Olefin production method and reaction device for producing olefin

Abstract

This olefin production method comprises reacting an alcohol at 150°C or higher, in a liquid phase state, and in the presence of a metal oxide and sulfuric acid that is not supported on the metal oxide, the alcohol having 6-36 carbon atoms. The ratio of the mass of the sulfuric acid to the mass of the metal oxide is preferably 3-23%. The production method may be carried out by using a device comprising: a reaction tank in which the alcohol, the metal oxide, and the sulfuric acid can be stirred while heating; and a collection unit that cools and collects the generated olefin, the device also comprising, between the reaction tank and the collection unit, a moisture adsorption section that accommodates a moisture adsorbent.

Description

Olefin production method and reactor for producing olefins

[0001] The present invention relates to a method for producing olefins and a reaction apparatus for producing olefins. This application claims priority to Japanese Patent Application No. 2023-136610, filed on August 24, 2023, and incorporates the entire disclosure of said Japanese Patent Application by reference.

[0002] Methods for obtaining olefins by utilizing the dehydration reaction of alcohols are known. For example, Patent Document 1 (JP 2013-203705 A) discloses a method for producing an internal olefin having a double bond inside the alkyl chain using a long-chain aliphatic primary alcohol as a raw material. Patent Document 1 discloses the use of a composite oxide containing titanium oxide and silicon oxide and / or zirconium oxide as a catalyst, with the titanium oxide content being 20 to 95 mol %.

[0003] Patent Document 2 (JP 2014-224107 A) discloses a method for producing olefins, in which two or more alcohols having different carbon numbers are used as raw materials to perform olefination. Patent Document 2 discloses the use of a solid acid catalyst having a structure in which an aluminum oxide support carries an acid such as sulfuric acid. Specifically, the document discloses a solid acid catalyst that is a sintered body obtained by impregnating γ-alumina with water-diluted sulfuric acid and calcining it at 500°C for 3 hours.

[0004] Patent Document 3 (JP 2008-538206 A) discloses a method for producing olefins from alcohols using trifluoromethanesulfonic acid as a catalyst. The examples in Patent Document 3 describe an example in which dodecanol, tetradecanol, or other alcohols and trifluoromethanesulfonic acid are introduced into a distillation apparatus and heated at 240° C. for several hours.

[0005] JP 2013-203705 A JP 2014-224107 A JP 2008-538206 A

[0006] Patent Documents 1 and 2 disclose that the reaction temperature in the production of olefins from alcohols can be set to approximately 200°C to 300°C. However, in practice, reaction temperatures of 260°C or higher are often used, and reactions carried out at temperatures lower than this tend to require a long reaction time or a large amount of catalyst. On the other hand, from the viewpoint of energy consumption, it is preferable to be able to produce olefins at a low temperature in a short time. Therefore, one of the objects of the present invention is to provide a method for producing olefins that can be carried out at a low temperature and in a short time compared to conventional techniques.

[0007] The method for producing an olefin according to the present disclosure is a production method in which an alcohol having 6 to 36 carbon atoms is reacted in a liquid phase at 150°C or higher in the presence of a metal oxide and sulfuric acid that is not supported on a metal oxide.

[0008] The above production method provides a method for producing an olefin that can be carried out in a lower temperature range and in a shorter time than conventional techniques.

[0009] FIG. 1 is a schematic diagram showing an outline of a reaction apparatus used in the production method according to the present disclosure.

[0010] [Outline of the embodiment] First, embodiments of the olefin production method according to the present disclosure will be listed and described. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less."

[0011] The method for producing an olefin according to the present disclosure is a production method in which an alcohol having 6 to 36 carbon atoms is reacted in a liquid phase at 150°C or higher in the presence of a metal oxide and sulfuric acid that is not supported on a metal oxide.

[0012] Various proposals have been made in the past for the production of olefins from alcohols. For example, Patent Document 1 proposes a method for efficiently producing internal olefins having a double bond inside the alkyl chain. Patent Document 2 proposes a method for producing olefins in high yield by suppressing olefin polymerization. Patent Document 3 proposes a method for producing hydrocarbons that can be carried out under mild conditions and causes almost no side reactions. On the other hand, due to demands for energy reduction, etc., there is a need for a method that can efficiently produce olefins from alcohols at a lower temperature and in a shorter time than conventional methods.

[0013] In this regard, the prior art also describes that the conversion reaction from alcohol to olefin can be carried out at temperatures of about 200°C or higher. However, when the reaction is carried out at temperatures of about 235 to 260°C, the reaction occurs but takes a long time, the reaction rate is insufficient, a large amount of catalyst is required, and so on, and satisfactory results are not necessarily obtained. In view of this situation, a method for producing olefins from alcohol in high yield through a reaction at a lower temperature and in a shorter time than conventional methods has been investigated. It has been found that by using a metal oxide and sulfuric acid not supported on a metal oxide as a catalyst in the olefination reaction, olefins can be obtained from alcohol in high yield through a reaction in a short time even in a temperature range of 230°C or lower.

[0014] In the manufacturing method, the mass ratio of the sulfuric acid to the metal oxide may be 3% or more and 23% or less, and within this range, the effects of the present disclosure can be reliably obtained.

[0015] In the production method, the alcohol may be a linear or branched primary or secondary alcohol having 8 to 24 carbon atoms. When an olefin is obtained using an alcohol in this range, the effects of the present disclosure are more pronounced.

[0016] In the production method, the metal oxide may be one or more selected from the group consisting of oxides of elements selected from elements in Groups 3 to 6 and Groups 12 and 13 of the Periodic Table. When the above-mentioned types of metal oxides are used, the effects of the present disclosure are more pronounced.

[0017] In the manufacturing method, the metal oxide may be one or more selected from the group consisting of zirconium oxide, titanium oxide, aluminum oxide, silica alumina, tungsten oxide, scandium oxide, yttrium oxide, hafnium oxide, vanadium oxide, and niobium oxide. When the above-mentioned types of metal oxide are used, the effects of the present disclosure are more pronounced.

