WO2015111580A1

WO2015111580A1 - Method for producing polyene

Info

Publication number: WO2015111580A1
Application number: PCT/JP2015/051401
Authority: WO
Inventors: 拓真西尾; 川上　公徳; 宇都宮　賢
Original assignee: 三菱化学株式会社
Priority date: 2014-01-21
Filing date: 2015-01-20
Publication date: 2015-07-30
Also published as: JP2017048117A

Abstract

　The purpose of the present invention is to provide a method for subjecting a raw material containing a hydrocarbon having a plurality of carboxylate groups to an elimination reaction under moderate reaction conditions, and producing a polyene at improved yield. The present invention pertains to a method for producing a polyene by an elimination reaction of carboxylic acid from a raw material containing a hydrocarbon, wherein the hydrocarbon has a plurality of carboxylate groups, the concentration of the hydrocarbon in the raw material is 0.1-95 mol%, and the elimination reaction is carried out in a temperature range of 250-800ºC.

Description

Method for producing polyene

The present invention relates to a method for producing polyene.

There is known a method for producing a polyene such as butadiene by an elimination reaction using a hydrocarbon substituted with a plurality of functional groups such as 1,3-butanediol as a raw material.
For example, Patent Document 1 describes that 1,3-butadiene is obtained in a yield of 27% by subjecting 2,3-butanediol to a dehydration reaction at 380 ° C. in the presence of a hydroxyapatite catalyst. Non-patent document 1 reports that 1,3-butadiene can be obtained in a yield of 4 to 27% by subjecting 1,3-butanediol to a dehydration reaction at 200 to 250 ° C. in the presence of a silica alumina catalyst. ing.

Non-Patent Document 2 discloses that 2,3-butanediol is dehydrated at 200 to 300 ° C. in the presence of an HZSM-5 zeolite catalyst modified with boric acid, and 0,2% of 1,3-butadiene is obtained. It is reported that it can be obtained at a rate. In Non-Patent Document 3, 1,5-pentanediol diacetate purified by fractional distillation under reduced pressure was heated to 575 ± 5 ° C., and 1,4-pentadiene was obtained in a yield of 64%. It has been reported that 1,2-pentanediol diacetate purified by fractional distillation was heated to 590 ± 5 ° C. and 1,3-pentadiene was obtained in a yield of 61.1 to 65.3%. In Non-Patent Document 4, 2,3-butylene glycol diacetate having a purity of 99 to 100% was heated to 475 ° C. to 600 ° C., and 1,3-butadiene was obtained in a yield of 30.0 to 81.5%. Has been reported.

Korean Published Patent No. 2011-96125

However, in these conventionally known techniques, for example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2, polyene is produced by dehydrating a hydrocarbon having a hydroxyl group, but the yield is not sufficient. . Furthermore, in Non-Patent Document 3 and Non-Patent Document 4, polyene is produced from a hydrocarbon having a carboxylate group. However, a hydrocarbon having a carboxylate group is eliminated at a high concentration, and side reactions occur. It often contains a large amount of impurities that are difficult to remove.

An object of the present invention is to eliminate impurities that are difficult to separate and remove by subjecting a raw material containing hydrocarbons having a plurality of carboxylate groups to a desorption reaction under mild reaction conditions, which could not be achieved by the prior art. An object of the present invention is to provide a method for producing a polyene by suppressing the side reaction to be generated and improving the yield.

As a result of intensive studies to solve the above-mentioned problems, the present inventors, in a method for producing a polyene by removing a carboxylic acid from a raw material containing a hydrocarbon having a plurality of carboxylate groups, It was found that by setting the hydrocarbon concentration in a specific range and performing the elimination reaction in a specific temperature range, side reactions can be suppressed and a high-purity polyene can be obtained in a high yield. It came to be completed.

