Method for producing internal olefin, method for producing internal olefin sulfonate, and method for low-temperature stabilization

Abstract

The present invention provides a method for producing an internal olefin to obtain an internal olefin sulfonate having high low-temperature stability, a method for producing an internal olefin sulfonate using the internal olefin, and a low-temperature stabilization method.　This method for producing an internal olefin is characterized by including a step for carrying out internal isomerization of a C8-24 α-olefin using a fixed bed reactor having solid acid catalyst particles packed inside a reactor tube, the ratio (D / dp) of the inner diameter D of the reactor tube to the average particle diameter dp of the solid acid catalyst particles being 25 or greater.

Description

[Technical field]

[0001] The present invention relates to a method for producing an internal olefin, a method for producing an internal olefin sulfonate using the internal olefin, and a low-temperature stabilization method. [Background technology]

[0002] Conventionally, anionic surfactants, particularly alkyl sulfates and polyoxyalkylene alkyl ether sulfates, have been widely used as cleaning ingredients for household and industrial use due to their excellent detergency and foaming power. As one type of anionic surfactant, olefin sulfonates, particularly internal olefin sulfonates obtained from an internal olefin having a double bond inside the olefin instead of at its terminal, have been reported.

[0003] The internal olefin sulfonate is generally obtained by reacting an internal olefin with sulfur trioxide to sulfonate it, neutralizing the resulting sulfonated product, and then preferably hydrolyzing it.

[0004] For example, Patent Document 1 proposes a method for producing an internal olefin sulfonate, which includes a step of obtaining an internal olefin from a primary aliphatic alcohol having from 8 to 24 carbon atoms, a step of obtaining a sulfonated product by sulfonating the internal olefin, and a step of neutralizing the sulfonated product and then subjecting the neutralized product to a hydrolysis treatment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-156462 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional internal olefin sulfonates have a problem of poor stability at low temperatures, resulting in the formation of precipitates when stored in a low-temperature environment of around 0°C.

[0007] The present invention provides a method for producing an internal olefin sulfonate having high low-temperature stability, a method for producing an internal olefin sulfonate using the internal olefin, and a method for low-temperature stabilization. [Means for solving the problem]

[0008] The present invention provides a method for producing an internal olefin, comprising a step of internally isomerizing an α-olefin having a carbon number of 8 to 24 using a fixed-bed reactor having a reaction tube filled with solid acid catalyst particles, The present invention relates to a method for producing an internal olefin, wherein a ratio (D / dp) of an average particle diameter dp of the solid acid catalyst particles to an inner diameter D of the reaction tube is 25 or more.

[0009] The present invention also relates to a method for producing an internal olefin sulfonate, which comprises a step of sulfonating the internal olefin obtained by the above-mentioned production method.

[0010] The present invention further relates to a method for stabilizing an internal olefin sulfonate at low temperature, which comprises sulfonating the internal olefin obtained by the above-mentioned production method, and further neutralizing the sulfonate to obtain an internal olefin sulfonate. Effect of the Invention

[0011] According to the present invention, in the process of internally isomerizing α-olefins having carbon numbers of 8 to 24, the ratio (D / dp) of the inner diameter D of the reaction tube of the fixed bed reactor to the average particle diameter dp of the solid acid catalyst particles is adjusted to 25 or more, thereby making it possible to produce an internal olefin for obtaining an internal olefin sulfonate having high low-temperature stability. The internal olefin sulfonate produced using the internal olefin obtained by the production method of the present invention has a feature that it has high low-temperature stability and is unlikely to produce precipitates even when stored in a low-temperature environment of around 0°C. Although the reason for this is unclear, it is believed that the double bond position of the internal olefin as the raw material and the content ratio of internal olefins having different double bond positions affect the low-temperature stability of the internal olefin sulfonate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] <Production method of internal olefins> The method for producing an internal olefin of the present invention includes a step of internally isomerizing an α-olefin having a carbon number of 8 to 24 using a fixed-bed reactor having a reaction tube packed with solid acid catalyst particles.

[0014] An internal olefin is an olefin that has a double bond at a position other than the end of the carbon chain, i.e., an olefin that has a double bond at the second or higher position of the carbon chain. Internal isomerization of an α-olefin means converting the double bond at the α-position to a position at the second or higher position of the carbon chain, thereby converting the α-olefin into an olefin that has a double bond at a position other than the end of the carbon chain (internal olefin).

[0015] From the viewpoint of cleaning performance when the internal olefin sulfonate is used as a cleaning agent, the carbon number of the α-olefin is preferably 10 or more, more preferably 12 or more, and even more preferably 14 or more, and is preferably 22 or less, more preferably 18 or less.

[0016] In the process of internally isomerizing α-olefins, a fixed-bed reactor having a reaction tube filled with solid acid catalyst particles can be used.

[0017] From the viewpoint of increasing the conversion rate of α-olefins to internal olefins, the solid acid catalyst particles are preferably solid acid catalyst particles containing one or more elements selected from aluminum, iron, and gallium, more preferably solid acid catalyst particles containing aluminum, and even more preferably γ-alumina and / or aluminum phosphate.

[0018] The average particle diameter dp (equivalent sphere diameter) of the solid acid catalyst particles is, from the viewpoints of handleability, catalytic activity, and the relationship with the inner diameter D of the reaction tube, preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 6 mm or less, more preferably 5 mm or less.

[0019] The packed height of the solid acid catalyst particles is preferably 100 mm or more, more preferably 1000 mm or more, from the viewpoint of the production efficiency of the internal olefin. The upper limit of the packed height is preferably 8000 mm or less, from the viewpoint of the installation space of the reaction tube.

[0020] The inner diameter D of the reaction tube may be, for example, 10 mm or more, and is preferably 50 mm or more, more preferably 500 mm or more, and is preferably 2500 mm or less, more preferably 2000 mm or less, from the viewpoint of the relationship between the production efficiency of internal olefins and the average particle diameter dp of the solid acid catalyst particles.

