JP2014177423A - METHOD FOR PRODUCING α-OLEFIN LOW POLYMER - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-term continuous operation method in a production process of an α-olefin low polymer.SOLUTION: In a method for producing an α-olefin low polymer by performing a low polymerization reaction of an α-olefin in a reaction solvent in the presence of a catalyst in a reactor, a portion of gas of a gas phase part in the reactor is introduced into a heat exchanger, and when a condensate and a non-condensable gas, obtained from an outlet of the heat exchanger, and the reaction solvent, obtained by separating a reaction solution obtained from an outlet of the reactor, are circulation supplied to the reactor, the condensate and/or the reaction solvent are atomized and supplied to the gas phase part of the reactor, and the non-condensable gas is supplied to a liquid phase part of the reactor.

Description

  The present invention relates to a method for producing an α-olefin low polymer.

Conventionally, a method for producing an α-olefin low polymer using an α-olefin such as ethylene as a raw material has been reported.
For example, Patent Document 1 describes a production method in which an α-olefin low polymer mainly composed of 1-hexene is obtained with high yield and high selectivity using a chromium-based catalyst.
Conventionally, the low polymerization reaction for obtaining an α-olefin low polymer mainly composed of 1-hexene is generally an exothermic reaction, and thus the reaction is performed while removing the heat of reaction generated in the reactor. Various industrial methods capable of continuously producing an α-olefin low polymer have been studied.

  In Patent Document 2, in the production method of ethylene into an α-olefin oligomer having an average molecular weight of 50 to 350 in the presence of a catalyst, a gas phase gas in a reactor is used as a refrigerant, Condenser that is not in direct contact with the reactor, cools part of the gas in the gas phase in the reactor, removes heat using the condensed liquid, and prevents contamination of the heat exchanger that removes the heat of polymerization It is described to do.

Furthermore, in Patent Document 3, in the method for producing an α-olefin low polymer, the gas in the reactor is introduced into the heat exchanger, and the condensate obtained from the outlet of the heat exchanger and the gas are supplied to the reactor. A method of circulation is described, and in order to suppress entrainment of the reaction liquid in the gas phase portion, it is described that the gas linear velocity in the gas phase portion in the reactor is controlled within a predetermined range.
In Patent Document 4, when an α-olefin low polymer such as 1-hexene is produced by oligomerizing ethylene in the presence of an organic solvent and a homogeneous catalyst in a reactor, propylene or the like is added to the top of the reactor. A method of cooling the inside of a reactor using a coolant is described, and in order to improve the internal cooling cycle, a condenser is used and the top temperature of the reactor is about 15 ° C. to about 20 ° C. Things are described.

  Patent Document 5 describes that when hydrocarbon is oligomerized, liquefied hydrocarbon (α-olefin) is supplied from the bottom of the reactor liquid phase, and Patent Document 6 describes liquefied hydrocarbon and liquefied evaporability. Is supplied from the bottom of the reactor liquid phase.

Japanese Patent Laid-Open No. 08-239419 Japanese translation of publication No. 2006-500412 JP 2009-120588 A Special table 2009-503155 International Publication No. 09/060342 Pamphlet International Publication No. 09/060343 Pamphlet

In general, in a reaction for obtaining an α-olefin low polymer using an α-olefin such as ethylene as a raw material, dirt substances such as a by-product polymer and a deactivation catalyst are present in the reaction solution. A method of cooling and condensing the gas phase in the reactor in which a very small amount of contaminants such as biopolymers and deactivated catalyst is cooled by a heat exchanger (condenser) and circulating the condensed liquid and non-condensed gas to the reactor is preferable.

However, in this method, since bubbles burst at the gas-liquid interface of the reactor, mist of the reaction solution is generated in the reactor gas phase. The mist reaches the heat exchanger (condenser) at the outlet of the reactor together with the gas due to entrainment of droplets, contaminates the inlet portion of the cooling transmission surface of the condenser, and has a problem of hindering long-term stable operation.
The present invention has been made to solve the above-described problems in the method for producing a low polymer of α-olefin. That is, an object of the present invention is to provide a method for producing an α-olefin low polymer capable of long-term stable operation.

Therefore, as a result of intensive studies to solve the above problems, the present inventor supplies atomized cooling liquid to the gas phase portion of the reactor to cool the gas in the gas phase portion in the reactor. Thus, it was found that long-term stable operation is possible without the condenser's cooling transmission surface becoming dirty.
That is, the gist of the present invention resides in the following [1] to [8].
[1] In a method for producing an α-olefin low polymer by performing a low polymerization reaction of α-olefin in a reaction solvent in a reaction solvent in the presence of a catalyst, a part of gas in a gas phase portion in the reactor Is introduced into the heat exchanger, and the condensate obtained from the outlet of the heat exchanger, the non-condensed gas, and the reaction solvent obtained by separating the reaction liquid obtained from the outlet of the reactor are circulated and supplied to the reactor. The condensate and / or the reaction solvent is atomized and supplied to the gas phase part of the reactor, and the non-condensable gas is supplied to the liquid phase part of the reactor. A method for producing a polymer.
[2] The reaction solvent obtained by separating the condensate obtained from the outlet of the heat exchanger and / or the reaction liquid obtained from the outlet of the reactor is atomized by a sprayer [1] ] The manufacturing method of the alpha-olefin low polymer of description.
[3] The atomization method of the sprayer is one or more methods selected from the group consisting of a centrifugal force method, a shear force method, and a pressure method, according to [1] or [2] Of producing an α-olefin low polymer.
[4] The method for producing an α-olefin low polymer according to any one of [1] to [3], wherein a gas phase part gas outlet temperature of the reactor is 10 ° C. or more lower than a liquid phase temperature. .
[5] A part of the non-condensable gas obtained from the outlet of the heat exchanger is introduced into a gas-liquid separator,
The method for producing an α-olefin low polymer according to any one of [1] to [4], further comprising a step of separating into a condensate and a non-condensable gas.
[6] Any one of [1] to [5], wherein the catalyst is composed of a combination of a chromium compound (a), a nitrogen-containing compound (b), and an aluminum-containing compound (c). The manufacturing method of the alpha-olefin low polymer of description.
[7] The method for producing an α-olefin low polymer as described in [6], wherein the catalyst further has a halogen-containing compound (d).
[8] The method for producing an α-olefin low polymer according to any one of [1] to [7], wherein the α-olefin is ethylene.