[0018] In the production method, the ratio of the total mass of the metal oxide and sulfuric acid to the alcohol may be 0.5% or more, which allows the effects of the present disclosure to be clearly obtained while reducing the cost of the olefin production method.

[0019] The reaction apparatus according to the present disclosure is an apparatus for the olefin production method, and includes a reaction vessel capable of heating and stirring alcohol, metal oxide, and sulfuric acid, a collection section for cooling and collecting the produced olefin, and a moisture adsorption section containing a moisture adsorbent between the reaction vessel and the collection section. This reaction apparatus makes it possible to separate and collect the produced olefin from the alcohol, and also adsorbs the produced moisture, allowing the reaction to proceed while removing moisture from the reaction vessel. This facilitates olefin recovery and makes it easier to control the temperature of the reaction vessel, allowing olefins to be produced efficiently while reducing energy consumption.

[0020] The production method according to the present disclosure is a method for obtaining olefins from alcohols using the above-described reactor. This production method makes it easier to recover olefins and enables efficient production of olefins while reducing energy consumption.

[0021] [Specific Example of Embodiment] Hereinafter, the olefin production method according to the present disclosure will be described in more detail.

[0022] [Catalyst] In the production method according to the present disclosure, a metal oxide and sulfuric acid not supported on a metal oxide are used in combination in the production of olefins. The metal oxide and sulfuric acid are thought to function as catalysts.

[0023] Examples of metal oxides include oxides of elements from Groups 1 to 14 of the periodic table. Among these, oxides of elements selected from Groups 3 to 6 and Groups 12 and 13 of the periodic table are preferred. Metal oxides with a metal valence of 3 or 4 are more preferred. Examples include zirconium oxide, titanium oxide, calcium oxide, yttrium oxide, aluminum oxide (alumina), silica-alumina (silicon oxide / aluminum oxide), zeolite, tungsten oxide, scandium oxide, yttrium oxide, hafnium oxide, vanadium oxide, and niobium oxide. Of these, oxides of elements selected from Groups 4 and 13 of the periodic table are more preferred, and the metal oxide is preferably one or more selected from the group consisting of zirconium oxide, titanium oxide, aluminum oxide, and silica-alumina. The metal oxide is more preferably zirconium oxide. The metal oxide may be a so-called composite metal oxide. Multiple types of metal oxides may be used in combination. When multiple types of metal oxides are used, the metal oxide preferably includes zirconium oxide. The content of zirconium oxide relative to the total amount of metal oxides is preferably 50 wt % or more, and more preferably 80 wt % or more.

[0024] The crystal structure and shape of the metal oxide used in the production method according to the present disclosure are not particularly limited. For example, the shape of the metal oxide may be powder, particles, or a pellet or tablet-shaped molded product. ５０ The specific surface area is not particularly limited, but for example, the BET specific surface area is ２ / g or more 300m ２ / g or less, and ２ / g or more 300m ２ / g or less, and ２ / g or more 150m ２ / g or less is preferred.

[0025] The mass ratio of the metal oxide to the alcohol raw material is not limited as long as the effects of the present disclosure can be obtained, but it is sufficient that the mass ratio is 0.4% or more relative to the alcohol, preferably 1% or more, and more preferably 2% or more. If the mass ratio is 0.4% or more, the catalytic effect can be exerted. There is no particular upper limit on the mass ratio of the metal oxide to the alcohol raw material, but adding an excess does not increase the reaction efficiency, so in order to obtain olefins at reasonable cost, the mass ratio is at most 25% or less, preferably 10% or less, and more preferably 5% or less.

[0026] Sulfuric acid commonly used in industry can be used. Sulfuric acid may be used undiluted, or may be used diluted with, for example, water or an alcohol having 5 or less carbon atoms, such as methanol, ethanol, or propanol. Fuming sulfuric acid may also be used. The mass ratio of sulfuric acid to the raw alcohol is not limited as long as the effects of the present disclosure are obtained, but it may be 0.05% or more relative to the alcohol, preferably 0.1% or more, more preferably 0.14% or more, and even more preferably 0.2% or more. There is no particular upper limit for the mass ratio of sulfuric acid to the raw alcohol, but adding an excess does not increase the reaction efficiency. Therefore, in order to obtain olefins at reasonable cost, the mass ratio is at most less than 5%, more preferably 0.5% or less. Generally, concentrated sulfuric acid with a concentration of 98% or more is preferably used, and is preferably introduced into the reaction vessel in a liquid state.

[0027] The mass ratio of sulfuric acid to metal oxide is not limited as long as the effects of the present disclosure are obtained, but is preferably 3% or more, more preferably 4% or more, and even more preferably 10% or more. The mass ratio of sulfuric acid to metal oxide is preferably 23% or less, more preferably 20% or less, and even more preferably 15% or less. When the mass ratio of sulfuric acid to metal oxide is 3% or more and 23% or less, olefins can be efficiently produced.

[0028] The mass ratio of the catalyst (total amount of metal oxide and sulfuric acid) to the raw material alcohol is not limited as long as the effects of the present disclosure are obtained, but is 0.5% or more, preferably 1% or more. The upper limit of the mass ratio of the catalyst to the alcohol is not particularly limited, but from the viewpoint of reasonable cost, it is 26% or less, preferably 6% or less. Hereinafter, the mass ratio of the catalyst added to the alcohol may be referred to as the catalyst amount (%).

[0029] In the production method according to the present disclosure, a metal oxide and sulfuric acid are used as catalysts, but the sulfuric acid is present in a state not supported on the metal oxide. An example of a state in which sulfuric acid is supported on a metal oxide is a so-called solid acid catalyst. Here, a solid acid catalyst refers to a composite in which a metal oxide supports sulfuric acid. A solid acid catalyst is generally a composite obtained by calcining a metal oxide impregnated with an acid, so the metal oxide and the acid are added together. However, since sulfuric acid in a liquid state makes it easier to adjust the ratio of sulfuric acid to metal oxide to an appropriate range and has higher catalytic activity, it is preferable to add the metal oxide and liquid sulfuric acid separately. The metal oxide may be a metal oxide supported on an acid (solid acid catalyst), or a combination of a metal oxide and a solid acid catalyst may be used. In the production method according to the present disclosure, the reaction is carried out in the presence of a metal oxide and sulfuric acid not supported on a metal oxide. There are no limitations on the method of adding the metal oxide and sulfuric acid, and sulfuric acid and metal oxide may be added separately. Here, "added separately" is not limited to the case where the metal oxide and sulfuric acid are separately added when the catalyst is added to the reaction tank, but also includes the case where the sulfuric acid and the metal oxide are mixed together in advance and added to the reaction tank, or the case where the solid acid catalyst as the metal oxide and sulfuric acid are added to the reaction tank.

[0030] [Alcohol] The alcohol used in the production method according to the present disclosure is an alcohol having 6 to 36 carbon atoms. There are no limitations as long as the effects of the present disclosure are obtained, but it is typically an alcohol having 8 to 30 or 8 to 24 carbon atoms, and is a linear or branched primary or secondary alcohol. The alcohol is preferably a monohydric alcohol. The alcohol may also contain a cyclic hydrocarbon group such as a saturated alicyclic hydrocarbon group or an aromatic hydrocarbon group. Specific examples of such alcohols include 1-hexanol, 1-octanol, 2-octanol, 2-methylheptanol, 6-methylheptanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 2-decyltetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-heneicosanol, 1-docosanol, 1-tricosanol, 1-tetracosanol, 2-cyclohexylethanol, and 2-phenylethanol. Among these, the use of alcohols containing no cyclic hydrocarbon groups, such as 1-hexanol, 1-octanol, 2-octanol, 1-decanol, 2-decanol, 1-dodecanol, 1-tetradecanol, 1-octadecanol, and 2-decyltetradecanol, is preferred because they have a particularly clear effect of efficiently producing olefins at low temperatures in a short period of time. Only one type of alcohol may be used as a raw material, or two or more types may be used in combination.

[0031] The alcohol used in the production method according to the present disclosure has a boiling point of 150°C or higher and 450°C or lower. In the method according to the present disclosure, the reaction is carried out with the alcohol in a liquid phase. When an alcohol having a boiling point of 150°C or higher and 450°C or lower is used as a raw material, the alcohol is easily maintained in a liquid state in the reaction system, making it possible to carry out the reaction at normal pressure or reduced pressure. Furthermore, for the above reasons, the alcohol used in the production method according to the present disclosure preferably has a melting point of 150°C or lower.

[0032] [Solvent] In the production method according to the present disclosure, a solvent may not be used. Furthermore, a solvent, particularly an organic solvent, may be used as needed. The organic solvent is not particularly limited as long as it is liquid at the reaction temperature and does not inhibit the reaction. Examples of organic solvents that can be used include hydrocarbon organic solvents such as saturated aliphatic hydrocarbons, unsaturated aliphatic hydrocarbons, and aromatic hydrocarbons. When using an organic solvent, it is preferable to use one that can be separated from the product after the reaction by, for example, utilizing the difference in boiling points.

[0033] Examples of saturated aliphatic hydrocarbons include compounds having 10 to 35 carbon atoms, such as tridecane, hexadecane, octadecane, eicosane, docosane, triacontane, and squalane. Furthermore, the saturated aliphatic hydrocarbon may be a mixture of liquid paraffin, naphthenic hydrocarbons, and isoparaffinic hydrocarbons.

[0034] Examples of unsaturated aliphatic hydrocarbons include eicosene, henicosene, docosene, tricosene, and squalene. The unsaturated aliphatic hydrocarbons may be a mixture. Examples of aromatic hydrocarbons include alkyl benzenes and alkyl naphthalenes such as n-dodecylbenzene, n-tridecylbenzene, n-tetradecylbenzene, n-pentadecylbenzene, n-hexadecylbenzene, and diisopropylnaphthalene.

[0035] [Other Components] In the production method according to the present disclosure, other components may be used in addition to the components described above, as long as the effects according to the present disclosure can be obtained. Examples of other components include a dehydrating agent and water.

[0036] [Production Method] The production method according to the present disclosure is a method for producing an olefin, in which an alcohol having 6 to 36 carbon atoms is reacted in a liquid phase at 150°C or higher in the presence of a metal oxide and sulfuric acid that is not supported on a metal oxide. Specifically, the production method includes, for example, a first step of preparing an alcohol having 6 to 36 carbon atoms, a metal oxide, and sulfuric acid that is not supported on a metal oxide, and a second step of charging the alcohol, the metal oxide prepared in the first step, and sulfuric acid into a reaction vessel and maintaining the alcohol in the presence of the metal oxide and sulfuric acid that is not supported on a metal oxide at 150°C or higher under conditions where the alcohol is in a liquid state.

[0037] The first step is a preparation step. In the first step, an alcohol as a raw material, a metal oxide as a catalyst, and sulfuric acid not supported on a metal oxide are prepared. In the production method according to the present disclosure, in addition to these essential materials, an organic solvent, a dehydrating agent, water, and the like may be used as needed.

[0038] The second step is a reaction step for olefination. The reaction is carried out in a liquid phase in the presence of a metal oxide and sulfuric acid not supported on the metal oxide. An alcohol, a metal oxide, and sulfuric acid are charged into a reaction vessel. As long as a metal oxide and sulfuric acid not supported on the metal oxide are present in the reaction step, there are no limitations on the method for charging the metal oxide and sulfuric acid. For example, the metal oxide and sulfuric acid may be charged separately or as a premix. The metal oxide may be charged in the form of a solid acid catalyst. Next, the temperature is raised to a predetermined temperature, and the reaction is carried out.

