JP6077325B2 - Method for producing conjugated diene compound - Google Patents

Description

  The present invention relates to a method for producing a conjugated diene compound using an α, β-unsaturated aldehyde as a raw material. According to the idea of the present inventors, α, β-unsaturated alcohol is produced from α, β-unsaturated aldehyde and alcohol by regioselective hydrogen transfer reaction, and dehydration reaction that takes place continuously. The present invention relates to a process for producing a conjugated diene compound, which proceeds continuously in the presence of a specific catalyst. In view of the future basic chemicals market, butadiene currently obtained from the C4 fraction of naphtha steam cracking can be produced from bioethanol obtained from agricultural products such as corn.

  A conjugated diene compound has a carbon-carbon double bond at positions 1 and 3, respectively, and occupies an important position among chemical products because of its high reactivity or polymerization reactivity. Industrially important conjugated diene compounds are those having 4 and 5 carbon atoms, such as butadiene, chloroprene, isoprene and cyclopentadiene.

  In particular, butadiene is a monomer material for polymerization such as styrene-butadiene rubber (SBR), butadiene rubber (BR), which is the main structural material of tires for transportation equipment, and a raw material of ABS resin used in various household appliance housings. . As demand is expected to expand in the global market, C4 fraction purification obtained by naphtha “steam cracking” (patent documents 3 and 4), or dehydrogenation of n-butene (patent documents 1 and 2), In addition to the method of selectively obtaining 1,3-butadiene by dehydration reaction of the alcohol by using a reaction to obtain a corresponding alcohol by hydrogenation from a saturated aldehyde (see Patent Document 5), a more mild reaction Development of a new method for producing butadiene with a high yield depending on conditions is desired.

Several studies have been conducted so far using ethanol as a starting material.
In the so-called Lebedev method, a method of dehydrogenating and dehydrating ethanol at 400 ° C. using a MgO—SiO 2 catalyst has been reported, but there was a problem that the butadiene selectivity was about 40% (non- Patent Document 1).
In the synthesis of butadiene from α, β-unsaturated aldehydes, there are examples in which reaction, Ta ₂ O ₅ —MgO / SiO ₂ , Ta ₂ O ₅ / SiO ₂ catalyst system have been studied, but high temperature conditions of 350 ° C. to 420 ° C. However, there was room for improvement in conversion and selectivity (Non-patent Document 2).

JP 2012-67048 A JP 2012-197272 A JP2011-178919A JP 2010-265188 A JP-A-7-204509

“Industrial Organic Chemistry” Weissermel, HJ. By Arpe, translated by Mitsuaki Mukayama B. B. Corson et al, “Butadien from Ethyl Alchol”, Vol. 42 (2) 359-373, (1950)

  The object of the present invention is to provide a corresponding conjugate with high conversion and high selectivity from an α, β-unsaturated aldehyde obtained by aldol condensation of an aldehyde obtained by alcohol dehydrogenation or olefin oxidation. It is to provide a method for producing a diene compound.

In the first aspect of the present invention, an α, β-unsaturated aldehyde and the like are present on a solid oxide support in the presence of a metal selected from the following group (I) and / or a catalyst supporting at least one of the metal oxides. The present invention relates to a method for producing a conjugated diene corresponding to the α, β-unsaturated aldehyde by supplying a mixed gas containing an alcohol at a molar ratio of 2 or more and performing a hydrogen transfer reaction and a dehydration reaction.
(I) Group Cr, Mn, Fe

In the second aspect of the present invention, a metal selected from the following group (I) and / or at least one of the metal oxides, and a metal selected from the following group (II) and / or the metal are used as the solid oxide support. In the presence of a catalyst supporting at least one oxide, a mixed gas containing an α, β-unsaturated aldehyde and an equal mole or more of alcohol is supplied, and the α, β-unsaturated by hydrogen transfer reaction or dehydration reaction is supplied. The present invention relates to a method for producing a conjugated diene corresponding to an aldehyde.
(I) Group Cr, Mn, Fe
(II) group Co, Ni

  A third aspect of the present invention relates to the method for producing a conjugated diene according to the first or second aspect of the present invention, wherein the alcohol has a boiling point equal to or lower than that of the α, β-unsaturated aldehyde.