  According to the present invention, long-term stable operation in the production process of an α-olefin low polymer is possible.

It is a manufacturing flow figure showing one form of the manufacturing method of the alpha olefin low polymer of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. The drawings used are for explaining the present embodiment and do not represent the actual size.
[Α-olefin]
In the method for producing an α-olefin low polymer of the present invention, examples of the α-olefin used as a raw material include substituted or unsubstituted α-olefins having 2 to 30 carbon atoms. Specific examples of such α-olefins include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene and the like. Among these, ethylene is suitable as the α-olefin of the raw material of the present invention. When ethylene is used as the raw material, 1-hexene, which is a trimer of ethylene, can be obtained with high yield and high selectivity.

  Moreover, when using ethylene as a raw material, impurity components other than ethylene may be included in the raw material. Specific components include methane, ethane, nitrogen, oxygen, water, acetylene, carbon dioxide, carbon monoxide, hydrogen sulfide and the like. For methane, ethane, and nitrogen, 0.1 mol% or less with respect to the starting ethylene, and for sulfur components such as oxygen, water, acetylene, carbon dioxide, carbon monoxide, hydrogen sulfide, etc., 1 molppm or less with respect to the starting ethylene It is preferable that

[catalyst]
The catalyst used in the present invention is not particularly limited as long as it is a catalyst capable of producing a α-olefin low polymer by low polymerization reaction of the raw material α-olefin, but is preferably a catalyst having an aluminum-containing compound.
Furthermore, it is more desirable that the transition metal-containing compound, the nitrogen atom-containing compound, and the aluminum-containing compound are used as constituent components of the catalyst, and the chromium-based catalyst is composed of components derived from those compounds. Moreover, it is more preferable to contain a halogen-containing compound as a constituent component of the catalyst from the viewpoint of improving the catalytic activity and the selectivity of the target α-olefin low polymer.

[Transition metal-containing compounds]
The metal contained in the transition metal-containing compound suitably used as a constituent component of the catalyst of the present invention is not particularly limited as long as it is a transition metal, but among them, transition metals of Groups 4 to 6 of the periodic table are preferably used. . Specifically, it is preferably at least one metal selected from the group consisting of chromium, titanium, zirconium, vanadium and hafnium, more preferably chromium or titanium, and most preferably chromium.

  The transition metal-containing compound is one or more compounds represented by the general formula MeZn. Here, in the general formula, Me is a transition metal element, Z is any organic group, inorganic group, or negative atom, n is an integer of 1 to 6, and 2 or more is preferable. When n is 2 or more, Z may be the same or different from each other. The organic group may be a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, and specifically includes a carbonyl group, an alkoxy group, a carboxyl group, a β-diketonate group, a β-keto. Examples include a carboxyl group, a β-ketoester group, an amide group, and the like. In addition, examples of the inorganic group include metal salt forming groups such as a nitrate group and a sulfate group. Examples of negative atoms include oxygen and halogen. In addition, the transition metal containing compound containing a halogen is not contained in the halogen containing compound mentioned later.

In the case of a transition metal-containing compound whose transition metal is chromium (hereinafter sometimes referred to as a chromium-containing compound), specific examples include chromium (IV) -tert-butoxide, chromium (III) acetylacetonate, chromium (III ) Trifluoroacetylacetonate, chromium (III) hexafluoroacetylacetonate, chromium (III) (2,2,6,6-tetramethyl-3,5-heptanedionate), Cr (PhCOCHCOPh) ₃ (where Ph represents a phenyl group.), Chromium (II) acetate, chromium (III) acetate, chromium (III) 2-ethylhexanoate, chromium (III) benzoate, chromium (III) naphthenate, chromium (III) _{heptanoate, Cr (CH 3 COCHCOOCH 3)} 3, a first chromium chloride, chromic chloride, bromide first click Arm, bromide chromic, first chromium iodide, chromic iodide, first chromium fluoride, and the second chromium fluoride.

In the case of a transition metal-containing compound in which the transition metal is titanium (hereinafter sometimes referred to as a titanium-containing compound), specific examples include TiCl ₄ , TiBr ₄ , TiI ₄ , TiBrCl ₃ , TiBr ₂ Cl ₂ , Ti (OC _{2 H 5) 4, Ti (} OC 2 H 5) 2 Cl 2, Ti (O-n-C 3 H 7) 4, Ti (O-n-C 3 H 7) 2 Cl 2, Ti (O-iso -C ₃ H _{7) 4,
Ti (O-iso-C 3} H 7) 2 Cl 2, Ti (O-n-C 4 H 9) 4, Ti (O-n-C 4 H 9) 2 Cl 2, Ti (O-iso-C _{4 H 9) 4, Ti (} O-iso-C 4 H 9) 2 Cl 2, Ti (O-tert-C 4 H 9) 4, Ti (O-tert-C 4 H 9) 2 Cl 2, TiCl ₄ (thf) ₂ (wherein thf represents tetrahydrofuran), Ti ((CH ₃ ) ₂ N) ₄ , Ti ((C ₂ H ₅ ) ₂ N) ₄ , Ti ((n-C ₃ H ₇ ) ₂ N) ₄ , Ti ((iso-C ₃ H ₇ ) ₂ N) ₄ , Ti ((n-C ₄ H ₉ ) ₂ N) ₄ , Ti ((tert-C ₄ H ₉ ) ₂ N) ₄ , Ti (OSO ₃ CH ₃ ) ₄ , Ti (OSO ₃ C ₂ H ₅ ) ₄ , Ti (OSO ₃ C ₃ H ₇ ) ₄ , Ti (OSO ₃ C ₄ H ₉ ) ₄ , TiCp ₂ Cl ₂ , T
iCp ₂ ClBr, Ti (OCOC ₂ H ₅ ) ₄ , Ti (OCOC ₂ H ₅ ) ₂ Cl ₂ , Ti (OCOC ₃ H ₇ ) ₄ , Ti (OCOC ₃ H ₇ ) ₂ Cl ₂ , Ti (OCOC ₃ H ₇ ) ₄ , Ti (OCOC ₃ H ₇ ) ₂ Cl ₂ , Ti (OCOC ₄ H ₉ ) ₄ , Ti (OCOC ₄ H ₉ ) ₂ Cl _{2 and the} like.