[0039] The reaction temperature can be set to the boiling point of the raw material alcohol or lower. When the reaction is carried out at a temperature higher than the boiling point of the raw material alcohol, the reaction may be carried out under pressure to maintain the raw material alcohol in a liquid state. The specific reaction temperature can be selected depending on the type of raw material alcohol, but may be 150°C or higher, preferably 170°C or higher, and more preferably 200°C or higher. Furthermore, from the viewpoints of energy efficiency and equipment load, the reaction temperature may be 300°C or lower, preferably 270°C or lower, and more preferably 240°C or lower. From the viewpoint of energy saving, a lower reaction temperature is preferable, but a reaction temperature in the range of 210°C to 250°C is suitable because it provides high reaction efficiency. In the production method according to the present disclosure, by using the above-mentioned catalyst, olefins can be obtained in a short time even at about 230°C.

[0040] The pressure during the reaction may be normal pressure, or may be reduced or increased as necessary. When the reaction is carried out under reduced pressure, the pressure may be, for example, 0.001 MPa or more and 0.09 MPa or less. The pressure may also be changed during the second step. It is also preferable to distill and separate the product olefin from the raw material alcohol by controlling the pressure.

[0041] The inside of the reactor may be filled with an inert gas atmosphere, such as nitrogen gas or argon gas.

[0042] The reaction time can be selected depending on the reaction temperature, the type of catalyst, the amount used, etc., but is, for example, from 0.5 hours to 10 hours, preferably from 1 hour to 7 hours, and more preferably from 2 hours to 5 hours. It has been confirmed that, according to the production method of the present disclosure, olefination proceeds even in a reaction time of 2.5 hours at a temperature of about 230°C.

[0043] According to the production method of the present disclosure, the alcohol conversion rate is 25% or more, preferably 30% or more, more preferably 60% or more, and even more preferably 90% or more. The alcohol conversion rate (%) is calculated by subtracting 100 from the amount of alcohol present in the liquid after the reaction.

[0044] According to the production method of the present disclosure, the higher the content of olefins in the recovered product after the reaction, the less by-products such as ethers, polymers, etc. are, and therefore, desirable. The content of olefins is 5% or more, preferably 15% or more, more preferably 30% or more, even more preferably 50% or more, and most preferably 75% or more.

[0045] The olefins obtained by the production method according to the present disclosure typically contain 1 to 15% α-olefins and 85 to 99% internal olefins. The olefins also contain 1 to 15% branched olefins. Because the olefins obtained by the production method of the present invention contain a large amount of internal olefins, the olefins obtained can be suitably used as raw materials or intermediate materials for lubricants, surfactants, etc.

[0046] In the production method according to the present disclosure, it is preferable to carry out the reaction while separating the olefin from the alcohol by utilizing the difference in boiling points between the alcohol and the olefin produced from the alcohol. By carrying out the reaction in this manner, it is possible to suppress the production of olefin polymers as by-products. Distillation can be used as a separation method. At the same time, in order to suppress a decrease in the temperature of the reaction vessel, it is preferable to carry out the reaction while separating the water produced as the alcohol is dehydrated. As a separation method, for example, water can be adsorbed using a moisture adsorbent.

[0047] [Reaction Apparatus] FIG. 1 shows an example of a reaction apparatus used in the production method according to the present disclosure. The reaction apparatus has a distillation column at the top of the reaction vessel. The reaction vessel 1 is charged with an alcohol raw material, a metal oxide catalyst, and sulfuric acid not supported on a metal oxide. The reaction vessel 1 is equipped with a stirrer 10. A thermometer 11 is inserted into the reaction vessel 1, allowing the temperature inside the reaction vessel to be detected. The reaction vessel 1 is heated using a heating device (not shown). The top of the reaction vessel 1 is equipped with a tube 2 serving as a moisture adsorption section for accommodating a moisture adsorbent 6. The tube 2 has a side pipe 12. Known moisture adsorbents such as molecular sieves (crystalline zeolites) can be used as the moisture adsorbent 6. Water generated in the reaction vessel 1 during the dehydration reaction, which converts alcohol to olefins, becomes water vapor and diffuses upward from the reaction vessel 1 because the temperature inside the reaction vessel 1 is above the boiling point of water. The water vapor is cooled in the cooling section 3 and the cooling section 9, turns into water, and flows back to the cylindrical section 2, where it is adsorbed by the water adsorbent 6. In this way, water is separated from inside the reaction vessel 1.

[0048] Cooling section 3 and cooling section 9 are provided at the top of cylindrical section 2. In the example of FIG. 1, two stages of cooling section 3 and cooling section 9 are provided, but a single cooling section or multiple cooling sections may be provided as needed. Cooling section 4 branches off between cooling section 3 and cooling section 9. A collection vessel 5 is provided at the end of cooling section 4. A pump 13 is provided between cooling section 4 and collection vessel 5 via a branch pipe 8. The pump 13 can be used to increase or decrease the pressure in the reaction system as needed.

[0049] The olefins produced in the reaction have a lower boiling point than the raw material alcohol. This difference in boiling point can be utilized to recover the olefins by distillation. Specifically, the gaseous olefins can be cooled in the cooling section 4 and collected as a liquid in the collection vessel 5. The cooling section 4 and the collection vessel 5 constitute the olefin collection section.

[0050] 1, the reaction apparatus shown in Fig. 1 can separate the produced olefins by distillation, while quickly removing water produced during the dehydration of alcohol from the reaction vessel, thereby preventing water from refluxing into the reaction vessel. This allows for the recovery of high-purity olefins, facilitates temperature control, and reduces the energy consumption required for the reaction.

[0051] In addition to the above-mentioned reactors, it is also possible to react alcohol in a reactor without providing a distillation column above the reactor, and then remove the reaction solution from the reactor and recover the produced olefins by solid-liquid separation and distillation. Alternatively, a reactor may be used in which a metal oxide is filled in a tubular vessel, and alcohol to which sulfuric acid has been added is passed through the tubular vessel filled with the metal oxide to react the alcohol, and then the olefins are recovered by distillation. From the viewpoints of energy efficiency and reaction efficiency, it is preferable to use a reactor having a distillation column above the reactor.