[0021] The fixed-bed reactor is preferably a fixed-bed reactor having a reaction tube installed vertically from the viewpoint of handling of the solid acid catalyst particles and installation space of the fixed-bed reactor. The fixed-bed reactor is preferably a single-tube type having one reaction tube from the viewpoint of simplifying the equipment and reducing pressure loss, and is preferably a multi-tube type having multiple reaction tubes from the viewpoint of removing reaction heat.

[0022] In the internal olefin production method of the present invention, the average particle diameter dp of the solid acid catalyst particles and the inner diameter D of the reaction tube are adjusted so that the ratio (D / dp) of the average particle diameter dp of the solid acid catalyst particles to the inner diameter D of the reaction tube is 25 or more. From the viewpoint of obtaining an internal olefin that is a raw material for producing an internal olefin sulfonate having high low-temperature stability, D / dp is preferably 200 or more, more preferably 400 or more. From the viewpoint of the handleability of the solid acid catalyst particles and the installation space of a fixed-bed reactor, the upper limit of D / dp is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less.

[0023] The reaction temperature during the internal isomerization of an α-olefin is preferably 300° C. or lower, more preferably 290° C. or lower, and even more preferably 280° C. or lower, from the viewpoint of obtaining an internal olefin that is a raw material for producing an internal olefin sulfonate having high low-temperature stability. The lower limit of the reaction temperature is preferably 100° C. or higher, more preferably 150° C. or higher, and even more preferably 170° C. or higher, from the viewpoint of increasing the conversion rate of an α-olefin to an internal olefin.

[0024] The pressure during the internal isomerization of an α-olefin is, from the viewpoint of increasing the conversion rate of an α-olefin to an internal olefin and from the viewpoint of obtaining an internal olefin that is a raw material for producing an internal olefin sulfonate having high low-temperature stability, preferably 0.03 MPa or more, more preferably 0.05 MPa or more, even more preferably 0.1 MPa or more, in absolute terms, and is also preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less.

[0025] In the step of internally isomerizing α-olefins, an inert gas may be introduced into the fixed bed reactor. Examples of the inert gas include nitrogen, argon, and helium, and nitrogen is preferred from the viewpoint of availability. The amount of the inert gas introduced is preferably 0.1 moles or more, more preferably 0.2 moles or more, and is preferably 10 moles or less, more preferably 1 mole or less, per mole of the raw material α-olefin, from the viewpoint of improving the reaction rate and productivity.

[0026] In the step of internally isomerizing α-olefins, the WHSV (the mass of α-olefin supplied per hour relative to the unit mass of the solid acid catalyst) is, from the viewpoint of reaction efficiency and from the viewpoint of obtaining an internal olefin that is a raw material for producing an internal olefin sulfonate having high low-temperature stability, preferably 0.03 / hr or more, more preferably 0.05 / hr or more, even more preferably 0.07 / hr or more, even more preferably 0.09 / hr or more, and is also preferably 7 / hr or less, more preferably 5 / hr or less, even more preferably 2.5 / hr or less, even more preferably 2 / hr or less, even more preferably 1.5 / hr or less, and even more preferably 1 / hr or less.

[0027] In the process of internally isomerizing α-olefins, the LHSV (liquid hourly space velocity) is, from the viewpoint of reaction efficiency and from the viewpoint of obtaining an internal olefin that is a raw material for producing an internal olefin sulfonate having high low-temperature stability, preferably 0.03 / hr or more, more preferably 0.05 / hr or more, even more preferably 0.07 / hr or more, and is preferably 5 / hr or less, more preferably 4 / hr or less, even more preferably 2.5 / hr or less, even more preferably 2 / hr or less, even more preferably 1.5 / hr or less, and even more preferably 1 / hr or less.

[0028] The internal olefin obtained by the above step may be purified by distillation or the like to remove by-products such as the raw material α-olefin and dimers.

[0029] The average double bond positions of the internal olefin is preferably 2 or more, more preferably 3 or more, even more preferably 3.5 or more, even more preferably 4 or more, and is preferably 4.8 or less, more preferably 4.6 or less, even more preferably 4.5 or less, from the viewpoint of obtaining an internal olefin sulfonate having high low-temperature stability, and from the viewpoint of cleaning performance and foaming performance when the internal olefin sulfonate is used as a cleaning agent.

[0030] The internal olefins may be used alone or in combination of two or more. When two or more internal olefins are used in combination, it is preferable to use an internal olefin having 16 carbon atoms and an internal olefin having 18 carbon atoms in combination from the viewpoint of cleaning performance when the internal olefin sulfonate is used as a cleaning agent.

[0031] <Method of producing internal olefin sulfonate> The method for producing an internal olefin sulfonate of the present invention includes a step of sulfonating the internal olefin obtained by the above-mentioned production method. The above-mentioned sulfonation step is preferably a sulfonation step of reacting the internal olefin obtained by the above-mentioned production method with sulfur trioxide to obtain a sulfonated product. The method for producing an internal olefin sulfonate of the present invention preferably includes a neutralization step of neutralizing the obtained sulfonated product to obtain a neutralized product, and further preferably includes a step of hydrolyzing the obtained neutralized product to obtain a hydrolysis product.

[0032] In the present invention, the internal olefin sulfonate is a sulfonate obtained by sulfonating the internal olefin, and then preferably neutralizing the internal olefin after the sulfonation, and more preferably hydrolyzing the internal olefin after the neutralization. That is, when the internal olefin is sulfonated, it is converted into β-sultone, γ-sultone, and olefin sulfonic acid, which are further converted into hydroxysulfonate and olefin sulfonate through a neutralization step and preferably a hydrolysis step. The obtained product is mainly a mixture of these. In the present invention, these products and the mixture thereof are collectively referred to as internal olefin sulfonate.

[0033] <Sulfonation process> The sulfonation step is a step of sulfonating the internal olefin, and is preferably a step of reacting the internal olefin with sulfur trioxide to obtain a sulfonated product.