  A fourth aspect of the present invention relates to the method for producing a conjugated diene according to any one of the first to third aspects of the present invention, wherein the α, β-unsaturated aldehyde is crotonaldehyde.

  A fifth aspect of the present invention relates to the method for producing a conjugated diene according to any one of the first to fourth aspects of the present invention, wherein the alcohol is ethyl alcohol.

  A sixth aspect of the present invention relates to the method for producing a conjugated diene according to any one of the first to fifth aspects of the present invention, wherein the solid oxide support contains silica.

  According to the present invention, a conjugated diene compound having a corresponding number of carbon atoms can be obtained using an α, β-unsaturated aldehyde as a raw material and an alcohol. Also, butadiene can be produced from bioethanol that does not depend on petroleum resources, through conversion to aldehyde by a known dehydrogenation reaction and synthesis of crotonaldehyde, which is an α, β-unsaturated aldehyde by aldol condensation. .

<Solid oxide as carrier>
There is no restriction | limiting in particular in the solid oxide used as a support | carrier. Silica, alumina, magnesia, calcia, titania, zirconia and the like can be used. Of these, silica, alumina, titania, and zirconia are preferable. Among these, silica is particularly preferable. One type of carrier may be used, or two or more types may be used in combination. When using 2 or more types of support | carriers together, the mixture which mixed silica and an alumina can also be used, for example, and complex oxides, such as a silica-alumina, can also be used.

  The specific surface area of the carrier is preferably 10 to 2000 m2 / g, more preferably 50 to 1500 m2 / g, and still more preferably 100 to 1000 m2 / g. When the specific surface area of the support is smaller than the above range, it becomes difficult to produce a catalyst having more useful components supported on the surface, and when the specific surface area is larger than the above range, industrial production becomes difficult. The specific surface area of the carrier can be measured by a nitrogen gas adsorption method.

<Metal of Group (I) and Metal of Group (II)>
As described in the above [Technical Field] paragraph, the present inventors have produced α, β-unsaturated alcohol from α, β-unsaturated aldehyde and alcohol by regioselective hydrogen transfer reaction, and The continuous dehydration reaction is considered to be involved in the production of the conjugated diene compound. At present, the reaction mechanism of the group (I) metal and the group (II) metal as the catalytically active component in the present invention is not clear. In the “dehydration reaction” and “regioselective hydrogen transfer reaction”, it is considered that the metal of group (II) plays a main role in the “regioselective hydrogen transfer reaction”. A conjugated diene compound can be obtained simply by using a metal of group (I) as a catalyst, but the yield is lower than when a metal of group (II) is used in combination.

<Metal of group (I)>
In the present invention, at least one metal selected from the group (I) and / or the metal oxide (hereinafter, “metal” includes its oxide) is supported on a solid oxide. The present inventors have found that, as a metal contained in the group (I), Cr, Mn, and Fe, which are adjacent elements on the periodic table, are suitable from the first transition metal element.

<Metal of group (II)>
In the present invention, at least one metal selected from the group (II) and / or the metal oxide is supported together with at least one metal selected from the group (I). The present inventors have found that Co and Ni, which are adjacent elements on the periodic table, are suitable from the first transition metal element as the metal contained in the group (II). Although the detailed reaction mechanism is not clear, the present inventors consider that the electron arrangement, the ionic radius, etc. which these have approximately are related. Moreover, the interaction with (I) genus is considered similarly.

  In the present invention, a metal selected from the group (I) and, if necessary, a metal selected from the group (II) to the support is 0.1% by mass to 10% by mass with respect to the support mass before supporting. Carry in range. If the amount is less than 0.1% by mass, the effects of the present invention cannot be exhibited sufficiently, and if it exceeds 10% by weight, the economic efficiency is lowered. The shape of the carrier may be any of a columnar shape, a tablet shape, a powdery shape, and a granular shape, but from the viewpoint of performing high-speed continuous processing, a granular catalyst with a small pressure loss is preferable in view of being packed in a packed tower.

  The ratio of the catalyst in the conjugated diene production is usually represented by LHSV (1 / hr) which is a contact speed between the catalyst and the raw material (based on the sum of aldehyde and alcohol) as a liquid, and is 0.1 to 3 Within the range, 0.2 to 1 is more preferable.