In the case of a transition metal-containing compound in which the transition metal is zirconium (hereinafter, sometimes referred to as a zirconium-containing compound), specific examples include ZrCl ₄ , ZrBr ₄ , ZrI ₄ , ZrBrCl ₃ , ZrBr ₂ Cl ₂ , Zr (OC _{2 H 5) 4, Zr (} OC 2 H 5) 2 Cl 2, Zr (O-n-C 3 H 7) 4, Zr (O-n-C 3 H 7) 2 Cl 2, Zr (O-iso _{-C 3 H 7) 4, Zr} (O-iso-C 3 H 7) 2 Cl 2, Zr (O-n-C 4 H 9) 4, Zr (O-n-C 4 H 9) 2 Cl 2 , Zr (O-iso-C ₄ H ₉ ) ₄ , Zr (O-iso-C ₄ H ₉ ) ₂ Cl ₂ , Zr (O-tert-C ₄ H ₉ ) ₄ , Zr (O-tert-C ₄ H ₉ ) ₂ Cl ₂ , Zr ((CH ₃ ) ₂ N) ₄ , Zr ((C ₂ H ₅ ) ₂ N) ₄ , Zr ((n
_{-C 3 H 7) 2 N)} 4, Zr ((iso-C 3 H 7) 2 N) 4, Zr ((n-C 4 H 9) 2 N) 4, Zr ((tert-C 4 H 9 ) ₂ N) ₄ , Zr (OSO ₃ CH ₃ ) ₄ , Zr (OSO ₃ C ₂ H ₅ ) ₄ , Zr (OSO ₃ C ₃ H ₇ ) ₄ , Zr (OSO ₃ C ₄ H ₉ ) ₄ , Zr
Cp ₂ Cl ₂ , ZrCp ₂ ClBr, Zr (OCOC ₂ H ₅ ) ₄ , Zr (OCOC ₂ H ₅ ) ₂ Cl ₂ , Zr (OCOC ₃ H ₇ ) ₄ , Zr (OCOC ₃ H ₇ ) ₂ Cl ₂ , Zr (OCOC ₃ H ₇ ) ₄ , Zr (OCOC ₃ H ₇ ) ₂ Cl ₂ , Zr (OCOC ₄ H ₉ ) ₄ , Zr (
OCOC ₄ H ₉ ) ₂ Cl ₂ , ZrCl ₂ (HCOCFCOF) ₂ , ZrCl ₂ (CH ₃ C
OCFCOCH ₃ ) _{2 and the} like.

In the case of a transition metal-containing compound whose transition metal is hafnium (hereinafter sometimes referred to as a hafnium-containing compound), a specific example is dimethylsilylene bis {1- (2-methyl-4-isopropyl-4H-azurenyl)}. Hafnium dichloride, dimethylsilylenebis {1- (2-methyl-4-phenyl-4H-azurenyl)} hafnium dichloride, dimethylsilylenebis [1- {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] Hafnium dichloride, dimethylsilylenebis [1- {2-methyl-4- (4-fluorophenyl) -4H-azurenyl}] hafnium dichloride, dimethylsilylenebis [1- {2-methyl-4- (3-chlorophenyl)- 4H-azulenyl}] hafnium dichloride, dimethylsilylene bis [1 {2-methyl-4- (2,6-dimethylphenyl) -4
H-azurenyl}] hafnium dichloride, dimethylsilylenebis {1- (2-methyl-4,6-diisopropyl-4H-azurenyl)} hafnium dichloride, diphenylsilylenebis {1- (2-methyl-4-phenyl-4H- Azulenyl)} hafnium dichloride, methylphenylsilylenebis {1- (2-methyl-4-phenyl-4H-azurenyl)} hafnium dichloride, methylphenylsilylenebis [1- {2-methyl-4- (1-naphthyl)- 4H-azulenyl}] hafnium dichloride, dimethylsilylenebis {1- (2-ethyl-4-phenyl-4H-azurenyl)} hafnium dichloride, dimethylsilylenebis [1- {2-ethyl-4- (1-anthracenyl)- 4H-azulenyl}] hafnium dichloride, dimethyl Lucylylenebis [1- {2-ethyl-4- (2-anthracenyl) -4H-azurenyl}] hafnium dichloride, dimethylsilylenebis [1- {2-ethyl-4- (9-phenanthryl) -4H-azulenyl}] hafnium Dichloride, dimethylmethylenebis [1- {2-methyl-4- (4-biphenylyl) -4H-azurenyl}] hafnium dichloride, dimethylgermylenebis [1- {2-methyl-4- (4-biphenylyl) -4H -Azulenyl}] hafnium dichloride, dimethylsilylenebis {1- (2-ethyl-4- (3,5-dimethyl-4-trimethylsilylphenyl-4H-azurenyl)} hafnium dichloride, dimethylsilylene-2 [1- {2-methyl -4- (4-biphenylyl) -4H-azurenyl}] [1- {2- Til-4- (4-biphenylyl) indenyl}] hafnium dichloride, dimethylsilylene {1- (2-ethyl-4-phenyl-4H-azulenyl)} {1- (2-methyl-4,5-benzoindenyl) } Hafnium dichloride, dimethylsilylene bis {1- (2-methyl-4-phenylindenyl)} hafnium dichloride, dimethylsilylene bis {1- (2-methyl-4,5-benzoindenyl)} hafnium dichloride, dimethylsilylene And bis [1- {2-methyl-4- (1-naphthyl) indenyl}] hafnium dichloride.
Among these transition metal-containing compounds, chromium-containing compounds are preferable, and among chromium-containing compounds, chromium (III) 2-ethylhexanoate is particularly preferable.

