JP2013234139A - Method of producing olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing an internal olefin with high selectivity when an olefin is produced by an intramolecular dehydration reaction of a secondary alcohol.SOLUTION: In a method of producing an olefin (B) represented by formula (II) by performing an intramolecular dehydration reaction of a secondary alcohol (A) represented by formula (I) in a gaseous phase condition in the presence of a solid catalyst (C) including an oxide or oxides of one or more elements selected from elements belonging to the periodic table group 1-15, water is supplied along with the secondary alcohol (A) to a reactor. (In the formula, R is a group selected from 1-20C hydrocarbon groups).

Description

  The present invention relates to a method for regioselectively producing an internal olefin by intramolecular dehydration of a specific secondary alcohol.

  As a method for producing olefins by intramolecular dehydration of secondary alcohols such as methyl alkyl carbinol (the alkyl group has 2 or more carbon atoms), for example, Patent Documents 1 to 3 disclose various secondary alcohols. A method for producing olefins by dehydration in the presence of an oxide catalyst is disclosed. However, these methods are intended for the production of terminal olefins, and few methods for obtaining internal olefins with high selectivity have been known. For example, Patent Document 1 discloses the influence of oxygen molecules on the amount of olefin produced during the dehydration reaction of a secondary or tertiary alcohol using a vanadosilicate catalyst, but discloses the regioselectivity. I don't mean.

  Patent Document 2 discloses that α-olefin (terminal olefin) is obtained by intramolecular dehydration of 2-alcohol in the presence of a metal-containing catalyst having atomic number 21, 39, 58 to 71, 90 supported on alumina satisfying a specific surface area. A method of manufacturing is disclosed. However, there is no disclosure about the influence on the production of internal olefins. Patent Document 3 discloses a method for producing a terminal olefin by intramolecular dehydration of methylhydrocarbylcarbinol (wherein the hydrocarbyl group is a hydrocarbon group having 2 to 20 carbon atoms) using a specific zirconium catalyst. Although disclosed, Patent Document 2 similarly does not mention any influence on the production of internal olefins.

  As described above, since an efficient method for selectively producing an internal olefin by intramolecular dehydration of a secondary alcohol was not known, in order to obtain an internal olefin, a terminal olefin was usually prepared once. Later, a method of isomerizing to an internal olefin in the presence of a specific catalyst has been adopted (for example, Patent Document 4). However, such an isomerization method is not economical because it requires a two-step process from alcohol.

Japanese Laid-Open Patent Publication No. Hei9-100244 US Patent No. 4490567 US Patent No. 5210363 JP-A-8-40944

  In such a situation, the problem to be solved by the present invention is a method for producing olefins by intramolecular dehydration reaction of a secondary alcohol in the presence of a catalyst. Is to develop a manufacturing method that can provide high selectivity.

  As a result of intensive studies to solve the above problems, the present inventor performs an intramolecular dehydration reaction of a secondary alcohol in the presence of a specific amount of water in the presence of a solid catalyst containing an oxide of a specific element. As a result, the technology can be improved to an industrial level, and the present invention has been completed.

That is, the present invention includes the following matters.
[1] A secondary class represented by the following general formula (I) in the presence of a solid catalyst (C) containing an oxide of one or more elements selected from Group 1 to Group 15 elements of the Periodic Table In the method for producing an olefin (B) represented by the general formula (II) by carrying out an intramolecular dehydration reaction of the alcohol (A) under a gas phase condition, water is added to the reactor together with the secondary alcohol (A). The manufacturing method characterized by supplying.

In general formulas (I) and (II), R is a group selected from hydrocarbon groups having 1 to 20 carbon atoms.
[2] An oxide of one or more elements selected from Group 1 to Group 15 elements of the periodic table is SiO ₂ , Al ₂ O ₃ , P ₂ O ₅ , ZrO ₂ , Ta ₂ O ₅ , WO ₃ And the production method according to [1] above, which is selected from the group consisting of Cs ₂ O.
[3] The above-mentioned [1] or [2], wherein the intramolecular dehydration reaction is advanced so that the water supply rate (R2) represented by the following formula 1 is maintained at 5 to 95 mol%. Manufacturing method.

[In the formula (1), Q1 is the feed amount (mol / hr) of the secondary alcohol (A), Q2 is the feed amount of water (mol / hr), Q3 is the feed amount of dilution gas (mol / hr) is there. ]
[4] The production method according to any one of [1] to [3], wherein the intramolecular dehydration reaction is performed using a fixed bed flow reactor.
[5] The production method according to any one of [1] to [4], wherein the secondary alcohol (A) is 4-methyl-2-pentanol or 2-octanol.

  According to the production method of the present invention, internal olefins can be efficiently obtained by performing an intramolecular dehydration reaction of a secondary alcohol.

It is drawing which shows how to obtain | require alcohol conversion, olefin (B) selectivity, and olefin (B ') selectivity in Example 10 of this-application specification. In the drawing, the horizontal axis represents the reaction temperature (° C.), the vertical axis represents the conversion and selectivity (%), 4MP2 [4-methylpentene-2] is olefin (B), and 4MP1 [4-methylpentene-1] is olefin. (B ′), 2MP2 and 2MP1 are isomers with methyl group rearrangement of 4MP2 and 4MP1, respectively. Others is a by-product other than 4MP1, 4MP2, 2MP1, and 2MP2.

  The present invention is a second compound represented by the following general formula (I) in the presence of a solid catalyst (C) containing an oxide of one or more elements selected from Group 1 to Group 15 elements of the Periodic Table. In a method for producing an olefin (B) represented by the general formula (II) by carrying out an intramolecular dehydration reaction of a secondary alcohol (A) under gas phase conditions, water is reacted with a secondary alcohol (A) in a reactor. It is a manufacturing method characterized by supplying to. In the following description, the olefin (B) represented by the general formula (II) may be simply referred to as “internal olefin”. In the present invention, the main by-product is an olefin (B ′) represented by the following general formula (III). In the following description, the olefin (B ′) may be referred to as a “terminal olefin”.

  In the general formulas (I), (II), and (III), R is a group selected from hydrocarbon groups having 1 to 20 carbon atoms. Specific examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, amyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, Examples thereof include a phenyl group, a tolyl group, a benzyl group, and a phenethyl group. Among the secondary alcohols (A) represented by the general formula (I) having such R, 2-butanol, 2-pentanol, 3-methyl-2-butanol, 2-hexanol, 3- Methyl-2-pentanol, 4-methyl-2-pentanol, 2-heptanol, 4-methyl-2-hexanol, 5-methyl-2-hexanol, 2-octanol, 4-methyl-2-heptanol, 5- Methyl-2-heptanol, 2-nonanol, 4-methyl-2-octanol, 5-methyl-2-octanol, 6-methyl-2-octanol, 2-decanol, 4-methyl-2-nonanol, 5-methyl- Alcohols having 4 to 10 carbon atoms such as 2-nonanol, 6-methyl-2-nonanol and 7-methyl-2-nonanol are preferred in terms of activity and selectivity. 4-methyl-2-pentanol or 2-octanol is more preferable.

The catalyst in the present invention includes an oxide of one or more elements selected from Group 1 to Group 15 elements of the Periodic Table, and among the elements of Groups 1 to 15 of the Periodic Table, Al, Si, P, Mo, W, Nb, Ti, Ta, Zr, Hf, and Cs are preferable. As oxides of Group 1 to Group 15 elements of the periodic table, alkali metal oxides such as Na ₂ O, K ₂ O, Rb ₂ O, Cs ₂ O, Al ₂ O ₃ , SiO ₂ , P ₂ O ₅ , oxides such as MoO ₃ , WO ₃ , Nb ₂ O ₅ , TiO ₂ , Ta ₂ O ₅ , ZrO ₂ , HfO ₂ , and MoO ₃ —ZrO ₂ , WO ₃ —Al ₂ O ₃ , WO ₃ —SiO ₂ , complex oxides such as Cs ₂ O—P ₂ O ₅ —SiO ₂ can be exemplified. In the present invention, an oxide selected from the group consisting of SiO ₂ , Al ₂ O ₃ , P ₂ O ₅ , ZrO ₂ , Ta ₂ O ₅ , WO ₃ , and Cs ₂ O is particularly preferable.

