Method for producing internal olefin and method for regenerating activity of catalyst

Abstract

A method for producing an internal olefin, the method comprising a step in which a starting material olefin is subjected to an isomerization reaction in the presence of the catalyst R described below.　Catalyst R: a catalyst that is obtained by holding a catalyst, which has been used for an olefin isomerization reaction at a reaction temperature (T1), at a temperature (hereinafter referred to as "catalyst holding temperature (T2)") that is higher than the reaction temperature (T1) in the presence of an olefin

Description

METHOD FOR PRODUCING INTERNAL OLEFINS AND METHOD FOR REGENERATING CATALYST ACTIVITY

[0001] The present invention relates to a process for producing internal olefins and a process for regenerating the activity of a catalyst.

[0002] Internal olefins are widely used in petroleum drilling base oils, chemical raw materials, and the like. Internal olefins are produced by double bond isomerization, metathesis, or the like using 1-olefins as raw materials. For example, JP 2008-517062 A (Patent Document 1) describes a method for isomerizing 1-alkenes to internal alkenes, comprising: a) combining at least one 1-alkene with a catalyst in a liquid phase at a temperature of about 50°C to about 200°C, wherein the catalyst is formed by contacting (i) at least one Group 8 transition metal salt and (ii) at least one alkylaluminum compound to obtain a first mixture; and b) combining the first mixture of step a) with at least one acid-washed clay at a temperature of about 100°C to about 300°C to form a final mixture. Furthermore, JP-A No. 2016-539128 (Patent Document 2) discloses a method for isomerizing olefins, which comprises a step of contacting at least one olefin-containing raw material with a catalyst exhibiting double bond isomerization activity in a reaction zone to obtain an olefin isomerization product, and the catalyst has a surface area of ​​200 m ２ / g of a gamma-alumina-titania catalyst.

[0003] The present invention relates to a method for producing an internal olefin, which comprises a step of isomerizing a raw material olefin in the presence of the following catalyst R: Catalyst R: Reaction temperature (T １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) (hereinafter referred to as "catalyst holding temperature (T ２ ))

[0004] FIG. 2 is a graph showing the change in catalyst activity over time in the continuous reaction of step 1 in Example 1.

[0005] Patent Document 1 studies how to obtain a final mixture containing internal alkenes and a low level of oligomers. Patent Document 2 studies how to improve the resistance to oxygen-containing compounds, which are poisons. However, Patent Documents 1 and 2 leave room for further study on the problem that when raw olefins are isomerized industrially in the presence of a catalyst, the internal isomerization activity of the catalyst decreases over time. Conventionally, catalysts whose activity has decreased after undergoing the isomerization reaction of raw olefins have often been discarded. Hereinafter, the "internal isomerization activity of the catalyst" will also be simply referred to as the "catalytic activity."

[0006] Therefore, the present invention relates to a method for producing an internal olefin, which can regenerate the activity of a catalyst that has been reduced by the isomerization reaction of a feed olefin, and a method for regenerating the activity of the catalyst.

[0007] The present inventors have found that the above-mentioned problems can be solved by maintaining a catalyst used in an olefin isomerization reaction under specific temperature conditions in the presence of an olefin. More specifically, while there are concerns about catalyst deactivation due to polymerization or coking of the feed olefin, and further catalyst deactivation due to poisoning substances in the feed, the present inventors have found that it is possible to regenerate the activity of the catalyst by performing a temperature adjustment treatment in the presence of the feed olefin and / or the presence of an internal olefin obtained by the isomerization reaction of the feed olefin. That is, the present invention relates to a method for producing an internal olefin, which comprises a step of isomerizing a feed olefin in the presence of the following catalyst R. Catalyst R: Reaction temperature (T １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) (hereinafter referred to as "catalyst holding temperature (T ２ The present invention also relates to a method for regenerating the activity of a catalyst, which comprises the steps of: １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ )

[0008] According to the present invention, there are provided a method for producing an internal olefin, which can regenerate the activity of a catalyst that has been reduced by the isomerization reaction of a feed olefin, and a method for regenerating the activity of a catalyst.

[0009] [Method for Producing Internal Olefins] The method for producing internal olefins of the present invention is a method for producing internal olefins, which comprises a step of isomerizing a raw material olefin in the presence of the following catalyst R. Catalyst R: Reaction temperature (T １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) (hereinafter referred to as "catalyst holding temperature (T ２ Here, "in the presence of an olefin" means in the presence of a raw material olefin and / or in the presence of an internal olefin obtained by the isomerization reaction of the raw material olefin. １ ) isomerized in the presence of the raw material olefin. １ ) exceeding the catalyst holding temperature (T ２ ) may be a catalyst obtained by maintaining the temperature at the reaction temperature (T １ ) in the presence of an olefin, the catalyst obtained in step 1 is subjected to the isomerization reaction of an olefin at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ ) to obtain catalyst R, and the step of isomerizing the raw olefin in the presence of catalyst R is referred to as step 3.

[0010] The production method of the present invention has the effect of regenerating the activity of a catalyst that has been reduced by the isomerization reaction of a feed olefin. The reason for this is not entirely clear, but it is thought to be as follows: As the isomerization reaction of the feed olefin progresses, poisoning components accumulate on the catalyst surface, and the activity of the catalyst is thought to decrease over time. However, by maintaining the catalyst that has been subjected to the isomerization reaction of the feed olefin under specific temperature conditions, it is thought that the poisoning components accumulated on the catalyst surface are somehow removed, and the activity of the catalyst is regenerated. Note that the above mechanism of the effect of the present invention is only a hypothesis, and is not limited thereto.

[0011] The raw material olefin and catalyst used in the present invention will be explained below, and then step 1 (a step for obtaining a catalyst used in the isomerization reaction), step 2 (a catalyst regeneration step), and step 3 (an isomerization reaction step) will be described in detail.

[0012] [Raw Material Olefin] From the viewpoint of reactivity, the raw material olefin is preferably an olefin having a carbon number of 8 to 36. From the viewpoint of the usefulness of the resulting internal olefin, the number of carbon atoms of the raw material olefin is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 24 or less, more preferably 22 or less, even more preferably 18 or less. Examples of raw material olefins include octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, heneicosene, docosene, tricosene, and tetracosene. From the viewpoint of availability, at least one selected from hexadecene and octadecene is preferred.