  There are no particular limitations on the loading method, and it is sufficient that the metal selected from the groups (I) and (II) as the active component is finally sufficiently dispersed. Known impregnation methods and precipitation methods Can be produced by coprecipitation. Further, the method or step of incorporating the metal component into the catalyst is optional as long as the activity is not substantially inhibited. When two or more kinds of metals are supported, both simultaneous support and sequential support are possible. For example, an impregnation method of impregnating, drying and calcining a precursor of an active ingredient soluble in a porous carrier particle or fine powder previously formed, a precipitation method of preparing by precipitation from an aqueous solution of a salt of the active ingredient, and the like can be mentioned. A preferred method is a method in which a mesoporous silica is impregnated with a metal selected from the group (I) and / or an oxide thereof, and, if necessary, a metal selected from the group (II) and / or an oxide thereof, and then subjected to a firing treatment. Is preferred.

<Α, β-unsaturated aldehyde>
The α, β-unsaturated aldehyde according to the present invention is a conjugated diene compound having a carbon number corresponding to the carbon number. The α, β-unsaturated aldehyde is not particularly limited, but crotonaldehyde from which butadiene can be obtained is preferable from the viewpoint of market size.

<Alcohol>
The alcohol used in the reaction according to the present invention is used as a hydrogen donor. There is no restriction | limiting in particular in the alcohol to be used. Specifically, primary or secondary alcohols such as methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, isobutanol, benzyl alcohol, cyclohexanol, etc. can be used. Although it is selected in consideration of availability of by-products, ethanol is particularly preferable from the viewpoint of bioethanol availability. From the viewpoint of obtaining a mixed gas of an α, β-unsaturated aldehyde and an alcohol, the alcohol preferably has a boiling point equal to or lower than that of the α, β-unsaturated aldehyde. When crotonaldehyde is used as a raw material, its boiling point is 104 ° C. at normal pressure, and those having a lower boiling point are methanol (boiling point at normal pressure (hereinafter the same): 65 ° C.), ethanol (78 ° C.), isopropanol (82 ° C), propanol (97 ° C), 2-butanol (99 ° C) are suitable.
The mixing ratio of the alcohol with respect to the α, β-unsaturated aldehyde is equal to or greater than 1 mol, preferably 2 to 30 mol. If it is less than this range, side reactions may occur. If this range is exceeded, excess alcohol impairs economic efficiency. A particularly preferred range is 3 to 10 moles.

(Example)
(Catalyst adjustment)
(Method for producing Cr-supported catalyst)
An aqueous solution in which 1.2 g of chromium nitrate nonahydrate (Cr (NO ₃ ) ₃ -9H ₂ O manufactured by Kanto Chemical Co., Ltd., molecular weight of 400.15) was dissolved in 33 ml of water was prepared, and spherical silica Q- manufactured by Fuji Silysia Chemical Ltd. 10 (about 2 mmφ) and mixed with 30 g of chromium on silica. The resulting chromium-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a chromium-supported silica catalyst. At this time, the amount of chromium supported is about 0.5% by mass. The increase / decrease amount of the chromium carrying amount was the same as the increase / decrease amount of chromium nitrate nonahydrate.

(Manufacture of Co-supported catalyst)
An aqueous solution in which 3.0 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 291.03) was dissolved in 39 ml of water was prepared, and spherical silica Q manufactured by Fuji Silysia Chemical Ltd. Cobalt was supported on silica by mixing with 30 g of -10 (about 2 mmφ). The obtained cobalt-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a cobalt-supported silica catalyst. At this time, the amount of cobalt supported is about 2%. The increase / decrease amount of the cobalt carrying amount was the same as the increase / decrease amount of cobalt nitrate hexahydrate.

(Manufacture of both Cr and Co supported catalysts)
1.5 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, molecular weight 291.03) and 0.59 g of chromium nitrate nonahydrate (Cr (NO ₃ manufactured by Kanto Chemical Co., Ltd.) ) Prepare an aqueous solution of ₃ -9H ₂ O, molecular weight 400.15) dissolved in 16 ml of water, mix with 15 g of spherical silica Q-10 (about 2 mmφ) manufactured by Fuji Silysia Chemical, and carry cobalt and chromium on the silica. did. The obtained cobalt and chromium-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a cobalt and chromium-supported silica catalyst.
At this time, the cobalt loading is about 2% and the chromium loading is about 0.5%. The increase / decrease amount of the loading amount of cobalt and chromium was performed by the increase / decrease amount of the addition amount of each compound.