[Nitrogen-containing compounds]
In the present invention, the nitrogen-containing compound suitably used as a constituent component of the catalyst is not particularly limited, and examples thereof include amines, amides, and imides.

Examples of amines include pyrrole compounds. Specific examples include pyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, 2,5-diethylpyrrole, 2,4-diethylpyrrole, 2,5. -Di-n-propyl pyrrole, 2,5-di-n-butyl pyrrole, 2,5-di-n-pentyl pyrrole, 2,5-di-n-hexyl pyrrole, 2,5-dibenzyl pyrrole, 2 , 5-diisopropylpyrrole, 2-methyl-5-ethylpyrrole, 2,5-dimethyl-3-ethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5-tetrachloro Pyrrole such as pyrrole, 2-acetylpyrrole, indole, 2-methylindole, dipyrrole in which two pyrrole rings are bonded via a substituent, or derivatives thereof Body, and the like. Examples of the derivatives include metal pyrolide derivatives, and specific examples include, for example, diethylaluminum pyrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, diethylaluminum (2,5-dimethylpyrrolide), ethylaluminum. Bis (2,5-dimethyl pyrolide), aluminum tris (2,5-dimethyl pyrolide), diethyl aluminum (2,5-diethyl pyrolide), ethyl aluminum bis (2,5-diethyl pyrolide), aluminum tris Aluminum pyrolides such as (2,5-diethyl pyrolide), sodium pyrolide, sodium pyrolides such as sodium (2,5-dimethyl pyrolide), lithium pyrolide, lithium (2,5-dimethyl pyrolide) ) Etc. Umupiroraido acids, potassium pyrrolide, potassium (2,5-dimethyl pyrrolide) potassium pyrrolide such like. Aluminum pyrolides are not included in the above-mentioned aluminum-containing compound. Moreover, the pyrrole compound containing a halogen is not contained in the above-mentioned halogen-containing compound.

Examples of amides include, for example, acetamide, N-methylhexaneamide, succinamide, maleamide, N-methylbenzamide, imidazole-2-carboxamide, di-2-thenoylamine, β-lactam, δ-lactam, ε-caprolactam or Examples thereof include salts of these with metals of Group 1, 2 or 13 of the periodic table.
Examples of the imides include 1,2-cyclohexanedicarboximide, succinimide, phthalimide, maleimide, 2,4,6-piperidinetrione, perhydroazesin-2,10-dione, and 1 of the periodic table, And salts with Group 2 or 13 metals. Examples of the sulfonamides and sulfonamides include, for example, benzenesulfonamide, N-methylmethanesulfonamide, N-methyltrifluoromethylsulfonamide, and salts thereof with a metal of Groups 1 to 2 or 13 in the periodic table. Is mentioned. These compounds may be used as a single compound or a plurality of compounds.
In the present invention, among these, amines are preferable, among which pyrrole compounds are more preferable, and 2,5-dimethylpyrrole or diethylaluminum (2,5-dimethylpyrrolide) is particularly preferable.

[Aluminum-containing compounds]
The aluminum-containing compound suitably used as the catalyst component of the present invention is not particularly limited, and examples thereof include a trialkylaluminum compound, a halogenated alkylaluminum compound, an alkoxyalkylaluminum compound, and an alkylaluminum hydride compound. Examples of the trialkylaluminum compound include trimethylaluminum, triethylaluminum, and triisobutylaluminum. Specific examples of the halogenated alkylaluminum compound include diethylaluminum monochloride, ethylaluminum sesquichloride, and ethylaluminum dichloride. Specific examples of the alkoxyaluminum compound include diethylaluminum ethoxide. Specific examples of the alkylaluminum hydride compound include diethylaluminum hydride. Among these, trialkylaluminum compounds are preferable, and triethylaluminum is more preferable. These compounds may be used as a single compound or as a mixture of a plurality of compounds.

[Halogen-containing compounds]
As a constituent component of the catalyst of the present invention, it is preferable to further contain a halogen-containing compound in addition to the above-described components. The halogen-containing compound is not particularly limited, but is a halogenated alkylaluminum compound, a benzyl chloride skeleton-containing compound, a linear halogenated hydrocarbon having 1 or more carbon atoms having 3 or more halogen atoms, and 3 or more halogens. One or more compounds of a cyclic halogenated hydrocarbon having 3 or more carbon atoms having an atom are included (the halogenated alkylaluminum compound is not included in the aluminum-containing compound). For example, diethylaluminum chloride, ethylaluminum sesquichloride, benzyl chloride, (1-chloroethyl) benzene, 2-methylbenzyl chloride, 3-methylbenzyl chloride, 4-methylbenzyl chloride, 4-ethylbenzyl chloride, 4-isopropylbenzyl chloride 4-tert-butylbenzyl chloride, 4-vinylbenzyl chloride, α-ethyl-4-methylbenzyl chloride, α, α′-dichloro-o-xylene, α, α′-dichloro-m-xylene, α, α '-Dichloro-p-xylene, 2,4-dimethylbenzyl chloride, 2,5-dimethylbenzyl chloride, 2,6-dimethylbenzyl chloride, 3,4-dimethylbenzyl chloride, 2,3,5,6-tetramethyl Benzyl chloride, 1- (chloromethyl) ) Naphthalene, 1- (chloromethyl) -2-methylnaphthalene, 1,4-bis-chloromethyl-2,3-dimethylnaphthalene, 1,8-bis-chloromethyl-2,3,4,5,6 7-hexamethylnaphthalene, 9- (chloromethyl) anthracene, 9,10-bis (chloromethyl) anthracene, 7- (chloromethyl) benzanthracene, 7-chloromethyl-12-methylbenzanthracene, carbon tetrachloride, 1 , 1,1-trichloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,2,3-trichlorocyclopropane, 1,2,3,4,5,6-hexachlorocyclohexane, , 4-bis (trichloromethyl) -2,3,5,6-tetrachlorobenzene and the like.

