Oligomerization catalyst system deactivation and related ethylene oligomerization process

Abstract

Disclosed is a process for deactivating a transition metal-based catalyst system containing a promoter comprising an aluminoxane and optionally an aluminum alkyl wherein the catalyst system is contacted with a C4-C18 alcohol promoter deactivating agent, the molar amount of OH of the promoter deactivator is in the range of 0.5 to 1.5 times {(number of moles of aluminum of the aluminoxane) + (number of moles of aluminum of the aluminum alkyl) + (number of moles of aluminum of the aluminum alkyl)}. Related methods of deactivating a residual catalyst system in a reactor effluent stream and related ethylene oligomerization processes are also described.

Description

[0001] Citation of Related Applications

[0002] This application is filed as a PCT international patent application on November 10, 2023, and claims the benefit and priority of U.S. Patent Application No. 18 / 054,934, filed on November 14, 2022. The disclosure of the U.S. provisional patent application is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure generally relates to methods for deactivating catalyst systems, and more particularly, to methods for deactivating catalyst systems containing aluminoxane and an alkylaluminum cocatalyst. Background Art

[0004] There are various multi-component catalyst systems suitable for the production of 1-hexene or 1-octene by ethylene oligomerization. Once the oligomer product is formed in the oligomerization reactor and subsequently discharged, it is generally necessary to deactivate the catalyst system to prevent further oligomerization of ethylene and to prevent isomerization of the 1-hexene or 1-octene product. The present invention generally aims at these purposes. Summary of the Invention

[0005] The Summary of the Invention is provided to introduce a selection of concepts that are further described herein in a simplified form. The Summary of the Invention is not intended to identify essential or necessary features of the claimed subject matter. The Summary of the Invention is also not intended to be used to limit the scope of the claimed subject matter.

[0006] Methods for deactivating catalyst systems are described herein. In one aspect, for example, a method for deactivating a transition metal-based catalyst system containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum may include contacting the catalyst system with a C4-C 18 alcohol cocatalyst deactivator, wherein the molar amount of OH in the cocatalyst deactivator is in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}.

[0007] Another method involves deactivating a residual transition metal-based catalyst system in an effluent stream from an oligomerization reactor, the catalyst system containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum. This method may include contacting the effluent stream (the effluent stream containing unreacted ethylene, an oligomer product, a residual transition metal-based catalyst system containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum, and an organic reaction medium) with a C4-C 18 alcohol cocatalyst deactivator, wherein the molar amount of OH in the cocatalyst deactivator is in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}.

[0008] The present invention also describes an oligomerization process. Representative processes may include: A) introducing ethylene, a transition metal-based catalyst system or catalyst system component, an organic reaction medium, and optionally hydrogen into an oligomerization reactor, the transition metal-based catalyst system or catalyst system component containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum; B) forming an oligomer product in the oligomerization reactor, the oligomer product comprising hexene and octene; C) discharging an effluent stream from the oligomerization reactor, the effluent stream comprising unreacted ethylene, the oligomer product, a residual transition metal-based catalyst system (containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum), and the organic reaction medium; and D) contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}.

[0009] The foregoing summary and the following detailed description both provide examples and are merely illustrative. Accordingly, the foregoing summary and the following detailed description should not be considered restrictive. Further, features or variations may be provided in addition to those features or variations set forth herein. For example, certain aspects may relate to various combinations and sub-combinations of features described in the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A gas chromatogram showing the oligomerization experiments of Examples 1-5.

[0011] DEFINITIONS

[0012] To more clearly define the terms used herein, the following definitions are provided. Unless otherwise specified, the following definitions apply to the present disclosure. If a term is used in the present disclosure but not specifically defined herein, the definition in IUPAC Compendium of Chemical Terminology, 2nd Edition (1997) may be applied, provided that the definition does not conflict with any other disclosure or definition applied herein, or render any claim to which the definition is applied indefinite or unenforceable. If any definition or usage provided in any document incorporated herein by reference conflicts with the definition or usage provided herein, then the definition or usage provided herein shall control.

[0013] In this document, the features of the subject matter can be described such that combinations of different features can be envisioned within a particular aspect. For each aspect and / or feature disclosed herein, all combinations that do not adversely affect the designs, compositions, processes, and / or methods described herein are contemplated, with or without an explicit description of a particular combination. Additionally, any aspect and / or feature disclosed herein can be combined, unless otherwise explicitly stated, to describe inventive features consistent with this disclosure.

[0014] In this disclosure, although compositions, processes / methods, and systems are described in terms of "comprising" various materials, steps, and components, the compositions, processes / methods, and systems can also "consist essentially of" or "consist of" the various materials, steps, or components, unless otherwise specified. Unless otherwise indicated, the terms "a / an" and "the" are intended to include a plurality of alternatives, such as at least one.

[0015] Generally, families of elements are indicated using the numbering scheme indicated in the version of the periodic table published in Chemical and Engineering News, 63(5), 27, 1985. In some cases, families of elements may be indicated using the common names assigned to the families; for example, alkali metals indicate Group 1 elements, alkaline earth metals indicate Group 2 elements, transition metals indicate Groups 3-12 elements, and halogens or halide ions indicate Group 17 elements.

[0016] For any particular compound or group disclosed herein, unless otherwise indicated, any name or structure presented is intended to cover all conformational isomers, positional isomers, stereoisomers, and mixtures thereof that can be generated by a particular set of substituents. Unless otherwise specified, the name or structure also covers all enantiomers, diastereomers, and other optical isomers (if any), whether enantiomeric or racemic forms, and mixtures of stereoisomers, as known to those skilled in the art. For example, a general reference to a hexene (or hexenes) includes all straight-chain or branched-chain, acyclic or cyclic hydrocarbon compounds having six carbon atoms and one carbon-carbon double bond; a general reference to pentane includes n-pentane, 2-methylbutane, and 2,2-dimethylpropane; and a general reference to butyl includes n-butyl, sec-butyl, isobutyl, and tert-butyl.

[0017] Unless otherwise indicated, the terms "contact" and "combine" are used herein to describe compositions, processes / methods, and systems in which materials are contacted or combined together in any order, in any manner, and for any length of time. For example, materials can be blended, mixed, slurried, dissolved, reacted, treated, impregnated, compounded, or otherwise contacted or combined in some other manner or by any suitable method or technique.

[0018] Whenever used in this specification and the claims, the term "hydrocarbon" refers to a compound containing only carbon and hydrogen. Other identifiers may be used to indicate the presence of specific groups in the hydrocarbon (e.g., "halohydrocarbon" indicates the presence of one or more halogen atoms replacing an equal number of hydrogen atoms in the hydrocarbon).

[0019] Whenever used in this specification and the claims, the term "olefin" refers to a hydrocarbon having at least one carbon-carbon double bond that is not part of an aromatic ring or aromatic ring system. Unless otherwise specifically stated, the term "olefin" includes aliphatic and aromatic, cyclic and acyclic, and / or straight-chain and branched-chain hydrocarbons having at least one carbon-carbon double bond that is not part of an aromatic ring or ring system. Olefins having only one, only two, only three, etc. carbon-carbon double bonds can be identified by using the terms "mono-", "di-", "tri-", etc. in the name of the olefin. Olefins can be further identified by the position of one or more carbon-carbon double bonds.

[0020] As used herein, the term "α-olefin" refers to any olefin having a carbon-carbon double bond between the first and second carbon atoms of the longest continuous carbon atom chain. Unless otherwise expressly stated, the term "α-olefin" includes straight-chain and branched-chain α-olefins and α-olefins that may have more than one non-aromatic carbon-carbon double bond. As used herein, the term "normal α-olefin" refers to a straight-chain aliphatic hydrocarbon monoolefin having a carbon-carbon double bond between the first and second carbon atoms. As used herein, the term "internal straight-chain olefin" refers to a straight-chain aliphatic hydrocarbon monoolefin having a double bond that is not between the first and second carbon atoms.

[0021] The term "oligomer" refers to a compound containing from 2 to 20 monomer units. The terms "oligomer product" and "oligomeric product" include all products prepared by an "oligomerization" process, including "oligomers" and products that are not "oligomers" (e.g., products containing more than 20 monomer units, or solid polymers), but excluding other non-oligomeric components of the oligomerization reactor effluent stream, such as unreacted ethylene, organic reaction medium, and hydrogen, etc.

[0022] The terms "catalyst composition", "catalyst mixture", "catalyst system", etc. are not dependent on the actual product or composition resulting from the contact or reaction of the initial components of the disclosed or claimed catalyst composition / mixture / system, the nature of the active catalytic sites, or the fate of the alumoxane and / or alkylaluminum and transition metal compound or complex upon combination of these components. Thus, the terms "catalyst composition", "catalyst mixture", "catalyst system", etc. encompass the initial starting components of the composition and any products that may result from contacting these initial starting components. The terms "catalyst composition", "catalyst mixture", "catalyst system", etc. may be used interchangeably throughout this disclosure.

[0023] The present invention discloses several types of ranges. When any type of range is disclosed or claimed, it is intended that every possible number that such range could reasonably encompass be disclosed or claimed individually, including the endpoints of the range and any sub-ranges and combinations of sub-ranges encompassed therein. For example, when a chemical moiety having a certain number of carbon atoms is disclosed or claimed, it is intended that every possible number that such range could encompass, consistent with the disclosure herein, be disclosed or claimed individually. For example, a cocatalyst deactivator being an alcohol having from C4 to C 18 alcohol, or in alternative language, the disclosure of an alcohol having from 4 to 18 carbon atoms as used herein, refers to such alcohol compounds that may have 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms, and any range of carbon atoms between two of these numbers (e.g., C6-C 16 alcohol or C8-C 12 alcohol), and also includes any combination of ranges of carbon atoms between two of these numbers (e.g., C6 to C 10 and C 14 to C 18 alcohol). Similarly, all other ranges disclosed herein should be interpreted in a manner similar to this example.

[0024] In general, quantities, sizes, formulations, parameters, ranges, or other numerical or characteristic values are "about" or "approximately", whether or not expressly stated as such. Whether or not modified by the term "about" or "approximately", the claims include equivalents of the numerical or characteristic values.

[0025] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, typical methods and materials are described herein.

[0026] All publications and patents mentioned herein are incorporated herein by reference in their entirety for the purpose of describing and disclosing, for example, the constructs and methods described in the publications and patents, which constructs and methods may be used in conjunction with the presently described invention. Detailed Embodiments

[0027] In this paper, a cocatalyst deactivator is used to deactivate an ethylene oligomerization catalyst system, and the OH content of the cocatalyst deactivator is surprisingly low based on the amount of aluminum in the aluminoxane and alkylaluminum cocatalysts present in the catalyst system.

[0028] Deactivation Method

[0029] On the one hand, a method for deactivating a residual transition metal-based catalyst system containing a cocatalyst is disclosed herein, wherein the cocatalyst includes aluminoxane and optionally alkylaluminum. This method may include contacting the catalyst system with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}.

[0030] On the other hand, a method for deactivating a residual transition metal-based catalyst system in an effluent stream from an oligomerization reactor is provided herein, the catalyst system containing a cocatalyst including aluminoxane and optionally alkylaluminum. This method may include contacting the effluent stream (the effluent stream containing unreacted ethylene, oligomer product, a residual transition metal-based catalyst system containing a cocatalyst including aluminoxane and optionally alkylaluminum, and an organic reaction medium) with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}.

[0031] In yet another aspect, an oligomerization method is disclosed herein. This method may include: A) introducing ethylene, a transition metal-based catalyst system or catalyst system components, an organic reaction medium, and optionally hydrogen into an oligomerization reactor, the transition metal-based catalyst system or catalyst system components containing a cocatalyst including aluminoxane and optionally alkylaluminum; B) forming an oligomer product in the oligomerization reactor, the oligomer product including hexene and octene; C) discharging an effluent stream from the oligomerization reactor, the effluent stream containing unreacted ethylene, oligomer product, a residual transition metal-based catalyst system (containing a cocatalyst including aluminoxane and optionally alkylaluminum), and an organic reaction medium; and D) contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}.

[0032] Typically, the characteristics of these methods / processes for deactivating a catalyst system (e.g., cocatalysts, the relative amounts of aluminoxane:alkylaluminum if both are present, cocatalyst deactivators, and the relative amounts of cocatalyst deactivators, etc.) are described independently herein, and these characteristics can be combined without limitation and in any combination to further describe the disclosed methods / processes. In addition, additional steps can be performed before, during, and / or after the steps of these methods / processes and can be used without limitation and in any combination to further describe the methods for deactivating a catalyst system and the processes for ethylene oligomerization, unless otherwise specified. Further, and advantageously, these methods / processes can be performed continuously.

[0033] In the disclosed methods / processes, the catalyst system can contain a cocatalyst comprising an aluminoxane and optionally an alkylaluminum. Thus, in some aspects, the cocatalyst comprises both an aluminoxane and an alkylaluminum, while in other aspects, the cocatalyst comprises an aluminoxane (and no alkylaluminum is present). When both an aluminoxane and an alkylaluminum are present in the catalyst system, the relative amounts of aluminoxane to alkylaluminum (aluminoxane:alkylaluminum) in the catalyst system are not particularly limited. Nevertheless, illustrative and non-limiting ranges include a molar ratio of aluminoxane:alkylaluminum (based on aluminum) of from 100:1 to 1:100, 20:1 to 1:20, 10:1 to 1:10, 5:1 to 1:5, 10:1 to 1:1, or 8:1 to 2:1, etc. Typically, the molar amount of aluminoxane in the catalyst system is greater than the molar amount of alkylaluminum, but this is not required.

[0034] Any suitable aluminoxane can be used in the catalyst system, such as methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, tert-butylaluminoxane, sec-butylaluminoxane, isobutylaluminoxane, 1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane, isopentylaluminoxane, neopentylaluminoxane, etc., and any mixture or combination thereof. In one aspect, the aluminoxane can comprise the following (or consist essentially of the following, or consist of the following): methylaluminoxane (MAO); or, modified methylaluminoxane (MMAO); or, ethylaluminoxane; or, n-propylaluminoxane; or, isopropylaluminoxane; or, n-butylaluminoxane; or, tert-butylaluminoxane; or, sec-butylaluminoxane; or, isobutylaluminoxane; or, 1-pentylaluminoxane; or, 2-pentylaluminoxane; or, 3-pentylaluminoxane; or, isopentylaluminoxane; or, neopentylaluminoxane.

[0035] Similarly, there is no particular limitation on the alkylaluminum used in the catalyst system, and representative alkylaluminum compounds may include trimethylaluminum (TMA), triethylaluminum (TEA), tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum, etc., and any mixture or combination thereof. In one aspect, the alkylaluminum may comprise (or consist essentially of, or consist of) the following: trimethylaluminum (TMA); or, triethylaluminum (TEA); or, tri-n-propylaluminum (TNPA); or, tri-n-butylaluminum (TNBA); or, triisobutylaluminum (TIBA); or, tri-n-hexylaluminum; or, tri-n-octylaluminum.

[0036] The molar amount of OH in the cocatalyst deactivator in the disclosed method / process is in the range of 0.5 to 1.5 times of {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}. The numbers in the range of 0.5 to 1.5 may also be referred to as the effective amount of OH required for quenching based on aluminum. In one aspect, the minimum molar amount of OH (or the minimum effective amount of OH for quenching) may be at least 0.5, 0.6, 0.7, 0.8, 0.9, 1 or 1.1, while in another aspect, the maximum molar amount of OH (or the maximum effective amount of OH for quenching) may be 1.5, 1.4, 1.3 or 1.2. Generally, the molar amount of OH and the molar amount of aluminum (or the effective amount of OH for quenching based on aluminum) may be in the range of any minimum amount to any maximum amount described herein. For example, the molar amount of OH in the cocatalyst deactivator may be 0.5 to 1.4 times, 0.5 to 1.3 times, 0.6 to 1.5 times, 0.6 to 1.4 times, 0.6 to 1.3 times, 0.6 to 1.2 times, 0.7 to 1.5 times, 0.7 to 1.4 times, 0.7 to 1.3 times, 0.7 to 1.2 times, 0.8 to 1.4 times, 0.8 to 1.3 times, 0.9 to 1.5 times, 0.9 to 1.4 times, 0.9 to 1.3 times, 1 to 1.5 times, 1 to 1.4 times, 1 to 1.3 times, 1.1 to 1.5 times, 1.1 to 1.4 times, or 1.1 to 1.3 times of {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}. Although not wishing to be bound by the following theory, it is believed that an OH molar amount exceeding 1.5 will result in more free alcohol being produced in the oligomerization system, and the free alcohol may be recovered and have a negative impact on the fresh catalyst entering the reactor, and will lead to material waste and low cost efficiency. On the contrary, it is believed that a molar amount less than 0.5 will result in non-uniform and incomplete deactivation, especially when mixing and mass transfer limitations may prevent contact with all cocatalyst species in the effluent stream, and in cases where process conditions such as temperature may vary.

[0037] In the relationship between the number of moles of OH in the cocatalyst deactivator and the total amount of aluminum reflected by {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}, the number of moles of aluminum in the aluminoxane is counted once, while the number of moles of aluminum in the alkylaluminum is counted twice. Similarly, while not wishing to be bound by the following theory, it is believed that it takes about half to one OH per aluminum to deactivate the aluminoxane, and about two OH groups per aluminum to deactivate the alkylaluminum.

[0038] The methods and processes disclosed herein can be used with any suitable transition metal-based catalyst system that contains a cocatalyst comprising an aluminoxane and optionally an alkylaluminum. The metal in the catalyst system can be chromium, iron, cobalt, vanadium, titanium, zirconium, hafnium, etc., or any combination thereof. In one aspect, the transition metal-based catalyst system can include chromium; alternatively, iron; alternatively, cobalt; alternatively, vanadium; alternatively, titanium; alternatively, zirconium; alternatively, hafnium.

[0039] As described above, while not limited to use with any particular catalyst system, the methods and processes disclosed herein are particularly suitable for use in combination with a transition metal-based catalyst system or catalyst system components that include (i) a heteroatom ligand transition metal compound complex and a cocatalyst, or (ii) a heteroatom ligand, a transition metal compound, and a cocatalyst. Thus, the methods and processes can be used in combination with a transition metal-based catalyst system or catalyst system components that include (i) a heteroatom ligand chromium compound complex and a cocatalyst, or (ii) a heteroatom ligand, a chromium compound, and a cocatalyst. Other catalyst systems to which the disclosed methods and processes are particularly applicable include U.S. Patent Nos. 10,493,422, 10,464,862, 10,435,336, and 11,267,909.

[0040] In the methods / processes disclosed herein, the catalyst system is contacted with a C4-C 18 alcohol cocatalyst deactivator. In one aspect, for example, the cocatalyst deactivator can include a C6-C 16 alcohol, and in another aspect, the cocatalyst deactivator can include a C8-C 12 alcohol. The term alcohol is generally used to include monoalcohols, diols, and polyols, so the cocatalyst deactivator can include monoalcohol compounds, diol compounds, polyol compounds, or any combination thereof.

[0041] According to a particular aspect of the present invention, the cocatalyst deactivator may include butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, etc., and any mixture or combination thereof. Specific examples of cocatalyst deactivators that can be used to deactivate the catalyst system include, for example, 1-butanol, 2-butanol, isobutanol, sec-butanol, tert-butanol, 1-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, cyclohexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2-methyl-3-heptanol, 1-nonanol, 1-decanol, 2-decanol, 3-decanol, 4-decanol, 5-decanol, 1-undecanol, 2-undecanol, 7-methyl-2-decanol, 1-dodecanol, 2-dodecanol, 2-ethyl-1-decanol, etc., and any mixture or combination thereof. In a particular aspect disclosed herein, the cocatalyst deactivator may include 2-ethylhexanol.

[0042] The suitability of a particular cocatalyst deactivator for a particular catalyst system depends on many factors, one of which is the prevailing temperature when the catalyst system is in contact with the cocatalyst deactivator. Thus, the specific boiling point of the cocatalyst deactivator can be important. Accordingly, the minimum boiling point (at 1 atmosphere) of the cocatalyst deactivator can be 130 °C, 140 °C, 150 °C, 160 °C, or 170 °C; additionally or alternatively, the maximum boiling point (at 1 atmosphere) can be 300 °C, 280 °C, 250 °C, or 220 °C. Generally, the boiling point of the deactivator can be in the range of any of the minimum temperatures disclosed herein to any of the maximum temperatures disclosed herein. Thus, suitable non-limiting ranges can include the following: 130 °C to 300 °C, 130 °C to 220 °C, 140 °C to 280 °C, 150 °C to 250 °C, 160 °C to 280 °C, 160 °C to 250 °C, 170 °C to 300 °C, or 170 °C to 220 °C. For example, in an oligomerization process, it may be beneficial for the cocatalyst deactivator to be with the heavier products such that the cocatalyst deactivator is readily separable from 1-hexene and / or 1-octene, and thus, it may be advantageous to use a cocatalyst deactivator having a boiling point of at least 130 °C, more typically at least 150 °C, or at least 170 °C.

[0043] Another factor related to the applicability of the cocatalyst deactivator is that the deactivated catalyst system components (e.g., alkoxides) formed due to the contact of the catalyst system with the cocatalyst deactivator are advantageously soluble in the effluent stream (e.g., containing an organic reaction medium or hydrocarbon) at a minimum temperature of 130 °C, 140 °C, 150 °C, 160 °C, or 170 °C; additionally or alternatively, at a maximum temperature of 300 °C, 280 °C, 250 °C, or 220 °C. Generally, the deactivated catalyst system components can be dissolved in the effluent stream (e.g., containing hydrocarbon) within the range of any minimum temperature disclosed herein to any maximum temperature disclosed herein. Thus, suitable non-limiting ranges can include the following: 130 °C to 300 °C, 130 °C to 220 °C, 140 °C to 280 °C, 150 °C to 250 °C, 160 °C to 280 °C, 160 °C to 250 °C, 170 °C to 300 °C, or 170 °C to 220 °C. The deactivated catalyst system components are considered soluble if there is no visible precipitation at the corresponding temperature.

[0044] Although not required, generally, contacting the effluent stream or the catalyst system with the cocatalyst deactivator is a single addition that both deactivates the cocatalyst (e.g., stops the oligomerization of ethylene to hexene and / or octene, and / or stops the isomerization of hexene and / or octene) and stops the self-ignition activity of the cocatalyst (e.g., stops the air and moisture reactivity). Thus, it is advantageous that there is no need for multiple injections of the same deactivator or different deactivators with different functions.

[0045] Consistent with any method / process disclosed herein, and optionally, these methods / processes may further include a control system that includes the following steps: (i) determining the amount of catalytic activity remaining after adding the cocatalyst deactivator, and (ii) adjusting the amount of the cocatalyst deactivator based on the catalytic activity. For example, if some catalytic activity remains after adding the cocatalyst deactivator, a greater molar amount of OH can be added. Conversely, if there is no catalytic activity, the addition amount can be reduced. The amount of catalytic activity remaining after adding the cocatalyst deactivator can be determined by any suitable method, and one such method is to test the isomerization of the oligomer product of the resulting composition, such as 1-octene isomerization. That is, after adding the cocatalyst deactivator, it is determined whether the resulting composition can catalyze the isomerization of 1-octene or 1-dodecene, as shown in the following examples.

[0046] Now referring to the method / process in which the effluent stream from the oligomerization reactor is contacted with the cocatalyst deactivator, generally, the effluent stream is contacted with the cocatalyst deactivator before introducing the effluent stream into a separator to remove at least a portion of the unreacted ethylene. In this regard, the contacting step is carried out after reactor discharge but before at least a portion of the unreacted ethylene is flashed / removed from the effluent stream.

[0047] Alternatively, after removing at least a portion of the unreacted ethylene from the effluent stream in a separator, the effluent stream can be contacted with a cocatalyst deactivator. In this regard, the cocatalyst deactivator can be combined with the bottom stream from the separator / flasher after the ethylene removal step.

[0048] The effluent stream contains oligomer products, which can include hexene and octene, as well as other C4 + linear alpha olefins and other components. The amount of octene in the oligomer product can generally be in the range of 20 to 99 wt% based on the total amount of oligomers in the oligomer product. In one aspect, the minimum amount of octene in the oligomer product can be 20, 30, or 40 wt%. In another aspect, the maximum amount of octene in the oligomer product can be 99, 95, 92.5, 90, 87.5, or 85 wt%. Generally, the amount of octene in the oligomer product can be in the range of any minimum octene amount to any maximum octene amount in the oligomer product described herein. For example, based on the total weight of the oligomers in the oligomer product, the amount of octene can be 30 to 95 wt%, 40 to 95 wt%, 40 to 90 wt%, 20 to 90 wt%, 30 to 87.5 wt%, 30 to 85 wt%, 40 to 87.5 wt%, 40 to 85 wt%, 20 to 60 wt%, 30 to 55 wt%, or 40 to 55 wt% of octene.

[0049] Additionally or alternatively, the oligomer product can contain any suitable amount of hexene. In one aspect, the minimum amount of hexene in the oligomer product can be 15, 20, 25, 30, or 35 wt%. In another aspect, the maximum amount of hexene in the oligomer product can be 75, 65, 60, 55, or 50 wt%. Generally, the amount of hexene in the oligomer product can be in the range of any minimum hexene amount to any maximum hexene amount in the oligomer product described herein. For example, based on the total weight of the oligomers in the oligomer product, the amount of hexene can be 20 to 60 wt%, 25 to 55 wt%, or 30 to 50 wt% of hexene.

[0050] The amount of ethylene conversion in the oligomerization reactor is not particularly limited, and generally, the minimum ethylene conversion rate can be at least 20, 30, 35, 40, 45, or 50 wt%, while the maximum ethylene conversion rate can be 99, 95, 90, 80, 75, 70, or 65 wt%. Generally, the ethylene conversion rate in the reactor can be in the range of any minimum conversion rate to any maximum conversion rate described herein. For example, the ethylene conversion rate can be in the range of 20 to 95 wt%, 30 to 90 wt%, 40 to 80 wt%, 50 to 70 wt%, or 55 to 65 wt%. The ethylene conversion rate is based on the amount of ethylene entering the reactor and the amount of ethylene in the effluent stream.

[0051] Now referring to step A) of the oligomerization process, ethylene, a transition metal-based catalyst system or catalyst system components, an organic reaction medium, and optionally hydrogen are introduced into an oligomerization reactor, and the transition metal-based catalyst system or catalyst system components contain a cocatalyst comprising aluminoxane and optionally an alkylaluminum. The use of hydrogen in step A) is optional, so in one aspect, there is no hydrogen in step A), while in another aspect, there is hydrogen in step A).

[0052] Examples

[0053] The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the present invention in any way. After reading the description herein, various other aspects, modifications, and their equivalents can be contemplated by those of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims.

[0054] GC-FID data was collected on an Agilent Technologies 7890A instrument equipped with a 50 m length Agilent DB-5 GC column having an inner diameter of 0.32 mm and a film thickness of 0.25 μm. The sample (0.05 mL) was injected into the inlet at 300 °C with a split ratio of 25:1 using He as the carrier gas. The initial column temperature was 40 °C, ramped at a rate of 3 °C / min until 80 °C, then ramped at a rate of 13 °C / min until 300 °C, and the hold time was 15 min. Peak integration was performed manually, and peak identification was carried out using authentic samples.

[0055] Examples 1-5

[0056] In Examples 1-5, an illustrative chromium / MAO / alkylaluminum catalyst system was used to determine the amount of cocatalyst deactivator required to deactivate the cocatalyst component of the catalyst system, particularly to prevent dimerization and / or isomerization of 1-dodecene at 175 °C. For Example 1, a vial was charged with 18.2 mg of a representative chromium catalyst (N 2 -phosphinoguanidine chromium(III) trichloride tetrahydrofuran complex), 1 g of xylene, and 1 g of n-tridecane (internal standard), and then the cocatalyst was added. The amounts of the cocatalyst were 60 equivalents of triethylaluminum (60:1 Al:Cr) and 400 equivalents of MMAO-21 (400:1 Al:Cr). MMAO-21 is a modified methylaluminoxane produced from a mixture of TMA and TIBA. After adding 10 g of 1-dodecene (about 95.2 wt%), the vial was heated to 175 °C in 30 minutes and then maintained at that temperature for 1 hour. After cooling to room temperature, the contents of the vial were quenched thoroughly with water and then analyzed by GC.

[0057] Example 2 is a control sample of 1-dodecene starting material (purity approximately 95.2 wt%) with no other materials added. Examples 3 - 5 were conducted similarly to Example 1, except that the 2-ethyl-1-hexanol cocatalyst deactivator was added after 1-dodecene but before heating to 175 °C. In Example 3, the amount of 2-ethyl-1-hexanol added was 1.95 times the OH molar amount equal to {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}. Example 4 was conducted with an OH molar amount equal to 1.60 times {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}, and Example 5 was conducted with an OH molar amount equal to 1.24 times {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}. Examples 1 - 5 are summarized in Figure 1 and Table 1 below.

[0058] As Figure 1 and the data in Table 1 show, Example 1 had significant 1-dodecene isomerization and dimerization, as expected in the absence of a cocatalyst deactivator. However, in the presence of the cocatalyst deactivator, Examples 3 - 5 behaved the same as the control Example 2 (1-dodecene control). No isomerization or dimerization was found in Examples 3 - 5, and the 1-dodecene purity was the same as that of the 1-dodecene control in Example 2.

[0059] It is not surprising that the use of 1.95 molar amounts in Example 3 inhibited isomerization / dimerization, but it was unexpected that a much lower amount of 1.24 used in Example 5 had a similar effect. These data indicate that much lower amounts of the cocatalyst deactivator can be used to successfully deactivate the catalyst system without introducing excessive OH into the oligomerization reactor system, thereby avoiding associated cost and performance drawbacks.

[0060] Table 1

[0061]

[0062] *The OH molar amount of the cocatalyst deactivator is based on {(the molar amount of aluminum in aluminoxane)+(the molar amount of aluminum in alkylaluminum)+(the molar amount of aluminum in alkylaluminum)}.

[0063] Examples 6 - 10

[0064] Examples 6-10 were carried out similarly to Examples 1-5, except that in Examples 6-10 an illustrative MAO catalyst system was used to determine the amount of cocatalyst deactivator required to deactivate the aluminoxane component of the catalyst system (no alkylaluminum component was present in the catalyst system), specifically the amount required to prevent the dimerization and / or isomerization of 1-dodecene at 170 °C. For Example 6, a vial was charged with 10 g of a 7 wt% solution of MMAO-3A in n-heptane. MMAO-3A is a modified methylaluminoxane produced from a mixture of TMA and TIBA. After adding 12.5 mL g of 1-dodecene (about 95-96 wt%), the vial was heated to 170 °C in 15 minutes and then maintained at that temperature for 1 hour. After cooling to room temperature, the contents of the vial were quenched thoroughly with water and then analyzed by GC.

[0065] Example 7 was a control sample of the 1-dodecene starting material (purity about 95-96 wt%) with no other materials added. Examples 8-10 were carried out similarly to Example 6, except that the 2-ethyl-1-hexanol cocatalyst deactivator was added after the 1-dodecene but before heating to 170 °C. The amount of 2-ethyl-1-hexanol added in Example 8 was such that the molar amount of OH was equal to 1.0 times {(the molar amount of aluminum in the aluminoxane) + (the molar amount of aluminum in the alkylaluminum) + (the molar amount of aluminum in the alkylaluminum)}. Example 9 was carried out with the molar amount of OH equal to 0.8 times {(the molar amount of aluminum in the aluminoxane) + (the molar amount of aluminum in the alkylaluminum) + (the molar amount of aluminum in the alkylaluminum)}. