such as butadiene using ethanol as a starting material, further improvement in production efficiency (yield) of olefins is desired.

  In view of such problems, an object of the present invention is to provide an olefin production apparatus, a dehydrogenation catalyst, and an acid-base catalyst production method capable of improving the production efficiency of olefins such as butadiene.

  In order to solve the above-mentioned problems, an olefin production apparatus of the present invention is an olefin production apparatus that produces olefin using ethanol as a starting material, which contains a dehydrogenation catalyst that promotes a dehydrogenation reaction. A first reactor for converting acetaldehyde to produce acetaldehyde, and an acid-base catalyst for promoting condensation reaction, dehydration reaction, and hydrogenation reaction, and acetaldehyde produced in the first reactor by the acid-base catalyst, And a second reactor that converts ethanol to produce olefins.

  Further, the dehydrogenation catalyst may be configured to contain at least ZnO.

Further, the dehydrogenation catalyst may include ZnO prepared with Na ₂ CO ₃ .

Further, the acid-base catalyst may include at least MgO and SiO ₂ .

The acid-base catalyst hydrolyzes and condenses the magnesium alkoxide and silicon alkoxide to form a mixture of MgO in the gel state and SiO _{2 in} the gel state, and the mixture is dried and dried. The mixture may be produced by firing.

  The molar ratio of Mg and Si in the acid-base catalyst may be 9: 1.

  Moreover, the separator which isolate | separates acetaldehyde from the product produced | generated by the 1st reactor may be further provided, and the acetaldehyde isolate | separated by the separator may be introduce | transduced into a 2nd reactor.

In order to solve the above-described problems, the dehydrogenation catalyst of the present invention is a dehydrogenation catalyst that promotes a dehydrogenation reaction, and is characterized by including ZnO prepared with Na ₂ CO ₃ .

In order to solve the above-mentioned problem, the production method of the acid-base catalyst of the present invention comprises hydrolyzing and condensation-polymerizing magnesium alkoxide and silicon alkoxide to form a gel state of MgO and a gel state of SiO ₂ . The method includes a step of generating a mixture, a step of drying the mixture, and a step of firing the dried mixture.

  Further, the molar ratio of Mg and Si in the mixture in the step of generating the mixture may be 9: 1.

  According to the present invention, it is possible to improve the production efficiency of olefins such as butadiene.

It is a figure for demonstrating the reaction mechanism considered when synthesize | combining (manufacture) 1, 3- butadiene from ethanol. It is a figure for demonstrating the olefin manufacturing apparatus concerning embodiment. It is a figure for demonstrating the selectivity of the acetaldehyde by the dehydrogenation catalyst comprised including ZnO. It is a flowchart for demonstrating the flow of a process of the manufacturing method of the dehydrogenation catalyst concerning embodiment. It is a flowchart for demonstrating the flow of a process of the manufacturing method of the acid-base catalyst concerning embodiment. It is a diagram for explaining the examination results of the ratio of MgO and SiO ₂ in the MgO / SiO _2.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

FIG. 1 is a diagram for explaining a reaction mechanism considered when synthesizing (manufacturing) 1,3-butadiene from ethanol. As shown in FIG. 1, first, ethanol (C ₂ H ₅ OH) is converted to acetaldehyde (CH ₃ CHO) by dehydrogenation reaction (indicated by 1-A in FIG. 1). The obtained acetaldehyde becomes 3-hydroxybutanal (CH ₃ CH (OH) CH ₂ CHO) by a condensation reaction (indicated by 2-B in FIG. 1).

3-Hydroxybutanal becomes crotonaldehyde (CH ₃ CH═CHCHO) by a dehydration reaction (indicated by 3-C in FIG. 1), and crotonaldehyde together with ethanol undergoes a hydrogenation reaction (4- D) to 2-buten-1-ol (CH ₃ CH═CHCH ₂ OH).

Then, 2-buten-1-ol, (in FIG. 1, indicated by 5-C) dehydration reaction makes 1,3-butadiene _{(CH 2 = CH-CH =} CH 2). In this way, 1,3-butadiene is produced from ethanol.

  Among such reaction mechanisms, in the dehydrogenation reaction (1-A), a dehydrogenation catalyst is used, and a condensation reaction (2-B), a dehydration reaction (3-C, 5-C), a hydrogenation reaction (4- In D), an acid-base catalyst will be used.

  Conventionally, when an olefin such as 1,3-butadiene is produced using ethanol as a starting material, one catalyst that functions as both a dehydrogenation catalyst and an acid-base catalyst is accommodated in the reactor, and ethanol is contained in the reactor. Olefin was produced by introducing. However, in this case, the dehydrogenation reaction and the dehydration reaction of ethanol as a raw material compete. Optimized to reduce dehydration reaction, the reactions (condensation reaction, dehydration reaction, and hydrogenation reaction) indispensable for the production of olefins such as 1,3-butadiene are no longer appropriate. However, there was a limit to improving the production efficiency of olefins.

  Therefore, in this embodiment, an olefin production apparatus capable of improving the production efficiency of olefins by optimizing both the reaction promoted by the dehydrogenation catalyst and the reaction promoted by the acid-base catalyst is described. To do.

(Olefin production apparatus 100)
FIG. 2 is a diagram for explaining the olefin production apparatus 100 according to the present embodiment. As shown in FIG. 2, the olefin production apparatus 100 includes a first reactor 110, a separator 120, a second reactor 130, and a purifier 140, and produces olefin using ethanol as a starting material. To do.

  The first reactor 110 contains a dehydrogenation catalyst that promotes the dehydrogenation reaction, and ethanol is introduced. When ethanol is introduced into the first reactor 110, the dehydrogenation catalyst converts the ethanol to produce a first product containing acetaldehyde. The first product contains unreacted ethanol and by-products such as ethylene, acetone, and hydrogen in addition to the main product acetaldehyde.

The dehydrogenation catalyst accommodated in the first reactor 110 includes, for example, ZnO (zinc oxide), and preferably ZnO (hereinafter referred to as “Na ₂ CO ₃ ) prepared with Na ₂ CO ₃ (sodium carbonate). ₃ / ZnO ”).

Here, the conversion rate (dehydrogenation reaction) of ethanol from acetaldehyde was performed using three kinds of dehydrogenation catalysts composed of ZnO, and the content of acetaldehyde in the obtained first product (hereinafter referred to as “acetaldehyde”) , Referred to as “selectivity of acetaldehyde”) will be described. In addition, as a dehydrogenation catalyst including ZnO, ZnO prepared with Na ₂ CO ₃ / ZnO, NH ₄ OH (ammonia water) (hereinafter referred to as “NH ₄ OH / ZnO”), Pt (platinum) ) Doped ZnO (hereinafter referred to as “Pt / ZnO”).

FIG. 3 is a diagram for explaining the selectivity of acetaldehyde by a dehydrogenation catalyst including ZnO. In FIG. 3, Na ₂ CO ₃ / ZnO is white, NH ₄ OH / ZnO is black, and Pt / ZnO is hatched.

As shown in FIG. 3, when Na ₂ CO ₃ / ZnO is used, the selectivity of acetaldehyde exceeds 80%, but when NH ₄ OH / ZnO is used, the selectivity of acetaldehyde is about 45%. Low. Therefore, it was found that Na ₂ CO ₃ / ZnO is superior to NH ₄ OH / ZnO as a dehydrogenation catalyst for promoting the conversion reaction (dehydrogenation reaction) from ethanol to acetaldehyde.

On the other hand, when Pt / ZnO is used, the selectivity of acetaldehyde exceeds 90%, and the selectivity of acetaldehyde is higher than that of Na ₂ CO ₃ / ZnO. However, since Pt / ZnO contains Pt which is a rare metal, the cost is much higher than that of Na ₂ CO ₃ / ZnO. Therefore, by using Na ₂ CO ₃ / ZnO as a dehydrogenation catalyst, ethanol can be converted into acetaldehyde at low cost and as efficiently as Pt / ZnO.