[0034] From the viewpoint of improving reactivity, sulfur trioxide is preferably reacted as sulfur trioxide gas. The sulfur trioxide gas is preferably diluted with an inert gas such as air or nitrogen to a concentration of preferably 1 to 30% by volume, more preferably 1.5 to 10% by volume.

[0035] The amount of sulfur trioxide used is preferably 0.8 mol or more, more preferably 0.9 mol or more, and even more preferably 0.95 mol or more, per mol of internal olefin from the viewpoint of improving the yield of the sulfonated product, and is preferably 1.2 mol or less, more preferably 1.1 mol or less, and even more preferably 1.05 mol or less, from the viewpoint of economic efficiency and suppressing coloration of the sulfonated product.

[0036] In the sulfonation reaction in which an internal olefin reacts with sulfur trioxide, a thin-film sulfonation reactor equipped with an external jacket is preferably used from the viewpoint of reacting a liquid internal olefin with gaseous sulfur trioxide.

[0037] The treatment temperature in the sulfonation step is preferably 0° C. or higher from the viewpoint of preventing solidification of sulfur trioxide and the sulfonated product, and is preferably 50° C. or lower from the viewpoint of suppressing coloration of the sulfonated product.

[0038] Since the sulfonation reaction is an exothermic reaction, it is preferable to provide an external jacket for the sulfonation reactor and pass cooling water through it for cooling. The temperature of the cooling water passed through the external jacket of the sulfonation reactor is preferably 0°C or higher from the viewpoint of improving the reaction rate, and is preferably 30°C or lower, more preferably 20°C or lower, from the viewpoint of suppressing side reactions and reducing impurities such as internal olefins and inorganic salts in the finally obtained internal olefin sulfonate.

[0039] The sulfonation reaction rate is preferably 95% or more, more preferably 97% or more, and even more preferably 98% or more from the viewpoint of improving the yield of the sulfonated product, and is preferably 99.8% or less from the viewpoint of suppressing coloration of the sulfonated product due to excess sulfur trioxide.

[0040] <Neutralization process> The neutralization step is a step in which the sulfonated product obtained in the sulfonation step is neutralized to obtain a neutralized product.

[0041] The alkali compound used for neutralization may be an inorganic alkali compound or an organic alkali compound. As the inorganic alkali compound, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate can be used. As the organic alkali compound, for example, an amine compound having 1 to 6 carbon atoms such as ammonia and 2-aminoethanol can be used.

[0042] The alkali compound used for neutralization is preferably an inorganic alkali compound, more preferably an alkali metal hydroxide, from the viewpoints of availability and economy, more preferably at least one selected from sodium hydroxide and potassium hydroxide, even more preferably sodium hydroxide from the viewpoint of ease of use, and even more preferably potassium hydroxide from the viewpoint of low-temperature stability.

[0043] The alkaline compound used for neutralization is preferably used as an alkaline aqueous solution from the viewpoint of handling. The concentration of the alkaline aqueous solution is preferably 1% by mass or more, more preferably 4.5% by mass or more, even more preferably 7% by mass or more, still more preferably 10% by mass or more, and even more preferably 12% by mass or more from the viewpoint of economic efficiency and from the viewpoint of suppressing the generation of impurities such as internal olefins and inorganic salts. Also, from the viewpoint of productivity in the hydrolysis step, it is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 23% by mass or less, still more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0044] The amount of the alkali compound used for neutralization is preferably 1 molar or more, more preferably 1.03 molar or more, relative to the sulfonic acid groups, from the viewpoint of suppressing the formation of impurities such as internal olefins and inorganic salts and from the viewpoint of improving reactivity, and is preferably 2.5 molar or less, more preferably 2.0 molar or less, and even more preferably 1.5 molar or less, from the viewpoint of economy and suppressing the formation of impurities such as internal olefins and inorganic salts.

[0045] In the neutralization step, the temperature when the sulfonated product is mixed with the alkaline aqueous solution and the temperature during the neutralization reaction are preferably 40° C. or lower, more preferably 35° C. or lower, even more preferably 30° C. or lower, and still more preferably 25° C. or lower, from the viewpoint of suppressing the generation of impurities such as internal olefins and inorganic salts due to side reactions, and are preferably 0° C. or higher, more preferably 10° C. or higher, even more preferably 15° C. or higher, and still more preferably 20° C. or higher, from the viewpoint of improving the reactivity.

[0046] In the neutralization step, any type of mixer may be used as long as it can efficiently mix the sulfonated product and the alkaline aqueous solution and apply shear force to the oily product. Examples of such mixers include static mixers, collision mixers, impeller mixers, and vibration mixers. Examples of static mixers include a static mixer manufactured by Noritake. Examples of impingement mixers include a high-pressure emulsifier manufactured by Nanomizer. Examples of impeller mixers include a Milder manufactured by Matsubo and a Homoxer manufactured by Primix. Among these, impeller mixers are preferred from the viewpoint of equipment costs.

[0047] From the viewpoints of suppressing the formation of by-products and improving productivity, the neutralization step is preferably carried out by a so-called continuous method in which the reaction liquid is circulated using a loop reactor while the sulfonated product and the alkaline aqueous solution are added and the reaction liquid is simultaneously withdrawn.

[0048] In the neutralization step, the neutralization time is preferably 5 minutes or more, more preferably 8 minutes or more, even more preferably 10 minutes or more, and even more preferably 12 minutes or more from the viewpoint of sufficiently carrying out the neutralization reaction, and is preferably 100 minutes or less, more preferably 50 minutes or less, even more preferably 40 minutes or less, still more preferably 30 minutes or less, still more preferably 20 minutes or less, and even more preferably 15 minutes or less from the viewpoint of improving productivity.

