JP4272633B2 - Method for producing olefin oligomer - Google Patents

Description

  The present invention relates to a method for producing an olefin oligomer. Specifically, the present invention relates to a method for producing an olefin oligomer by reacting an olefin in the presence of a specific solid acid catalyst.

  Conventionally, the polymerization of butene oligomers has been industrially carried out using a homogeneous acid catalyst such as aluminum chloride and boron trifluoride (for example, Patent Document 1 and Patent Document 2).

  However, when a homogeneous acid catalyst is used, there are industrial problems such as a step of separating the product and the catalyst, waste acid treatment, and corrosion of the apparatus. In addition, a large amount of waste needs to be treated, and the burden on the environment is large. Therefore, development of a solid acid catalyst has been conventionally performed. Examples of conventional solid acid catalysts include metal oxide catalysts containing V, Cr, Mo, and W elements (Patent Document 3), and alumina-based catalysts that are variously modified using alumina as a support (for example, Patent Document 4 and Patent Documents). 5), composite oxide catalyst of alumina such as silica-alumina, silica-titania (for example, Patent Document 6, Patent Document 7), composite oxide catalyst of zirconium oxide and molybdenum oxide (for example, Patent Document 8, Patent Document 9) , Activated clay (Patent Document 10), heteropolyacid catalyst (for example, Patent Document 11 and Patent Document 12), gallium compound supported catalyst (Patent Document 13), and the like.

  Most of the above-mentioned patent documents relate to catalyst activity and product selectivity, but the industrially most important problem in the case of using a solid acid catalyst is catalyst life. When a catalyst having a short catalyst life such that the catalyst activity rapidly decreases as the reaction time elapses, it becomes difficult to maintain satisfactory productivity, and the catalyst needs to be replaced. In such a case, the use period of the catalyst is shortened. As a result, the cost of the catalyst is increased and the economic loss is increased. Moreover, since production must be stopped for a certain period for replacement, it is industrially disadvantageous to use a catalyst having a short catalyst life. In patents relating to conventional solid acid catalysts there is little mention of this important catalyst life.

  As a cause of lowering the catalytic activity, in the reaction in which carbonium ions are generated as in this reaction, cyclization and dehydrogenation proceeds using this carbonium ion as an initiator, and via so-called coke via polycyclic aromatics. Is generated, and this coke covers the catalyst surface, so that the catalytic activity is reduced (for example, Non-Patent Document 1). The coke generation rate is strongly influenced by the reaction temperature, and the coke is more likely to be generated at higher temperatures (for example, Non-Patent Document 2). In the above patents, there are almost no examples referring to the catalyst life. In Patent Document 4, a flow test in the case of using an alumina catalyst whose surface is chlorinated, and in Patent Document 10, heteropolyacid is added to silica by 40% by weight. As a result of repeated use of the supported catalyst three times, there is some description that the reaction results hardly change. In the case of Patent Document 4, the reaction time is about 1800 hours, which is a comparatively long life evaluation, but the reaction temperature is from 0 ° C. to around room temperature, and the result is a low temperature that is not easily affected by coke precipitation. It is not helpful. In the case of Patent Document 10, the reaction temperature is 120 ° C., which is a relatively high temperature at which coke is likely to be produced. However, the reaction time is 1 hour and the catalyst is reused only three times. This is an insufficient result to evaluate the life.

US Pat. No. 2,677,002 U.S. Pat. No. 3,212,125 JP-T-2001-510500 JP-A-57-82325 JP-A-56-139428 JP-A-56-139430 JP-A-57-149233 JP-A-56-139429 JP 2005-15384 A JP-A-57-149232 JP-A-57-102825 JP 57-14538 A JP-A-52-1555692 J. et al. Catal. , 138, 343, 1992 Stud. Surf. Sci. Catal. 68, 1991

  Although the method using the solid acid catalyst can efficiently produce an olefin oligomer with high yield, there is a problem that the activity continuously decreases when used in the reaction.

  The inventors of the present invention have solved the above-mentioned problems, and have intensively searched for a method in which a decrease in activity and a decrease in selectivity are hardly observed even when the solid acid catalyst is repeatedly reused, thereby completing the present invention. That is, the present invention provides a method for producing an olefin oligomer from an olefin in the presence of a solid acid catalyst, and the presence of a pore volume of a mesoporous portion having a pore diameter of 20 to 500 mm as a solid acid catalyst with respect to a pore volume of 9 to 500 mm. A method for producing an olefin oligomer, comprising using a polysiloxane having an organic sulfonic acid group in a proportion of 0 to 20%.