  Referring back to FIG. 2, the separator 120 is composed of, for example, a fractionation tower, and fractionates the first product produced by the first reactor 110 to produce acetaldehyde, ethanol, and others (ethylene, acetone, etc.). , Hydrogen, etc.). A part of acetaldehyde and ethanol separated by the separator 120 is sent to the second reactor 130 at the subsequent stage.

  With the configuration including the separator 120, only substances (acetaldehyde and ethanol) that are starting materials for the reaction performed in the second reactor 130 can be introduced into the second reactor 130. The yield of the main product in can be improved.

  In the second reactor 130, the reaction proceeds most efficiently when the molar ratio of acetaldehyde and ethanol is 1: 1. Therefore, after the ethanol separated in the separator 120 and the amount of ethanol sent to the second reactor 130 is determined to increase efficiency, the excess ethanol in the second reactor 130 is separated. From the reactor 120 to the first reactor 110.

  The second reactor 130 contains an acid-base catalyst that promotes a condensation reaction, a dehydration reaction, and a hydrogenation reaction, and acetaldehyde and ethanol separated by the separator 120 are introduced. When acetaldehyde and ethanol are introduced into the second reactor 130, acetaldehyde and ethanol are converted by an acid-base catalyst to form C4 olefin such as 1,3-butadiene, C5 olefin such as 1,3-pentadiene, 2, A second product containing an olefin such as a C6 olefin such as 4-hexadiene, 1,3,5-hexatriene is produced.

Here, the acid-base catalyst accommodated in the second reactor 130 includes, for example, MgO and SiO ₂ . An acid-base catalyst comprising MgO and SiO ₂ (hereinafter referred to as “MgO / SiO ₂ ”) performs a conversion reaction (condensation reaction, dehydration reaction, hydrogenation reaction) from acetaldehyde and ethanol to an olefin. The content of olefin in the second product obtained in this way (hereinafter referred to as “olefin selectivity”) is as high as about 40%. Therefore, acetaldehyde and ethanol can be efficiently converted into olefins by using MgO / SiO ₂ as the acid-base catalyst.

  The purifier 140 is composed of, for example, a fractionation tower, and fractionates the second product produced by the second reactor 130 and separates it into C4 olefin, C5 olefin, C6 olefin, and the like. Thus, purified C4 olefin, C5 olefin, and C6 olefin can be produced.

  As described above, according to the olefin production apparatus 100 according to the present embodiment, the reaction field using the dehydrogenation catalyst and the reaction field using the acid-base catalyst are separately provided, which is promoted by the dehydrogenation catalyst. While optimizing the reaction (dehydrogenation reaction), the reactions (condensation reaction, dehydration reaction, and hydrogenation reaction) promoted by the acid-base catalyst can be optimized. Thereby, it becomes possible to improve the overall production efficiency of olefins.

(Method for producing dehydrogenation catalyst)
Next, a method for manufacturing the above _Na 2 _CO 3 / ZnO which function as dehydrogenation catalysts. FIG. 4 is a flowchart for explaining the processing flow of the method for producing a dehydrogenation catalyst according to the present embodiment. As shown in FIG. 4, the method for producing a dehydrogenation catalyst includes an aqueous solution preparation step S110, a precipitation generation step S120, a washing step S130, a drying step S140, and a firing step S150. Hereinafter, each process is explained in full detail.

(Aqueous solution preparation step S110)
In the aqueous solution preparation step S110, Zn (NO ₃ ) ₂ .6H ₂ O (zinc nitrate hexahydrate) is dissolved in water to prepare a zinc nitrate aqueous solution. Also, Na ₂ CO ₃ (sodium carbonate) is dissolved in water to prepare an aqueous sodium carbonate solution.

