JP5115368B2 - Process for producing unsaturated alcohol - Google Patents

Description

  The present invention relates to a method for producing an unsaturated alcohol, and more particularly to a method for producing an unsaturated alcohol by a dehydration reaction of alcohol using a catalyst containing zirconium oxide and a rare earth metal oxide.

  Unsaturated alcohols typified by crotyl alcohol are important substances in the chemical industry as chemical intermediates and pharmaceutical intermediates. As a method for producing such an unsaturated alcohol, a method has been proposed in which cerium oxide is used as a catalyst, and an unsaturated alcohol is produced from both terminal diols (see Patent Document 1). According to this method, for example, allyl alcohol can be produced from 1,3-propanediol, and crotyl alcohol and 3-hydroxy-1-butene can be produced from 1,3-butanediol, respectively. Furthermore, 3-buten-1-ol can also be produced from 1,4-butadiol in good yield by the above method (see Patent Document 2). However, in these methods, for example, in addition to the production of 1,3-butadiene and tetrahydrofuran (hereinafter referred to as THF), the produced 3-buten-1-ol is converted into an aldehyde by a side reaction, and 3-butene- There is a problem that the selectivity of 1-ol is lowered.

  As a method for avoiding the above problem, a method for producing 3-buten-1-ol from 1,4-butadiol using zirconium oxide or base-treated zirconium oxide as a catalyst has been reported (Non-patent Document). 1 and 2). According to this method, it is possible to suppress the generated 3-buten-1-ol from being converted into an aldehyde by a side reaction, but it is difficult to suppress the generation of THF combined with 1,4-butanediol. .

Japanese Patent Laid-Open No. 2004-306011 Japanese Patent Laid-Open No. 2005-238095 Catalysis Communications, Vol. 6, 2005, 480-484 Journal of Molecular Catalysis A, 243, 2006, 52-59.

  The present invention has been made in view of the above circumstances, and an object thereof is a method for producing an unsaturated alcohol by alcohol dehydration reaction, which suppresses the formation of by-products and efficiently produces an unsaturated alcohol. It is to provide a method of obtaining.

  As a result of intensive studies, the present inventors have made it possible to carry out a dehydration reaction of only one hydroxyl group of a diol at a high conversion and high selectivity if a catalyst having a rare earth metal oxide supported on zirconium oxide is used. The present inventors have found what can be done and have completed the present invention.

  That is, the gist of the present invention is that, in a method for producing an unsaturated alcohol from a raw material alcohol by a dehydration reaction in the presence of a catalyst, the catalyst contains zirconium oxide and a rare earth metal oxide, and the rare earth metal oxidation relative to the total weight of the catalyst. The present invention resides in a method for producing an unsaturated alcohol, wherein a catalyst having a content of 0.01% by weight or more and less than 10% by weight is used.

  By this invention, the by-product produced | generated when manufacturing unsaturated alcohol can be suppressed, and unsaturated alcohol can be manufactured with a high conversion and selectivity.

  Hereinafter, the present invention will be described in detail.

  First, the catalyst used in the present invention will be described. In the present invention, a catalyst containing zirconium oxide and a rare earth metal oxide and having a rare earth metal oxide content of 0.01 wt% or more and less than 10 wt% based on the total weight of the catalyst is used.

  The method for preparing zirconium oxide is not particularly limited, and those prepared by hydrolysis of various inorganic and organic zirconium compounds may be used, and commercially available zirconium oxide can also be used. In addition, if the zirconium oxide is calcined before preparing the catalyst of the present invention, the yield of unsaturated alcohol can be greatly improved. The firing temperature of zirconium oxide is preferably in the range of 400 to 1000 ° C. The shape of zirconium oxide is not particularly limited, and can be used as a powder or after being shaped according to the reaction mode. The crystal system of zirconium oxide includes tetragonal crystal, cubic crystal, and monoclinic crystal, and monoclinic crystal is preferable in the present invention.