That is, the gist of the present invention is as follows.
[1] A method for producing a polyene by desorbing a carboxylic acid from a raw material containing a hydrocarbon,
The hydrocarbon has a plurality of carboxylate groups;
The concentration of the hydrocarbon in the raw material is 0.1 mol% or more and 95 mol% or less, and
A method for producing a polyene, wherein the elimination reaction is performed at 250 ° C or higher and 800 ° C or lower.
[2] The polyene according to [1], wherein the raw material contains a product obtained by an esterification reaction between a hydrocarbon having a plurality of hydroxyl groups and at least one of carboxylic acid and carboxylic anhydride. Production method.
[3] The raw material further includes a hydrocarbon having a plurality of hydroxyl groups, and a molar ratio of the hydrocarbon having the plurality of hydroxyl groups to the hydrocarbon having the plurality of carboxylate groups is 0.9 or less. The method for producing a polyene according to [1] or [2].
[4] The method for producing a polyene according to any one of [1] to [3], wherein the elimination reaction is continuous.
[5] The method for producing a polyene according to any one of [1] to [4], wherein the elimination reaction is performed in the presence of a solid packing.
[6] The method for producing a polyene according to [5], wherein the solid filler is at least one selected from the group consisting of silica alumina, mullite, and stainless steel.
[7] The method for producing a polyene according to any one of [1] to [6], wherein the hydrocarbon having a plurality of carboxylate groups is diacetoxybutane.
[8] The method for producing a polyene according to any one of [1] to [7], wherein the carboxylic acid is acetic acid.
[9] The method for producing a polyene according to any one of [2] to [8], wherein the hydrocarbon having a plurality of hydroxyl groups is butanediol.

According to the method for producing a polyene of the present invention, it is possible to produce a high-purity polyene in a high yield with few impurities that are difficult to remove due to side reactions.

Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
The method for producing a polyene of the present invention is a method for producing a polyene by eliminating a carboxylic acid from a raw material containing a hydrocarbon having a plurality of carboxylate groups, wherein the plurality of carboxylates in the raw material are produced. This is a method for producing a polyene in which the concentration of the hydrocarbon having a group is in a specific range and the elimination reaction is performed in a specific temperature range.

The carboxylate group is a group represented by the following formula (1).

(In formula (1), R ¹ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)
Among these, R ¹ is preferably a substituted or unsubstituted alkyl group, more preferably a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, because the yield of polyene is increased.
When R ¹ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. , Isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like.
Among these, a methyl group, an ethyl group, and an n-propyl group are preferable, and a methyl group is more preferable.
Examples of the substituent include aryl groups such as phenyl group, tolyl group, xylyl group, and naphthyl group, and halogen atoms such as chlorine, bromine, iodine, and fluorine.

The number of carboxylate groups in the hydrocarbon having a plurality of carboxylate groups is plural, preferably 2 or more and 3 or less, more preferably 2. If the carboxylate group is 4 or more hydrocarbons, the yield of polyene may be low, and the selectivity of the target polyene may be low.

In addition, “yield” represents the ratio of hydrocarbons having a plurality of carboxylate groups to polyenes. “Selectivity” represents the ratio of a hydrocarbon having a plurality of carboxylate groups converted to another compound by reaction to become a polyene.

The number of carbon atoms in the hydrocarbon having a plurality of carboxylate groups (excluding the carbon number of the carboxylate group) is preferably 4 or more and 6 or less, more preferably 4 or more and 5 or less. More preferably. That is, hexane having a plurality of carboxylate groups, pentane having a plurality of carboxylate groups, butane having a plurality of carboxylate groups is preferable, pentane having a plurality of carboxylate groups, and a plurality of carboxylate groups More preferred is butane having a plurality of carboxylate groups. When the number of carbon atoms is not more than the above upper limit, the selectivity of the target polyene produced by the elimination reaction tends to be high, which is preferable.

The hydrocarbon having a plurality of carboxylate groups is preferably diacetoxybutane. Examples of the diacetoxybutane include 1,2-diacetoxybutane, 1,3-diacetoxybutane, 1,4-diacetoxybutane, and 2,3-diacetoxybutane, but the selectivity is good. More preferred are 1,3-diacetoxybutane, 1,4-diacetoxybutane and 2,3-diacetoxybutane, and more preferred are 1,3-diacetoxybutane and 2,3-diacetoxybutane. In addition, it is preferable that the polyene manufactured by the manufacturing method of the polyene of this invention is a conjugated diene from a viewpoint of industrial applicability.