[0013] The number of double bond positions in the starting olefin is not particularly limited, but from the viewpoint of availability, it is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. That is, the starting olefin is preferably a 1-olefin, a 2-olefin, a 3-olefin, or a 4-olefin, more preferably a 1-olefin, a 2-olefin, or a 3-olefin, and even more preferably a 1-olefin or a 2-olefin. The starting olefin may be a mixture of two or more olefins having different double bond positions. From the viewpoint of availability, the average number of double bond positions in the starting olefin is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.8 or less, and preferably 1.0 or more. From the viewpoint of availability, the starting olefin preferably contains at least a 1-olefin, and the 1-olefin is preferably a linear 1-olefin.

[0014] The starting olefin may be obtained by any method, and commercially available olefins having from 8 to 36 carbon atoms, preferably 1-olefins having from 8 to 36 carbon atoms, may be used as the starting olefin, or the compound may be produced by a dehydration reaction using an aliphatic primary alcohol having from 8 to 36 carbon atoms (a linear aliphatic primary alcohol having from 8 to 36 carbon atoms) as the starting material (starting alcohol). The reaction is represented by the following reaction formula:

[0015]

[0016] Here, R represents an alkyl group having 4 or more carbon atoms, and from the viewpoint of usefulness, it is preferably a linear alkyl group having 4 or more carbon atoms. An aliphatic primary alcohol (raw material alcohol) (10) produces a 1-olefin (1) by intramolecular dehydration as shown in (IV), and also produces a 1-olefin (1) via a reaction intermediate dialkyl ether (11) by intermolecular dehydration as shown in (V) and (VI). A portion of the produced 1-olefin (1) undergoes an isomerization reaction to become an internal olefin such as a 2-olefin, in which the double bond is located closer to the terminal.

[0017] The raw material alcohol may be either a petroleum-derived alcohol or an alcohol derived from a natural raw material. Examples of naturally-derived aliphatic primary alcohols include those derived from coconut oil, palm oil, palm kernel oil, soybean oil, rapeseed oil, beef tallow, lard, tall oil, and fish oil. Examples of aliphatic primary alcohols include n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, n-heptadecanol, n-octadecanol, n-nonadecanol, n-eicosanol, n-heneicosanol, n-docosanol, n-tricosanol, and n-tetracosanol. Of these, n-hexadecanol and n-octadecanol are preferred.

[0018] The method for producing a raw material olefin from a raw material alcohol is not particularly limited, and may be a known method, but it is preferably produced by a liquid-phase dehydration reaction in the presence of a solid catalyst, preferably a solid acid catalyst, and the solid catalyst is preferably an aluminum-containing metal oxide. The reaction temperature of the liquid-phase dehydration reaction is preferably 255° C. or higher and 300° C. or lower. The reaction pressure is preferably atmospheric pressure.

[0019] [Catalyst] In the present invention, the reaction temperature (T １ The catalyst used in the olefin isomerization reaction step (step 1) is heated to a reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２)) and is then subjected to a catalyst regeneration step (step 2) in which the catalyst (catalyst R) obtained by the catalyst regeneration step (step 2) is retained in a catalyst storage tank. The catalyst (catalyst R) obtained by the catalyst regeneration step (step 2) is then subjected to a feed olefin isomerization reaction step (step 3). From the viewpoint of reactivity, the catalyst used in step 1 preferably contains an element from the third to fifth periods, more preferably at least one selected from aluminum (Al), silicon (Si), titanium (Ti), iron (Fe), zinc (Zn), yttrium (Y), zirconium (Zr), and tin (Sn), and even more preferably contains aluminum (Al). From the viewpoints of reactivity and ease of operation, the catalyst is preferably a solid catalyst, more preferably a solid acid catalyst, and even more preferably a solid Lewis acid catalyst. Specifically, the catalyst is preferably at least one selected from an aluminum oxide catalyst (hereinafter also referred to simply as "aluminum oxide"), an aluminum phosphate catalyst, and a zeolite (aluminosilicate) catalyst, more preferably an aluminum oxide catalyst.

[0020] Aluminum oxide (Al ２ O ３ Examples of the crystal form of aluminum oxide include γ, δ, and θ, and from the viewpoint of reactivity, the aluminum oxide is preferably γ-alumina. From the viewpoint of reactivity, the purity of aluminum oxide in the aluminum oxide catalyst is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more, and the upper limit is not particularly limited, but is 100% by mass.

[0021] The reaction system in the olefin isomerization reaction is not particularly limited and may be a heterogeneous system or a homogeneous system, with a heterogeneous system being preferred from the viewpoint of efficiently providing the catalyst obtained in step 1 to step 2 and efficiently recovering the internal olefin produced in step 1. Here, a homogeneous system refers to a system in which the catalyst and the olefin are compatible, and a heterogeneous system refers to a system in which the catalyst and the olefin are immiscible. When the reaction system in the olefin isomerization reaction in step 1 is a heterogeneous system, the catalyst in the present invention is preferably a solid catalyst.

[0022] The solid catalyst may be used as a powdered solid catalyst as it is, or may be used as a granulated or molded product. Examples of the shape of the solid catalyst include powder, granules, beads, noodles, pellets, etc. From the viewpoint of solid-liquid separation in a suspension-bed batch reaction and from the viewpoint of reducing pressure drop in a fixed-bed continuous reaction, the shape of the solid catalyst is preferably a molded product such as granules, beads, noodles, or pellets, more preferably beads or noodles, and even more preferably beads.

[0023] When the solid catalyst is in the form of a powder, the average particle size of the solid catalyst is, from the viewpoint of reactivity, preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and preferably 300 μm or less, more preferably 200 μm or less, even more preferably 100 μm or less, even more preferably 30 μm or less. The average particle size of the powdered solid catalyst can be determined by a method such as a laser diffraction / scattering method.

[0024] When the solid catalyst is in the form of granules, the average particle size of the solid catalyst is, from the viewpoint of reactivity, preferably 0.2 mm or more, more preferably 0.4 mm or more, even more preferably 0.6 mm or more, and preferably 2.0 mm or less, more preferably 1.3 mm or less, even more preferably 0.8 mm or less. The average particle size of the granular solid catalyst can be determined by the following method. Specifically, after vibrating for 5 minutes using sieves of 2000, 1400, 1000, 710, 500, 355, 250, 180, 125, 90, 63, and 45 μm specified in JIS Z8801-1 (established on May 20, 2000, and last revised on November 20, 2006), the 50% average diameter is calculated from the undersieve mass distribution by sieving, and this is defined as the average particle size. Specifically, sieves of 2000, 1400, 1000, 710, 500, 355, 250, 180, 125, 90, 63, and 45 μm as specified in JIS Z8801-1 (established May 20, 2000, last revised November 20, 2006) are stacked on a tray in order from the smallest mesh size, and 100 g of granules are added from the top 2000 μm sieve. The sieve is then covered with a lid and attached to a low-tap type sieve shaker (manufactured by HEIKO Seisakusho, tapping 156 times / minute, rolling: 290 times / minute). Vibration is then carried out for 5 minutes, after which the mass of the granules remaining on each sieve and on the tray is measured, and the mass proportion (%) of the granules on each sieve is calculated. The mass proportions of the granules on the sieves with smaller openings are added up in order from the receiving tray, and the particle size at which the total is 50% is taken as the average particle size.