[0052] EXAMPLES The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0053] [Measurement and Calculation Methods] 1. NMR In some of the following examples and comparative examples, nuclear magnetic resonance (NMR) was used to confirm the alcohol conversion rate and the proportion of olefins present in the recovered product after the reaction. １ H-NMR measurement was performed. Measurement conditions: Apparatus: JNM-ECX series FT NMR apparatus, 400 MHz, manufactured by JEOL Ltd. Solvent: Chloroform-d Conditions: 16 scans, room temperature Since the recovered material was divided into the distillate and the residual liquid in the reaction vessel (bottle residue), １H-NMR measurement was carried out. In the obtained NMR chart, a peak derived from the alcohol, a peak derived from the olefin, and peaks derived from the by-product polymer and ether were identified. From the area ratio of each peak and the number of protons derived from the peak, the abundance ratio of olefin and alcohol in the recovered product and the alcohol conversion rate were calculated. The abundance ratio (%) of olefin and alcohol relative to the total recovered product and the alcohol conversion rate (%) were calculated using the following formulas. Olefin abundance ratio (%) in the total recovered products = (olefin abundance ratio (%) in the distillate × yield of the distillate / total yield) + (olefin abundance ratio (%) in the bottom liquid × yield of the bottom liquid / total yield) ... Formula (1) Alcohol abundance ratio (%) in the total recovered products = (alcohol abundance ratio (%) in the distillate × yield of the distillate / total yield) + (alcohol abundance ratio (%) in the bottom liquid × yield of the bottom liquid / total yield) ... Formula (2) Alcohol conversion rate (%) = 100 - (alcohol abundance ratio (%) in the distillate × yield of the distillate / total yield) + (alcohol abundance ratio (%) in the bottom liquid × yield of the bottom liquid / total yield) ... Formula (3)

[0054] 2. GC In the following examples and comparative examples, gas chromatography (GC) was used to (i) confirm the alcohol conversion rate, (ii) confirm the proportion of olefins present in the recovered product after the reaction, and (iii) identify the olefins. Measurement samples for (i) and (ii) were prepared by diluting the recovered product with hexane and then filtering. Measurements were performed under the following conditions: Measurement conditions: Apparatus: Shimadzu GC-2010Plus; Column: Frontier Laboratories Ltd. Ultra ALLOY Capillary Column UA17-15W-0.25F (30 m x 0.250 mm, 0.10 micron); Vaporizer temperature: 350°C; Injection method: Total injection; Carrier gas: Nitrogen (column flow rate: 1.48 mL / min); Temperature conditions: 50°C to 350°C, heated at 12.5°C / min, then held at 350°C for 15 minutes. The olefin and alcohol abundance ratios and alcohol conversion rates were calculated based on the areas of the olefin peaks, alcohol peaks, and by-product polymers and ether peaks in the resulting GC chart. When the recovered product was separated into the distillate and the residual liquid in the reactor (bottom liquid), GC analysis was performed on each to calculate the olefin and alcohol abundance ratios and alcohol conversion rate. Next, the ratio of olefins to the total recovered material and the alcohol conversion were calculated using the calculated results and the above-mentioned formulas (1) to (3). (iii) Identification of olefins (identification of the position of the double bond in the olefin) was evaluated by reacting the olefin obtained by the production method of the present invention with dimethyl disulfide to obtain a dithiolated derivative, and separating it into its components by GC. The peaks in the obtained GC chart were compared with the GC peaks of dithiolated olefins of known structure to identify the position of the double bond in the olefin obtained by the production method of the present invention. The ratio of each olefin produced was calculated based on the area of ​​each peak. Measurements were performed under the same conditions as in (i) and (ii).

[0055] Comparative Example 1: A reaction was carried out using the apparatus outlined in Figure 1. 200 g of 1-dodecanol (Kalcol (registered trademark) 2098, manufactured by Kao Corporation) and 4 g of zirconium oxide (RC-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) were added to a 500 mL four-neck flask and stirred at 250°C for 5 hours under a nitrogen atmosphere. Water was supplied to the cooling section 3, but there was no reflux and distillation was not possible. Therefore, 200 g of a turbid brown liquid (100% yield) was recovered from the flask, and the component ratios (ratios of olefins and alcohols present) and the alcohol conversion rate in the recovered product were evaluated by GC.

[0056] Example 1: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 6 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.3 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230 °C for 2.5 hours under a nitrogen atmosphere. Water was supplied to the cooling section 3, but there was no reflux and distillation was not possible. Therefore, 279 g of a turbid brown liquid was recovered from the flask, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having 12 carbon atoms was confirmed by GC.

[0057] Example 2: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 6 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.43 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230°C for 0.5 hours under a nitrogen atmosphere. The components cooled in cooling section 3 were refluxed. The water supply to cooling section 3 was then stopped, and the product was recovered by distillation after stirring at 230°C for 2 hours. The product recovered by distillation was treated with sodium sulfate to adsorb the water in the recovered material. After the adsorption treatment, 157 g of a colorless, transparent liquid was obtained. 51 g of a turbid brown liquid remaining in the flask was also recovered. The products recovered by distillation and the residual liquid were each measured by GC, and the component ratios relative to the total recovered products and the alcohol conversion were calculated using the above formula. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0058] [Example 3] The reaction and evaluation were carried out in the same manner as in Example 2, except that the amount of sulfuric acid was changed to 0.53 g. 159 g of a colorless, transparent liquid was recovered by distillation, and 43.81 g of liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion were calculated in the same manner as in Example 2. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0059] Example 4 The reaction and evaluation were carried out in the same manner as in Example 2, except that the amount of sulfuric acid was changed to 0.6 g. 166 g of a colorless, transparent liquid was recovered by distillation, and 44 g of liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion rate were calculated in the same manner as in Example 2. The production of a monoolefin having a carbon number of 12 was confirmed by GC. The produced olefin was reacted with dimethyl disulfide, and the produced olefin was identified by GC. The olefins produced were 2.1% 1-dodecene, 12.9% trans-2-dodecene, 6.6% cis-2-dodecene, 13.8% trans-3-dodecene, 4.7% cis-3-dodecene, 15.6% trans-4-dodecene, 26.9% cis-4-dodecene and trans-5-dodecene, 7.2% cis-5-dodecene and 6-dodecene, and 10.2% branch-dodecene.