The hydrocarbon concentration having a plurality of carboxylate groups in the raw material is 0.1 mol% or more and 95 mol% or less, and the lower limit is preferably 1 mol%, more preferably 5 mol%. The upper limit is preferably 90 mol%, more preferably 85 mol%, still more preferably 80 mol%, and particularly preferably 70 mol%. If the concentration of the hydrocarbon having a plurality of carboxylate groups is too low, the cost required for the production of the polyene may increase. If the concentration of the hydrocarbon having a plurality of carboxylate groups is too high, there may be many side reactions that produce impurities that are difficult to remove.

In the reaction of the present invention for producing polyene by elimination reaction of carboxylic acid from a raw material containing hydrocarbon having a plurality of carboxylate groups (hereinafter sometimes referred to as “carboxylic acid elimination reaction”), the purpose is as follows. There are multiple types of compounds that may be produced in addition to the polyene. When the hydrocarbon having a plurality of carboxylate groups has 4 carbon atoms, one of the compounds is 1 such as 3-acetoxy-1-butene, 1-acetoxy-2-butene, 4-acetoxy-1-butene, etc. It is a compound from which molecular carboxylic acid has been eliminated, and is an intermediate of the target polyene. These intermediates can be reused as raw materials.
On the other hand, by-products such as butenes such as 1-butene, cis-2-butene, trans-2-butene, and isobutene; These are impurities that are not converted to the desired polyene and are difficult to remove.
According to the production method of the present invention, the elimination reaction under mild reaction conditions in the carboxylic acid elimination reaction not only increases the yield of the target polyene, but also by-products of MEK derivatives that are difficult to remove. Can be suppressed.

Further, the raw material may further contain a hydrocarbon having a plurality of hydroxyl groups. As the hydrocarbon having a plurality of carboxylate groups in the present invention, a product obtained by esterifying a starting material containing a hydrocarbon having a plurality of hydroxyl groups can be used. When this esterification reaction does not proceed easily, some of the hydrocarbons having a plurality of hydroxyl groups used for charging may remain in the obtained product. These hydrocarbons having a plurality of hydroxyl groups may be contained in the raw material as long as the effects are not impaired in the production method of the present invention. In this case, the molar ratio of the hydrocarbon having a plurality of hydroxyl groups to the hydrocarbon having a plurality of carboxylate groups is preferably 0.9 or less, more preferably 0.8 or less, More preferably, it is 0.7 or less. It is preferable that the molar ratio is equal to or less than the upper limit because side reactions in which impurities that are difficult to remove tend to be effectively suppressed.

In the method for producing a polyene of the present invention, a raw material containing a hydrocarbon having a plurality of carboxylate groups is subjected to elimination reaction of a carboxylic acid within a specific temperature range. The temperature range in which the carboxylic acid is eliminated is 250 ° C. or higher and 800 ° C. or lower. The lower limit is preferably 260 ° C, more preferably 270 ° C, still more preferably 280 ° C, still more preferably 300 ° C, and particularly preferably 350 ° C. The upper limit is preferably 750 ° C, more preferably 700 ° C, still more preferably 650 ° C, still more preferably 600 ° C, and particularly preferably 500 ° C. If the temperature for the elimination reaction is too low, the elimination reaction rate of the carboxylic acid may decrease. If the temperature for the elimination reaction is too high, there may be a side reaction that produces impurities that are difficult to remove.
According to the production method of the present invention, the MEK derivative which is an impurity that is difficult to remove as well as increasing the yield of the target polyene by performing the elimination reaction under mild reaction conditions in the carboxylic acid elimination reaction. Can be suppressed.

The carboxylic acid eliminated by the elimination reaction is a compound represented by the following formula (2).

In the formula (2), R ¹ is the same as in the formula (1). Therefore, as the carboxylic acid to be eliminated, acetic acid, propionic acid, and butyric acid are preferable, and acetic acid is more preferable.
The method for producing the polyene of the present invention can be appropriately selected from a batch method and a continuous method, but a raw material containing hydrocarbons having a plurality of carboxylate groups is continuously supplied to the reaction system. In addition, it is preferable to produce the polyene by continuously performing the elimination reaction. As the reaction system, it is preferable that there is a portion for holding a solid packing described later, and the raw material can be continuously supplied, and the produced polyene and the released carboxylic acid are discharged out of the system. However, there is no particular limitation as long as it is a tube reactor, a tank reactor, a fixed bed reactor, a fluidized bed reactor, etc. A type reactor, a fixed bed type reactor, and a tank type reactor are preferred.