[0025] When the solid catalyst is in the form of beads, the diameter of the solid catalyst is preferably 1 mm or more, more preferably 1.5 mm or more, even more preferably 2 mm or more, and preferably 5 mm or less, more preferably 4 mm or less, even more preferably 3 mm or less, from the viewpoints of reactivity and ease of catalyst recovery. The diameter of the solid catalyst may be the average value of three measurements. The diameter of the bead-shaped solid catalyst can be measured using a vernier caliper.

[0026] When the solid catalyst has a noodle-like shape, the diameter of the solid catalyst is preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 0.7 mm or more, from the viewpoints of reactivity and catalyst strength, and preferably 2.5 mm or less, more preferably 2.3 mm or less, even more preferably 2.0 mm or less. Here, the diameter of the solid catalyst may be an average value measured at positions 1 / 4, 1 / 2, and 3 / 4 of the length from one end in the longitudinal direction. Furthermore, when the solid catalyst has a noodle-like shape, the length of the solid catalyst is preferably 2 mm or more, more preferably 2.5 mm or more, even more preferably 3 mm or more, from the viewpoints of uniformly packing the catalyst in the reaction system and catalyst strength, and is preferably 8 mm or less, more preferably 6 mm or less, even more preferably 5.5 mm or less. The diameter and length of the noodle-like solid catalyst can be measured using vernier calipers.

[0027] When the solid catalyst is in the form of pellets, the diameter and length of the solid catalyst are preferably 1.5 mm or more, more preferably 2.0 mm or more, and even more preferably 2.5 mm or more, from the viewpoints of reactivity and catalyst strength, and are preferably 5.0 mm or less, more preferably 4.0 mm or less, and even more preferably 3.0 mm or less. The diameter and length of the pellet-shaped solid catalyst can be measured with a vernier caliper.

[0028] The specific surface area of ​​the solid catalyst is preferably 80 m from the viewpoint of reactivity and reaction selectivity. ２ / g or more, more preferably 100m ２ / g or more, more preferably 120m ２ / g or more, and preferably 300m ２ / g or less, more preferably 280m ２ / g or less, more preferably 250m ２ The specific surface area of ​​the solid catalyst can be measured by a method generally used to determine specific surface area, such as the BET method, and can be measured, for example, by a nitrogen adsorption method using a specific surface area measuring device.

[0029] From the viewpoints of reactivity and reaction selectivity, the average pore diameter of the solid catalyst is preferably 4 nm or more, more preferably 5 nm or more, and even more preferably 6 nm or more, and is preferably 20 nm or less, more preferably 17 nm or less, and even more preferably 15 nm or less. The average pore diameter of the solid catalyst can be determined, for example, by pretreating a sample at 250°C for 5 hours using a specific surface area / pore size distribution analyzer, and then calculating the pore size (pore diameter) at the peak top of the pore size distribution using the Barrett-Joyner-Halenda method (BJH method). The BJH method is a method for calculating pore size distribution based on capillary coagulation and multilayer adsorption of nitrogen gas, using cylindrical pores that are not connected to other pores as a model. Details of the BJH method are described in Shimadzu Review (Vol. 48, No. 1, pp. 35-44, published in 1991).

[0030] From the viewpoints of reactivity and reaction selectivity, the pore volume of the solid catalyst is preferably 0.1 mL / g or more, more preferably 0.15 mL / g or more, even more preferably 0.2 mL / g or more, and is preferably 0.8 mL / g or less, more preferably 0.75 mL / g or less, even more preferably 0.7 mL / g or less. The pore volume of the solid catalyst can be measured by a method generally used to determine pore volume, such as mercury intrusion porosimetry, and can be measured, for example, by mercury intrusion porosimetry using a mercury porosimeter.

[0031] The acid amount of the solid catalyst is preferably 0.1 mmol / g or more, more preferably 0.15 mmol / g or more, even more preferably 0.2 mmol / g or more, from the viewpoints of reactivity and reaction selectivity, and is preferably 1.5 mmol / g or less, more preferably 1.0 mmol / g or less, even more preferably 0.9 mmol / g or less, even more preferably 0.85 mmol / g or less, even more preferably 0.8 mmol / g or less. The acid amount of the solid catalyst is measured by ammonia temperature programmed desorption (NH ３ -TPD) or the like, and can be measured by a method for determining the amount of acid.

[0032] From the viewpoint of catalyst strength, the crushing strength of the solid catalyst is preferably 1 daN or more, more preferably 1.5 daN or more, even more preferably 2 daN or more, and preferably 11 daN or less, more preferably 10 daN or less, even more preferably 9 daN or less. The crushing strength of the solid catalyst can be measured, for example, by applying a compressive force to the granulated or molded catalyst using a destructive testing device. The crushing pressure in this specification is indicated by the magnitude of the force at which cracks begin to appear in the catalyst when a compressive force is applied to the granulated or molded catalyst.

[0033] The amount of catalyst used is preferably adjusted appropriately depending on the reaction method. When the reaction method is batchwise, the amount of catalyst used is, from the viewpoint of reactivity, preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, per 100 parts by mass of the raw material olefin. When the reaction method is continuous, the amount of catalyst used can be adjusted appropriately depending on the supply amount (flow rate) of the raw material olefin.

[0034] [Step 1: Step of Obtaining a Catalyst to be Used in an Isomerization Reaction] Step 1 is a step of obtaining a catalyst at a reaction temperature (T １ The olefin may be the raw material olefin described above, and the isomerization reaction in step 1 may be an internal isomerization reaction or may include an isomerization reaction in which a 2-olefin is converted into a 1-olefin.