[0049] In the case of the continuous method, the neutralization time can be expressed as an average residence time obtained by dividing the volume of the loop reactor by the total amount of sulfonated product and alkaline aqueous solution added per unit time. The average residence time is preferably 8 minutes or more, more preferably 10 minutes or more, and even more preferably 12 minutes or more from the viewpoint of suppressing neutralization heat, and is preferably 100 minutes or less, more preferably 60 minutes or less, more preferably 40 minutes or less, even more preferably 30 minutes or less, even more preferably 20 minutes or less, and even more preferably 15 minutes or less from the viewpoint of improving productivity. In addition, in the case of the continuous method, the circulation ratio of the reaction liquid is preferably 3 times or more, more preferably 6 times or more, and even more preferably 9 times or more from the viewpoint of improving reactivity, and is preferably 30 times or less, more preferably 20 times or less, and even more preferably 15 times or less from the viewpoint of suppressing the pressure rise in the reactor. Here, the circulation ratio is the ratio of the total content volume circulating in the reactor to the flow rate input into the reactor, and is expressed as (total circulation amount in the reactor) / (input amount into the reactor).

[0050] In the neutralization step, water-soluble organic solvents such as alcohol and acetone, and surfactants such as polyoxyethylene alkyl ether and α-olefin sulfonic acid can be allowed to coexist. Such coexisting substances are preferably not used because they may deteriorate during the neutralization reaction, remain in the final product, or impose a burden on the purification step, and when used, are preferably used in an amount of 20% by mass or less in the mixed liquid, more preferably 10% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less.

[0051] <Hydrolysis process> The production method of the present invention preferably includes a hydrolysis step in which the obtained neutralization product is hydrolyzed.

[0052] In the hydrolysis step, the temperature during hydrolysis is preferably 120° C. or higher, more preferably 140° C. or higher, and even more preferably 160° C. or higher, from the viewpoint of improving reactivity, and is preferably 220° C. or lower, and more preferably 180° C. or lower, from the viewpoint of suppressing decomposition of the product.

[0053] The hydrolysis reaction may be carried out in a batch reactor or in a continuous reactor.

[0054] The treatment time for the hydrolysis step is preferably 30 minutes or more, more preferably 45 minutes or more, from the viewpoint of completing the reaction, and is preferably 4 hours or less, more preferably 3.5 hours or less, even more preferably 3 hours or less, still more preferably 2 hours or less, and even more preferably 90 minutes or less, from the viewpoint of improving productivity.

[0055] The concentration of the internal olefin sulfonate aqueous solution obtained by the hydrolysis step is, from the viewpoint of productivity, preferably 15 mass% or more, more preferably 30 mass% or more, even more preferably 35 mass% or more, still more preferably 40 mass% or more, still more preferably 45 mass% or more, still more preferably 48 mass% or more, and still more preferably 50 mass% or more, and from the viewpoint of the viscosity of the aqueous solution, etc., it is preferably 75 mass% or less, more preferably 70 mass% or less, still more preferably 65 mass% or less, and still more preferably 60 mass% or less.

[0056] The internal olefin sulfonate can be used for various applications as it is, but may be further purified by desalting, decolorization, etc.

[0057] The internal olefin sulfonate obtained by the production method of the present invention has high low-temperature stability and is unlikely to produce precipitates even when stored in a low-temperature environment of around 0° C. In addition, the internal olefin sulfonate has good purity and color, and can be suitably used for various applications such as body cleansers, shampoos, laundry detergents, and dishwashing detergents.

[0058] <Low temperature stabilization method> The internal olefin obtained by the production method of the present invention is sulfonated and further neutralized to obtain an internal olefin sulfonate, and the obtained internal olefin sulfonate can be stabilized at low temperature. The internal olefin and internal olefin sulfonate refer to the internal olefin and internal olefin sulfonate described above. The term "low temperature stable" means that the state is unlikely to change at room temperature or lower, and can be confirmed, for example, by a reduction in the occurrence of precipitates at a temperature of -5°C under normal pressure.