According to the method for producing a polyene of the present invention, it is possible to suppress the by-product of the MEK derivative that is difficult to remove. Specifically, the ratio of the produced MEK derivative to the hydrocarbon having a plurality of carboxylate groups charged as a raw material (MEK derivative yield) can be 5.0% or less. The yield of MEK derivative is more preferably 4.5% or less, further preferably 4.0% or less, and particularly preferably 3.5% or less.
According to the production method of the present invention, not only is the elimination reaction carried out under mild reaction conditions in the carboxylic acid elimination reaction to increase the yield of the target polyene, but it is particularly difficult to remove among the by-products. It is particularly excellent in that it can suppress MEK derivatives, which are undesirable by-products.

An example of the production flow of polyene containing the reaction system is shown below.
A raw material containing a hydrocarbon having a plurality of carboxylate groups is continuously supplied to the reaction system, the carboxylic acid elimination reaction is continuously carried out, and the reaction mixture after the elimination reaction is discharged out of the reaction system, Polyene is separated and purified from the discharged reaction mixture. Further, the carboxylic acid is removed from the reaction mixture after separating the polyene, the unreacted hydrocarbon having a plurality of carboxylate groups is recovered, and the recovered hydrocarbon having a plurality of carboxylate groups is newly added. Mix with raw materials and reuse.

In the polyene production method of the present invention, a polyene is produced by a carboxylic acid elimination reaction, which is generally an endothermic reaction. Therefore, there is a possibility that the elimination reaction temperature gradually decreases. In order to suppress a decrease in the elimination reaction temperature, it is preferable that a solid packing (hereinafter sometimes referred to as “packing”) inert to the elimination reaction is present in the reaction system.
The material constituting the packing may be any material that does not induce side reactions in the reaction system, such as silica alumina, zirconium oxide, titanium oxide, magnesium oxide, alundum, silica, mullite, carborundum, stainless steel, Examples thereof include silicon carbide, silicon nitride, steatite, earthenware, porcelain, iron, and various ceramics. Among them, at least one selected from the group consisting of silica alumina, mullite, and stainless steel is preferable.

The shape of the filler is not particularly limited. For example, the shape of the filler can be powder, spherical, columnar, cylindrical, wire mesh, plate, or the like. It is commercially available. For example, a Raschig ring, a lessing ring, a ball ring, an interlock saddle, a Berle saddle, a ceramic ball, McMahon, Dixon, etc. can be used as a material that can be obtained easily.

The raw material containing a hydrocarbon having a plurality of carboxylate groups supplied to the reaction system may be a gas or a liquid. When the state of the raw material is a gas, it is preferable from the viewpoint of maintaining the temperature of the desorption reaction that the raw material further contains a gas that does not inhibit the desorption reaction. Examples of the gas include nitrogen gas, argon gas, neon gas, carbon dioxide gas, carboxylic acid, and water vapor, which are easy to use and easy to remove after the elimination reaction. Acid and water vapor are more preferable.

Further, the reaction time of the elimination reaction is preferably 0.1 seconds or more and 50 seconds or less. The lower limit is more preferably 0.5 seconds. The upper limit is more preferably 45 seconds and even more preferably 40 seconds. When the reaction time is in an appropriate range, the yield of polyene produced from the raw material is high and the yield can be increased.
In addition, the reaction time in the manufacturing method of the polyene of this invention can be calculated | required according to a following formula.