  In the present invention, the ratio of each component of the transition metal-containing compound (a), the nitrogen-containing compound (b), the aluminum-containing compound (c), and the halogen-containing compound (d), which are catalyst components preferably used as a catalyst, Although it is not particularly limited, it is usually 1 mol to 50 mol, preferably 2 mol to 30 mol, and 1 mol of the aluminum-containing compound (c) with respect to 1 mol of the transition metal-containing compound (a). -200 mol, preferably 10 mol-150 mol. Alternatively, when the halogen-containing compound (d) is included, the halogen-containing compound (d) is 1 to 50 mol, preferably 2 to 30 mol, per 1 mol of the transition metal-containing compound (a).

In the present invention, the amount of the catalyst used is not particularly limited, but is usually 1.0 × 10 ⁻⁷ mol to 0.5 mol in terms of transition metal element of the transition metal-containing compound (a) per liter of the solvent described later. The amount is preferably 5.0 × 10 ⁻⁷ mol to 0.2 mol, more preferably 1.0 × 10 ⁻⁶ mol to 0.05 mol.
In the present invention, when ethylene is used as the α-olefin, the low polymerization of ethylene brings ethylene and the chromium-based catalyst into contact with each other in such a manner that the transition metal-containing compound (a) and the aluminum-containing compound (c) do not contact with each other in advance. Is preferred.

According to the contact mode as described above, ethylene trimerization reaction can be selectively performed to obtain 1-hexene which is a trimer of ethylene with a selectivity of 90% or more from ethylene as a raw material. Further, in this case, the ratio of 1-hexene to hexene can be 99% or more.
Here, the “a mode in which the transition metal-containing compound (a) and the aluminum-containing compound (c) do not contact with each other in advance” is not limited to the start of the low polymerization reaction of ethylene, and the additional ethylene and catalyst components thereafter This also means that such a mode is maintained in the supply to the reactor. Moreover, it is desirable to use the same aspect also about a batch reaction format.

The following (1)-(9) are mentioned as a contact aspect in said continuous reaction form.
(1) A method in which a mixture of catalyst components (a), (b) and (d) and catalyst component (c) are simultaneously introduced into a reactor.
(2) A method in which a mixture of the catalyst components (b) to (d) and the catalyst component (a) are simultaneously supplied to the reactor.
(3) A method in which the mixture of the catalyst components (a) and (b) and the mixture of the catalyst components (c) and (d) are simultaneously supplied to the reactor.
(4) A method in which a mixture of catalyst components (a) and (d) and a mixture of catalyst components (b) and (c) are simultaneously fed to the reactor.
(5) A method in which the mixture of the catalyst components (a) and (b), the catalyst component (c), and the catalyst component (d) are simultaneously supplied to the reactor.
(6) A method in which the mixture of the catalyst components (c) and (d), the catalyst component (a), and the catalyst component (b) are simultaneously supplied to the reactor.
(7) A method in which the mixture of the catalyst components (a) and (d), the catalyst component (b), and the catalyst component (c) are simultaneously supplied to the reactor.
(8) A method in which the mixture of the catalyst components (b) and (c), the catalyst component (a), and the catalyst component (d) are simultaneously supplied to the reactor.
(9) A method in which the catalyst components (a) to (d) are simultaneously and independently supplied to the reactor.
Each of the catalyst components described above is usually dissolved in a reaction solvent described later used for a low polymerization reaction of ethylene and supplied to the reactor.

[Reaction solvent]
In the method for producing an α-olefin low polymer of the present invention, the α-olefin low polymerization reaction can be carried out in a reaction solvent. Although it does not specifically limit as such a reaction solvent, A saturated hydrocarbon is used suitably, Preferably, for example, butane, pentane, 3-methylpentane, n-hexane, n-heptane, 2-methylhexane, octane , Cyclohexane, methylcyclohexane, 2,2,4-trimethylpentane, decalin and the like chain saturated hydrocarbons having 1 to 20 carbon atoms, or alicyclic saturated hydrocarbons having 1 to 20 carbon atoms. In addition, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, mesitylene, tetralin, and α-olefin low polymers produced by low polymerization reaction, specifically, for example, obtained when trimerizing ethylene. 1-hexene, decene, etc. can also be used. These can be used alone or as a mixed solvent.

Among these solvents, chain saturated hydrocarbons having 4 to 10 carbon atoms from the point that production or precipitation of by-products such as polyethylene can be suppressed, and that high catalytic activity tends to be obtained. Alternatively, it is preferable to use an alicyclic saturated hydrocarbon. Specifically, n-heptane or cyclohexane is preferable, and n-heptane is most preferable.
[Production method of α-olefin low polymer]
Next, as a method for producing an α-olefin low polymer of the present invention, a method for producing 1-hexene (ethylene trimer) using ethylene as a raw material as an α-olefin will be described as an example.

  FIG. 1 is a diagram for explaining an example of a manufacturing flow of 1-hexene in the present embodiment. In the production flow example 1 shown in FIG. 1, a fully mixed stirring reactor 10 for polymerizing ethylene in the presence of a chromium-based catalyst, and an ethylene gas in the reactor 10 and a vapor component vaporized from a liquid phase are cooled and condensed. A reflux condensing system 2 is provided as a main device.

  Furthermore, a degassing tank 20 for separating unreacted ethylene gas from the reaction liquid extracted from the reactor 10, an ethylene separation tower 30 for distilling off ethylene in the reaction liquid extracted from the degassing tank 20, A high boiling point separation column 40 for separating a high boiling point substance (hereinafter sometimes referred to as HB (high boiler)) in the reaction liquid extracted from the ethylene separation column 30, and from the top of the high boiling point separation column 40. A hexene separation column 50 for distilling the extracted reaction liquid and distilling 1-hexene is shown.

Further, a compressor 17 is provided for circulating unreacted ethylene separated in the degassing tank 20 and the condenser 16 to the reactor 10 through a circulation pipe 21.
In FIG. 1, the reactor 10 includes, for example, a well-known type equipped with a stirrer 10a, a baffle, a jacket, and the like. As the stirrer 10a, a stirring blade in the form of a paddle, a fiddler, a propeller, a turbine, or the like is used in combination with a baffle such as a flat plate, a cylinder, or a hairpin coil.