[0059] The present invention and preferred embodiments thereof are described below. <1> A method for producing an internal olefin, comprising: a step of internally isomerizing an α-olefin having a carbon number of 8 to 24 using a fixed-bed reactor having a reaction tube filled with solid acid catalyst particles, 1. A method for producing an internal olefin, wherein a ratio (D / dp) of an average particle diameter dp of the solid acid catalyst particles to an inner diameter D of the reaction tube is 25 or more. <2> The number of carbon atoms in the α-olefin is preferably 10 or more, more preferably 12 or more, and even more preferably 14 or more, and is preferably 22 or less, and more preferably 18 or less. <1> The method for producing an internal olefin according to claim 1 . <3> The solid acid catalyst particles are preferably solid acid catalyst particles containing one or more elements selected from aluminum, iron, and gallium, more preferably solid acid catalyst particles containing aluminum, and even more preferably γ-alumina and / or aluminum phosphate. <1> or <2> The method for producing an internal olefin according to claim 1 . <4> The average particle diameter dp of the solid acid catalyst particles is preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 6 mm or less, more preferably 5 mm or less. <1> ~ <3> 3. The method for producing an internal olefin according to claim 1 , <5> The packing height of the solid acid catalyst particles is preferably 100 mm or more, more preferably 1000 mm or more, and preferably 8000 mm or less. <1> ~ <4> 3. The method for producing an internal olefin according to claim 1 , <6> The filling height is preferably 1000 mm or more and 8000 mm or less. <1> ~ <5> 3. The method for producing an internal olefin according to claim 1 , <7> The inner diameter D of the reaction tube may be 10 mm or more, preferably 50 mm or more, more preferably 500 mm or more, and is preferably 2500 mm or less, more preferably 2000 mm or less. <1> ~ <6> 3. The method for producing an internal olefin according to claim 1 , <8> The fixed bed reactor is a fixed bed reactor in which reaction tubes are installed vertically, and is preferably a single-tube or multi-tube type. <1> ~ <7> 3. The method for producing an internal olefin according to claim 1 , <9> The ratio (D / dp) of the inner diameter D of the reaction tube to the average particle diameter dp of the solid acid catalyst particles is preferably 200 or more, more preferably 400 or more. <1> ~ <8> 3. The method for producing an internal olefin according to claim 1 , <10> The upper limit of the D / dp is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less. <1> ~ <9> 3. The method for producing an internal olefin according to claim 1 , <11> The D / dp is preferably 200 or more and 2000 or less, more preferably 400 or more and 1500 or less, and even more preferably 400 or more and 1000 or less. <1> ~ <10> 3. The method for producing an internal olefin according to claim 1 , <12> The reaction temperature for internally isomerizing α-olefins is 300°C or less. <1> ~ <11> 3. The method for producing an internal olefin according to claim 1 , <13> The reaction temperature during internal isomerization of α-olefins is preferably 300° C. or less, more preferably 290° C. or less, and even more preferably 280° C. or less. <1> ~ <12> 3. The method for producing an internal olefin according to claim 1 , <14> The lower limit of the reaction temperature when internally isomerizing an α-olefin is preferably 100° C. or higher, more preferably 150° C. or higher, and even more preferably 170° C. or higher. <1> ~ <13> 3. The method for producing an internal olefin according to claim 1 , <15> The pressure during the internal isomerization of α-olefins is preferably 0.03 MPa or more, more preferably 0.05 MPa or more, even more preferably 0.1 MPa or more, and is preferably 1 MPa or less, more preferably 0.5 MPa or less, even more preferably 0.2 MPa or less, in terms of absolute pressure. <1> ~ <14> 3. The method for producing an internal olefin according to claim 1 , <16> In the step of internally isomerizing α-olefins, an inert gas may be introduced into the fixed bed reactor, and the inert gas is preferably nitrogen. <1> ~ <15> 3. The method for producing an internal olefin according to claim 1 , <17> The amount of the inert gas introduced is preferably 0.1 moles or more, more preferably 0.2 moles or more, and is preferably 10 moles or less, more preferably 1 mole or less, relative to 1 mole of the raw material α-olefin. <16> The method for producing an internal olefin according to claim 1 . <18> In the internal isomerization step, the WHSV (the mass of α-olefins supplied per hour relative to the unit mass of the solid acid catalyst) is 0.03 / hr or more and 7 / hr or less. <1> ~ <17> 3. The method for producing an internal olefin according to claim 1 , <19> In the step of internally isomerizing α-olefins, the WHSV is preferably 0.03 / hr or more, more preferably 0.05 / hr or more, even more preferably 0.07 / hr or more, even more preferably 0.09 / hr or more, and is preferably 7 / hr or less, more preferably 5 / hr or less, even more preferably 2.5 / hr or less, even more preferably 2 / hr or less, even more preferably 1.5 / hr or less, even more preferably 1 / hr or less. <1> ~ <18> 3. The method for producing an internal olefin according to claim 1 , <20> The WHSV is preferably 0.03 / hr or more and 7 / hr or less, more preferably 0.05 / hr or more and 5 / hr or less, even more preferably 0.07 / hr or more and 2.5 / hr or less, even more preferably 0.09 / hr or more and 2 / hr or less, even more preferably 0.09 / hr or more and 1.5 / hr or less, even more preferably 0.09 / hr or more and 1 / hr or less. <1> ~ <19> 3. The method for producing an internal olefin according to claim 1 , <21> In the internal isomerization step, the LHSV (liquid hourly space velocity) is 0.03 / hr or more and 5 / hr or less. <1> ~ <20> 3. The method for producing an internal olefin according to claim 1 , <22> In the step of internally isomerizing α-olefins, the LHSV (liquid hourly space velocity) is preferably 0.03 / hr or more, more preferably 0.05 / hr or more, even more preferably 0.07 / hr or more, and is preferably 5 / hr or less, more preferably 4 / hr or less, even more preferably 2.5 / hr or less, even more preferably 2 / hr or less, even more preferably 1.5 / hr or less, even more preferably 1 / hr or less. <1> ~ <21> 3. The method for producing an internal olefin according to claim 1 , <23> The LHSV is preferably 0.03 / hr or more and 5 / hr or less, more preferably 0.05 / hr or more and 4 / hr or less, even more preferably 0.07 / hr or more and 2.5 / hr or less, even more preferably 0.07 / hr or more and 2 / hr or less, even more preferably 0.07 / hr or more and 1.5 / hr or less, even more preferably 0.07 / hr or more and 1 / hr or less. <1> ~ <22> 3. The method for producing an internal olefin according to claim 1 , <24> The internal olefin has an average double bond position of 2 or more and 4.8 or less. <1> ~ <23> 3. The method for producing an internal olefin according to claim 1 , <25> The average double bond positions of the internal olefin is preferably 2 or more, more preferably 3 or more, even more preferably 3.5 or more, even more preferably 4 or more, and is preferably 4.8 or less, more preferably 4.6 or less, even more preferably 4.5 or less. <1> ~ <24> 3. The method for producing an internal olefin according to claim 1 , <26> The internal olefin is preferably a combination of an internal olefin having 16 carbon atoms and an internal olefin having 18 carbon atoms. <1> ~ <25> 3. The method for producing an internal olefin according to claim 1 , <27> The above <1> ~ <26> 2. A method for producing an internal olefin sulfonate, comprising: a step of sulfonating the internal olefin obtained by the method for producing an internal olefin sulfonate according to claim 1. <28> The sulfonation step is a step of reacting the internal olefin with sulfur trioxide to obtain a sulfonated product. <27> A method for producing the internal olefin sulfonate according to the present invention. <29> The sulfur trioxide is reacted as sulfur trioxide gas. <28> A method for producing the internal olefin sulfonate according to the present invention. <30> The sulfur trioxide gas is preferably