JP2015048336A - Method for producing butadiene and/or 3-butene-2-ol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To industrially produce butadiene and/or 3-butene-2-ol from 2,3-butanediol at a high selectivity coefficient without using thorium oxide.SOLUTION: In the production method, using the alkali metal salt of phosphoric acid as a catalyst, 2,3-butanediol is dewatered to produce butanediol and/or 3-butene-2-ol. As the alkali metal salt of phosphoric acid, at least one kind selected from the group consisting of K, Rb and Cs or their mixture is used. The 3-butene-2-ol is dewatered in the presence of an acid catalyst to produce butadiene.

Description

  The present invention relates to a process for producing butadiene and / or 3-buten-2-ol from 2,3-butanediol.

  Butadiene is a raw material for butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, ABS resin and the like, and is one of the most important organic compounds in the chemical industry. Butadiene can be converted into adiponitrile, which is an intermediate for the synthesis of nylon 66, chloroprene, which is a raw material for chloroprene rubber, and 1,4-butanediol, which is a raw material for polybutylene terephthalate. These butadiene-based polymer compounds are widely used not only in industrial products such as automobile tires, electric wire coatings, and engineering plastics, but also in everyday items such as clothing, and the demand for butadiene is increasing year by year. Yes.

  Butadiene is produced mainly by extraction and separation from a C4 fraction during ethylene production by a naphtha cracker. However, it is expected that the supply of butadiene will be insufficient in the future as the raw material for ethylene shifts to natural gas. Therefore, in recent years, a method for producing butadiene using natural gas as a raw material has begun to be studied. However, due to issues such as future depletion of fossil resources and global warming due to greenhouse gas emissions, there is an increasing need to realize sustainable butadiene production. There is a need to develop manufacturing methods.

  3-Buten-2-ol is a typical secondary allyl alcohol, and can be almost quantitatively converted to butadiene by dehydrating one molecule using a known technique (Non-patent Document 1). It can be said. Therefore, the technology for producing 3-buten-2-ol is very important.

  2,3-butanediol is a kind of polyol used as a raw material for inks, perfumes, liquid crystals, insecticides, softening reagents, explosives, plasticizers, etc., and industrially 2-butene oxide in perchloric acid aqueous solution It is manufactured by the method of hydrolyzing. On the other hand, 2,3-butanediol can be produced by a microbial fermentation method using monosaccharides such as glucose and xylose as a raw material (Patent Document 1), and thus is a substance that can be derived from biomass resources. Therefore, if butadiene and / or 3-buten-2-ol can be produced by dehydration of 2,3-butanediol, butadiene and / or 3-buten-2-ol, and further existing synthesis using these as raw materials The resin can be replaced with a biomass resource-derived substance.

  It is known that dehydration of 2,3-butanediol can be performed using an acid catalyst. For example, a method of dehydrating by bringing 2,3-butanediol into contact with acidic clay has been disclosed (Non-patent Document 2). Moreover, the method of dehydrating by processing 2,3-butanediol in sulfuric acid aqueous solution is disclosed (nonpatent literature 3). Moreover, the method of dehydrating by making a 2, 3- butanediol contact with a zeolite is disclosed (nonpatent literature 4). However, the main product in these processes is methyl ethyl ketone, not 3-buten-2-ol or butadiene.

A method for selectively producing butadiene and / or 3-buten-2-ol by dehydration of 2,3-butanediol has been reported. Non-Patent Document 5 uses a method using a thorium oxide (ThO ₂ ) catalyst, Patent Document 2 uses a cesium oxide-supported silica catalyst, and Patent Document 3 uses a composite catalyst of hydroxyapatite and alumina. Document 6 discloses a method using dimethyl sulfoxide, respectively.

On the other hand, butadiene and / or 3-buten-2-ol can also be produced by dehydration of 1,3-butanediol. In Patent Document 4, sodium dihydrogen phosphate (NaH ₂ PO ₄ ), calcium monohydrogen phosphate (CaHPO ₄ ), phosphoric acid (H ₃ PO ₄ ), and butylamine phosphate (BuNH ₂ · H ₃ PO ₄ ) are used. A method using a mixed catalyst is disclosed, and the selectivity for butadiene is reported to be 77%. Non-Patent Document 7 discloses a method of using cerium oxide (CeO ₂ ) as a catalyst, and the total selectivity of butadiene and 3-buten-2-ol is 52.5% (butadiene: 4.6%). 3-buten-2-ol: 47.9%), and methyl ethyl ketone selectivity is reported to be 2.5%.