  By carrying out the method of the present invention, an olefin oligomer can be produced continuously for a long period of time, and even if the solid acid catalyst is repeatedly used, no decrease in activity and selectivity is observed, which is extremely industrially valuable.

  Hereinafter, the present invention will be further described by showing in detail the production method for a specific solid acid catalyst (polysiloxane having an organic sulfonic acid group) used in the present invention.

  The organic polymer siloxane catalyst having a sulfonic acid group-containing hydrocarbon group used in the present invention is described in Japanese Patent Application Laid-Open No. 2004-190021. Any hydrocarbon group having a sulfonic acid group can be used in the present invention as long as it is a hydrocarbon group having at least one sulfonic acid group. The hydrocarbon having a sulfonic acid group is preferably a hydrocarbon group having at least one sulfonic acid group-containing hydrocarbon group and having 1 to 20 carbon atoms. More preferably, it is a substituted or unsubstituted aromatic hydrocarbon group having 6 or more and 20 or less carbon atoms, more preferably 6 or more and 15 or less carbon atoms and having at least one sulfonic acid group (a sulfonic acid group is directly bonded to the aromatic group). Or a hydrocarbon group substituted with an aromatic group may be substituted with a sulfonic acid group), and preferably has at least one sulfonic acid group having 1 to 15 carbon atoms, more preferably Includes at least one hydrocarbon group selected from the group consisting of substituted or unsubstituted aliphatic and alicyclic hydrocarbon groups having 1 to 10 carbon atoms.

  Examples of the hydrocarbon group having such a sulfonic acid group-containing hydrocarbon group include aromatic groups such as a phenyl group, a tolyl group, a naphthyl group, and a methylnaphthyl group that are nucleus-substituted by at least one sulfonic acid group, A methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i- group substituted with at least one sulfonic acid group such as an aromatic substituted alkyl group such as a benzyl group or a naphthylmethyl group. Butyl group, t-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, cyclohexyl group, methylcyclohexyl group And ethylcyclohexyl group. Furthermore, these aromatic hydrocarbon groups or saturated / unsaturated aliphatic hydrocarbon (including alicyclic compounds) groups are substituted with halogen atoms, alkoxy groups, nitro groups, hydroxy groups, etc. in addition to sulfonic acid groups. It may be a hydrocarbon group having a group.

  Such an organic polymer siloxane can be prepared by the following method. Examples of preparation methods that are easy to implement include (1) a preparation method in which alkoxysilane having a sulfonic acid group-containing hydrocarbon group and tetraalkoxysilane are mixed in any proportion, hydrolyzed, and co-condensed; (2) water-soluble Preparation method of so-called alkoxysilane by sol-gel method, such as a preparation method in which hydrolyzate of alkoxysilane having a sulfonic acid group-containing hydrocarbon group and tetraalkoxysilane are mixed at an arbitrary ratio, hydrolyzed and co-condensed Also known is a preparation method by so-called silylation in which (3) alkoxysilane having a sulfonic acid group-containing hydrocarbon group is silylated to a silanol group present in the organic polymer siloxane to fix the sulfonic acid group.

  These organic polymer siloxanes are porous substances, and the pore distribution of the porous substances can be measured by a nitrogen adsorption method. In the present invention, an ASAP2000 measuring device manufactured by Micromeritics was used as the measuring device, and the surface area and the volume having a pore diameter of 9 to 500 mm and the volume of 20 to 500 mm were calculated from the pore distribution measurement results.

The specific surface area of 9 to 500 Å pores is as high as 500 to 1500 m ² / g, and what is important in the present invention is the pore volume of 9 to 500 細孔 pore diameter of the organic polymer siloxane that is this porous material. The present inventors have found that an organic polymer siloxane catalyst having a pore volume of 20 to 500 mm (mesoporous part) and having a pore volume of 0 to 20% is a catalyst having a long catalyst life in an olefin oligomerization reaction.