(Precipitation generation process S120)
In the precipitation generation step S120, a sodium carbonate aqueous solution is added to the zinc nitrate aqueous solution prepared in the aqueous solution preparation step S110 until pH 8 is reached. This makes it possible to produce a precipitate of ZnCO ₃ (zinc carbonate).

(Washing step S130)
In washing | cleaning process S130, the solution containing the precipitation of the zinc carbonate obtained by precipitation production | generation process S120 is suction-filtered, and zinc carbonate is isolate | separated. Subsequently, the separated zinc carbonate is dispersed in water and washed, and then suction filtration is performed again to separate the zinc carbonate.

(Drying step S140)
In the drying step S140, the zinc carbonate washed by performing the washing step S130 is dried at about 100 ° C. for about 24 hours.

(Baking step S150)
In the firing step S150, the zinc carbonate dried in the drying step S140 is fired at 400 ° C. for 4 hours using, for example, an electric furnace. Thus, Na ₂ CO ₃ / ZnO (ZnO prepared with Na ₂ CO ₃ ) can be produced.

(Production method of acid-base catalyst)
Subsequently, a manufacturing method of the MgO / SiO ₂ which functions as an acid-base catalyst is described. FIG. 5 is a flowchart for explaining a processing flow of the method for producing an acid-base catalyst according to the present embodiment. As shown in FIG. 5, the manufacturing method of an acid-base catalyst includes a solution preparation step S210, a gel mixture generation step S220, a reduced-pressure drying step S230, a drying step S240, and a firing step S250. Hereinafter, each process is explained in full detail.

(Solution preparation step S210)
In the solution preparation step S210, magnesium alkoxide and silicon alkoxide are dissolved in ethanol, and a volume amount of water substantially equal to ethanol is added to prepare an ethanol-water solution of magnesium alkoxide and silicon alkoxide. As the magnesium alkoxide, for example, one or more selected from the group of magnesium methoxide, magnesium ethoxide, magnesium propoxide, and magnesium butoxide can be used. In addition, as the silicon alkoxide, for example, one or more selected from the group of silicon methoxide, silicon ethoxide (tetraethylorthosilicate), silicon propoxide, and silicon butoxide can be used.

(Gel mixture production process S220)
In the gel mixture generation step S220, the ethanol-water solution of magnesium alkoxide and silicon alkoxide prepared in the solution preparation step S210 is stirred for 1 hour while being heated to about 70 ° C. Subsequently, aqueous ammonia (50 vol /%) is added to an ethanol-water solution of magnesium alkoxide and silicon alkoxide to make it basic, and the mixture is further stirred for 1 hour while maintaining at about 70 ° C. Then, the resulting solution is stirred for about 24 hours while being cooled to room temperature (for example, 25 ° C.). Then, hydrolysis reaction and condensation polymerization reaction proceed, and a mixture of gel state MgO and gel state SiO ₂ is generated.

(Decompression drying step S230)
In the vacuum drying step S230, the suspension of the mixture of the gel state MgO and the gel state SiO ₂ obtained in the gel mixture generation step S220 is placed under reduced pressure, the solvent is evaporated, and the gel state MgO And a mixture of SiO _{2 in} a gel state are dried.

(Drying step S240)
In the drying step S240, the mixture of MgO and SiO ₂ dried under reduced pressure in the reduced pressure drying step S230 is dried at about 100 ° C. for about 24 hours.

(Baking step S250)
In the firing step S250, the mixture of MgO and SiO ₂ dried in the drying step S240 is fired at 500 ° C. for 4 hours using, for example, an electric furnace. Thus, MgO / SiO ₂ can be manufactured.