International Publication No. 2013/054874 Korean Published Patent No. 10-2012-0998818 Korean Published Patent No. 10-2012-0107353 US Pat. No. 2,444,538

Journal of Molecular Catalysis, A: Chemical, vol. 256, p. 106-112 (2006) Journal of the Japanese Agricultural Chemical Society vol. 18, p. 143-150 (1942) Industrial Engineering Chemistry Product Research and Development, vol. 21, 473-477 (1982) Industrial & Engineering Chemistry Research, vol. 52, p. 56-60 (2013) Journal of Council Science Industrial Research in Australia, vol. 18, p. 412-423 (1945). Helvetica Chimica Acta, vol. 64, 389-398 (1981) Journal of Molecular Catalysis, A: Chemical, vol. 221, p. 177-183 (2004)

  As described above, when 2,3-butanediol is dehydrated using an acid catalyst, the main product is methyl ethyl ketone, and hardly produces butadiene and / or 3-buten-2-ol. In the methods disclosed in Non-Patent Document 2, Non-Patent Document 3, and Non-Patent Document 4, methyl ethyl ketone is produced with a selectivity of 66 mol%, 96 mol%, 90 mol% or more, respectively.

  In addition, as described above, a method for selectively producing butadiene and / or 3-buten-2-ol from 2,3-butanediol has been reported, and the oxidation disclosed in Non-Patent Document 5 is reported. In the method using a thorium catalyst, the total selectivity of butadiene and 3-buten-2-ol is 87.1 mol% (butadiene: 25.1 mol%, 3-buten-2-ol: 62.0 mol%). is there. However, thorium oxide is a radioactive substance and is difficult to use in industrial applications.

  In the method disclosed in Patent Document 2, the total selectivity of butadiene and 3-butene-ol is 62 mol% (butadiene: 62 mol%, 3-buten-2-ol: 0 mol%). The selectivity for methyl ethyl ketone is reported to be 33%. However, as shown in Comparative Example 1 of the present application, as a result of the inventors further trying this method, the total selectivity of butadiene and 3-buten-2-ol was 42.3 mol% (butadiene: 32.9 mol%). 3-buten-2-ol: 11.6 mol%), and the selectivity was very low.

  In the method disclosed in Patent Document 3, the total selectivity of butadiene and 3-buten-2-ol remains at 48 mol% (butadiene: 48 mol%, 3-buten-2-ol: 0 mol%), In this case, the selectivity for methyl ethyl ketone is 43%.

  In the method disclosed in Non-Patent Document 6, the total selectivity of butadiene and 3-buten-2-ol is as low as 21 mol% (butadiene: 0 mol%, 3-buten-2-ol: 21 mol%). In this case, the selectivity of methyl ethyl ketone is 53%.

  As described above, in the case where thorium oxide, which is a radioactive substance, is not used, there is no method for producing butadiene and / or 3-buten-2-ol from 2,3-butanediol with high selectivity. Development of a process for producing butadiene and / or 3-buten-2-ol that can be applied to the field is eagerly desired.

  As described above, butadiene and / or 3-buten-2-ol can also be selectively produced by dehydration of 1,3-butanediol (Patent Document 4, Non-Patent Document 7). However, according to Non-Patent Document 7, when 2,3-butanediol is dehydrated using a cerium oxide catalyst in the same manner as 1,3-butanediol, dehydration of butadiene and 3-buten-2-ol It is reported that the total selectivity is only 2.7% (butadiene: 0 mol%, 3-buten-2-ol: 2.7%), and the methyl ethyl ketone selectivity is 64.0%. That is, although 1,3-butanediol and 2,3-butanediol have similar chemical structures, the reactivity with respect to dehydration is greatly different. Under these conditions, dehydration of 2,3-butanediol involves the use of methyl ethyl ketone. It is clearly shown that butadiene and / or 3-buten-2-ol cannot be selectively produced due to the preferential progress of dehydration in the route of formation.