The “volume flow rate of the raw material in the reaction system” in the above formula (1) is the volume flow rate of the raw material at the reaction temperature in the reaction system.
In the polyene production method of the present invention, the raw material containing a hydrocarbon having a plurality of carboxylate groups is an esterification of a hydrocarbon having a plurality of hydroxyl groups and at least one of a carboxylic acid and a carboxylic anhydride. It is preferable to include the product obtained by the reaction. That is, the hydrocarbon having a plurality of carboxylate groups is preferably obtained by an esterification reaction between a hydrocarbon having a plurality of hydroxyl groups and at least one of carboxylic acid and carboxylic anhydride. . Here, the product obtained by the esterification reaction may contain a hydrocarbon having one carboxylate group. In the range where the effect of the present invention is exerted, for example, in the range of 50 mol% or less, preferably 40 mol% or less, more preferably 10 mol% or less in the raw material, a hydrocarbon having one carboxylate group is contained in the raw material. You may go out.

The esterification reaction between a hydrocarbon having a plurality of hydroxyl groups and a carboxylic acid and / or carboxylic anhydride will be described below.
The esterification reaction can be efficiently performed using a reaction apparatus. In the reaction apparatus, a hydrocarbon having a plurality of hydroxyl groups is reacted with a carboxylic acid and / or a carboxylic anhydride. Specifically, a compound having a plurality of hydroxyl groups is supplied to the reaction apparatus, and carboxylic acid and / or carboxylic anhydride is supplied to the reaction apparatus. The product produced by the reaction in the reactor is discharged out of the reactor. The compound having a plurality of hydroxyl groups and the carboxylic acid and / or carboxylic anhydride may be supplied separately to the reaction apparatus, or may be supplied to the reaction apparatus after mixing in advance.

Details of the esterification reaction will be described below.
The hydrocarbon having a plurality of hydroxyl groups is not particularly limited, but the number of carbons in the hydrocarbon having a plurality of hydroxyl groups is preferably 4 or more and 6 or less, and more preferably 4 or more and 5 or less. 4 is more preferable. When the number of carbon atoms is less than or equal to the upper limit value, the selectivity of the target polyene tends to increase due to the subsequent elimination reaction, which is preferable.
That is, hexane having a plurality of hydroxyl groups, pentane having a plurality of hydroxyl groups, butane having a plurality of hydroxyl groups is preferable, pentane having a plurality of hydroxyl groups, butane having a plurality of hydroxyl groups is more preferred. Preferably, butane having a plurality of hydroxyl groups is more preferable.

The number of hydroxyl groups in the hydrocarbon having a plurality of hydroxyl groups is plural, preferably 2 or more and 3 or less, more preferably 2.
The hydrocarbon having a plurality of hydroxyl groups is preferably butanediol. Examples of the butanediol include 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2,3-butanediol, and the selectivity is reduced by an elimination reaction that is performed after the esterification reaction. 1,3-butanediol, 1,4-butanediol, and 2,3-butanediol are more preferable, and 1,3-butanediol and 2,3-butanediol are still more preferable because they are favorable.

The butanediol is not particularly limited, and examples thereof include those produced industrially from naphtha-derived raw materials and those produced by fermentation from plant-derived raw materials.

The carboxylic acid used in the esterification reaction can be represented by the following formula (3).

In the formula (3), R ¹ is the same as that in the formula (1), and is preferably acetic acid.
For example, when a hydrocarbon having a plurality of hydroxyl groups and 1,3-butanediol and acetic acid as carboxylic acids are used for esterification reaction, 1,3 as hydrocarbons having a plurality of carboxylate groups are used. Diacetoxybutane is mainly obtained. When 1,6-hexanediol and acetic acid are respectively employed for esterification, 1,6-diacetoxyhexane is mainly obtained as a hydrocarbon having a plurality of carboxylate groups.

The carboxylic acid anhydride can be represented by the following formula (4).

In the formula (4), R ² and R ³ are the same as R ^{1 in the} formula (1), and the R ² and R ³ may be the same or different.
For example, when 1,3-butanediol and acetic anhydride are respectively employed as hydrocarbons having a plurality of hydroxyl groups and carboxylic acid and subjected to esterification reaction, 1, hydrocarbons having a plurality of carboxylate groups are 3-diacetoxybutane is mainly obtained. Further, when 1,6-hexanediol and acetic anhydride are respectively employed for esterification, 1,6-diacetoxyhexane is mainly obtained as a hydrocarbon having a plurality of carboxylate groups.