[0060] [Example 5] The reaction and evaluation were carried out in the same manner as in Example 2, except that the amount of sulfuric acid was changed to 1.2 g. 113 g of a colorless, transparent liquid was recovered by distillation, and 104 g of a liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion rate were calculated in the same manner as in Example 2. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0061] Comparative Example 2 The same formulation as in Example 4 was used except that zirconium oxide was not added, and the mixture was stirred for 2.5 hours at 230° C. Water was supplied to cooling section 3, but reflux did not occur and distillation was not possible, so 294 g of liquid was recovered from the flask and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC measurement.

[0062] The catalyst configurations, reaction conditions, and analysis results of the recovered materials after the reaction in Examples 1 to 5 and Comparative Examples 1 and 2 are summarized in Table 1.

[0063] As shown in Table 1, in Examples 1 to 5, zirconium oxide and sulfuric acid were used as catalysts, and olefins were obtained at a reaction temperature of 230°C for a reaction time of 2.5 hours. In particular, in Examples 2 to 5, in which the mass ratio of sulfuric acid to the metal oxide was 6% or more and 20% or less, olefins were obtained in high yields. In contrast, in Comparative Example 1, in which only zirconium oxide was used as the catalyst, the reaction did not proceed even after heating for 5 hours at 250°C, which is a higher reaction temperature than in Examples 1 to 5. Furthermore, in Comparative Example 2, in which only sulfuric acid was used as the catalyst, some conversion of alcohol occurred at 230°C, but no olefins were produced, and only by-products were obtained.

[0064] Example 6: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 3 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.6 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230 °C for 2.5 hours under a nitrogen atmosphere. The components cooled by the cooling section 3 were refluxed, but the reaction solution could not be distilled. Therefore, 241 g of liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having 12 carbon atoms was confirmed by GC.

[0065] Example 7: A reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 4.5 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.63 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230°C for 1 hour under a nitrogen atmosphere. The components cooled in cooling section 3 were refluxed. The water supply to cooling section 3 was then stopped, and the product was recovered by distillation after stirring at 230°C for 1.5 hours. The product recovered by distillation was treated with sodium sulfate to adsorb the water in the recovered material. After the adsorption treatment, 127 g of a colorless, transparent liquid was obtained. Additionally, 93 g of the liquid remaining in the flask was recovered. The products recovered by distillation and the residual liquid were each measured by GC, and the component ratios relative to the total recovered products and the alcohol conversion were calculated using the above formula. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0066] [Example 8] The reaction and evaluation were carried out in the same manner as in Example 7, except that the amount of zirconium oxide was changed to 5.24 g. 184 g of a colorless, transparent liquid was recovered by distillation, and 46 g of liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion were calculated in the same manner as in Example 7. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0067] Example 9 The reaction and evaluation were carried out in the same manner as in Example 7, except that the amount of zirconium oxide was changed to 12 g. 115 g of a colorless, transparent liquid was recovered by distillation, and 115.5 g of a liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion were calculated in the same manner as in Example 7. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0068] Example 10 Reaction and evaluation were carried out in the same manner as in Example 7, except that the amount of zirconium oxide was changed to 15 g. 94 g of a colorless, transparent liquid was recovered by distillation, and 124 g of liquid remained in the flask. The component ratios relative to the total recovered material and the alcohol conversion were calculated in the same manner as in Example 7. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0069] The catalyst configurations, reaction conditions, and analysis results of the recovered materials after the reactions in Examples 6 to 10 are summarized in Table 2.

[0070] As shown in Table 2, in Examples 6 to 10, olefins were obtained when zirconium oxide and sulfuric acid were used as catalysts and the reaction was carried out at a reaction temperature of 230°C for a reaction time of 2.5 hours. In particular, in Examples 7 and 8, in which the mass ratio of sulfuric acid to the metal oxide was 10 to 15%, olefins were obtained in high yields.

[0071] Example 11: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 3 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.3 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230 °C for 2.5 hours under a nitrogen atmosphere. The components cooled in the cooling section 3 were refluxed. Since the reaction solution could not be distilled even after the supply of water to the cooling section 3 was stopped, 276 g of liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin with 12 carbon atoms was confirmed by GC.

[0072] [Example 12] The reaction and evaluation were carried out in the same manner as in Example 2, except that the amount of zirconium oxide was changed to 9 g and the amount of sulfuric acid was changed to 0.9 g. 160 g of a colorless, transparent liquid was recovered by distillation, and 54.5 g of liquid remained in the flask. The product recovered by distillation and the remaining liquid were each measured by GC, and the component ratios relative to the total recovered material and the alcohol conversion rate were calculated using the above-mentioned formula. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0073] Example 13: 498 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 10 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 1 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 1000 mL four-neck flask and stirred at 210 °C for 2.5 hours under a nitrogen atmosphere. The components cooled by the cooling section 3 were refluxed. Since the reaction solution could not be distilled even after stopping the supply of water to the cooling section 3, 460 g of liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having 12 carbon atoms was confirmed by GC.

[0074] The catalyst configurations, reaction conditions, and analysis results of the recovered materials after the reactions in Examples 11 to 13 are summarized in Table 3.

[0075] As shown in Table 3, in Examples 11 and 12, zirconium oxide and sulfuric acid were used as catalysts, and olefins were obtained at a reaction temperature of 230° C. for a reaction time of 2.5 hours. In Example 13, zirconium oxide and sulfuric acid were used as catalysts, and olefins were obtained at a reaction temperature of 210° C. for a reaction time of 2.5 hours.

[0076] Example 14: A reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 6 g of γ-alumina (STREM CHEMICALS, INC.), and 0.6 g of sulfuric acid (FUJIFILM Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230°C for 2.5 hours under a nitrogen atmosphere. Since there was no reflux of the components cooled by the cooling section 3 and distillation was not possible, 293 g of a brown, turbid liquid was recovered from the flask, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having 12 carbon atoms was confirmed by GC.