(Examination of MgO / SiO ₂ butadiene selectivity due to differences in production methods)
MgO / SiO ₂ is produced by two kinds of production methods of the acid-base catalyst shown in FIG. 5 (hereinafter referred to as “sol-gel method”) and the kneading method, and each MgO / SiO ₂ is used. And 1,3-butadiene conversion reaction (dehydrogenation reaction, condensation reaction, dehydration reaction, hydrogenation reaction) from ethanol, and the content of 1,3-butadiene in the resulting product (hereinafter referred to as “butadiene”). The selectivity is referred to as "."

As a result, when MgO / SiO ₂ produced by the sol-gel method was used, the selectivity of butadiene was 37%, and when MgO / SiO ₂ produced by the kneading method was used, the selectivity of butadiene was 22%. .

From the above results, it was found that MgO / SiO ₂ having a higher butadiene selectivity can be produced by the sol-gel method.

(Examination of the ratio of Mg and Si in MgO / SiO ₂ )
Moreover, the optimal ratio of Mg and Si in MgO / SiO ₂ was examined. Here, four types of MgO / SiO ₂ with a ratio of Mg: Si of 100: 0 (mol%), 90:10 (mol%), 75:25 (mol%), and 50:50 (mol%) are used. The butadiene selectivity and ethylene selectivity were measured.

Figure 6 is a diagram for explaining the examination results of the ratio of MgO and SiO ₂ in the MgO / SiO _2. In FIG. 6, the selectivity of butadiene is indicated by a circle, and the selectivity of ethylene is indicated by a square.

As shown in FIG. 6, when the ratio of Mg and Si in MgO / SiO ₂ was 50:50 (mol%), the selectivity for butadiene was 35% and the selectivity for ethylene was 44%. It was found that when the Mg ratio in MgO / SiO ₂ was increased, the selectivity for butadiene increased and the selectivity for ethylene decreased. More specifically, MgO / SiO ₂ having a ratio of Mg to Si of 75:25 (mol%) has a butadiene selectivity of 37% and an ethylene selectivity of 20%, and the ratio of Mg to Si is 90:10 the MgO / SiO ₂ of (mol%), butadiene selectivity of 40%, the selectivity of ethylene was 18 percent. In the case of a compound having a Mg: Si ratio of 100: 0 (mol%), that is, MgO, the selectivity of butadiene was 17% and the selectivity of ethylene was 15%.

From the above results, it was found that the selectivity of butadiene was highest when the molar ratio of Mg and Si in MgO / SiO ₂ was 9: 1. Therefore, by using MgO / SiO ₂ having a molar ratio of Mg and Si of 9: 1 as the acid-base catalyst, acetaldehyde and ethanol can be efficiently converted into olefins.

When using the sol-gel method, the molar ratio of Mg to Si is adjusted by adjusting the ratio of magnesium alkoxide and silicon alkoxide in the ethanol-water solution of magnesium alkoxide and silicon alkoxide prepared in solution preparation step S210. 9: 1 MgO / SiO ₂ can be produced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

For example, in the embodiment described above, Na ₂ CO ₃ / ZnO has been described as an example of the dehydrogenation catalyst accommodated in the first reactor 110. However, a compound containing at least ZnO can be used as the dehydrogenation catalyst. For example, Pt / ZnO may be used. Moreover, as long as a dehydrogenation reaction is accelerated | stimulated and ethanol can be converted into acetaldehyde, the other substance which does not contain ZnO may be sufficient.

In the above embodiment, as the acid-base catalyst contained in the second reactor 130, the MgO / SiO ₂ has been described as an example. However, other substances may be used as long as they can promote condensation reaction, dehydration reaction, and hydrogenation reaction to convert acetaldehyde and ethanol into olefin.

  Moreover, in the said embodiment, the case where the dehydrogenation catalyst accommodated in the 1st reactor 110 and the acid-base catalyst accommodated in the 2nd reactor 130 were mentioned as an example was demonstrated as an example. However, the dehydrogenation catalyst accommodated in the first reactor 110 and the acid-base catalyst accommodated in the second reactor 130 are the same substance (a substance that functions as both a dehydrogenation catalyst and an acid-base catalyst). Also good.