  Therefore, even if a method for selectively producing butadiene and / or 3-buten-2-ol by dehydration of 1,3-butanediol has been reported, the same method can be used for dehydration of 2,3-butanediol. It is clear that butadiene and / or 3-buten-2-ol can not be selectively produced as applied.

  An object of the present invention is to provide a method for producing butadiene and / or 3-buten-2-ol with a high selectivity from 2,3-butanediol without using a radioactive substance.

  As a result of intensive studies to solve the above problems, the present inventors have dehydrated 2,3-butanediol using an alkali metal salt of phosphoric acid as a catalyst, thereby allowing butadiene and / or 3-butene-2. -A method for producing oar was found and the present invention was completed.

  That is, the present invention provides a method for producing butadiene and / or 3-buten-2-ol by dehydrating 2,3-butanediol using an alkali metal salt of phosphoric acid as a catalyst.

  In one embodiment of the present invention, the catalyst is a catalyst prepared by dehydration condensation of an alkali metal dihydrogen phosphate or a dialkali metal hydrogen phosphate.

  In one embodiment of the present invention, the alkali metal is at least one selected from the group consisting of K, Rb, and Cs.

  In one embodiment of the present invention, the reaction temperature of 2,3-butanediol dehydration reaction is 400 ° C. or higher and 550 ° C. or lower.

  Another aspect of the present invention includes a step of producing butadiene by dehydrating 3-buten-2-ol produced in the step of dehydrating 2,3-butanediol in the presence of an acid catalyst.

  The dehydration process for producing butadiene and / or 3-buten-2-ol from 2,3-butanediol of the present invention can be described by the following reaction formula.

  According to the present invention, butadiene and / or 3-buten-2-ol can be produced from 2,3-butanediol with high selectivity without using a radioactive substance.

It is a figure which shows an example of the fixed bed flow-type gaseous-phase flow reaction apparatus.

  Hereinafter, typical embodiments for carrying out the present invention will be described in detail, but the present invention is not limited to the following embodiments.

  In the present invention, the biomass resource means an organic resource derived from a renewable organism, and refers to a resource made of organic matter generated by a plant immobilizing carbon dioxide using solar energy. Specifically, corn, sugarcane, potatoes, wheat, rice, soybeans, pulp, kenaf, rice straw, straw, bagasse, corn stover, switchgrass, weeds, waste paper, wood, charcoal, natural rubber, cotton, soybean oil , Palm oil, safflower oil, castor oil and the like.

  In the present invention, a biomass resource-derived substance means a substance derived from a biomass resource by fermentation, chemical conversion or the like, a substance that can be induced, or a derived substance. In the present invention, 2,3-butanediol derived from biomass resources and 2,3-butanediol derived from fossil resources such as petroleum can be used as raw materials.

  2,3-butanediol has three optical isomers: (2R, 3R) -2,3-butanediol, (2S, 3S) -2,3-butanediol, and meso-2,3-butanediol. Exists. The 2,3-butanediol of the present invention may be any isomer or a mixture of a plurality of isomers.

  As disclosed in Patent Document 1, 2,3-butanediol derived from biomass resources can be produced by microbial fermentation of sugars obtained from biomass resources. In microorganisms that ferment sugars as a carbon source, Klebsiella pneumoniae, Klebsiella oxymora, and Paenibacillus polymyxa are naturally present and produce (2R, 3R) -2,3-butanediol and meso-2,3-butanediol. Can do. In addition, it is known that (2S, 3S) -2,3-butanediol is selectively produced in the genus Ocribactrum as shown in International Publication No. 2007/094178. In addition, Clostridium autoethanogenum is also known as a microorganism that ferments using carbon monoxide as a carbon source as described in International Publication No. 2009/151342, and 2,3-butanediol produced from such a microorganism is also included in the present invention. Can be the target of

  In addition to these, a method using a microorganism imparted with 2,3-butanediol-producing ability by gene recombination may be used. Specific examples include “Applied Microbiology and Biotechnology, Vol. 87, No. 6, p. 2001-2009 ( 2010) ”.