[0077] Comparative Example 3 A reaction was carried out and evaluated under the same conditions as in Example 14, except that sulfuric acid was not added. As in Example 14, the reaction solution could not be refluxed or distilled, so 299 g of a cloudy white liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC.

[0078] Example 15: The reaction was carried out under the same conditions as in Example 14, except that γ-alumina was replaced with titanium oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and evaluation was performed. As in Example 14, the reaction solution could not be refluxed or distilled, so 291.5 g of a turbid brown liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having 12 carbon atoms was confirmed by GC.

[0079] Comparative Example 4 A reaction was carried out and evaluated under the same conditions as in Example 15, except that sulfuric acid was not added. As in Example 14, the reaction solution could not be refluxed or distilled, so 300 g of a gray, turbid liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC.

[0080] Example 16 A reaction was carried out and evaluated under the same conditions as in Example 14, except that γ-alumina was replaced with silica alumina (Neobead SA, manufactured by Mizusawa Industrial Chemicals, Ltd.). As in Example 14, the reaction solution could not be refluxed or distilled, so 297 g of a turbid brown liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0081] Comparative Example 5 A reaction was carried out and evaluated under the same conditions as in Example 16, except that sulfuric acid was not added. As in Example 16, the reaction solution could not be refluxed or distilled, so 295 g of a cloudy white liquid in the flask was recovered, and the component ratios and alcohol conversion rate in the recovered product were evaluated by GC.

[0082] Comparative Example 6 Reaction and evaluation were carried out in the same manner as in Example 14, except that γ-alumina was changed to zirconium oxide (RC-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) and sulfuric acid was changed to trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) The reaction solution could not be refluxed or distilled, so 286 g of a turbid brown liquid in the flask was recovered, and the component ratios in the recovered product and the alcohol conversion rate were evaluated by GC.

[0083] Comparative Example 7 In a 200 mL three-neck flask, 50 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098) and 3% SO 4 ４ -ZrO ２ 1 g of ethanol (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was added and stirred for 5 hours at 250° C. in a nitrogen atmosphere. Water was supplied to cooling section 3, but reflux did not occur and distillation was not possible, so 50 g of a cloudy gray liquid was recovered from the flask, and the component ratios in the recovered product and the alcohol conversion rate were evaluated by GC.

[0084] The catalyst configurations, reaction conditions, and analysis results of the recovered materials after the reactions in Examples 14 to 16 and Comparative Examples 3 to 7 are summarized in Table 4. In Table 4, the metal oxide (Al ２ O ３ The description "metal oxide, etc.) / sulfuric acid (10%)" indicates that the mass ratio of sulfuric acid to the metal oxide is 10%. The description "catalyst amount (%)" indicates the mass ratio of the catalyst (total of metal oxide and sulfuric acid) to the raw material alcohol.

[0085] As shown in Table 4, in Examples 14 to 16, alumina, titanium oxide, silica-alumina, and sulfuric acid were used as metal oxides, and olefins were obtained at a reaction temperature of 230°C for a reaction time of 2.5 hours. On the other hand, in Comparative Example 3, which used only alumina as a catalyst; Comparative Example 4, which used only titanium oxide; and Comparative Example 5, which used only silica-alumina; no alcohol conversion occurred at 230°C. In Comparative Example 6, which used zirconium oxide and trifluoromethanesulfonic acid, some alcohol conversion occurred, but no olefins were produced. Furthermore, in Comparative Example 7, which used a solid acid catalyst of zirconium oxide supported on sulfuric acid, alcohol conversion occurred after a 5-hour reaction at 250°C, a reaction temperature higher than in the Examples, but only a small amount of olefin was produced. This is thought to be because sulfuric acid supported on zirconium oxide had lower catalytic activity than liquid sulfuric acid. Comparative Example 6 demonstrated that sulfuric acid is a better acid to combine with a metal oxide as a catalyst. Comparative Example 7 demonstrated that using a metal oxide and liquid sulfuric acid is more effective in producing olefins than using sulfuric acid supported on a metal oxide.

[0086] Example 17 A reaction was carried out using the apparatus outlined in Figure 1. 300 g of 1-octanol (Kao Corporation, Kalcol (registered trademark) 0898), 6 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.6 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 200°C for 1 hour under a nitrogen atmosphere. The components cooled in cooling section 3 were refluxed. Thereafter, the supply of water to cooling section 3 was stopped, and the mixture was stirred for 2 hours, after which the product was recovered by distillation. 204 g of a colorless, transparent liquid was obtained by distillation. The product recovered by distillation was １ The olefin content and alcohol conversion were evaluated by H-NMR. 9 g of a brown, turbid liquid remaining in the flask was recovered. This remaining liquid was analyzed by GC. １The component ratios and alcohol conversion rates relative to the total recovered material were calculated by combining the results of H-NMR measurement. The production of monoolefins with a carbon number of 8 was confirmed by NMR. The produced olefins were reacted with dimethyl disulfide, and the produced olefins were identified by GC. The produced olefins were 10.8% 1-octene, 26.9% trans-2-octene, 18.8% cis-2-octene, 19.0% trans-3-octene, 16.2% cis-3-octene, 3.8% 4-octene, and 4.5% branch-octene.

[0087] Example 18: A reaction was carried out using the apparatus outlined in Figure 1. 158 g of 2-octanol (manufactured by Kokura Synthetic Industries, Ltd.), 3.2 g of zirconium oxide (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 0.3 g of sulfuric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 200 mL four-neck flask and stirred at 170°C for 2 hours under a nitrogen atmosphere. The components cooled in cooling section 3 were refluxed. The supply of water to cooling section 3 was then stopped, and the product was recovered by distillation after stirring at 170°C for 0.5 hours. The product recovered by distillation was treated with sodium sulfate to adsorb the water in the recovered product. After the adsorption treatment, 110 g of a colorless, transparent liquid was obtained. 13 g of a brown, cloudy liquid remaining in the flask was also recovered. The product recovered by distillation and the remaining liquid were each １ Measurements were performed by H-NMR, and the results of each measurement were added together to calculate the component ratio and alcohol conversion rate relative to the total recovered product. The production of a monoolefin having a carbon number of 8 was confirmed by NMR. The produced olefins were reacted with dimethyl disulfide, and the produced olefins were identified by GC. The produced olefins were 9.0% 1-octene, 25.1% trans-2-octene, 55.2% cis-2-octene, 4.6% trans-3-octene, 3.8% cis-3-octene, 0.8% 4-octene, and 1.5% branch-octene.