  Although it does not restrict | limit especially as a rare earth metal which comprises a rare earth metal oxide, From a viewpoint that a metal ion radius is large, Yb (ytterbium), Er (erbium), Tm (thulium), Lu (lutetium), Dy (dysprosium) And at least one selected from the group consisting of Ho (holmium). Among these, Yb (ytterbium) or Lu (lutetium) is particularly preferable. The content of the rare earth metal oxide with respect to the total weight of the catalyst (total amount of zirconium oxide and rare earth metal oxide) is 0.01 wt% or more and less than 10 wt%, preferably 3.0 wt% or more and 9.0 wt%. % Or less. When the content of the rare earth metal oxide is less than the above range, sufficient catalytic activity cannot be obtained, and when it exceeds the above range, the cost is high for the catalyst performance. The rare earth metal content in the catalyst can be measured by IPC emission spectrometry or the like.

  The method for preparing the catalyst is not particularly limited, and is obtained by using a rare earth metal oxide precursor, for example, hydroxide, carbonate, nitrate, acetate, for example, supported on zirconium oxide as an aqueous solution. A method in which the catalyst precursor is calcined is preferred. The firing conditions are not particularly limited as long as the rare earth metal oxide precursor can be converted into the rare earth metal oxide, but the firing temperature is preferably in the range of 700 to 1000 ° C. When the calcination temperature is too low, a homogeneous catalyst cannot be obtained, and when it is too high, the crystal system may be transferred to lower the catalyst activity. In addition, the catalyst precursor can be calcined without using a special calcining apparatus and using a reactor for producing unsaturated alcohol (that is, a gas phase flow reactor). That is, the reactor is filled with a catalyst precursor, and before the reaction, it is heated to a predetermined temperature and fired to convert the rare earth metal oxide precursor to the rare earth metal oxide.

  Next, a method for producing an unsaturated alcohol from raw material alcohol will be described. As the raw material alcohol, a diol having 3 to 6 carbon atoms is suitable, and specific examples thereof include 1,3-diol, 1,4-diol, 1,5-diol, 1,6-diol, and the like. . A diol having a branched structure may be used, and specific examples thereof include 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 2-methyl-1,5-pentane. Examples include diol, 2-ethyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 1,6-hexanediol, and the like. The raw alcohol may be a mixture, in which case a corresponding mixture of unsaturated alcohols is obtained. In addition, the raw alcohol may usually contain 50% by weight or less of water.

Furthermore, an organic solvent that does not participate in the reaction may be present. Specifically, diglyme, diphenyl ether, dibenzyl ether, diallyl ether, tetrahydrofuran (TH
F), ethers such as dioxane, amides such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, ketones such as cyclohexanone, n-butyl acetate, γ-butyrolactone, Esters such as di (n-octyl) phthalate, aromatic hydrocarbons such as toluene, xylene and dodecylbenzene, aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and n-octane And by-products generated by the reaction, reaction products themselves, and the like.

  Examples of the unsaturated alcohol produced from the above raw material alcohol include 2-methyl-2-propen-1-ol, 3-buten-1-ol, 4-penten-1-ol, 2-methyl-4-pentene- 1-ol, 2-methyl-1-penten-4-ol, 2-ethyl-4-penten-1-ol, 2-ethyl-1-penten-4-ol, 2-ethyl-5-hexene-1- All, 2-ethyl-1-hexen-5-ol, 5-hexen-1-ol and the like.

  The present invention relates to a process for producing an unsaturated alcohol from a diol at both ends, specifically, 3-buten-1-ol from 1,4-butanediol and 4-penten-1-ol from 1,5-pentanediol. It is particularly suitable as a method for producing This is because the diol and catalyst interact in a preferred form for the reaction. In addition, when a normal acid catalyst is used for a diol, an intramolecular cyclization reaction proceeds. However, since the terminal hydroxyl group can be selectively dehydrated when using the present invention, it is usually difficult to produce. It becomes possible to produce an unsaturated alcohol. As a by-product of the dehydration reaction of 1,4-butanediol, in addition to THF, dehydration and isomerization products cis-2-buten-1-ol, trans-2-buten-1-ol, excess dehydration There are butadiene as a product and gamma butyrolactone as a dehydrogenation product, and the content in the reaction solution is 10% or less for the dehydration isomerization product and 5% or less for the other by-products.