diluted with an inert gas such as air or nitrogen to a concentration of 1 to 30% by volume, more preferably 1.5 to 10% by volume. <29> 2. A method for producing the internal olefin sulfonate according to claim 1 . <31> The amount of sulfur trioxide used is preferably 0.8 mol or more, more preferably 0.9 mol or more, and even more preferably 0.95 mol or more, and is 1.2 mol or less, more preferably 1.1 mol or less, and even more preferably 1.05 mol or less, relative to 1 mol of the internal olefin. <28> ~ <30> 3. The method for producing the internal olefin sulfonate according to claim 1 , <32> The sulfonation reaction of reacting the internal olefin with sulfur trioxide is carried out using a thin-film sulfonation reactor equipped with an external jacket. <28> ~ <31> 3. The method for producing the internal olefin sulfonate according to claim 1 , <33> The treatment temperature in the sulfonation step is preferably 0° C. or higher and preferably 50° C. or lower. <27> ~ <32> 3. The method for producing the internal olefin sulfonate according to claim 1 , <34> The sulfonation reactor is provided with an external jacket and cooled by passing cooling water through it. <32> or <33> 2. A method for producing the internal olefin sulfonate according to claim 1 . <35> The temperature of the cooling water passed through the outer jacket of the sulfonation reactor is preferably 0° C. or higher, preferably 30° C. or lower, more preferably 20° C. or lower. <34> 2. A method for producing the internal olefin sulfonate according to claim 1 . <36> The sulfonation reaction rate is preferably 95% or more, more preferably 97% or more, even more preferably 98% or more, and preferably 99.8% or less. <27> ~ <35> 3. The method for producing the internal olefin sulfonate according to claim 1 , <37> a neutralization step of neutralizing the obtained sulfonated product to obtain a neutralized product. <27> ~ <36> 3. The method for producing the internal olefin sulfonate according to claim 1 , <38> The alkaline compound used for neutralization is preferably an inorganic alkaline compound, more preferably an alkali metal hydroxide, still more preferably at least one selected from sodium hydroxide and potassium hydroxide, still more preferably sodium hydroxide, still more preferably potassium hydroxide. <37> 2. A method for producing the internal olefin sulfonate according to claim 1 . <39> The alkaline compound is used as an alkaline aqueous solution. <38> 2. A method for producing the internal olefin sulfonate according to claim 1 . <40> The concentration of the alkaline aqueous solution is preferably 1% by mass or more, more preferably 4.5% by mass or more, even more preferably 7% by mass or more, still more preferably 10% by mass or more, still more preferably 12% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 23% by mass or less, still more preferably 20% by mass or less, and still more preferably 15% by mass or less. <39> 2. A method for producing the internal olefin sulfonate according to claim 1 . <41> The amount of the alkali compound used is preferably 1 mole or more, more preferably 1.03 mole or more, and preferably 2.5 mole or less, more preferably 2.0 mole or less, and even more preferably 1.5 mole or less, based on the amount of sulfonic acid groups. <38> ~ <40> 3. The method for producing the internal olefin sulfonate according to claim 1 , <42> In the neutralization step, the temperature when the sulfonated product is mixed with the alkaline aqueous solution and the temperature during the neutralization reaction are preferably 40° C. or lower, more preferably 35° C. or lower, even more preferably 30° C. or lower, still more preferably 25° C. or lower, and preferably 0° C. or higher, more preferably 10° C. or higher, even more preferably 15° C. or higher, and still more preferably 20° C. or higher. <37> ~ <41> 3. The method for producing the internal olefin sulfonate according to claim 1 , <43> The mixer in the neutralization step is a stirring blade type mixer. <37> ~ <42> 3. The method for producing the internal olefin sulfonate according to claim 1 , <44> The neutralization step is carried out in a so-called continuous manner, in which the sulfonated product and an alkaline aqueous solution are added while circulating the reaction liquid in a loop reactor, and the reaction liquid is simultaneously withdrawn. <37> ~ <43> 3. The method for producing the internal olefin sulfonate according to claim 1 , <45> The neutralization time is preferably 5 minutes or more, more preferably 8 minutes or more, even more preferably 10 minutes or more, even more preferably 12 minutes or more, and is preferably 100 minutes or less, more preferably 50 minutes or less, even more preferably 40 minutes or less, even more preferably 30 minutes or less, even more preferably 20 minutes or less, even more preferably 15 minutes or less. <37> ~ <44> 3. The method for producing the internal olefin sulfonate according to claim 1 , <46> The average residence time in the continuous process is preferably 8 minutes or more, more preferably 10 minutes or more, even more preferably 12 minutes or more, and is preferably 100 minutes or less, more preferably 60 minutes or less, even more preferably 40 minutes or less, even more preferably 30 minutes or less, even more preferably 20 minutes or less, even more preferably 15 minutes or less. <44> or <45> 2. A method for producing the internal olefin sulfonate according to claim 1 . <47> In the continuous method, the circulation ratio of the reaction solution is preferably 3 times or more, more preferably 6 times or more, even more preferably 9 times or more, and is preferably 30 times or less, more preferably 20 times or less, even more preferably 15 times or less. <44> ~ <46> 3. The method for producing the internal olefin sulfonate according to claim 1 , <48> In the neutralization step, no surfactant (coexisting substance) is used. <37> ~ <47> 3. The method for producing the internal olefin sulfonate according to claim 1 , <49> When a surfactant (coexisting substance) is used in the neutralization step, the surfactant is preferably used in an amount of 20% by mass or less in the mixed liquid, more preferably 10% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less. <37> ~ <47> 3. The method for producing the internal olefin sulfonate according to claim 1 , <50> hydrolyzing the resulting neutralized product to obtain a hydrolysis product. <37> ~ <49> 3. The method for producing the internal olefin sulfonate according to claim 1 , <51> The temperature during hydrolysis is preferably 120° C. or higher, more preferably 140° C. or higher, even more preferably 160° C. or higher, and is preferably 220° C. or lower, more preferably 180° C. or lower. <50> 2. A method for producing the internal olefin sulfonate according to claim 1 . <52> The treatment time of the hydrolysis step is preferably 30 minutes or more, more preferably 45 minutes or more, and preferably 4 hours or less, more preferably 3.5 hours or less, even more preferably 3 hours or less, still more preferably 2 hours or less, and even more preferably 90 minutes or less. <50> or <51> 2. A method for producing the internal olefin sulfonate according to claim 1 . <53> The concentration of the aqueous solution of internal olefin sulfonate obtained by the hydrolysis step is preferably 15 mass% or more, more preferably 30 mass% or more, even more preferably 35 mass% or more, still more preferably 40 mass% or more, still more preferably 45 mass% or more, still more preferably 48 mass% or more, still more preferably 50 mass% or more, preferably 75 mass% or less, more preferably 70 mass% or less, still more preferably 65 mass% or less, still more preferably 60 mass% or less. <50> ~ <52> 3. The method for producing the internal olefin sulfonate according to claim 1 , <54> <27> ~ <53> 2. Use of an internal olefin sulfonate obtained by the production method according to any one of claims 1 to 11 in a body detergent, shampoo, laundry detergent, or dish detergent. <55> <1> ~ <26> 2. A method for stabilizing an internal olefin sulfonate at low temperature, comprising sulfonating the internal olefin obtained by the production method according to any one of the above items 1 to 11, and further neutralizing the sulfonate to obtain an internal olefin sulfonate. EXAMPLES