  Although it can be prepared by the following method as a method of reducing the existence ratio of the pore volume having a pore diameter of 20 to 500 mm (mesoporous part), the organic polymer siloxane used in the present invention is limited only to these preparation methods. It will never be done. An easy preparation method is to improve the yield of sulfonation when preparing a sulfonic acid group-containing hydrocarbon group, and further to improve the molar amount of tetraethoxysilane and alkoxy having a sulfonic acid group-containing hydrocarbon group. It can be prepared by adjusting the ratio to the “molar amount of silane”. Specifically, in the synthesis of an alkoxysilane having phenylsulfonic acid, an excess of 2.5 equivalents of sulfuric anhydride as a sulfonating agent is added to the raw material phenyltrichlorosilane to raise the reaction temperature and sulfonate. Further, an alkoxylated product with alcohol is used as a raw material for preparing a sol-gel. Although it does not specifically limit as alcohol, Preferably the alcohol which has a linear saturated carbon which has a C1-C5 alkyl group is mention | raise | lifted. As a method for preparing a sol-gel of an organic polymer siloxane, the above-described alkoxysilane having a sulfonic acid group-containing hydrocarbon group and tetraethoxysilane are mixed, and ethanol or the like is used as a uniform mixed solvent. At this time, it is important that “molar amount of alkoxysilane having a sulfonic acid group-containing hydrocarbon group”: “molar amount of tetraethoxysilane” is 1: 3-7. After adding 1 equivalent of water to the amount of hydrolyzable groups, the mixture is heated and stirred and concentrated under acidic conditions. The obtained high-viscosity liquid is generally called silica sol. To the silica sol described above, excess water, aqueous ammonia and the like are added with respect to the amount of hydrolyzable groups, and gelled under basic conditions. Moreover, if necessary at this time, it can be heated and aged for a long time. The resulting gel can be isolated by distilling off the solvent. In this gel, since sulfonic acid is in an ammonium salt form, it is necessary to return it to an acid form by acid treatment in order to use it as a solid acid catalyst.

  In the production method of the present invention, as the raw material olefin, ethylene, propylene, butenes (isobutene, 1-butene, trans-2-butene, cis-2-butene), pentenes, hexenes, etc. are used alone or Can be used as a mixture. Moreover, the C4 fraction (BB fraction) produced | generated by the naphtha decomposition | disassembly can be used, and also the spent-BB fraction which extracted the butadiene from the BB fraction can also be used. Although reaction temperature changes with the usage-amount of a catalyst etc., -20-150 degreeC is suitable normally, Especially preferably, it is -15-140 degreeC. When the reaction temperature is -20 ° C or lower, the yield of butene polymer decreases. When the reaction temperature is 150 ° C. or higher, the pressure in the reaction tank is 3 Mpa or higher, and the apparatus becomes a complex high-pressure apparatus. The reaction pressure is usually 1 to 10 Mpa, preferably a pressure enabling a liquid phase reaction, and is carried out in the range of 1 to 5 Mpa. The reaction time varies depending on the amount of catalyst used, reaction temperature, etc., but usually 5 to 180 minutes is appropriate. The reaction may be performed with or without a solvent. When using a solvent, usually saturated hydrocarbons such as n-hexane and cyclohexane are used. The reaction system can be carried out by any known system such as a batch system or a continuous system. After completion of the reaction, the catalyst used in the present invention can be recovered by filtration and reused as it is. The production method of the present invention does not have the problem of corrosion of the reactor unlike the AlCl 3 method, and further, the reaction product does not need to be washed with alkali and water, so that the subsequent purification can be made very easy.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, this embodiment is merely an example, and the present invention is not limited thereto.
In addition, with respect to the pore volume having a pore diameter of 9 to 500 mm, the ratio of the pore volume having a pore diameter of 20 to 500 mm (mesoporous portion) is represented by the mesopore existence ratio (the value of the pore volume of 20 to 500 mm being 9 to 500 mm). The value is divided by the value of the pore volume.

  Moreover, the catalyst life evaluation was evaluated by repeatedly using the catalyst by a batch test. As a measure of the catalyst life at this time, the degree of reduction in the isobutene conversion rate from the initial stage to the final round of the repeated reaction test is expressed as deterioration rate {deterioration rate (%) = (initial conversion rate−final conversion rate) ÷ initial conversion rate × 100. } And used as a measure of catalyst life.

[Example 1]
An organic polymer siloxane catalyst was prepared according to the examples of JP-A-2004-190021.