  The dehydration reaction according to the present invention is usually carried out under gas phase conditions. However, if necessary, the reaction can be carried out while maintaining the liquid phase under pressure. Various methods known in chemical engineering can be employed for the contact method between the catalyst and the secondary alcohol, the charging of the secondary alcohol as a raw material, and the recovery method of the product olefin. That is, it can be carried out in the presence of a solid catalyst in a fixed bed type or a fluidized bed type, or a continuous type or a batch type. In the case of large-scale industrial operation, it is preferable to employ a continuous reaction using a fixed bed flow reactor packed with a solid catalyst.

  In the present invention, the reaction temperature for obtaining the internal olefins (B) by dehydrating the secondary alcohols (A) in the presence of a catalyst is 100 to 500 ° C, preferably 200 to 450 ° C. More preferably, it is 250-400 degreeC. If the reaction temperature is low, the conversion rate of the secondary alcohol cannot be sufficiently increased, and if the reaction temperature is high, an isomerization reaction accompanied by a large amount of the generated olefin or rearrangement of the alkyl group may easily occur. Not desirable. The reaction pressure can be reacted in the range of normal pressure to 2 MPa.

In the production method of the present invention, the supply rate of the secondary alcohol (A) varies depending on the amount of the catalyst used, the type of the secondary alcohol (A), the reaction temperature, and the reaction pressure. The speed (WHSV) is 0.1 to 50 hr ⁻¹ , preferably 0.5 to 15 hr ⁻¹ , more preferably ¹ to 10 hr ⁻¹ . When WHSV is low, a sequential reaction such as isomerization accompanied by rearrangement of the alkyl group occurs and the selectivity of the internal olefin (B) is lowered. When WHSV is high, the conversion rate of the secondary alcohol (A), the internal olefin ( Since the selectivity of B) is low, it is not preferable.

  In the intramolecular dehydration reaction according to the present invention, water coexists with the secondary alcohol (A) in the reaction system. The water supply rate in the present invention is such that the water supply rate R2 represented by the following formula (1) is 5 to 95 mol%, preferably 15 to 93 mol%, more preferably 25 to 90 mol%, particularly preferably. The dehydration reaction is carried out so as to maintain 45 to 87 mol%. When the water supply rate is low, the effect of improving the selectivity of the internal olefin (B) due to the coexistence of water is small, and when the water supply rate is high, the conversion rate of the secondary alcohol (A) is low, which is not preferable.

[In the above formula (1), Q1 is the secondary alcohol (A) feed amount (mol / hr), Q2 is the water feed amount (mol / hr), Q3 is the dilution gas feed amount (mol / hr) It is. ]

  In addition, supply rate R1 of alcohol (A) in following formula (2) is the range of 1-95 mol%, Preferably it is the range of 2-90 mol%, More preferably, it is the range of 4-85 mol%. Further, in the dehydration reaction according to the present invention, a diluent gas can be used in combination as necessary. An inert gas such as nitrogen, carbon dioxide, helium, and argon can be used as the diluent gas. The dilution gas supply rate R3 represented by the formula (3) is in the range of 0 to 88 mol%, preferably 2 to 2. It is in the range of 84 mol%, more preferably in the range of 4 to 80%. Q1, Q2 and Q3 in formula (2) and formula (3) have the same meaning as those in formula 1, and the total of R1, R2 and R3 is 100 mol%.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