[0060] The present invention will be specifically described below based on examples. In the following examples and comparative examples, "%" means "mass %" unless otherwise specified. Various measurement and evaluation methods are as follows.

[0061] <Method for measuring the average particle diameter dp (equivalent sphere diameter) of solid acid catalyst particles> 50 solid acid catalyst particles were randomly selected, and the minor and major axis diameters were measured using a caliper. The arithmetic mean of the minor and major axis diameters was used to calculate the specific surface area of ​​a cylinder having the diameter of the base and the height of the cylinder, respectively. The diameter of a sphere having the same specific surface area was then taken as the average particle diameter dp (sphere equivalent diameter) of the solid acid catalyst particles.

[0062] <Method for measuring the double bond distribution of internal olefins> The double bond positions of the internal olefins were measured by gas chromatography (hereinafter abbreviated as GC). Specifically, the internal olefins were reacted with dimethyl disulfide to form dithiolated derivatives, and each component was then separated by GC. The double bond positions of the internal olefins were determined from the respective peak areas, and the average double bond position was calculated by the following formula. The equipment and conditions used for the measurement are as follows: [Apparatus and measurement conditions] GC equipment: HP6890 (manufactured by Hewlett Packard) Column: Ultra-Alloy-1HT capillary column, 30m x 250μm x 0.15μm (Frontier Labs, Inc.) Detector: Flame ionization detector (FID) Injection temperature: 300℃ Detector temperature: 350℃ He flow rate: 4.6mL / min [Calculation formula for average double bond position]

number

[0063] Example 1 (Production of 1-hexadecene) A single-tube fixed-bed reactor with a vertically installed reaction tube was used, and γ-alumina was filled as solid acid catalyst particles to a height of 0.4 m in the reaction tube. The temperature in the reaction tube was adjusted to 290°C, and 1-hexadecanol (product name: Kalcol 6098, manufactured by Kao Corporation) was supplied at 0.9 L per hour (LHSV = 1 / hr, WHSV = 1.1 / hr) and nitrogen was supplied from the top of the reactor at atmospheric pressure so that the molar ratio was 0.3 times that of 1-hexadecanol, to carry out an olefination reaction. The reaction tube outlet liquid was cooled to 70°C to recover crude 1-hexadecene. The obtained crude 1-hexadecene was transferred to a distillation flask and distilled at 150 to 160°C / 9 mmHg to obtain 1-hexadecene with an olefin purity of 100%. (Internal isomerization reaction) A single-tube fixed-bed reactor with a vertically installed reaction tube was used, and γ-alumina was filled as solid acid catalyst particles to a height of 0.2 m in the reaction tube. The D / dp was 29. The temperature in the reaction tube was adjusted to 220°C, and the produced 1-hexadecene was supplied at 0.09 L per hour (LHSV = 0.2 / hr, WHSV = 0.2 / hr) and nitrogen was supplied from the top of the reactor at atmospheric pressure so that the molar amount was 0.3 times that of 1-hexadecene, to carry out an internal isomerization reaction. The reaction tube outlet liquid was cooled to 70°C, and an internal olefin with a carbon number of 16 was recovered. The average double bond position of the obtained internal olefin was 4.1.

[0064] (Method of producing carbon number 16 internal olefin sulfonate (C16IOS)) The produced internal olefin having 16 carbon atoms was placed in a thin-film sulfonation reactor having an external jacket, and sulfonation reaction was carried out using sulfur trioxide gas (1.1% by volume, remaining air) under the condition that cooling water at 20°C was passed through the reactor external jacket. The molar ratio of SO3 / internal olefin during the sulfonation reaction was set to 1.005. The obtained sulfonated product was mixed with an alkaline aqueous solution (potassium hydroxide 17% by mass, remaining water) prepared with potassium hydroxide (alkali agent) in an amount 1.05 times the theoretical acid value by mole, and neutralized at 30°C by a continuous method (using a Milder mixer (product name: Milder MDN303V, manufactured by Matsubo Co., Ltd.), average residence time 30 minutes, circulation ratio 9 times). The neutralized product was heated in an autoclave at 170°C for 1 hour to carry out hydrolysis, and a liquid containing 55% by mass of potassium internal olefin sulfonate having 16 carbon atoms was obtained.

[0065] Examples 2 to 8, Comparative Example 1 An internal olefin having a carbon number of 16 was produced in the same manner as in Example 1, except that the conditions of the internal isomerization reaction were changed to those shown in Table 1. Then, using the obtained internal olefin having a carbon number of 16, a potassium internal olefin sulfonate-containing liquid having a carbon number of 16 was produced in the same manner as in Example 1.