  The reaction temperature of the dehydration reaction is usually 250 ° C to 450 ° C, preferably 300 to 400 ° C. When the reaction temperature is less than the above range, the conversion rate of the raw material alcohol is not sufficiently improved, and when it exceeds the above range, generation of by-products such as carbonyl compounds and excess dehydrates is not sufficiently suppressed, The selectivity of unsaturated alcohol as the target product is not sufficiently improved. The reaction pressure is not particularly limited, but is usually normal pressure to 1 MPa. When the pressure is too high, the cost of the reactor increases, which is not preferable. The reaction system may be any of a fixed bed, a moving bed, and a fluidized bed. Further, any of batch type, semi-batch type and continuous flow type can be adopted. Industrially, a continuous flow type is preferable.

  Moreover, in this invention, the supply rate (ml / h) of the reaction raw material per 1g of catalyst is 0.01-5 normally, Preferably it is 0.03-3, More preferably, it is 0.1-1. When the feed rate (ml / h) of the reaction raw material per 1 g of the catalyst exceeds the above range, the conversion rate of the raw material alcohol is not sufficiently improved, and when it is less than the above range, the selectivity of the unsaturated alcohol is sufficiently high. Does not improve. In addition, a normal gas-phase flow reactor can be used as the reactor, and nitrogen gas is preferably used as the carrier gas for the vaporized raw alcohol. The concentration of the raw material alcohol supplied to the catalyst layer can be selected from an appropriate range.

  In the present invention, distillation is usually employed as a method for separating raw alcohol, produced unsaturated alcohol, by-product, solvent and the like from the reaction solution. Distillation may be performed continuously or batchwise. The separated and recovered raw materials are recycled to the reactor again as necessary.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.

  In the following examples, the dehydration reaction was carried out using a fixed bed atmospheric pressure gas flow reaction apparatus mainly composed of a reactor having an inner diameter of 18 mm and a total length of 300 mm. At the upper end of the reactor, there is a carrier gas inlet and a raw material inlet, and at the lower end, a reaction crude liquid collection container having a gas outlet is installed. In order to heat and vaporize the raw material in advance, the reactor has a vaporized layer between the raw material inlet and the reaction layer. The reaction crude liquid collected in the collection container was measured by gas chromatography (“GC-8A”, “TC-WAX” capillary column manufactured by Shimadzu Corporation), and after correcting the calibration curve, the yield of the target product, The remaining amount of the raw material was determined, and the conversion rate (%; molar basis) and the selectivity (%; molar basis) were determined from this value. The conversion rate is (amount of raw material−remaining amount of raw material) / amount of raw material, and the selectivity is the yield of the target product / (amount of raw material−remaining amount of raw material). Value.

Example 1:
(Catalyst preparation)
An aqueous solution obtained by dissolving 1.354 g of ytterbium nitrate pentahydrate (purity 99.9%) in 10 g of water was impregnated with 6.0 g of zirconium oxide (specific surface area 56 m ² / g), and then calcined at 800 ° C. for 3 hours. The thing was used as a catalyst. In the catalyst thus prepared, the ratio (% by weight) of Yb (ytterbium) in the entire catalyst was 7.9% by weight as calculated as follows.

X = Amount of ytterbium nitrate pentahydrate (g) × {atomic weight of ytterbium / molecular weight of ytterbium nitrate}
Ratio of Yb (ytterbium) in the whole catalyst (wt%) = X / {X + Amount of zirconium oxide used (g)} × 100
(However, the atomic weight of ytterbium was 173.04.)

(Dehydration reaction of 1,4-butanediol)
A fixed bed gas phase flow reactor was charged with 0.574 g of the catalyst prepared above. Nitrogen gas was flowed from the upper part of the apparatus with the catalyst layer as a carrier gas at a flow rate of 1.56 L / h. Along with this nitrogen gas, 2.82 ml / h of 1,4-butanediol (manufactured by Wako Pure Chemical Industries, Ltd., reagent special grade) vaporized in the vaporized layer was supplied to produce 3-buten-1-ol. The reaction conditions and reaction results are shown in Table 1.