(Method for producing Ni-supported catalyst)
An aqueous solution in which 3.0 g of nickel nitrate hexahydrate (Ni (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 290.79) was dissolved in 39 ml of water was prepared, and spherical silica Q manufactured by Fuji Silysia Chemical Ltd. Mixed with 30 g of -10 (about 2 mmφ), nickel was supported on silica. The obtained nickel-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a nickel-supported silica catalyst. At this time, the nickel loading is about 2%. The increase / decrease amount of the nickel carrying amount was the same as the increase / decrease amount of nickel nitrate hexahydrate.

(Method for producing Cr, Ni supported catalyst)
1.5 g of nickel nitrate hexahydrate (Ni (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, molecular weight 290.79) and 0.59 g of chromium nitrate nonahydrate (Cr (NO ₃ manufactured by Kanto Chemical)) ) Prepare an aqueous solution of ₃ -9H ₂ O, molecular weight 400.15) dissolved in 16 ml of water, mix with 15 g of spherical silica Q-10 (about 2 mmφ) manufactured by Fuji Silysia Chemical, and carry nickel and chromium on the silica. did. The obtained nickel and chromium-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a nickel and chromium-supported silica catalyst.
At this time, the nickel loading is about 2% by mass and the chromium loading is about 0.5% by mass. The amount of nickel and chromium supported was increased or decreased by the amount of each compound added.

(Method for producing Fe-supported catalyst)
An aqueous solution in which 1.5 g of iron nitrate nonahydrate (Fe (NO ₃ ) ₃ -9H ₂ O manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 403.85) was dissolved in 44 ml of water was prepared, and spherical silica Q manufactured by Fuji Silysia Chemical Ltd. It was mixed with 40 g of -10 (about 2 mmφ), and iron was supported on silica. The obtained iron-supporting silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain an iron-supporting silica catalyst. At this time, the iron loading is about 0.5% by mass. The increase / decrease amount of the iron loading was the increase / decrease amount of iron nitrate nonahydrate.

(Method for producing Fe, Co supported catalyst)
1.5 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, molecular weight 291.03) and 0.55 g of iron nitrate nonahydrate (Fe (NO manufactured by Wako Pure Chemical Industries, Ltd.) ₃ ) An aqueous solution in which ₃ -9H ₂ O, molecular weight 403.85) is dissolved in 16 ml of water is prepared, mixed with 15 g of spherical silica Q-10 (about 2 mmφ) manufactured by Fuji Silysia Chemical, and iron and cobalt are deposited on the silica. Supported. The obtained iron and cobalt-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain an iron and cobalt-supported silica catalyst.
At this time, the amount of cobalt supported is about 2% by mass, and the amount of iron supported is about 0.5% by mass. The increase / decrease amount of the loading amount of cobalt and iron was performed by the increase / decrease amount of the addition amount of each compound.

(Method for producing Mn-supported catalyst)
An aqueous solution in which 1.1 g of manganese nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd., Mn (NO ₃ ) ₂ -6H ₂ O, molecular weight 287.04) was dissolved in 44 ml of water was prepared, and spherical silica Q manufactured by Fuji Silysia Chemical Ltd. Mixed with 40 g of -10 (about 2 mmφ), manganese was supported on silica. The obtained manganese-supported silica was dried at 110 ° C. overnight and further calcined in air at 500 ° C. for 3 hours to obtain a manganese-supported silica catalyst. At this time, the amount of manganese supported is about 0.5% by mass. The amount of manganese supported was increased or decreased by the amount of manganese nitrate hexahydrate.