  Examples of the carbon source of the fermentation raw material include sugars such as glucose, fructose, sucrose, xylose, arabinose, galactose, mannose, and starch. Furthermore, the saccharide may be a commercial product, but it may be a decomposed product such as recycled resources or biomass derived from plants, and a cellulose, hemicellulose, or lignin raw material decomposed by chemical or biological treatment is also used. be able to. In addition, in the case of the aforementioned Clostridium autoethanogenum, carbon monoxide is a carbon source, which is obtained from incomplete combustion of coal, oil, and biomass resources, as well as hydrogen and methane generated when producing coke used for iron making It is also possible to use a mixed gas of

  2,3-butanediol derived from fossil resources is available on the market and can be easily obtained.

  The catalyst used in the present invention will be described.

In the present invention, the “alkali metal salt of phosphoric acid” means the following (A), (B) or (C).
(A): “alkali metal phosphate” represented by the general formula (I) “M _n H _3-n PO ₄ ” (meaning a monomer that has not been dehydrated and condensed);
(B): (A) a mixture of “alkali metal phosphates” with different alkali metals, or (C): “alkaline phosphates” in which all or some of the phosphate groups in (A) or (B) are dehydrated and condensed. Metal dehydration condensate ".

In the general formula (I), M represents an alkali metal, that is, Li (lithium), Na (sodium), K (potassium), Rb (rubidium) or Cs (cesium). N represents a positive real number of 3 or less. That is, the salt of “phosphoric acid” includes dihydrogen phosphate (H ₂ PO ₄ ⁻ ), monohydrogen phosphate (HPO ₄ ²⁻ ), and phosphate (PO ₄ ³⁻ ).

  In the present invention, as the alkali metal phosphate dehydration condensate, a commercially available product can be used as it is, or it can be prepared by dehydration condensation of an alkali metal phosphate (monomer). For example, the alkali metal phosphate can be prepared by dehydration condensation by heating to 300 to 600 ° C. using an electric furnace or the like under air flow.

In the present invention, among alkali metal salts of phosphoric acid, it is preferable to use alkali metal dihydrogen phosphate or dialkali metal hydrogen phosphate as a catalyst. Specifically, the alkali metal dihydrogen phosphate is one or more selected from the group consisting of LiH ₂ PO ₄ , NaH ₂ PO ₄ , KH ₂ PO ₄ , RbH ₂ PO ₄ and CsH ₂ PO _4. A mixture of these or a dehydration condensate thereof can be preferably used. In addition, as the dialkali metal hydrogen phosphate, one or a mixture of two or more selected from the group consisting of Li ₂ HPO ₄ , Na ₂ HPO ₄ , K ₂ HPO ₄ , Rb ₂ HPO ₄ and Cs ₂ HPO ₄ , Alternatively, these dehydration condensates can be preferably used.

  Alkali metal dihydrogen phosphate dehydration condensate, dihydrogen alkali metal phosphate dehydration condensate are commercially available, or alkali metal dihydrogen phosphate (monomer) or dialkali metal hydrogen phosphate (monomer) Can be prepared by heating to 300 to 600 ° C. under air flow using an electric furnace or the like.

  The alkali metal contained in the catalyst is preferably at least one selected from the group consisting of K, Rb, and Cs. When these alkali metal-containing catalysts are used, the selectivity of methyl ethyl ketone produced by dehydration of 2,3-butanediol tends to be low, and the total selectivity of butadiene and / or 3-buten-2-ol tends to be high. There is.

  The alkali metal salt of phosphoric acid used as a catalyst in the present invention may be retained and used on silica gel, activated carbon, or other commonly used carriers.

  The dehydration step of 2,3-butanediol in the present invention can be performed by a gas phase flow reaction. The gas phase flow reaction is a reaction format in which a tubular reactor is filled with a solid catalyst and the vaporized raw material is allowed to flow through a catalyst layer for reaction. Specific examples include a fixed bed flow type in which the catalyst is allowed to stand, a moving bed flow type in which the catalyst is moved, and a fluidized bed flow type in which the catalyst is fluidized. In the present invention, any of these reaction modes can be applied.

  In the gas phase flow reaction, the vaporized raw material can be passed through the catalyst layer together with the carrier gas. Although it does not restrict | limit especially as carrier gas, Inert gas, such as nitrogen, helium, argon, or hydrogen, or these mixed gas is used preferably. The carrier gas may contain water vapor, air, oxygen and the like.