[1] Catalytic Reaction Test Method The catalytic activity evaluation in the following examples or comparative examples was carried out under the conditions of the following catalytic reaction test method unless otherwise specified.
After filling 1.0 / 8 g of the catalyst obtained below into a 3/8 inch reaction tube, the reaction tube was heated in a tubular electric furnace in a nitrogen stream, and after the catalyst layer reached a predetermined temperature, nitrogen, secondary A predetermined amount of alcohol and water was supplied, and the reaction was performed at normal pressure. Detailed conditions are shown in Tables 1 and 2. In the present invention, WHSV (space velocity based on catalyst weight) is a value defined by the following equation.
WHSV (hr ⁻¹ ) = secondary alcohol flow rate (g / hr) / catalyst (g)

[2] Analytical method for activity evaluation The product was analyzed using a FID gas chromatograph, and the alcohol conversion rate and the selectivity of the produced olefin were calculated on the basis of carbon atoms. In each solid catalyst type, each WHSV, and each Q1 / Q2 / Q3 (molar ratio), the activity was evaluated by the value of selectivity of the produced olefin (B) at an alcohol conversion of 80%. The method for determining the selectivity of the produced olefins (B) and (B ′) at an alcohol conversion of 80% is as follows: secondary alcohol species, solid catalyst species, WHSV, and Q1 / Q2 / Q3 ( For each experiment in which the molar ratio was determined, the relationship between the reaction temperature and the alcohol conversion / olefin selectivity was plotted, and the olefin selectivity (B) and (B ′) at the time when the conversion reached 80% was plotted. I read from the figure. FIG. 1 shows a specific method for obtaining the alcohol conversion rate and the selectivity of olefins (B) and (B ′) by taking Example 10 of the present application as an example. In evaluating the effect of the present invention, the reason why the olefin selectivity at a conversion rate of 80% was selected was that the conversion rate was at least within the entire range of controllable reaction conditions including WHSV in the production method of the present invention. Is based on the experimental fact that the amount of by-products due to isomerization reaction accompanied by rearrangement of alkyl group is negligibly small.

[3] Catalysts used for activity evaluation The following five types of catalysts 1 to 5 were prepared and evaluated for activity.
(Catalyst 1) Commercially available Al ₂ O ₃ (Sumitomo Chemical Co., Ltd., NKHD-24), baked at 400 ° C. for 5 hours, and then crushed to have a particle diameter of 0.25 to 0.50 mm.
(Catalyst 2) Commercially available SiO ₂ (Fuji Silysia Chemical, Q10, 75 to 500 μm) baked in an electric furnace at 400 ° C. for 5 hours.
(Catalyst 3) A ZrO ₂ catalyst in which commercially available zirconium hydroxide (Nippon Light Metal) was calcined at 400 ° C. for 5 hours, then molded by a tablet molding machine, and crushed to have a particle diameter of 0.25 to 0.50 mm.
(Catalyst 4) Ta ₂ O ₅ (Wako Pure Chemicals, special grade) formed by a tablet molding machine and then crushed to have a particle size of 0.25 to 0.50 mm.
(Catalyst 5) An aqueous solution was prepared by dissolving 0.61 g of ammonium metatungstate (AMT-72 manufactured by Nippon Inorganic Chemical Co., Ltd.) in 15 ml of ion-exchanged water. The aqueous solution was impregnated with 5 g of activated alumina (NKHD-24 manufactured by Sumitomo Chemical Co., Ltd.), and then the water was evaporated by an evaporator. The obtained catalyst precursor powder was air calcined in an electric furnace at 500 ° C. for 5 hours, molded by a tablet molding machine, crushed and aligned to a particle size of 0.25 to 0.50 mm, and WO ₃ supporting 10 wt% ₃ / Al ₂ O ₃ catalyst.
(Catalyst 6) An aqueous solution was prepared by dissolving 1.54 g of phosphoric acid (concentration 85%, manufactured by Wako Pure Chemical Industries, Ltd.) in 50 ml of ion-exchanged water. The aqueous solution was impregnated with 10 g of silica (CARIACT-G10 manufactured by Fuji Silysia Chemical Ltd.), and then water was evaporated by an evaporator. The obtained catalyst precursor powder was air calcined in an electric furnace at 600 ° C. for 2 hours to prepare P ₂ O ₅ / SiO ₂ having a P / Si atomic ratio of 0.08 / 1. An aqueous solution was prepared by dissolving 0.75 g of cesium hydroxide (manufactured by Kanto Chemical Co., Ltd.) in 30 ml of ion-exchanged water. This aqueous solution was impregnated with 3 g of P ₂ O ₅ / SiO ₂ prepared as described above, and then water was evaporated by an evaporator. The obtained catalyst precursor powder was calcined in an electric furnace at 600 ° C. for 2 hours, molded by a tablet molding machine, crushed and aligned to a particle size of 0.25 to 0.50 mm, and the Cs / P / Si atomic ratio was 0. Cs ₂ O—P ₂ O ₅ / SiO ₂ catalyst that is 1 / 0.08 / 1.