  In the above-described embodiment, the configuration in which the ethanol separated by the separator 120 is introduced into the second reactor 130 has been described as an example. However, other ethanol may be introduced into the second reactor 130 in addition to or instead of the ethanol separated by the separator 120.

  In the above-described embodiment, the configuration in which the ethanol separated in the separator 120 and surplus in the second reactor 130 is returned to the first reactor 110 has been described as an example. However, the ethanol separated in the separator 120 and surplus in the second reactor 130 may not be returned to the first reactor 110.

  In the above embodiment, as the magnesium alkoxide, one or a plurality selected from the group of magnesium methoxide, magnesium ethoxide, magnesium propoxide, and magnesium butoxide has been described as an example, but other magnesium alkoxides are used. You can also. Similarly, one or a plurality of silicon alkoxides selected from the group of silicon methoxide, silicon ethoxide, silicon propoxide, and silicon butoxide have been described as examples, but other silicon alkoxides can also be used.

  In addition, each process of the manufacturing method of the dehydrogenation catalyst of this specification, and the manufacturing method of an acid-base catalyst does not necessarily need to process in time series along the order described as a flowchart, and performs parallel processing. May be included.

  INDUSTRIAL APPLICABILITY The present invention can be used for an olefin production apparatus that produces olefin using ethanol as a starting material, a dehydrogenation catalyst that can be used in the olefin production apparatus, and a method for producing an acid-base catalyst.

DESCRIPTION OF SYMBOLS 100 Olefin production apparatus 110 1st reactor 120 Separator 130 2nd reactor S210 Solution preparation process S220 Gel-like mixture production | generation process S230 Depressurization drying process S240 Drying process S250 Baking process

Claims (10)

An olefin production apparatus for producing olefin using ethanol as a starting material,
A first reactor that contains a dehydrogenation catalyst that promotes the dehydrogenation reaction, and that converts ethanol with the dehydrogenation catalyst to produce acetaldehyde;
An acid-base catalyst that promotes a condensation reaction, a dehydration reaction, and a hydrogenation reaction is accommodated, and the acid-base catalyst converts the acetaldehyde generated in the first reactor and ethanol to generate an olefin. A second reactor;
An olefin production apparatus comprising:   The olefin production apparatus according to claim 1, wherein the dehydrogenation catalyst includes at least ZnO. The dehydrogenation catalyst, olefin production apparatus according to claim 1 or 2, characterized in that it is configured to include a ZnO prepared by Na ₂ CO _3. The acid-base catalyst, at least MgO and olefin manufacturing apparatus according to comprise be configured of SiO ₂ from claim 1, wherein in any one of 3. The acid-base catalyst is
Magnesium alkoxide and silicon alkoxide are hydrolyzed and subjected to condensation polymerization to produce a mixture of gel state MgO and gel state SiO ₂ ,
Drying the mixture,
The olefin production apparatus according to claim 4, wherein the olefin production apparatus is produced by firing the dried mixture.   The olefin production apparatus according to claim 4 or 5, wherein a molar ratio of Mg and Si in the acid-base catalyst is 9: 1. Further comprising a separator for separating acetaldehyde from the product produced by the first reactor;
The olefin production apparatus according to any one of claims 1 to 6, wherein acetaldehyde separated by the separator is introduced into the second reactor. A dehydrogenation catalyst for promoting a dehydrogenation reaction,
A dehydrogenation catalyst comprising ZnO prepared with Na ₂ CO ₃ . A method for producing an acid-base catalyst, comprising:
A step of hydrolyzing and condensation-polymerizing magnesium alkoxide and silicon alkoxide to form a mixture of gel state MgO and gel state SiO ₂ ;
Drying the mixture;
Baking the dried mixture;
The manufacturing method of the acid-base catalyst characterized by including.   The method for producing an acid-base catalyst according to claim 9, wherein a molar ratio of Mg and Si in the mixture in the step of generating the mixture is 9: 1.

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