[0088] Example 19: The reaction was carried out using the apparatus outlined in Figure 1. 3040 g of 1-dodecanol (Kao Corporation, Kalcol (registered trademark) 2098), 61 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd., RC-100), and 6 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 5000 mL four-neck flask and stirred at 230 °C for 1.5 hours under a nitrogen atmosphere. The components cooled in cooling section 3 were refluxed. The supply of water to cooling section 3 was then stopped, and the product was recovered by distillation after stirring at 230 °C for 2.5 hours. The product recovered by distillation was treated with sodium sulfate to adsorb the water in the recovered product, yielding 2120 g of a colorless, transparent liquid. 380 g of a turbid brown liquid remaining in the flask was also recovered. The products recovered by distillation and the residual liquid were each measured by GC, and the results of each measurement were added together to calculate the component ratios relative to the total recovered products and the alcohol conversion. The production of a monoolefin having a carbon number of 12 was confirmed by GC.

[0089] Example 20: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of octadecanol (Kao Corporation, Kalcol (registered trademark) 8098), 6 g of zirconium oxide (Daiichi Kigenso Kagaku Kogyo Co., Ltd. RC-100), and 0.6 g of sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) were added to a 500 mL four-neck flask and stirred at 230 °C and 90 kPa for 1 hour. The water supply to the cooling section 3 was then stopped, the pressure was further reduced to 1 kPa, and the mixture was stirred at 230 °C for 2.5 hours, and the product was recovered by distillation. The product recovered by distillation was treated with sodium sulfate to adsorb the water in the recovered product, yielding 200 g of a colorless, transparent liquid. 39 g of a brown, turbid liquid remaining in the flask was recovered. The product and residue recovered by distillation were each measured by GC, and the measurement results were summed to calculate the component ratio and alcohol conversion rate relative to the total recovered product. The production of a monoolefin having 18 carbon atoms was confirmed by GC.

[0090] Example 21: The reaction was carried out using the apparatus outlined in Figure 1. 300 g of 2-decyltetradecanol (N-Jecol (registered trademark) 240A, manufactured by New Japan Chemical Co., Ltd.), 6 g of zirconium oxide (RC-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and 0.6 g of sulfuric acid (special grade, manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) were added to a 500 mL four-neck flask and stirred at 230 °C for 1 hour under a nitrogen atmosphere. The pressure was then reduced to 1 kPa and the mixture was stirred for 4.5 hours. Water was supplied to the cooling section 3 during the reaction process, but the reaction solution could not be distilled. Therefore, the turbid brown liquid in the flask was filtered, and 282 g of a brown liquid was recovered. The recovered product was measured by GC, and the component ratios and alcohol conversion rate in the recovered product were evaluated. The production of a monoolefin with 24 carbon atoms was confirmed by GC.

[0091] The catalyst configurations, reaction conditions, and analysis results of the recovered products after the reactions in Examples 17 to 21 are summarized in Table 5. In Table 5, the catalyst amount (%) indicates the mass ratio of the catalyst to the raw material alcohol (the total mass ratio of the metal oxide and sulfuric acid).

[0092] As shown in Table 5, in Examples 17 to 21, a primary alcohol or a secondary alcohol having 8 to 24 carbon atoms was used as the raw material alcohol. In Examples 17 to 21, zirconium oxide and sulfuric acid were used as catalysts, and the reaction was carried out at a temperature of 230°C or lower, resulting in the production of olefins in high yields.

[0093] The present invention is intended to cover a wide range of applications, including those related to the present invention, including those related to the present invention.

[0094] 1 Reaction tank, 2 Cylindrical section, 3, 4, 9 Cooling section, 5 Collection container, 6 Moisture adsorbent, 8 Branch pipe, 10 Agitator, 11 Thermometer, 12 Side pipe, 13 Pump.

Claims

1. A method for producing an olefin, comprising reacting an alcohol having 6 to 36 carbon atoms in the presence of a metal oxide and sulfuric acid not supported on a metal oxide in a liquid phase at a temperature of 150°C or higher.

2. The method for producing an olefin according to claim 1, wherein the mass ratio of the sulfuric acid to the metal oxide is 3% or more and 23% or less.

3. The method for producing an olefin according to claim 1 or 2, wherein the alcohol has 8 to 24 carbon atoms and is a linear or branched primary or secondary alcohol.

4. The method for producing an olefin according to claim 1 or 2, wherein the metal oxide is at least one selected from the group consisting of oxides of elements selected from Groups 3 to 6 and Groups 12 to 13 of the Periodic Table.

5. The method for producing an olefin according to claim 1 or 2, wherein the metal oxide is at least one selected from the group consisting of zirconium oxide, titanium oxide, aluminum oxide, silica alumina, tungsten oxide, scandium oxide, yttrium oxide, hafnium oxide, vanadium oxide and niobium oxide.

6. The method for producing an olefin according to claim 1 or 2, wherein the ratio by mass of the total amount of the metal oxide and sulfuric acid to the alcohol is 0.5% or more.

7. A reaction apparatus for a method for producing olefins according to claim 1 or 2, comprising: a reaction vessel capable of heating and stirring alcohol, metal oxide, and sulfuric acid not supported on a metal oxide; and a collection section for cooling and collecting the produced olefins, and a moisture adsorption section for accommodating a moisture adsorbent between the reaction vessel and the collection section.

8. A method for producing an olefin, comprising the step of obtaining an olefin from an alcohol using the reaction apparatus according to claim 7.

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