[Example 1]
4-methyl-2-pentanol (may be referred to as MIBC in the following description) is used as the secondary alcohol (A), Al ₂ O ₃ is used as the solid catalyst (C), and WHSV is 5 hours. ⁻¹ , the activity of the catalyst 1 was evaluated under the conditions of a reaction temperature of 280 ° C. and alcohol (A): H ₂ O: N ₂ = 50: 20: 30 (molar ratio). The results are shown in Table 1.

[Examples 2 to 12, Comparative Examples 1 to 9]
Using the catalyst species shown in Table 1, the activity was evaluated under the reaction conditions shown in Table 1. The results are summarized in Table 1.

Example 13
2-octanol is used as the secondary alcohol (A), Al ₂ O ₃ is used as the solid catalyst (C), WHSV is 2.5 hr ⁻¹ , reaction temperature is 265 ° C., alcohol (A): H ₂ O: The activity of the catalyst 1 was evaluated under the condition of N ₂ = 14: 52: 34 (molar ratio). The results are shown in Table 2.

[Example 14, Comparative Examples 10-11]
Using the catalyst species shown in Table 2, the activity was evaluated under the reaction conditions shown in Table 2. The results are summarized in Table 2.

Claims (5)

A secondary alcohol (A) represented by the following general formula (I) in the presence of a solid catalyst (C) containing an oxide of one or more elements selected from Group 1 to Group 15 elements of the Periodic Table In the method for producing an olefin (B) represented by the general formula (II) by carrying out an intramolecular dehydration reaction under gas phase conditions, water is supplied to the reactor together with the secondary alcohol (A). The manufacturing method characterized by this.
[In General Formulas (I) and (II), R is a group selected from hydrocarbon groups having 1 to 20 carbon atoms. ] An oxide of one or more elements selected from Group 1 to Group 15 elements of the periodic table is SiO ₂ , Al ₂ O ₃ , P ₂ O ₅ , ZrO ₂ , Ta ₂ O ₅ , WO ₃ , and Cs. _2. The production method according to claim 1, wherein the production method is selected from the group consisting of 2O. The production method according to claim 1 or 2, wherein the intramolecular dehydration reaction is advanced such that the water supply rate (R2) represented by the following formula 1 is maintained at 5 to 95 mol%.
[In the formula (1), Q1 is the feed amount (mol / hr) of the secondary alcohol (A), Q2 is the feed amount of water (mol / hr), Q3 is the feed amount of dilution gas (mol / hr) is there. ]   The production method according to any one of claims 1 to 3, wherein an intramolecular dehydration reaction is carried out using a fixed bed flow reactor. The production method according to any one of claims 1 to 4, wherein the secondary alcohol (A) is 4-methyl-2-pentanol or 2-octanol.