[0066] Example 9 (Production of 1-octadecene) A single-tube fixed-bed reactor with a vertically installed reaction tube was used, and γ-alumina was filled in the reaction tube as solid acid catalyst particles to a height of 0.4 m. The temperature in the reaction tube was adjusted to 290°C, and 1-octadecanol (product name: Kalcol 8098, manufactured by Kao Corporation) was supplied at 0.9 L per hour (LHSV = 1 / hr, WHSV = 1.1 / hr) and nitrogen was supplied from the top of the reactor at atmospheric pressure so that the amount was 0.3 molar times that of 1-octadecanol, to carry out an olefination reaction. The reaction tube outlet liquid was cooled to 70°C to recover crude 1-octadecene. The obtained crude 1-octadecene was transferred to a distillation flask and distilled at 175 to 180°C / 9 mmHg to obtain 1-octadecene with an olefin purity of 100%. (Internal isomerization reaction) A single-tube fixed-bed reactor with a vertically installed reaction tube was used, and γ-alumina was filled as solid acid catalyst particles to a height of 0.4 m in the reaction tube. The D / dp was 29. The temperature in the reaction tube was adjusted to 245°C, and the produced 1-octadecene was supplied at 0.2 L per hour (LHSV = 1.9 / hr, WHSV = 2.0 / hr) and nitrogen was supplied from the top of the reactor at atmospheric pressure so that the molar amount was 0.3 times that of 1-octadecene, to carry out an internal isomerization reaction. The reaction tube outlet liquid was cooled to 70°C, and an internal olefin with a carbon number of 18 was recovered. The average double bond position of the obtained internal olefin was 4.0.

[0067] (Method of producing carbon number 18 internal olefin sulfonate (C18IOS)) The produced internal olefin having 18 carbon atoms was placed in a thin-film sulfonation reactor having an external jacket, and sulfonation reaction was carried out using sulfur trioxide gas (1.1% by volume, remaining air) under the condition that cooling water at 20°C was passed through the reactor external jacket. The molar ratio of SO3 / internal olefin during the sulfonation reaction was set to 1.005. The obtained sulfonated product was mixed with an alkaline aqueous solution (potassium hydroxide 17% by mass, remaining water) prepared with potassium hydroxide (alkali agent) in an amount 1.05 times the theoretical acid value by mole, and neutralized at 30°C by a continuous method (using a Milder mixer (product name: Milder MDN303V, manufactured by Matsubo Co., Ltd.), average residence time 30 minutes, circulation ratio 9 times). The neutralized product was heated in an autoclave at 170°C for 1 hour to carry out hydrolysis, and a liquid containing 55% by mass of potassium internal olefin sulfonate having 18 carbon atoms was obtained.

[0068] Examples 10 to 12, Comparative Examples 2 and 3 An internal olefin having a carbon number of 18 was produced in the same manner as in Example 9, except that the conditions of the internal isomerization reaction were changed to those shown in Table 2. Then, using the obtained internal olefin having a carbon number of 18, a potassium internal olefin sulfonate-containing liquid having a carbon number of 18 was produced in the same manner as in Example 9.

[0069] The particle diameter dp of the solid acid catalyst particles (γ-alumina) used in the above examples was about 1 to 5 mm, and the reaction tubes packed with the solid acid catalyst particles each had a single diameter, with an inner diameter D of about 50 to 2000 mm.

[0070] <Evaluation of low temperature stability> 100 g of each of the prepared potassium internal olefin sulfonate-containing liquids was placed in a PS-13K wide-mouth bottle, sealed, and left in a thermostatic chamber at -5°C for one week. After one week, the appearance of the potassium internal olefin sulfonate was evaluated according to the following criteria. A: There is absolutely no change in appearance. B: A very small amount of precipitate is observed. C: A small amount of precipitate is observed. D: There is a lot of sediment at the bottom of the bottle.

[0071] [Table 1]

[0072] [Table 2] [Industrial Applicability]

[0073] The internal olefin obtained by the production method of the present invention is useful as a base oil for oil drilling oil, a raw material for detergents, a raw material for paper sizing agents, a base oil or raw material for lubricating oils, and a raw material for chemical products, etc. Furthermore, the internal olefin sulfonate obtained by the production method of the present invention is useful as a base material for various detergents.

Claims

1. A method for producing an internal olefin, comprising a step of internally isomerizing an α-olefin having a carbon number of 14 to 18 using a fixed-bed reactor having a reaction tube filled with solid acid catalyst particles, the solid acid catalyst particles contain aluminum; The solid acid catalyst particles have an average particle diameter dp of 1 mm or more and 6 mm or less, 2. A process for producing an internal olefin, wherein a ratio (D / dp) of an average particle diameter dp of the solid acid catalyst particles to an inner diameter D of the reaction tube is 200 or more.

2. 2. The method for producing an internal olefin according to claim 1, wherein the reaction temperature during the internal isomerization of the α-olefin is 300° C. or lower.

3. 3. The method for producing an internal olefin according to claim 1, wherein in the internal isomerization step, WHSV (the mass of α-olefin supplied per hour relative to the unit mass of the solid acid catalyst) is 0.03 / hr or more and 7 / hr or less.

4. 3. The method for producing an internal olefin according to claim 1, wherein in the internal isomerization step, LHSV (liquid hourly space velocity) is 0.03 / hr or more and 5 / hr or less.

5. The method for producing an internal olefin according to claim 1 or 2, wherein the internal olefin has an average double bond position of 2 or more and 4.8 or less.

6. A method for producing an internal olefin sulfonate, comprising a step of sulfonating the internal olefin obtained by the method according to claim 1 or 2.

7. 3. A method for stabilizing an internal olefin sulfonate at low temperatures, comprising sulfonating the internal olefin obtained by the method according to claim 1 or 2, and further neutralizing the sulfonate to obtain an internal olefin sulfonate.

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