  As shown in FIG. 1, ethylene is continuously supplied to the reactor 10 from the ethylene supply pipe 12 a through the compressor 17 and the first supply pipe 12. On the other hand, the transition metal-containing compound (a) and the nitrogen-containing compound (b) are supplied from the second supply pipe 13 through the catalyst supply pipe 13a, and further the halogen-containing compound (d) is supplied from the second supply pipe 13 through the catalyst supply pipe 14. Is done. The aluminum-containing compound (c) is supplied from the third supply pipe 15. At this time, these catalyst components are preferably supplied to the liquid phase part in the reactor 10. A solvent used for the low polymerization reaction of ethylene is supplied from the second supply pipe 13 to the reactor 10.

In this Embodiment, the operating conditions of the reactor 10 are 80 degreeC-250 degreeC normally, Preferably they are 100 degreeC-200 degreeC, More preferably, they are 120 degreeC-170 degreeC. The reaction pressure is usually in the range of normal pressure to 250 kg / cm ² , preferably 5 to 150 kg / cm ² , more preferably 10 to 100 kg / cm ² .
Furthermore, in the present invention, the trimerization reaction of ethylene has a molar ratio of 1-hexene to ethylene in the reaction solution ((1-hexene in the reaction solution) / (ethylene in the reaction solution)) of 0.05 to 1. .5 is preferable, and it is particularly preferable to carry out so as to be 0.10 to 1.0. That is, in the case of a continuous reaction, the catalyst concentration, reaction pressure, and other conditions are adjusted so that the molar ratio of ethylene to 1-hexene in the reaction solution falls within the above range. The reaction is preferably stopped when the molar ratio is in the above range. By doing in this way, the byproduct of a component with a boiling point higher than 1-hexene is suppressed, and the selectivity of 1-hexene tends to be further increased.

Here, in this invention, it is preferable that the gas linear velocity of the gaseous-phase part in the reactor 10 is 0.1 cm / s-10.0 cm / s, and is 0.3 cm / s-5.0 cm / s. It is more preferable, and it is still more preferable that it is 0.5 cm / s-3.0 cm / s. By controlling the gas linear velocity of the gas phase part of the reactor 10 within the above range, the ethylene gas in the reactor 10 and the vapor component vaporized from the liquid phase are sent to the reflux condensing system 2 as described later. The entrainment of the reaction liquid tends to be suppressed. For this reason, the frequency which wash | cleans the inside of the heat exchanger 16a which supplied the washing | cleaning liquid inside the heat exchanger 16a using the spray nozzle, and was dirty under the influence of entrainment of the reaction liquid reduces. As the washing liquid, a reaction solvent obtained by separating the reaction liquid obtained from the outlet of the reactor is usually used, and the temperature of the washing liquid is usually 110 ° C. or higher, desirably 115 ° C. or higher. Further, the pressure at the time of washing is desirably low, and is usually 71 kg / cm ² or less, desirably 31 kg / cm ² or less, and more desirably 10 kg / cm ² or less.

(Reflux condensation system 2)
Next, the reflux condensation system 2 will be described.
In the method for producing an α-olefin low polymer of the present invention, the gas component of the gas phase portion of the reactor vaporized from the raw material α-olefin gas such as ethylene in the reactor 10 and / or the liquid phase in the reactor is added. By cooling and condensing and circulatingly supplying the resulting condensate into the reactor 10, the heat of polymerization generated by the low polymerization reaction is removed.

As shown in FIG. 1, the reflux condensing system 2 includes an ethylene gas introduced into the liquid phase of the reactor 10 and a heat exchanger 16a for cooling and condensing vaporized vapor from the liquid phase, and an outlet of the heat exchanger 16a. A part of the resulting condensate and non-condensed gas components are introduced to separate the condensate and gas components into a gas-liquid separator 20e, and the gas components separated in the gas-liquid separator 20e through the pipe 12 And a blower 17a to be introduced into the liquid phase of the reactor 10. Further, the condensate obtained from the outlet of the heat exchanger 16a and the condensate separated in the gas-liquid separator 20e are respectively supplied to the nebulizer 10b (FIG. 1) in the gas phase of the reactor 10 through the pipes 2b and 2d. , Described in a rotating disk spraying type sprayer) and atomized.

  Liquid atomization is the conversion of a large droplet into many small droplets. The advantage is that it can be uniformly distributed over a wide range by increasing the number of droplets, and heat transfer is promoted by increasing the surface area. A nebulizer is used for atomization, and examples of the atomization method of the atomizer include a centrifugal force method, a shear force method, and a pressure method.

Among the centrifugal methods, the rotating disk spray method is preferable. Of the pressure methods, the nozzle spray method is more preferable.
In the rotating disk spray method, the ratio of the diameter of the rotating disk to the diameter of the reactor is usually 0.2 to
0.8, preferably 0.3-0.6, more preferably 0.4-0.5, supplying liquid to the center of the disk rotating at high speed, and at the outer periphery of the disk by centrifugal force Atomize the liquid. A plurality of weirs may be provided along the radial direction of the disk. There are three types of nozzle spraying methods: 1) pressurized nozzle, 2) dual fluid nozzle, and 3) pressurized dual fluid nozzle.

In the pressurized nozzle spray method, a pressurized liquid is introduced into a swirl chamber called a core, and the liquid to which a swirl force is applied passes through an orifice and becomes a film to be atomized.
In the two-fluid nozzle spray method, atomization is performed by bringing a compressed gas into contact with a liquid and shearing. The pressurized two-fluid nozzle spraying method is a method that takes advantage of the characteristics of the above-mentioned two types of nozzles, and has a pressurized nozzle in the center, and promotes atomization by flowing a low-pressure assist gas from its surroundings. it can.

Here, as the heat exchanger 16a, a multitubular vertical or horizontal heat exchanger that is normally used for cooling the fluid to be condensed is used. These are known as general reflux condensers, and in the present embodiment, a vertical multitubular heat exchanger is preferable.
It does not specifically limit as a material which comprises the heat exchanger 16a, Carbon steel, copper, titanium alloy, SUS304, SUS316, SUS316L etc. which are known as a material which comprises a normal reflux condenser are mentioned, According to a process Are appropriately selected. The heat transfer area of the heat exchanger 16a is appropriately determined according to the degree of heat removal load, the load control method, and the like.