  As the fixed bed flow type reaction apparatus, for example, the apparatus illustrated in FIG. 1 can be used. The apparatus shown in FIG. 1 includes a reaction tube 1 having a raw material introduction port 4 and a carrier gas introduction port 3, a reaction crude liquid collection vessel (cooler) 5, and a tubular furnace 2. It can be fixed inside the tube 1. The tube 1 can heat the reaction tube 1 to a desired temperature. The gas phase flow reaction using the apparatus of FIG. 1 can be carried out by supplying a carrier gas and a raw material from the carrier gas inlet 3 and the raw material inlet 4 respectively and introducing them into the reaction tube 1. The condensing liquid compound can be collected in the reaction crude liquid collecting container 5, and the non-condensing gas component can be recovered from the gas outlet 7.

  The reaction temperature in the dehydration step of 2,3-butanediol is preferably 400 ° C. or higher and 550 ° C. or lower. When the reaction temperature is less than the above range, a sufficient conversion rate of 2,3-butanediol may not be obtained. When the reaction temperature exceeds the above range, hydrocarbons having 1 to 4 carbon atoms are by-produced. However, sufficient selectivity of butadiene and / or 3-buten-2-ol, which are target products, may not be obtained.

In the 2,3-butanediol dehydration step, the weight space velocity (WHSV) of the raw material gas supplied to the reactor is not particularly limited, but is preferably 0.1 or more and 10 h ⁻¹ or less, more preferably 0.5 or more and 3 h. ^-1 or less. Here, WHSV indicates the weight of 2,3-butanediol supplied per unit time per unit weight of the catalyst.

  In the 2,3-butanediol dehydration step, the reaction pressure is not particularly limited, but is preferably 0.01 MPa or more and 0.5 MPa or less, and particularly easy to carry out under an atmospheric pressure that does not require an apparatus or operation for pressure reduction or pressurization. It is.

  As described above, Patent Document 2 discloses a method for producing butadiene and / or 3-buten-2-ol by dehydration reaction of 2,3-butanediol. In this document, a cesium oxide-supported silica catalyst is used at a reaction temperature of 400 ° C. According to the inventors' further examination, it was found that the catalyst of this document has a low total selectivity of butadiene and 3-buten-2-ol (see Comparative Example 1). On the other hand, in the method using the alkali metal salt of phosphoric acid of the present invention as a catalyst, butadiene and / or 3-buten-2-ol can be produced with good selectivity.

  3-Buten-2-ol produced by the method of the present invention can be quantitatively converted to butadiene by further subjecting it to a dehydration reaction. Therefore, the total selectivity of butadiene and 3-buten-2-ol can be regarded as the selectivity of butadiene substantially.

  Specifically, the conversion to 3-butadiene by dehydration reaction of 3-buten-2-ol can be performed using a solid acid catalyst. For example, in addition to silica-alumina disclosed in Non-Patent Document 1, Alumina, titania, zeolite or the like can be used. In this reaction, isolated and purified 3-buten-2-ol can be used, or crude production of 3-buten-2-ol obtained in the 2,3-butanediol dehydration step of the present invention. The product can be used as it is (see Reference Example 1).

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Catalyst preparation)
A dehydration condensate of an alkali metal salt of phosphoric acid is prepared by heating the alkali metal salt (monomer) of phosphoric acid to 350 to 600 ° C. under an air flow using an electric furnace (Denken KDF-S70G). Using this as a catalyst, 2,3-butanediol was dehydrated.

As an example, white crystals (6.5 g) were obtained by heating NaH ₂ PO ₄ (10.2 g, Wako Pure Chemical Industries, Ltd.) at 500 ° C. under air flow. The crystals were lightly crushed in a mortar to obtain a dehydrated condensate of sodium dihydrogen phosphate. The catalyst thus obtained is hereinafter referred to as “NaH ₂ PO ₄ -500” (“alkali metal salt of raw material phosphoric acid—heating temperature (° C.)”).

Similarly, “LiH ₂ PO ₄ -500”, “KH ₂ PO ₄ -350”, “KH ₂ PO ₄ -500”, “KH ₂ PO ₄ -600”, “K ₂ HPO ₄ -500”, “ RbH ₂ PO ₄ -500 "," _CsH 2 _PO 4 -500 "(both dehydrated condensate) was prepared.