The esterification reaction can be carried out using a known technique. The esterification reaction may be performed without a catalyst, but may be performed in the presence of a catalyst from the viewpoint of improving the production rate.
Examples of the catalyst include inorganic acids (mineral acids) such as sulfuric acid, phosphoric acid and hydrochloric acid; organic acids (sulfonic acids) such as p-toluenesulfonic acid and methanesulfonic acid; Lewis acids such as BF ₃ ; strong acidic cations Examples thereof include solid acid catalysts represented by exchange resins, zeolites, silica-alumina, and the like; nucleophiles represented by 4-dimethylaminopyridine and the like.
Since the esterification reaction with an acid catalyst is an equilibrium reaction, it is preferable to carry out the reaction while removing by-product water.
Moreover, as a reaction form, any of a batch type (batch type) and a continuous type can be selected suitably.

The mixing ratio of the hydrocarbon having a plurality of hydroxyl groups and the carboxylic acid and / or carboxylic anhydride is not particularly limited. For example, in the case of a hydrocarbon having a plurality of hydroxyl groups and a carboxylic acid, the ratio of the carboxylic acid Can be selected from the range of 1.5 to 10 times mol, preferably 2 to 8 times mol, of the number of moles of hydroxyl groups in the hydrocarbon having a plurality of hydroxyl groups. In the case of a hydrocarbon having a plurality of hydroxyl groups and a carboxylic acid anhydride, the ratio of the carboxylic acid anhydride is 0.5 to 5 with respect to the number of moles of hydroxyl groups in the hydrocarbon having a plurality of hydroxyl groups. It can be selected from the range of 1 mol, preferably 1 to 4 mol.

The reaction temperature, pressure, time, and the like can be appropriately set depending on the types of hydrocarbons having a plurality of hydroxyl groups and carboxylic acid and / or carboxylic anhydride as raw materials, and the reaction temperature is 25 ° C. to 200 ° C. Preferably, the reaction pressure is 1 kPa to 100 kPa, and the reaction time is about 0.1 to 48 hours. Furthermore, the esterification reaction may be a batch type or a continuous type. However, since the raw material containing the product obtained by the esterification reaction can be continuously supplied to the subsequent elimination reaction, it is continuous. The formula is preferred.
By producing a polyene using a raw material containing a product obtained by an esterification reaction under the above conditions, the polyene can be obtained with high selectivity and high yield.

(Quantification of each product)
The product discharged from the reaction system was collected, and the collected product was analyzed and quantified by gas chromatography (model number: GC-4000 manufactured by GL Science).

(Synthesis example)
After introducing 15.04 g (167 mmol) of 2,3-butanediol into a 300 mL three-necked flask, the inside of the three-necked flask was replaced with nitrogen, and 73.51 g of pyridine was charged.
The three-necked flask was placed in an ice bath, and 51.09 g of acetic anhydride was added over 15 minutes using a dropping funnel while stirring. Stirring was continued for another 30 minutes, and 0.05 g of 4-dimethylaminopyridine (DMAP) was added. After stirring for about 13 hours, it was confirmed that the raw materials had disappeared by gas chromatography, and then 50 mL of demineralized water and 70 mL of toluene were added to the reaction solution to extract the product. The organic layer was washed with 70 mL of 1N hydrochloric acid twice, once with 50 mL of demineralized water, twice with 70 mL of saturated multistory water, once with 50 mL of demineralized water, and once with 70 mL of 1N hydrochloric acid. Next, 80 g of sodium sulfate was added to the organic layer for dehydration, and the sodium sulfate was filtered and concentrated with an evaporator. Further, the remaining toluene and pyridine were removed by drying under reduced pressure at a pressure of 10 to 20 hPa and a temperature of 25 ° C. for 6 hours to clear 21.33 g (122 mmol, yield 73.4%) of 2,3-diacetoxybutane. Obtained as a liquid.

Example 1
A stainless steel tubular reactor having an inner diameter of 10.0 mm and a length of 500 mm was charged with 21.9 g of a mullite ball having a diameter of 2 mm (product name: FFB A-601, manufactured by Fujimi Incorporated), and silica alumina ( 1.0 g of JGC Catalysts & Chemicals N632L) was charged, and 28.0 g of the mullite ball was further charged thereon. The temperature in the stainless steel tubular reactor was measured by installing an insertion tube equipped with a thermocouple.