[0035] (Reaction type) The reaction system in step 1 is not particularly limited and may be a heterogeneous system or a homogeneous system. From the viewpoint of efficiently subjecting the catalyst used in step 1 to step 2 and from the viewpoint of ease of operation, a heterogeneous system is preferred. The reaction type of the isomerization reaction in step 1 is not particularly limited and a batch type or a continuous type can be selected as appropriate, but from the viewpoint of ease of operation, it is preferable to select a continuous type. Furthermore, when the reaction type is a continuous type, either a fixed bed method or a suspension bed method may be employed. Of these, a fixed bed method is preferred from the viewpoint of ease of operation. That is, the reaction type of the isomerization reaction in step 1 is preferably a continuous fixed bed method.

[0036] (Reaction temperature T １ The isomerization reaction temperature in step 1 is T １ (°C), the reaction temperature T １ From the viewpoints of reactivity and reaction selectivity, the reaction temperature is preferably 120°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, and is preferably 340°C or lower, more preferably 320°C or lower, even more preferably 300°C or lower.

[0037] (Reaction Pressure) The pressure inside the reaction vessel during the reaction is not particularly limited, and from the viewpoints of safety and ease of operation, the absolute pressure is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, and still more preferably 0.1 MPa, i.e., atmospheric pressure.

[0038] (Reaction atmosphere) During the reaction, an inert gas can be introduced into the reaction vessel. Examples of inert gases include nitrogen, argon, and helium, with nitrogen being preferred from the viewpoint of easy availability. It is preferable to circulate the inert gas as a carrier. The flow rate of the inert gas can be adjusted appropriately depending on the scale of the reaction apparatus and the reaction type, but is preferably 0.5 NL / hr or more, more preferably 1 NL / hr or more, and even more preferably 3 NL / hr or more, and is preferably 20 NL / hr or less, more preferably 10 NL / hr or less, and even more preferably 5 NL / hr or less. When the reaction type is batchwise, the inert gas can be circulated by circulating it above the reaction solution, bubbling it into the reaction solution, or the like.

[0039] (Reaction Time) The reaction time in the isomerization reaction is appropriately determined depending on the type and supply amount of the (raw material) olefin, the reaction temperature, etc. When the reaction is carried out batchwise, the reaction time is, from the viewpoints of reactivity and reaction selectivity, preferably 0.25 hours or more, more preferably 0.5 hours or more, even more preferably 1.0 hours or more, and preferably 20 hours or less, more preferably 16 hours or less, even more preferably 12 hours or less, even more preferably 8 hours or less, even more preferably 5 hours or less.

[0040] (Stirring rotation speed) When the reaction method is a batch type, the stirring rotation speed can be appropriately set depending on the scale of the reaction apparatus, and is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and is preferably 800 rpm or less, more preferably 700 rpm or less, even more preferably 600 rpm or less.

[0041] (LHSV (Liquid Hourly Space Velocity)) When the reaction system is a continuous system, the LHSV (Liquid Hourly Space Velocity), which represents the amount of olefin (starting material) supplied relative to the amount of catalyst used, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less, from the viewpoints of reactivity and reaction selectivity.

[0042] (Catalyst Obtained in Step 1) When the reaction system is a batch system, the catalyst obtained in Step 1 is appropriately separated from the reaction system and subjected to the catalyst regeneration step in Step 2. On the other hand, when the reaction system is a continuous system, the catalyst obtained in Step 1 can be subjected to the catalyst regeneration step in Step 2 without the need for an operation of separating it from the reaction system.

[0043] [Step 2: Catalyst Regeneration Step] In step 2, the catalyst obtained in step 1 is regenerated at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ ) to obtain catalyst R. From the viewpoint of catalyst regeneration efficiency, step 2 is preferably carried out in the presence of an olefin and in a flow of the olefin. The olefin used in step 2 may be the feed olefin described above, and does not have to be the same as the olefin used in steps 1 and 3. However, from the viewpoint of producing an internal olefin with few impurities, it is preferable that the olefin be the same type or have the same composition as the feed olefin used in step 3. Furthermore, when the catalyst regeneration step is carried out in the presence of the feed olefin used in step 3, special cleaning operations for the catalyst and equipment are not required after the catalyst regeneration step, which is preferable.

[0044] (Catalyst retention type) The catalyst retention type in step 2 is not particularly limited, and may be either a heterogeneous system or a homogeneous system, as in step 1. From the viewpoint of efficiently regenerating the catalyst activity reduced by the isomerization reaction of the (feedstock) olefins in step 1, a heterogeneous system is preferred. The catalyst retention type in step 2 is not particularly limited, and, as in step 1, a batch system or a continuous system can be appropriately selected. From the viewpoint of efficiently regenerating the catalyst activity reduced by the isomerization reaction of the (feedstock) olefins in step 1, it is preferable to select a continuous system. Furthermore, when the catalyst retention type is continuous, either a fixed bed method or a suspension bed method may be employed. Of these, a fixed bed method is preferred from the viewpoint of ease of operation. That is, the catalyst retention type in step 2 is preferably a continuous fixed bed method.

[0045] (Catalyst holding temperature T ２In step 2, in order to efficiently regenerate the activity of the catalyst that has been reduced by the olefin isomerization reaction in step 1, the catalyst obtained in step 1 is heated at a reaction temperature T １ In step 2, the catalyst obtained in step 1 is maintained at a temperature exceeding the reaction temperature T １ The catalyst holding temperature is maintained at a temperature exceeding T ２ (°C), the catalyst holding temperature T ２ is the reaction temperature T １ It is preferably a temperature 5°C or higher, more preferably a temperature exceeding 30°C, even more preferably a temperature 35°C or higher, even more preferably a temperature 40°C or higher, and even more preferably a temperature 45°C or higher.

[0046] That is, the catalyst holding temperature (T ２ ) and the reaction temperature of step 1 (T １ ) and the difference ΔT (T ２ -T １ From the viewpoint of efficiently regenerating the activity of the catalyst reduced by the isomerization reaction of the (raw material) olefin in Step 1, the catalyst temperature is preferably 5°C or higher, more preferably more than 30°C, even more preferably 35°C or higher, even more preferably 40°C or higher, and even more preferably 45°C or higher, and is preferably 150°C or lower, more preferably 130°C or lower, even more preferably 100°C or lower, and even more preferably 80°C or lower.

[0047] The catalyst holding temperature (T ２ ) is ΔT(T ２ -T １ The reaction temperature (T １ ), but from the viewpoint of efficiently regenerating the activity of the catalyst reduced by the isomerization reaction of the (raw material) olefin in step 1, the temperature is preferably 180°C or higher, more preferably 200°C or higher, even more preferably 210°C or higher, and is preferably 350°C or lower, more preferably 330°C or lower, even more preferably 320°C or lower.

[0048] The reaction temperature (T １ ) varies, the reaction temperature (T１ ) may be an average value. ２ ) fluctuates, the catalyst holding temperature (T ２ ) may be an average value. １ ) can be measured by a contact measurement method using a thermocouple. ２ ) can be measured by a contact measurement method using a thermocouple.

[0049] (Catalyst Retention Pressure) There are no particular limitations on the pressure inside the reaction vessel used in the catalyst retention step, and from the viewpoints of safety and ease of operation, the absolute pressure is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, and still more preferably 0.1 MPa, i.e., atmospheric pressure.

[0050] (Catalyst retention atmosphere) For catalyst retention, an inert gas can be introduced into the reaction vessel. Examples of inert gases include nitrogen, argon, and helium, with nitrogen being preferred from the viewpoint of availability. It is preferable to circulate the inert gas as a carrier. The flow rate of the inert gas can be adjusted appropriately depending on the scale of the reactor and the reaction type, but is preferably 0.01 NL / hr or more, more preferably 1 NL / hr or more, and even more preferably 3 NL / hr or more, and is preferably 20 NL / hr or less, more preferably 10 NL / hr or less, and even more preferably 5 NL / hr or less. When the reaction type is batchwise, the inert gas can be circulated by a method of passing the gas above the reaction liquid, a method of bubbling the gas into the reaction liquid, or the like.

[0051] (Catalyst Retention Time) The catalyst retention time in the catalyst regeneration process is determined by the catalyst retention temperature (T ２ When the catalyst is maintained batchwise, the catalyst maintenance time is preferably 0.25 hours or more, more preferably 0.5 hours or more, even more preferably 1.0 hours or more, from the viewpoint of efficiently regenerating the activity of the catalyst reduced by the isomerization reaction of the (raw material) olefin in step 1, and is preferably 20 hours or less, more preferably 16 hours or less, even more preferably 12 hours or less, even more preferably 10 hours or less.

[0052] (Stirring rotation speed) When the catalyst holding method is a batch type, the stirring rotation speed can be appropriately set depending on the scale of the reaction apparatus, and is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and is preferably 800 rpm or less, more preferably 700 rpm or less, even more preferably 600 rpm or less.

[0053] (LHSV (Liquid Hourly Space Velocity)) When the catalyst maintenance method is continuous, the LHSV (Liquid Hourly Space Velocity), which represents the amount of (feedstock) olefin supplied relative to the amount of catalyst used, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, from the viewpoint of efficiently regenerating the activity of the catalyst reduced by the isomerization reaction of (feedstock) olefin in step 1, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less.

[0054] (Catalyst Obtained in Step 2) When the catalyst is maintained in a batchwise manner, the catalyst obtained in Step 2 is appropriately separated from the catalyst maintenance system and is subjected to the isomerization reaction step in Step 3. On the other hand, when the catalyst is maintained in a continuous manner, the catalyst obtained in Step 2 can be subjected to the isomerization reaction step in Step 3 without the need for an operation of separating it from the catalyst maintenance system.

[0055] [Step 3: Isomerization Reaction Step] Step 3 is a step in which the raw material olefins are isomerized in the presence of the catalyst (catalyst R) obtained in Step 2. The isomerization reaction in Step 3 may be mainly an internal isomerization reaction, or may include an isomerization reaction in which 2-olefins are converted to 1-olefins.

[0056] (Reaction type) The reaction system in step 3 is not particularly limited, and may be either a heterogeneous system or a homogeneous system, as in steps 1 and 2, with a heterogeneous system being preferred from the viewpoint of ease of operation. The reaction type of the isomerization reaction in step 3 is not particularly limited, and, as in steps 1 and 2, a batch system or a continuous system can be selected as appropriate, but from the viewpoint of ease of operation, it is preferable to select a continuous system. Furthermore, when the reaction type is continuous, either a fixed bed method or a suspension bed method may be employed. Of these, a fixed bed method is preferred from the viewpoint of ease of operation. That is, the reaction type of the isomerization reaction in step 3 is preferably a continuous fixed bed method.

[0057] (Reaction temperature T ３ The isomerization reaction temperature in step 3 is T ３ (°C), the reaction temperature T ３ is the catalyst holding temperature T in step 2 from the viewpoint of reactivity and reaction selectivity. ２ Furthermore, the reaction temperature T ３ is the catalyst holding temperature T in step 2 from the viewpoint of reactivity and reaction selectivity. ２ The temperature is preferably 5°C or more lower, more preferably 10°C or more lower, and even more preferably 15°C or more lower.

[0058] That is, the catalyst holding temperature (T ２ ) and the reaction temperature (T ３ ) and the difference ΔT (T ２ -T ３ ) is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, and is preferably 150°C or lower, more preferably 130°C or lower, even more preferably 120°C or lower, from the viewpoints of reactivity and reaction selectivity.

[0059] The reaction temperature of step 3 (T ３ ) is ΔT(T ２ -T ３ ) in step 2 is set to be within the above range. ２) from the viewpoint of reactivity and reaction selectivity, the temperature is preferably 120°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, and is preferably 340°C or lower, more preferably 320°C or lower, even more preferably 300°C or lower.

[0060] The reaction temperature of step 3 (T ３ ) varies, the reaction temperature (T ３ ) may be an average value. ３ ) can be measured by the reaction temperature (T １ ) is the same as

[0061] (Reaction Pressure) There is no particular limitation on the pressure inside the reaction vessel during the reaction. From the viewpoints of safety and ease of operation, the absolute pressure is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, and still more preferably 0.1 MPa, i.e., atmospheric pressure.

[0062] (Reaction atmosphere) During the reaction, an inert gas can be introduced into the reaction vessel. Examples of inert gases include nitrogen, argon, and helium, with nitrogen being preferred from the viewpoint of easy availability. It is preferable to circulate the inert gas as a carrier. The flow rate of the inert gas can be adjusted appropriately depending on the scale of the reaction apparatus and the reaction type, but is preferably 0.01 NL / hr or more, more preferably 1 NL / hr or more, even more preferably 3 NL / hr or more, and preferably 20 NL / hr or less, more preferably 10 NL / hr or less, and even more preferably 5 NL / hr or less. When the reaction type is batchwise, the inert gas can be circulated by circulating it above the reaction solution, bubbling it into the reaction solution, or the like.

[0063] (Reaction Time) The reaction time in the isomerization reaction is appropriately determined depending on the type and supply amount of the raw material olefin, the reaction temperature, etc. When the reaction is carried out batchwise, the reaction time is, from the viewpoints of reactivity and reaction selectivity, preferably 0.25 hours or more, more preferably 0.5 hours or more, even more preferably 1.0 hours or more, and preferably 20 hours or less, more preferably 16 hours or less, even more preferably 12 hours or less, even more preferably 10 hours or less, even more preferably 5 hours or less.

[0064] (Stirring rotation speed) When the reaction method is a batch type, the stirring rotation speed can be appropriately set depending on the scale of the reaction apparatus, and is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and is preferably 800 rpm or less, more preferably 700 rpm or less, even more preferably 600 rpm or less.

[0065] (LHSV (Liquid Hourly Space Velocity)) When the reaction system is a continuous system, the LHSV (Liquid Hourly Space Velocity), which represents the feed rate of the raw material olefin relative to the amount of catalyst used, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less, from the viewpoints of reactivity and reaction selectivity.

[0066] (Separation of Internal Olefins) When the reaction system is a batch system, the internal olefin produced in step 3 is obtained by appropriately separating it from the catalyst that has undergone step 3. On the other hand, when the reaction system is a continuous system, the internal olefin produced in step 3 can be obtained without the need for an operation of separating it from the catalyst that has undergone step 3.

[0067] [Uses of Internal Olefin] The internal olefin obtained by the method for producing an internal olefin of the present invention is useful as a raw material or intermediate raw material for surfactants, organic solvents, softeners, sizing agents, etc., and is particularly useful as a raw material for surfactants.

[0068] In addition to the above-described embodiments, the present invention discloses the following method for producing an internal olefin. <1> A method for producing an internal olefin, comprising a step of isomerizing a raw material olefin in the presence of the following catalyst R. Catalyst R: Reaction temperature (T １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) (hereinafter referred to as "catalyst holding temperature (T ２ Hereinafter, the catalyst obtained by maintaining the reaction temperature (T １ ) to obtain a catalyst that has been subjected to an olefin isomerization reaction at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ ) to obtain catalyst R is referred to as step 2, and the step of isomerizing raw olefins in the presence of catalyst R is referred to as step 3. １ ) isomerized in the presence of the raw material olefin. １ ) (hereinafter referred to as "catalyst holding temperature (T ２ <3> The method for producing an internal olefin according to <1>, wherein the catalyst is obtained by maintaining the catalyst at a temperature (T ２ ) and the reaction temperature of step 1 (T １ ) and the difference ΔT (T ２ -T １ ) is preferably 5°C or higher, more preferably more than 30°C, even more preferably 35°C or higher, even more preferably 40°C or higher, even more preferably 45°C or higher, and is preferably 150°C or lower, more preferably 130°C or lower, even more preferably 100°C or lower, even more preferably 80°C or lower. ２ ) and the reaction temperature of step 1 (T １ ) and the difference ΔT (T ２ -T １ <6> The method for producing an internal olefin according to any one of <1> to <4>, wherein the catalyst holding temperature (T２<7> The method for producing internal olefins according to any one of <1> to <6>, wherein the catalyst temperature is preferably 180°C or higher, more preferably 200°C or higher, even more preferably 210°C or higher, and preferably 350°C or lower, more preferably 330°C or lower, even more preferably 320°C or lower. <7> The method for producing internal olefins according to any one of <1> to <6>, wherein the pressure in the reaction vessel used in the catalyst retention step of step 2 is preferably 1 MPa or lower, more preferably 0.5 MPa or lower, even more preferably 0.2 MPa or lower, even more preferably 0.1 MPa, in terms of absolute pressure, i.e., atmospheric pressure. <8> The method for producing internal olefins according to any one of <1> to <7>, wherein step 2 is carried out under an inert gas flow. <9> The method for producing internal olefins according to <8>, wherein the flow rate of the inert gas is preferably 0.01 NL / hr or higher, more preferably 1 NL / hr or higher, even more preferably 3 NL / hr or higher, and preferably 20 NL / hr or lower, more preferably 10 NL / hr or lower, even more preferably 5 NL / hr or lower. <10> The method for producing internal olefins according to any one of <1> to <9>, wherein the catalyst retention mode in step 2 is batchwise. <11> The method for producing internal olefins according to <10>, wherein the catalyst retention time in step 2 is preferably 0.25 hr or more, more preferably 0.5 hr or more, even more preferably 1.0 hr or more, and preferably 20 hr or less, more preferably 16 hr or less, even more preferably 12 hr or less, and even more preferably 10 hr or less. <12> The method for producing internal olefins according to <10> or <11>, wherein the stirring rotation speed in step 2 is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and preferably 800 rpm or less, more preferably 700 rpm or less, and even more preferably 600 rpm or less. <13> The method for producing internal olefins according to any one of <1> to <9>, wherein the catalyst retention mode in step 2 is continuous.<14> The method for producing an internal olefin according to <13>, wherein the LHSV (liquid hourly space velocity), which represents the feed rate of the raw material olefin relative to the amount of catalyst used in step 2, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less. <15> The reaction temperature (T ３ ) is the catalyst holding temperature (T ２ <16> The method for producing an internal olefin according to any one of <1> to <14>, wherein the catalyst holding temperature (T ２ ) and the reaction temperature (T ３ ) and the difference ΔT (T ２ -T ３ <17> The method for producing an internal olefin according to <15>, wherein the catalyst holding temperature (T ２ ) and the reaction temperature (T ３ ) and the difference ΔT (T ２ -T ３ <18> The method for producing an internal olefin according to <15> or <16>, wherein the reaction temperature (T ３<19> The method for producing an internal olefin according to any one of <15> to <18>, wherein the temperature in the reaction vessel in step 3 is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, even more preferably 0.1 MPa, in terms of absolute pressure, i.e., atmospheric pressure. <20> The method for producing an internal olefin according to any one of <15> to <19>, wherein step 3 is carried out under an inert gas flow. <21> The method for producing internal olefins according to <20>, wherein the flow rate of the inert gas is preferably 0.01 NL / hr or more, more preferably 1 NL / hr or more, even more preferably 3 NL / hr or more, and preferably 20 NL / hr or less, more preferably 10 NL / hr or less, even more preferably 5 NL / hr or less. <22> The method for producing internal olefins according to any of <15> to <21>, wherein the reaction type in step 3 is a batch type. <23> The method for producing internal olefins according to <22>, wherein the reaction time in step 3 is preferably 0.25 hr or more, more preferably 0.5 hr or more, even more preferably 1.0 hr or more, and preferably 20 hr or less, more preferably 16 hr or less, even more preferably 12 hr or less, even more preferably 10 hr or less, even more preferably 5 hr or less. <24> The method for producing an internal olefin according to <22> or <23>, wherein the stirring speed in step 3 is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and preferably 800 rpm or less, more preferably 700 rpm or less, even more preferably 600 rpm or less. <25> The method for producing an internal olefin according to any of <15> to <21>, wherein the reaction system in step 3 is continuous.<26> The method for producing an internal olefin according to <25>, wherein the LHSV (liquid hourly space velocity), which represents the feed rate of the raw material olefin relative to the amount of catalyst used in step 3, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less. <27> The reaction temperature (T １ <28> The method for producing an internal olefin according to any one of <1> to <26>, wherein the reaction temperature (T １<29> The method for producing an internal olefin according to any one of <1> to <28>, wherein the pressure in the reaction vessel in step 1 is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, and even more preferably 0.1 MPa, in terms of absolute pressure, i.e., atmospheric pressure. <30> The method for producing an internal olefin according to <1> to <29>, wherein step 1 is carried out under an inert gas flow. <31> The method for producing an internal olefin according to <30>, wherein the flow rate of the inert gas in step 1 is preferably 0.5 NL / hr or more, more preferably 1 NL / hr or more, even more preferably 3 NL / hr or more, and preferably 20 NL / hr or less, more preferably 10 NL / hr or less, and even more preferably 5 NL / hr or less. <32> The method for producing an internal olefin according to <1> to <31>, wherein the reaction type in step 1 is a batch type. <33> The method for producing an internal olefin according to <32>, wherein the reaction time in step 1 is preferably 0.25 hours or more, more preferably 0.5 hours or more, even more preferably 1.0 hours or more, and preferably 20 hours or less, more preferably 16 hours or less, even more preferably 12 hours or less, even more preferably 8 hours or less, and even more preferably 5 hours or less. <34> The stirring speed in step 1 is preferably 20 rpm or more, more preferably 100 rpm or more, even more preferably 300 rpm or more, and preferably 800 rpm or less, more preferably 700 rpm or less, and even more preferably 600 rpm or less. <35> The method for producing an internal olefin according to <1> to <31>, wherein the reaction system in step 1 is continuous. <36> The method for producing an internal olefin according to <35>, wherein the LHSV (liquid hourly space velocity), which represents the feed rate of the raw material olefin relative to the amount of the catalyst used in step 1, is preferably 0.05 / hr or more, more preferably 0.1 / hr or more, even more preferably 0.15 / hr or more, and is preferably 20 / hr or less, more preferably 15 / hr or less, even more preferably 10 / hr or less. <37> The method for producing an internal olefin according to any one of <1> to <36>, wherein the catalyst is a solid Lewis acid catalyst.<38> The method for producing internal olefins according to any one of <1> to <37>, wherein the catalyst preferably contains an element from Periods 3 to 5, more preferably at least one selected from aluminum (Al), silicon (Si), titanium (Ti), iron (Fe), zinc (Zn), yttrium (Y), zirconium (Zr), and tin (Sn), and further contains aluminum (Al). <39> The method for producing internal olefins according to any one of <1> to <38>, wherein the catalyst is preferably at least one selected from an aluminum oxide catalyst (hereinafter also simply referred to as "aluminum oxide"), an aluminum phosphate catalyst, and a zeolite (aluminosilicate) catalyst, more preferably an aluminum oxide catalyst. <40> The method for producing internal olefins according to <39>, wherein the aluminum oxide is preferably γ-alumina, and the purity of aluminum oxide in the aluminum oxide catalyst is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more, and the upper limit is not particularly limited, but is 100% by mass. <41> The method for producing an internal olefin according to any one of <1> to <40>, wherein the starting olefin has preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or 2 double bond positions. <42> The method for producing an internal olefin according to any one of <1> to <41>, wherein the starting olefin preferably contains a 1-olefin, and the 1-olefin is preferably a linear 1-olefin. <43> The method for producing an internal olefin according to any one of <1> to <42>, wherein the starting olefin has a carbon number of preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 24 or less, more preferably 22 or less, and even more preferably 18 or less. <44> The method for producing an internal olefin according to any one of <1> to <43>, wherein the starting olefin has a carbon number of 12 or more and 24 or less. <45> A method for regenerating catalyst activity, comprising the following steps: １ The catalyst used for the isomerization reaction of olefins at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２) <46> The step of maintaining the reaction temperature (T １ ) isomerized in the presence of the raw material olefin. １ ) exceeding the catalyst holding temperature (T ２ <47> The method for regenerating the activity of a catalyst according to <45> or <46>, wherein the step is preferably carried out under olefin flow. <48> The method for regenerating the activity of a catalyst according to any one of <45> to <47>, wherein the step is step 2 in the method for producing internal olefins according to any one of <1> to <44>.

[0069] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples in any way.

[0070] Example 1 [Step 1: Isomerization Reaction Step] A γ-alumina catalyst (manufactured by Mizusawa Industrial Chemicals, Ltd., product name "Neobead GB-13", γ-Al ２ O ３ , bead shape, diameter 2.0 mm, specific surface area 180 m ２ The reactor was filled with 400 mL of olefin (1-hexadecene, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) having an average pore diameter of 11.1 nm, a pore volume of 0.50 mL / g, an acid content of 0.28 mmol / g, and a crushing strength of 2.6 daN). 1-hexadecene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was fed as a raw material olefin at a rate of 100 mL / h. The reactor was operated at a nitrogen pressure of 0.1 MPaG and a reaction temperature (T １ After the reaction was completed, the catalyst layer was cooled to room temperature and depressurized, and the catalyst was extracted from the catalyst continuous evaluation device and used in the next step.