(Dehydration reaction of 2,3-butanediol)
In the following examples, comparative examples, and reference examples, the dehydration reaction of 2,3-butanediol was carried out by using a quartz Y-shaped reaction tube 1 having an inner diameter of 15 mm and a total length of 350 mm shown in FIG. Asahi Rika Seisakusho ARF-20KC) was used. A carrier gas inlet 3 and a raw material inlet 4 are provided in the upper part of the reaction tube, and a reaction crude liquid collecting container 5 having a gas outlet is connected under the reaction tube. The catalyst was filled in the central part of the reaction tube and fixed by sandwiching with quartz wool (6). The crude liquid recovered in the ice bathed collection container was diluted to 20 ml with methanol and quantified by gas chromatography measurement. In addition, gas products that did not aggregate in the ice bathed collection container were analyzed by gas chromatography directly connected to the gas outlet 7. The raw materials and products were quantified using an absolute calibration curve prepared using a standard. The conversion rate (mol%) of 2,3-butanediol and the selectivity (mol%) of each product were calculated by the following calculation formulas (Formula 1) and (Formula 2), respectively.

(Formula 1) Conversion (mol%) = (Amount of raw material−Remaining amount of raw material) / Amount of raw material × 100
(Formula 2) Selectivity (mol%) = (Yield of product) / (Amount of raw material−Remaining amount of raw material) × 100.

[Example 1]
LiH ₂ PO ₄ -500 (1.0 g) was charged into the reaction tube, and nitrogen was supplied from the top of the reaction tube at 30 ml / min. The temperature of the tubular furnace was raised to 500 ° C. and maintained at that temperature for 1 hour, and then 2,3-butanediol (Tokyo Kasei, meso-2,3-butanediol: 63%, (2R, 3R) -2, 3-butanediol: 29%, (2S, 3S) -2,3-butanediol: 8%) at 2 ml / h (WHSV: 1.97 h ⁻¹ ) from the top of the reaction tube to the catalyst layer together with a nitrogen stream Supplied. The reaction was performed for 5 hours, and the conversion of 2,3-butanediol and the selectivity of the product were calculated. The results are shown in Table 1.

[Example 2]
The reaction was carried out in the same manner as in Example 1 except that NaH ₂ PO ₄ -500 was used as the catalyst. The results are shown in Table 1.

[Example 3]
The reaction was performed in the same manner as in Example 1 except that KH ₂ PO ₄ -350 was used as the catalyst. The results are shown in Table 1.

[Example 4]
The reaction was performed in the same manner as in Example 1 except that KH ₂ PO ₄ -500 was used as the catalyst. The results are shown in Table 1.

[Example 5]
The reaction was carried out in the same manner as in Example 1 except that KH ₂ PO ₄ -600 was used as the catalyst. The results are shown in Table 1.

[Example 6]
The reaction was carried out in the same manner as in Example 1 except that K ₂ HPO ₄ -500 was used as the catalyst. The results are shown in Table 1.

[Example 7]
The reaction was performed in the same manner as in Example 1 except that RbH ₂ PO ₄ -500 was used as the catalyst. The results are shown in Table 1.

[Example 8]
The reaction was carried out in the same manner as in Example 1 except that CsH ₂ PO ₄ -500 was used as the catalyst. The results are shown in Table 1.

[Example 9]
The reaction was conducted in the same manner as in Example 8 except that the reaction temperature was 420 ° C. The results are shown in Table 1.

[Example 10]
The reaction was conducted in the same manner as in Example 8 except that the reaction temperature was 530 ° C. The results are shown in Table 1.

[Comparative Example 1]
According to Patent Document 2, a cesium oxide-silica composite was prepared. Cs ₂ CO ₃ (4.65 g: Wako Pure Chemical Industries, Ltd.) was dissolved in water (50 ml), and impregnated with silica gel (Davisil®, 35-60 mesh, Sigma-Aldrich, 10 g). The solution was heated at 80 ° C. with stirring for 24 hours to evaporate water and dried. The resulting powder was calcined at 600 ° C. under a stream of air to obtain a cesium oxide-silica composite (13.1 g). It was.