Next, the operation in the reflux condensing system 2 will be described.
The mixed gas of the ethylene gas introduced into the liquid phase part in the reactor 10 and the vaporized vapor in which a part of the liquid phase is vaporized by the polymerization heat generated by the low polymerization reaction of ethylene in the reactor 10 is sent through the pipe 2a. It is supplied to the heat exchanger 16a. The mixed gas supplied to the heat exchanger 16a is usually cooled and condensed to 100 ° C. or lower, preferably 80 ° C. or lower, more preferably 70 ° C. or lower by cooling water (not shown), and the condensate is pipe 2b. Is again circulated and supplied to the reactor 10. A part of the gas component obtained from the outlet of the heat exchanger 16a is separated into ethylene and condensate in the gas-liquid separator 20e supplied by the pipe 2c, and ethylene passes through the pipe 2e and the first supply pipe 12. Then, it is circulated and supplied to the liquid phase part of the reactor 10 by the blower 17a. Further, the condensate is circulated and supplied to the reactor 10 via the pipe 2d. Here, the condensate obtained from the outlet of the heat exchanger 16a and the condensate separated in the gas-liquid separator 20e are respectively supplied to the atomizer 10b (FIG. 1) in the gas phase of the reactor 10 via the pipes 2b and 2d. Is introduced into a rotating disk spray system) and atomized. The atomized condensate is dispersed in the gas phase section of the reactor and falls to the liquid surface while making countercurrent contact with the rising gas. By circulating and supplying the atomized condensate to the gas phase part of the reactor, it is possible to prevent the by-product polymer or the like from adhering to the heat exchanger 16a. The reason is presumed as follows. The first reason is that there is a mist containing a catalyst component and ethylene in the gas generated by the vaporization of the reaction solution, and the mist is atomized before reaching the heat exchanger (condenser). This is because it is absorbed into the condensate by coming into contact with the condensate and then falls to the liquid surface together with the condensate. The second reason is that when the low-temperature refined condensate comes into contact with the high-temperature rising gas, the high-temperature gas is cooled and condensate is generated from the gas. The condensation at that time occurs because the mist of the reaction liquid is used as a nucleus, so that the mist diameter increases, and if the mist diameter increases, it falls to the liquid surface without accompanying the gas. Here, the reaction solvent obtained by separating the reaction liquid obtained from the outlet of the reactor is atomized and circulated and supplied to the gas phase part of the reactor. Can be prevented from adhering.

Next, the reaction liquid that has reached a predetermined conversion rate in the reactor 10 is continuously extracted from the bottom of the reactor 10 through the pipe 11 and supplied to the degassing tank 20. At this time, the trimerization reaction of ethylene is stopped by the catalyst deactivator 2-ethylhexanol supplied from the deactivator supply pipe 11b. Unreacted ethylene degassed in the degassing tank 20 is circulated and supplied from the upper part of the degassing tank 20 to the reactor 10 through the heat exchanger 16, the circulation pipe 21, the compressor 17 and the first supply pipe 12. . Further, the reaction liquid from which the unreacted ethylene has been degassed is extracted from the bottom of the degassing tank 20.

The operating conditions of the degassing tank 20 are usually a temperature of 60 ° C. to 240 ° C., preferably 80 ° C. to 190 ° C., and the pressure is normal pressure to 150 kg / cm ² , preferably normal pressure to 90 kg / cm ² . is there.
Subsequently, the reaction liquid extracted from the bottom of the degassing tank 20 is supplied to the ethylene separation tower 30 through the pipe 22. In the ethylene separation tower 30, ethylene is distilled from the top of the tower by distillation and is circulated and supplied to the reactor 10 through the circulation pipe 31 and the first supply pipe 12. Moreover, the reaction liquid from which ethylene has been removed is extracted from the bottom of the column.

The operating conditions of the ethylene separation tower 30 are usually normal pressure to 30 kg / cm ² , preferably normal pressure to 20 kg / cm ² , and the reflux ratio (R / D) is usually 0 to 500. Preferably, it is 0.1-100.
Next, the reaction liquid in which ethylene is distilled in the ethylene separation tower 30 is extracted from the bottom of the ethylene separation tower 30 and supplied to the high boiling separation tower 40 through the pipe 32. In the high boiling separation tower 40, a high boiling point component (HB: high boiler) is extracted from the bottom of the tower through a pipe 42. Moreover, the distillate from which the high boiling point component was separated by the piping 41 is extracted from the top of the tower. The operating conditions of the high boiling separation tower 40 are usually a tower top pressure of 0.1 to 10 kg / cm ² , preferably 0.5 to ⁵ kg / cm ² , and the reflux ratio (R / D) is usually 0. -100, preferably 0.1-20.

  Subsequently, the reaction liquid extracted as a distillate from the top of the high boiling separation tower 40 is supplied to the hexene separation tower 50 through the pipe 41. In the hexene separation tower 50, 1-hexene obtained by distillation is distilled out from the top of the tower through a pipe 51. Further, heptane is extracted from the bottom of the hexene separation tower 50 and is circulated and supplied to the reactor 10 as a reaction solvent through the solvent circulation pipe 52, the pump 13 b, and the second supply pipe 13.

The operating conditions of the hexene separation tower 50 are usually a tower top pressure of 0.1 to 10 kg / cm ² , preferably 0.5 to ⁵ kg / cm ² , and a reflux ratio (R / D) is usually 0 to 100, preferably 0.1-20.