Nitrogen was supplied to a preheater heated to 350 ° C. at a flow rate of 4.6 L / hour (temperature: 0 ° C., pressure: converted to 1 atm), and 1,3-diacetoxybutane (Alfa Aesar reagent) Was supplied to the preheater at a flow rate of 3 mL / hour, and a uniform mixed gas (350 ° C.) of 1,3-diacetoxybutane and nitrogen gas was used as a raw material in the preheater (raw material composition = nitrogen: 92. 0 mol%, 1,3-diacetoxybutane: 8.0 mol%). The raw material was supplied to a stainless steel tubular reactor whose internal temperature was previously raised to 350 ° C. by an electric furnace, and a desorption reaction was carried out to produce 1,3-butadiene. The pressure was 50 kPa as a gauge pressure. Detailed conditions of the reaction are shown in Table 1. The reaction time was 5 seconds.
Table 1 shows the results of analysis by gas chromatography (model number: GC-4000, manufactured by GL Science).

(Example 2)
The stainless steel tubular reactor was filled with mullite balls only, the reaction temperature was 500 ° C., the nitrogen flow rate was 2.8 L / hour (temperature: 0 ° C., pressure: converted to 1 atm), In addition, 1,3-butadiene was produced in the same manner as in Example 1 except that 1,3-diacetoxybutane was used at a flow rate of 1.3 mL / hour. The reaction time was 8 seconds. The raw material composition was nitrogen: 92.0 mol% and 1,3-diacetoxybutane: 8.0 mol%.
The analysis results are shown in Table 1.

Example 3
1,3-butadiene was produced in the same manner as in Example 2, except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 8 seconds.
Raw material composition = nitrogen: 88.6 mol%, 1,3-diacetoxybutane: 8.0 mol%, acetic acid: 3.4 mol%
The results of analysis are shown in Table 1.

Example 4
1,3-butadiene was produced in the same manner as in Example 2 except that 1,3-diacetoxybutane was changed to 2,3-diacetoxybutane in the raw material. The reaction time was 8 seconds. The raw material composition was nitrogen: 92.0 mol% and 2,3-diacetoxybutane: 8.0 mol%.
The results of analysis are shown in Table 1.

(Example 5)
1,3-Butadiene was produced in the same manner as in Example 2 except that the stainless steel tubular reactor was not filled and the reaction pressure was 2 kPa as a gauge pressure. The reaction time was 5 seconds. The raw material composition was nitrogen: 92.0 mol% and 1,3-diacetoxybutane: 8.0 mol%.
The results of analysis are shown in Table 1.

(Example 6)
Except that the flow rate of nitrogen was 2.8 L / hour (temperature: 0 ° C., pressure: converted to 1 atm), and that the flow rate of 1,3-diacetoxybutane was 1.3 mL / hour. In the same manner as in Example 5, 1,3-butadiene was produced. The reaction time was 8 seconds. The raw material composition was nitrogen: 92.0 mol% and 1,3-diacetoxybutane: 8.0 mol%.
The results of analysis are shown in Table 1.

(Example 7)
1,3-butadiene was produced in the same manner as in Example 5 except that the pressure was changed to 50 kPa as a gauge pressure. The reaction time was 5 seconds. The raw material composition was nitrogen: 92.0 mol% and 1,3-diacetoxybutane: 8.0 mol%.
The results of analysis are shown in Table 1.

(Example 8)
1,3-Butadiene was produced in the same manner as in Example 6 except that the pressure was changed to 50 kPa as a gauge pressure. The reaction time was 8 seconds. The raw material composition was nitrogen: 92.0 mol% and 1,3-diacetoxybutane: 8.0 mol%.
Table 2 shows the results of the analysis.

Example 9
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 92.0 mol%, 1,3-diacetoxybutane: 7.2 mol%, 3-acetoxy-1-butanol: 0.3 mol%, 4-acetoxy-2-butanol: 0.5 Mol%
Table 2 shows the results of the analysis.

(Example 10)
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 92.0 mol%, 2,3-diacetoxybutane: 7.2 mol%, 2,3-butanediol: 0.8 mol%
Table 2 shows the results of the analysis.

(Example 11)
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 92.0 mol%, 2,3-diacetoxybutane: 4.0 mol%, 2,3-butanediol: 4.0 mol%
Table 2 shows the results of the analysis.

Example 12
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 88.8 mol%, 2,3-diacetoxybutane: 4.0 mol%, 2,3-butanediol: 4.0 mol%, acetic acid: 3.2 mol%
Table 2 shows the results of the analysis.

(Example 13)
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 70.0 mol%, 1,3-diacetoxybutane: 30.0 mol%
Table 2 shows the results of the analysis.

(Example 14)
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 50.0 mol%, 1,3-diacetoxybutane: 50.0 mol%
Table 2 shows the results of the analysis.

(Example 15)
1,3-butadiene was produced in the same manner as in Example 7 except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 10.0 mol%, 1,3-diacetoxybutane: 90.0 mol%
Table 3 shows the results of the analysis.

(Example 16)
1,3-butadiene was produced in the same manner as in Example 15, except that the reaction time was changed to 6 seconds.
Table 3 shows the results of the analysis.

(Comparative Example 1)
1,3-butadiene was produced in the same manner as in Example 1 except that the raw material composition introduced into the reactor was changed to the following and the reaction temperature was changed to 450 ° C. The reaction time was 5 seconds.
Raw material composition = nitrogen: 92.0 mol%, 1,3-butanediol: 8.0 mol%
Table 3 shows the results of the analysis.

(Comparative Example 2)
1,3-butadiene was produced in the same manner as in Comparative Example 1, except that the raw material composition introduced into the reactor was changed as follows. The reaction time was 5 seconds.
Raw material composition = nitrogen: 92.0 mol%, 2,3-butanediol: 8.0 mol%
Table 3 shows the results of the analysis.

In each of Examples 1 to 16, a high butadiene yield was achieved, and the production of methyl ethyl ketone and n-butenes was sufficiently suppressed, making it more difficult to remove due to side reactions than in Comparative Examples. Polyenes with few impurities and high purity can be produced in high yield.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on January 21, 2014 (Japanese Patent Application No. 2014-008593), the contents of which are incorporated herein by reference.

According to the method for producing a polyene of the present invention, it is possible to expand a field of use because a high-purity polyene can be produced in a high yield with few impurities caused by side reactions.

Claims

A method for producing a polyene by desorbing a carboxylic acid from a raw material containing a hydrocarbon,
The hydrocarbon has a plurality of carboxylate groups;
The concentration of the hydrocarbon in the raw material is 0.1 mol% or more and 95 mol% or less, and
A method for producing a polyene, wherein the elimination reaction is performed at 250 ° C or higher and 800 ° C or lower.
The method for producing a polyene according to claim 1, wherein the raw material contains a product obtained by an esterification reaction between a hydrocarbon having a plurality of hydroxyl groups and at least one of carboxylic acid and carboxylic anhydride.
The raw material further includes a hydrocarbon having a plurality of hydroxyl groups, and the molar ratio of the hydrocarbon having a plurality of hydroxyl groups to the hydrocarbon having a plurality of carboxylate groups is 0.9 or less. A process for producing the polyene according to 1 or 2.
The method for producing a polyene according to any one of claims 1 to 3, wherein the elimination reaction is continuous.
The method for producing a polyene according to any one of claims 1 to 4, wherein the elimination reaction is carried out in the presence of a solid packing.
The method for producing a polyene according to claim 5, wherein the solid filler is at least one selected from the group consisting of silica alumina, mullite and stainless steel.
The method for producing a polyene according to any one of claims 1 to 6, wherein the hydrocarbon having a plurality of carboxylate groups is diacetoxybutane.
The method for producing a polyene according to any one of claims 1 to 7, wherein the carboxylic acid is acetic acid.
The method for producing a polyene according to any one of claims 2 to 8, wherein the hydrocarbon having a plurality of hydroxyl groups is butanediol.