(Method for producing Mn, Co supported catalyst)
1.5 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ -6H ₂ O manufactured by Wako Pure Chemical Industries, molecular weight 291.03) and 0.40 g of manganese nitrate hexahydrate (Mn (NO manufactured by Wako Pure Chemical Industries, Ltd.) _{3) 2} -6H ₂ O, molecular weight 287.04) to prepare an aqueous solution dissolved in water of 17 ml, was mixed with Fuji Silysia chemical Ltd. spherical silica Q-10 (about 2 mm) 15 g, manganese and cobalt on the silica Supported. The obtained manganese and cobalt-supported silica was dried at 110 ° C. overnight, and further calcined in air at 500 ° C. for 3 hours to obtain a manganese and cobalt-supported silica catalyst.
At this time, the amount of cobalt supported is about 2% by mass, and the amount of manganese supported is about 0.5% by mass. The increase / decrease amount of manganese and cobalt supported was the increase / decrease amount of each compound added.

(Production of Ta supported catalyst)
A solution prepared by dissolving 0.90 g of tantalum ethoxide (Ta (OC ₂ H ₅ ) ₅ manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 406.25) in 22 ml of toluene in a nitrogen box was prepared, and spherical silica Q- manufactured by Fuji Silysia Chemical Ltd. 10 (about 2 mmφ) and mixed with 20 g, tantalum was supported on silica. The obtained tantalum-supported silica was dried overnight at room temperature under nitrogen flow, and further calcined in air at 500 ° C. for 3 hours to obtain a tantalum-supported silica catalyst. At this time, the amount of tantalum supported is about 2%. The obtained tantalum-supported silica catalyst was subjected to the reaction of Comparative Example 3, and the results are shown in Table 1.

(CuCrO ₄ catalyst)
Cu-0203T1 / 8 ″ manufactured by N.E. Chemcat was directly used as a catalyst. The reaction was carried out according to Comparative Example 4 and the results are shown in Table 1.

(Production of butadiene)
6 ml of the catalyst obtained above was filled in a SUS reaction tube (inner diameter: about 10 mm). About the catalyst which carry | supported cobalt and nickel as an active metal, the hydrogen treatment for 3 hours was implemented at 350 degreeC before reaction.
A raw material liquid in which crotonaldehyde and ethanol were mixed at a predetermined molar ratio was supplied by a liquid pump at a predetermined LHSV (based on the sum of crotonaldehyde and ethanol). In addition, by providing and setting a vaporizer before the reaction tube, the raw material liquid is gasified before being introduced into the reaction tube. The reaction was carried out at atmospheric pressure and a predetermined reaction temperature, and the reaction product was analyzed by gas chromatography. The raw material molar ratio, LHSV, and reaction temperature are as shown in Table 1.

(Evaluation of butadiene production method under each catalyst and reaction conditions)
Evaluation was made by “crotonaldehyde conversion rate”, “hydrogen transfer selectivity”, and “butadiene selectivity” obtained by the following formulas.

<Crotonaldehyde conversion>
Conversion rate of crotonaldehyde (%) = [1- (residual crotonaldehyde) / (crotonaldehyde in raw material)] × 100
The value of “residual crotonaldehyde” was obtained from the molar fraction of crotonaldehyde obtained from the chromatographic analysis peak area ratio after the reaction, and the value of “crotonaldehyde in raw material” was obtained from the chromatographic analysis peak area ratio in the raw material. It is the mole fraction of crotonaldehyde. From the above conversion rate, it can be seen that the ability to consume crotonaldehyde as a reaction substrate is superior or inferior.

<Butadiene selectivity>
Butadiene selectivity (%) = [produced butadiene / (1-unreacted raw material)] × 100
The value of “produced butadiene” is the mole fraction of butadiene determined from the chromatographic analysis peak area ratio after reaction, and the value of “unreacted raw material” is the mole of raw material determined from the chromatographic analysis peak area ratio after reaction. It is a fraction. From the above selectivity, the superiority or inferiority of the ability to produce butadiene is known.