Example 2:
3-Buten-1-ol was used in the same manner as in Example 1 except that the same catalyst as in Example 1 was used, and the feed rate (ml / h) of the reaction raw material per 1 g of catalyst was changed on the condition of dehydration reaction. Manufactured. The reaction conditions and reaction results are shown in Table 1.

Example 3:
(Catalyst preparation)
A catalyst was prepared in the same manner as in Example 1 except that zirconium oxide (specific surface area 100 m ² / g) was calcined at 800 ° C. for 3 hours before catalyst preparation.

(Dehydration reaction of 1,4-butanediol)
3-Buten-1-ol was produced in the same manner as in Example 1 except that the catalyst prepared above was used. The reaction conditions and reaction results are shown in Table 1.

Example 4:
3-Butene-1-ol was produced in the same manner as in Example 2, except that the same catalyst as in Example 3 was used and the reaction raw material rate (ml / hr) per gram of catalyst was changed as dehydration reaction conditions. . The reaction conditions and reaction results are shown in Table 1.

Comparative Example 1:
(Catalyst preparation)
2.00 g of ytterbium oxide (Kanto Chemical Industries: purity 99.9% or more, specific surface area 44 m ^{2 /} g) taken at 400 ° C. for 2 hours was used as a catalyst.

(Dehydration reaction of 1,4-butanediol)
3-Buten-1-ol was produced in the same manner as in Example 1 except that the catalyst prepared above was used. The reaction conditions and reaction results are shown in Table 1. The reaction conditions and reaction results are shown in Table 1.

Comparative Example 2:
(Catalyst preparation)
Ytterbium nitrate pentahydrate (impregnated with 10 g of zirconium oxide (specific surface area 100 m ² / g) in 100 g of water with a purity of 99.9% 6.228 g dissolved in water and then calcined at 400 ° C. for 2 hours as a catalyst In the catalyst thus prepared, the ratio (% by weight) of Yb (ytterbium) in the whole catalyst was calculated as follows and found to be 20.00% by weight.

X = Amount of ytterbium nitrate pentahydrate (g) × {atomic weight of ytterbium / molecular weight of ytterbium nitrate}
Ratio of Yb (ytterbium) in the whole catalyst (wt%) = X / {X + Amount of zirconium oxide used (g)} × 100
(However, the atomic weight of ytterbium was 173.04.)

(Dehydration reaction of 1,4-butanediol)
3-Buten-1-ol was produced in the same manner as in Example 1 except that the catalyst prepared above was used and the reaction conditions shown in Table 1 were adopted. The reaction conditions and reaction results are shown in Table 1.

Claims (7)

  In the method for producing an unsaturated alcohol from raw material alcohol by dehydration reaction in the presence of a catalyst, the catalyst contains zirconium oxide and a rare earth metal oxide, and the content ratio of the rare earth metal oxide to the total weight of the catalyst is 0.01. A method for producing an unsaturated alcohol, comprising using a catalyst having a weight percentage of not less than 10% by weight.   The manufacturing method according to claim 1, wherein the crystal system of zirconium oxide is monoclinic.   The rare earth metal is at least one selected from the group consisting of Yb (ytterbium), Er (erbium), Tm (thulium), Lu (lutetium), Dy (dysprosium) and Ho (holmium). The manufacturing method as described.   The method according to any one of claims 1 to 3, wherein the catalyst is a catalyst prepared by calcining in the range of 700 ° C to 1000 ° C.   The production method according to any one of claims 1 to 4, wherein a reaction temperature of the dehydration reaction is 250 ° C to 450 ° C.   The production method according to claim 1, wherein the raw alcohol is a both-end diol.   The production method according to any one of claims 1 to 6, wherein the raw material alcohol is 1,4-butanediol and the generated unsaturated alcohol is 3-buten-1-ol.