Hereinafter, the present invention will be described more specifically based on examples. In addition, this invention is not limited to a following example, unless it deviates from the summary.
[Example 1]
As shown in FIG. 1, in a process having a complete mixing and stirring type reactor 10, a degassing tank 20, an ethylene separation tower 30, a high boiling separation tower 40, and a hexene separation tower 50, a continuous low ethylene content is obtained. A polymerization reaction (140 ° C. × 71 kg / cm ² ) was performed. From the first supply pipe 12, unreacted ethylene separated from the degassing tank 20 and the ethylene separation tower 30 together with ethylene newly supplied from the ethylene supply pipe 12 a is brought into the liquid phase part of the reactor 10 by the compressor 17. Continuous supply. Further, the recovered n-heptane solvent separated in the hexene separation tower 50 was continuously supplied from the second supply pipe 13 to the liquid phase part of the reactor 10. Next, from the catalyst supply pipe 13a, an n-heptane solution containing chromium (III) 2-ethylhexanoate (a) and 2,5-dimethylpyrrole (b) is further added from the catalyst supply pipe 14 to the hexa An n-heptane solution of chloroethane (d) was continuously supplied to the liquid phase part of the reactor 10 via the second supply pipe 13. Further, an n-heptane solution of triethylaluminum (c) was continuously supplied from the third supply pipe 15 to the liquid phase part of the reactor 10.

  The catalyst is a solution of the reactor 10 so that the molar ratio of each component supplied to the reactor is (a) :( b) :( c) :( d) = 1: 25: 80: 5. Continuously fed to the phase section. The reaction solution continuously withdrawn from the reactor 10 was added in an amount of 3 equivalents of 2-ethylhexanol to the triethylaluminum (c) as a catalyst deactivator from the deactivator supply pipe 11b. It processed in the degassing tank 20, the ethylene separation tower 30, the high boiling separation tower 40, and the hexene separation tower 50.

  A mixed gas of the ethylene gas introduced into the reactor 10 and the vaporized vapor partially vaporized by the polymerization heat generated by the low polymerization reaction of ethylene in the reactor 10 is separated into a vertical type by a pipe 2a. It was supplied to the tubular heat exchanger 16a. The mixed gas supplied to the heat exchanger 16a was cooled with cooling water so that the outlet temperature was 80 ° C., and the condensate was circulated again to the reactor 10 through the pipe 2b.

A part of the gas component obtained from the outlet of the heat exchanger 16a is separated into ethylene gas and condensate in the gas-liquid separator 20e supplied by the pipe 2c, and the ethylene gas is piped by the pipe 2e and the blower 17a. 12 was circulated and supplied to the liquid phase part of the reactor 10. At this time, the actual gas linear velocity in the reactor gas phase was 1 cm / s.
The condensate was supplied to the rotating disc type sprayer 10b installed in the gas phase portion of the reactor 10 together with the condensate from the pipe 2b through the pipe 2d. At this time, the inlet temperature of the heat exchanger 16a was approximately 123 ° C. As a result of opening inspection after 100 days of operation, it was visually confirmed that the upper tube plate surface of the heat exchanger 16a and the tube inner surface (cooling transmission surface) were almost free from contamination.

[Comparative Example 1]
In Example 1, the reactor 10 is a reactor that does not have the rotating disk type sprayer 10b, and the condensate in the pipes 2b and 2d is supplied from the supply pipe to the gas phase part of the reactor to the inner wall in the reactor. All were carried out in the same manner except that it was supplied to the liquid phase part through the wall. The inlet temperature of the heat exchanger 16a was approximately 133 ° C. As a result of opening inspection after 95 days of operation, it was visually confirmed that polyethylene was thickly deposited on the upper tube plate surface of the heat exchanger 16a and partially blocked the tube.

DESCRIPTION OF SYMBOLS 1 ... Manufacturing flow example, 2 ... Reflux condensation system, 2a, 2b, 2c, 2d, 2e, 11, 22, 32, 41, 42, 51 ... Pipe, 10 ... Reactor, 10a ... Stirrer, 11b ... Deactivation Agent supply pipe, 12 ... first supply pipe, 12a ... ethylene supply pipe, 13 ... second supply pipe, 13a, 14 ... catalyst supply pipe, 13b ... pump, 15 ... third supply pipe, 16 ... heat exchanger, 16a ... heat exchanger (condenser), 17 ... compressor, 17a ... blower, 20 ... degassing tank, 20e ... gas-liquid separator, 21, 31 ... circulation piping, 30 ... ethylene separation tower, 40 ... high boiling separation tower 50 ... hexene separation tower, 52 ... solvent circulation piping

Claims (8)

In a method for producing an α-olefin low polymer by performing a low polymerization reaction of α-olefin in a reaction solvent in a reaction solvent in the presence of a catalyst, a part of gas in a gas phase portion in the reactor is subjected to heat exchange. When the reaction solution obtained by separating the condensed liquid obtained from the outlet of the heat exchanger, the non-condensed gas and the reaction liquid obtained from the outlet of the reactor is circulated and supplied to the reactor An α-olefin low polymer characterized in that the condensate and / or the reaction solvent is atomized and supplied to the gas phase part of the reactor, and the non-condensable gas is supplied to the liquid phase part of the reactor. Production method. The reaction solvent obtained by separating the condensate obtained from the outlet of the heat exchanger and / or the reaction liquid obtained from the outlet of the reactor is atomized by a sprayer. Of producing an α-olefin low polymer. The atomization method of the sprayer is at least one method selected from the group consisting of a centrifugal force method, a shear force method, and a pressure method. A method for producing a polymer. The method for producing an α-olefin low polymer according to any one of claims 1 to 3, wherein the gas phase gas outlet temperature of the reactor is lower by 10 ° C or more than the liquid phase temperature.   5. The method according to claim 1, further comprising a step of introducing a part of the non-condensable gas obtained from an outlet of the heat exchanger into a gas-liquid separator and separating the gas into a condensed liquid and a non-condensed gas. The manufacturing method of the alpha-olefin low polymer of any one of Claims 1. 6. The catalyst according to claim 1, wherein the catalyst is composed of a combination of a chromium compound (a), a nitrogen-containing compound (b), and an aluminum-containing compound (c). A method for producing an α-olefin low polymer. The method for producing an α-olefin low polymer according to claim 6, wherein the catalyst further comprises a halogen-containing compound (d). The method for producing an α-olefin low polymer according to any one of claims 1 to 7, wherein the α-olefin is ethylene.

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