<Hydrogen transfer selectivity>
Hydrogen transfer selectivity (%) = [(generated butadiene) + (generated crotyl alcohol)] / [(generated butadiene) + (generated crotyl alcohol) + (generated butanol) + (generated butyraldehyde) + (generated butene) ] × 100
The value of “produced butadiene” is the molar fraction of butadiene determined from the chromatographic analysis peak area ratio after reaction, and the value of “product crotyl alcohol” is crotyl determined from the chromatographic analysis peak area ratio after reaction. The molar fraction of alcohol, “product butanol” is the molar fraction of butanol determined from the chromatographic analysis peak area ratio after reaction, and the value of “product butyraldehyde” is the chromatographic analysis peak area ratio after reaction. The value of “butene”, the molar fraction of butyraldehyde obtained from the above, is the molar fraction of butene obtained from the chromatographic analysis peak area ratio after the reaction. From the hydrogen transfer selectivity, it can be seen that the ability to selectively hydrogenate the carbonyl moiety of crotonaldehyde is superior or inferior.

The results are summarized in Table 1.

First, it can be seen that the catalyst according to this example is excellent in “crotonaldehyde conversion”.
The initiation reaction for butadiene production is considered to produce crotyl alcohol as a reaction intermediate by the reaction of crotonaldehyde and ethanol. Then, the hydrogen transfer reaction from ethanol to crotonaldehyde proceeds with high selectivity (selectively hydrogenating only C = O bonds, not C = C double bonds in crotonaldehyde), and the target butadiene The conditions under which the reaction proceeds sequentially are established. This “crotonaldehyde conversion” is extremely important as the first step toward butadiene production.

  From the results of Examples 1 to 7, it is understood that the silica-supported Cr ((I) group metal) catalyst is excellent in “butadiene selectivity”. On the other hand, it is understood that the silica-supported Co ((II) group metal) catalyst of Comparative Example 1 is excellent in “hydrogen transfer selectivity” while having a low “butadiene selectivity”. From the results of Examples 8 to 10, it can be seen that the silica-supported Cr / Co catalyst is excellent in both “butadiene selectivity” and “hydrogen transfer selectivity”.

Hereinafter, it can be seen that the silica-supported Ni ((II) group metal) catalyst of Comparative Example 2 is excellent in “hydrogen transfer selectivity” but low in “butadiene selectivity”. From the results of Examples 11 to 13, it can be seen that the silica-supported Cr / Ni catalyst is excellent in both “butadiene selectivity” and “hydrogen transfer selectivity”.
Hereinafter, from the results of Examples 14 to 17, the silica-supported Fe ((I) group metal) catalyst and from the results of Examples 19 to 21, the silica-supported Mn ((I) group metal) catalyst is Cr or Cr. Although it is slightly inferior to the / Co catalyst system, it can be seen that the “butadiene selectivity” is excellent. And it turns out that the silica carrying | support Fe / Co catalyst of Example 18 and the silica carrying | support Mn / Co catalyst of Example 22 are excellent in both "butadiene selectivity" and "hydrogen transfer selectivity".

  According to the present invention, hydrogen transfer reaction is performed from bioethanol independent of petroleum resources to aldehyde by a known dehydrogenation reaction and synthesis of crotonaldehyde, which is an α, β-unsaturated aldehyde by aldol condensation. Butadiene can be produced by a dehydration reaction. Butadiene is growing in demand as a monomer material for polymerization, such as styrene-butadiene rubber (SBR), butadiene rubber (BR), which is the main structural material of tires for transportation equipment, and ABS resin used in various household housings. The production method of the present invention is effective when petroleum resources are tight in the future.

Claims (4)

Boiling point equal to or greater than 1 mole of crotonaldehyde and crotonaldehyde in the presence of a catalyst supporting at least one metal selected from the following group (I) and / or the metal oxide on a solid oxide support: A method for producing a conjugated diene corresponding to an aldehyde by supplying a mixed gas containing an alcohol having a lower boiling point than that of the crotonaldehyde and corresponding to an aldehyde by a hydrogen transfer reaction or a dehydration reaction.
(I) Group Cr, Mn, Fe A catalyst comprising the Cr metal and / or metal oxide and Co and / or Ni metal or metal oxide; the Mn metal and / or metal oxide and Co metal and / or metal oxide; 2. The method for producing a conjugated diene according to claim 1 , wherein the catalyst is a catalyst comprising: a metal comprising Fe and / or a metal oxide and a metal comprising Co and / or a metal oxide . The method for producing a conjugated diene according to any one of claims 1 to 2 , wherein the alcohol is ethyl alcohol. The method for producing a conjugated diene according to any one of claims 1 to 3 , wherein the solid oxide support contains silica.