[0071] <Quantitative Determination of Product> In the continuous reaction of step 1, the reaction solution was sampled from the outlet of the apparatus every 12 hours, and approximately one drop of the sampled reaction solution was placed in a sample tube. 1 mL of dimethyl disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) and 30 mg of iodine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added, and the mixture was thoroughly mixed and then allowed to stand at 65°C for 15 minutes. Next, 1 mL of 30% by mass aqueous sodium thiosulfate solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 1 mL of ethanol (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), and 2 mL of hexane (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) were added and mixed, and the upper phase was collected. A gas chromatograph analyzer "Agilent 6890A" (manufactured by Agilent Technology Inc.) was equipped with a column "Ultra ALLOY-1" (manufactured by Frontier Labs, Inc.: capillary column 30.0 m x 250 μm), and a flame ionization detector (FID) was used. The injection temperature was 300 ° C., the detector temperature was 350 ° C., and the He flow rate was 0.8 mL / min. The product was quantified. From the olefin content at each double bond position, the average double bond position (Ave. DBP) was calculated using the following formula 1. The change over time is shown in Figure 1. The results shown in Figure 1 confirm that the activity of the catalyst decreases over time due to the isomerization reaction of the raw material olefin in Step 1. Ave. DBP = (1-olefin + 2 x 2-olefin + 3 x 3-olefin + 4 x 4-olefin + 5 x 5-olefin + 6 x 6-olefin + 7 x 7-olefin + 8 x 8-olefin) / 100 (Equation 1)

[0072] <Evaluation of catalytic activity> A continuous catalytic reactor separate from that used in step 1 was filled with 10 mL of the catalyst that had undergone step 1, and a continuous reaction was carried out at a reaction temperature of 260°C for 6 hours while feeding 1-hexadecene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) at 80 mL / h and circulating nitrogen at 1.9 NL / h. The reaction solution sampled at the end of the reaction was subjected to quantitative analysis of the product by the method described above, and the average double bond position (Ave.DBP) was measured. １ ) was calculated.

[0073] [Step 2: Catalyst Regeneration Step] After the catalytic activity evaluation, 1-hexadecene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was fed into the continuous catalyst reactor at a rate of 80 mL / h, and nitrogen was circulated at a rate of 1.9 NL / h. The catalyst holding temperature (T ２ ) A continuous reaction was carried out under the conditions of 280°C and a catalyst holding time of 6 hours.

[0074] [Step 3: Isomerization Reaction Step] After Step 2, a continuous catalytic reaction was carried out in the continuous catalytic reaction apparatus under the same conditions as those for the catalytic activity evaluation described above. The reaction solution sampled at the end of the reaction was subjected to quantitative analysis of the product by the method described above, and the average double bond position (Ave.DBP) was measured. ２ ) was calculated.

[0075] Ave. DBP calculated above ２ and Ave. DBP １ Difference between (ΔAve.DBP (= Ave.DBP ２ - Ave. DBP １ )) is larger, the effect of regenerating the activity of the catalyst is higher.

[0076] Examples 2 to 11: Type and amount of feed olefin, amount of catalyst used, nitrogen flow rate, reaction temperatures T1, T ３ , catalyst holding temperature T ２ Each step was carried out in the same manner as in Example 1, except that the temperature and reaction time were changed as shown in Table 1, and the product was quantified in each step. In Examples 10 and 11, in which 1-octadecene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the raw material olefin, the average double bond position (Ave. DBP) was calculated from the olefin content at each double bond position using the following formula 2: Ave. DBP = (1-olefin + 2 x 2-olefin + 3 x 3-olefin + 4 x 4-olefin + 5 x 5-olefin + 6 x 6-olefin + 7 x 7-olefin + 8 x 8-olefin + 9 x 9-olefin) / 100 (Formula 2)

[0077]

[0078] From the results of the examples of the present invention, it was confirmed that the process for producing internal olefins of the present invention can reactivate a catalyst whose activity has decreased.

Claims

1. A method for producing internal olefins comprising the following steps 1 and 2. Step 1: Reaction temperature (T １ The catalyst subjected to the isomerization reaction of an olefin at the reaction temperature (T １ ) (hereinafter referred to as "catalyst holding temperature (T ２ ) to obtain catalyst R. Step 2: A step of isomerizing the raw olefin in the presence of the catalyst R obtained in step 1 to obtain an internal olefin.

2. The catalyst R is heated to a reaction temperature (T １ The catalyst used in the isomerization reaction of the raw olefin at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ The method for producing an internal olefin according to claim 1, wherein the catalyst is obtained by supporting the catalyst on a silica gel substrate.

3. The method for producing an internal olefin according to claim 2, wherein the carbon number of the raw material olefin is 12 or more and 24 or less.

4. The method for producing an internal olefin according to claim 2 or 3, wherein the raw material olefin contains a 1-olefin.

5. The catalyst holding temperature (T ２ ) and the reaction temperature (T １ ) and the difference ΔT (T ２ -T １ The method for producing an internal olefin according to any one of claims 1 to 3, wherein the temperature is higher than 30°C and not higher than 150°C.

6. In the presence of the catalyst R, the reaction temperature (T ３ ) isomerizing a raw material olefin, The reaction temperature (T ３ ) is the catalyst holding temperature (T ２ The method for producing an internal olefin according to any one of claims 1 to 3, wherein the total amount of the internal olefin is less than 100%.

7. The catalyst holding temperature (T ２ ) and the reaction temperature (T ３ ) and the difference ΔT (T ２ -T ３ 7. The method for producing an internal olefin according to claim 6, wherein the temperature of the reaction mixture is 10° C. or higher and 130° C. or lower.

8. The reaction temperature (T １ The method for producing an internal olefin according to any one of claims 1 to 3, wherein the temperature of the reaction is 160°C or higher and 300°C or lower.

9. The method for producing an internal olefin according to any one of claims 1 to 3, wherein the catalyst is a solid Lewis acid catalyst.

10. The method for producing an internal olefin according to any one of claims 1 to 3, wherein the catalyst is an aluminum oxide catalyst.

11. 1. A method for regenerating the activity of a catalyst, comprising the steps of: Reaction temperature (T １ The catalyst subjected to the isomerization reaction of an olefin at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ )

12. The process is carried out at a reaction temperature (T １ The catalyst used in the isomerization reaction of the raw olefin at the reaction temperature (T １ ) exceeding the catalyst holding temperature (T ２ 12. The method of claim 11, further comprising the step of:

13. 13. The method for regenerating the activity of a catalyst according to claim 12, wherein the carbon number of the feed olefin is 12 or more and 24 or less.

14. The method for regenerating the activity of a catalyst according to claim 12 or 13, wherein the feed olefin comprises a 1-olefin.

15. The method for regenerating the activity of a catalyst according to any one of claims 11 to 13, wherein the catalyst is a solid Lewis acid catalyst.

16. The method for regenerating the activity of a catalyst according to any one of claims 11 to 13, wherein the catalyst is an aluminum oxide catalyst.