(1) Synthesis of sulfonic acid group-containing alkoxysilane 100 ml of methylene chloride was placed in a two-necked 300 ml round bottom flask equipped with a dropping funnel, and 39.1 g (0.19 mol) of phenyltrichlorosilane was added thereto, and the mixture was ice-cooled. . To this, 20 ml of a methylene chloride solution containing 37.3 g (0.47 mol) of anhydrous sulfuric acid was added dropwise over 1 hour. After dripping, the external temperature was set to 60 ° C., and the reaction was carried out for 2 hours under reflux to carry out sulfonation reaction. Next, 46.0 g of ethanol was added dropwise over 1 hour while removing hydrogen chloride at an external temperature of 60 ° C., and then the external temperature was raised to 100 ° C. to distill off methylene chloride. Further, 46.0 g of ethanol was added dropwise and refluxed at an external temperature of 100 ° C. for 2 hours to carry out an ethoxylation reaction. 162.7 g of the obtained sulfonic acid group-containing ethoxysilane ethanol solution containing impurities was used as a raw material for the sulfonic acid component in the preparation of a sol-gel of an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group. At this time, sulfonic acid group-containing alkoxysilane and tetraethoxysilane are mixed at an arbitrary ratio to prepare an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group by sol-gel preparation, and the solid acid amount is measured. . The sulfonation yield (yield of the produced sulfonic acid group-containing ethoxysilane with respect to the charged phenyltrichlorosilane) was determined from the concentration of the sulfonic acid group-containing alkoxysilane obtained from the obtained acid amount. The sulfonation yield with the sulfonic acid group-containing alkoxysilane was 70%.

(2) Preparation of Catalyst A 138.0 g (0.11 mol) of the sulfonic acid group-containing alkoxysilane and 119.0 g (0.57 mol) of tetraethoxysilane were added to a 1000 ml round bottom flask equipped with a stirring rod. ), 100 ml of ethanol was added and mixed. To this, 24.0 g of water was added dropwise over 15 minutes and stirred at 60 ° C. for 3 hours. After allowing to cool, 120.0 g of water was added dropwise over 1 minute, and when 35 ml of 28% aqueous ammonia was added dropwise, the reaction solution rapidly solidified. This was allowed to stand at room temperature for 4 hours and then aged at 60 ° C. for 3 days. After aging, the solvent was distilled off at 100 ° C. under a reduced pressure of 10 mmHg to obtain a dry solid. Subsequently, the operation of adding 300 ml of 2N hydrochloric acid and stirring for 30 minutes at room temperature was repeated twice to return the sulfonic acid group to the H ⁺ type. After the acid treatment, it was washed with 500 ml of ion-exchanged water and dried at 100 ° C. under a reduced pressure of 10 mmHg for 10 hours. As a result of the above operation, 55.1 g of an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group was obtained as Catalyst A. When this solid acid amount was measured, it was 1.42 meq / g. In addition, the specific surface area measured by the nitrogen gas adsorption method was 464 m ² / g, the pore volume of pore diameter 9 to 500 mm was 0.21 cc / g, and the presence of pores was not observed at pore diameters 20 to 500 mm, and the mesopore The existence ratio was 0%.

(3) Oligomerization reaction of isobutene In a stainless steel reactor with an internal volume of 100 cc, 500 mg of the catalyst A, 14.00 g of n-hexane as a solvent, and 5.10 g of isobutene (manufactured by Aldrich) as a raw material olefin were charged and stirred at 100 rpm. And reacted at 100 ° C. for 1 hour. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. As shown in Table 1, the decrease in catalytic activity during the process of repeatedly using the catalyst was largely suppressed.

[Comparative Example 1]
(1) Preparation of catalyst B Mol. Cat1. , 43, 41 (1987), an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group was prepared. 72.0 g (0.30 mol) of phenyltriethoxysilane, 145.6 g (0.70 mol) of tetraethoxysilane, and 125 ml of ethanol were mixed in a two-neck 1000 ml round bottom flask equipped with a stir bar. To this was added dropwise 35 ml of 0.01N hydrochloric acid, and the mixture was heated and stirred until the volume of the mixed solution reached 120 ml. After allowing to cool, 60 ml of ethanol and 90 ml of cyclohexane were added and mixed. Subsequently, 270 g of water was added dropwise, and 50 ml of aqueous ammonia was further added dropwise. This was stirred at room temperature for 4 hours and then filtered off. Subsequently, it was washed with water and dried at 120 ° C. under reduced pressure to obtain 80.0 g of an organic polymer siloxane having a phenyl group. In a 500 ml two-necked round bottom flask, 10.0 g of the organic polymer siloxane having a phenyl group obtained above and 200 ml of a mixed solution of chlorosulfonic acid: chloroform = 1: 4 at a molar ratio were mixed. Sulfonation was performed for a period of time to obtain 8.5 g of an organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group. When this solid acid amount was measured, it was 1.10 meq / g. Moreover, the specific surface area measured by the nitrogen gas adsorption method is 772 m ² / g, the pore volume of pore diameter 9 to 500 mm is 0.21 cc / g, and the pore volume of pore diameter 20 to 500 mm is 0.06 cc / g. The mesopore existence ratio was 30%.

(2) Isobutene oligomerization Into a stainless steel reactor having an internal volume of 100 cc, 500 mg of the catalyst B, 14.00 g of n-hexane as a solvent, and 5.10 g of isobutene (manufactured by Aldrich) as a raw material olefin were charged, and stirred at 100 rpm. The reaction was performed at 100 ° C. for 1 hour. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. The results are shown in Table 1.

[Comparative Example 2]
(1) Oligomerization of isobutene In a stainless steel reactor with an internal volume of 100 cc, 500 mg of Y-type zeolite (Tosoh: HSZ-331HSA), 14.00 g of n-hexane as a solvent, and isobutene as a raw material olefin (manufactured by Aldrich) 10 g was charged and reacted at 100 ° C. for 1 hour under stirring at 100 rpm. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. The results are shown in Table 1.

[Example 2]
(1) Oligomerization reaction of isobutene In a 100 cc stainless steel reactor, 150 mg of catalyst A used in Example 1, 14.00 g of n-hexane as a solvent, and 12.90 g of isobutene (manufactured by Aldrich) as a raw material olefin were charged. The mixture was reacted at 150 ° C. for 3 hours under 100 rpm stirring. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. As a result, as shown in Table 2, as a result of using the catalyst repeatedly, the rate of decrease in the catalyst activity during the repetition test was small.

[Comparative Example 3]
(1) Preparation of catalyst C According to Example 3 of JP-A-57-102825, a silica-supported catalyst supporting about 40% by weight of a heteropolyacid, catalyst C, was prepared. To a 1000 ml beaker, 75 g of a 40% aqueous solution of tungstophosphoric acid, 50 g of silica gel (Aerosil 300) and 50 g of water were added and mixed on an oil bath at 100 ° C., and the water was evaporated. For 4 hours.

(2) Oligomerization of isobutene In a stainless steel reactor with an internal volume of 100 cc, 150 mg of the above catalyst C, 14.00 g of n-hexane as a solvent, and 12.90 g of isobutene (manufactured by Aldrich) as a raw material olefin were charged and stirred at 100 rpm. The reaction was carried out at 150 ° C. for 1 hour. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. The results are shown in Table 2.

[Example 3]
(1) Oligomerization reaction of isobutene In a stainless steel reactor having an internal volume of 100 cc, 250 mg of catalyst A used in Example 1, 14.00 g of n-hexane as a solvent, and 12.90 g of isobutene (manufactured by Aldrich) as a raw material olefin were charged. The reaction was carried out at 100 ° C. for 3 hours under stirring at 100 rpm. After completion of the reaction, the reaction solution was cooled with ice and released, and then the reaction solution was recovered and separated from the catalyst, and then analyzed by gas chromatography. The recovered catalyst was charged again into the reactor, and the same test was repeated. As shown in Table 3, the catalyst was used repeatedly as shown in Table 3, but there was almost no decrease in the catalyst activity.

According to the method of the present invention, an olefin oligomer can be produced continuously for a long period of time, and even if the solid acid catalyst is repeatedly used, there is no decrease in activity and selectivity, which is extremely useful industrially.

Claims (2)

An organic polymer siloxane having a sulfonic acid group-containing hydrocarbon group having a pore volume ratio of 0 to 20% in a mesoporous part having a pore diameter of 20 to 500 to a pore volume of 9 to 500 mm, The manufacturing method of the olefin oligomer characterized by making an olefin contact the said catalyst. The process according to claim 1, wherein the olefin is a butene containing at least one of isobutene, 1-butene, trans-2-butene, and cis-2-butene.