  The reaction was carried out in the same manner as in Example 1 except that a cesium oxide-silica composite (5.0 g) was used as the catalyst and the reaction temperature was 400 ° C. The results are shown in Table 1.

[Comparative Example 2]
The reaction was performed in the same manner as in Comparative Example 1 except that the amount of catalyst was 1.0 g and the reaction temperature was 500 ° C. The results are shown in Table 1.

[Reference Example 1]
(Preparation of crude purified 3-buten-2-ol)
3-buten-2-ol (2.09 g, Sigma-Aldrich), methyl ethyl ketone (0.64 g, Wako Pure Chemical Industries), isobutyraldehyde (0.20 g, Wako Pure Chemical Industries), and distilled water (2.10 g) were mixed. A solution was prepared.

(Reaction using crude purified 3-buten-2-ol)
Example 1 except that the catalyst is alumina (reference catalyst: JRC-ALO-6), the feed solution is the above mixed solution (2 ml), the reaction temperature is 300 ° C., and the reaction time is 1 hour. The reaction was carried out in the same manner. Table 2 shows the amount of each compound before and after the reaction.

In Examples 1 to 10, when 2,3-butanediol was dehydrated using an alkali metal salt of phosphoric acid as a catalyst, the by-product of methyl ethyl ketone was suppressed, and the total selectivity of butadiene and 3-buten-2-ol was increased. It was shown to be very high. It was shown that the total selectivity of butadiene and 3-buten-2-ol is higher especially when using a catalyst whose alkali metal is K, Rb or Cs. Further, Comparative Examples 1 and 2 showed that the total selectivity of butadiene and 3-buten-2-ol obtained in the present invention was significantly higher than that of the known art.

  From Examples 3 to 5, it was shown that the heating temperature for preparing the catalyst is not particularly limited as long as the alkali metal salt of phosphoric acid can be dehydrated and condensed.

  From Examples 8 to 10, it was shown that the reaction temperature was 420 ° C. to 530 ° C., and butadiene and / or 3-buten-2-ol could be produced with high selectivity.

  In Reference Example 1, to reproduce 3-buten-2-ol in a crudely purified state in which 2,3-butanediol was recovered from the crude liquid collected in Example 8, 3-buten-2-ol, methyl ethyl ketone, A solution in which isobutyraldehyde and distilled water were mixed was prepared. Furthermore, butadiene was produced from 3-buten-2-ol in a roughly purified state using a solid acid catalyst. Reference Example 1 showed that 3-buten-2-ol produced from 2,3-butanediol can be quantitatively converted to butadiene even in a crudely purified state.

  According to the present invention, butadiene and / or 3-buten-2-ol can be produced from 2,3-butanediol derivable from biomass resources with high selectivity without using a radioactive substance. Since 3-buten-2-ol can be easily converted to butadiene, the present invention makes it possible to substitute the raw material of butadiene from fossil resources to biomass resources. Since butadiene is a raw material for industrial chemicals such as synthetic rubbers and plastics, the present invention is extremely useful industrially.

1 reaction tube 2 electric tubular furnace 3 carrier gas inlet 4 raw material inlet 5 reaction crude liquid collection container (cooler)
6 Catalyst layer 7 Gas outlet

Claims (5)

  A method for producing butadiene and / or 3-buten-2-ol, comprising a step of dehydrating 2,3-butanediol using an alkali metal salt of phosphoric acid as a catalyst.   The production method according to claim 1, wherein the alkali metal salt of phosphoric acid is a condensate prepared by dehydration condensation of an alkali metal dihydrogen phosphate, a dialkali metal hydrogen phosphate, or a mixture thereof.   The production method according to claim 1 or 2, wherein the alkali metal of the alkali metal salt of phosphoric acid is at least one selected from the group consisting of K, Rb and Cs, or a mixture thereof.   The manufacturing method of any one of Claims 1-3 whose reaction temperature of the dehydration process of 2, 3- butanediol is 400 degreeC or more and 550 degrees C or less. The process according to any one of claims 1 to 4, comprising a step of producing butadiene by dehydrating 3-buten-2-ol produced in the step of dehydrating 2,3-butanediol in the presence of an acid catalyst. The manufacturing method as described.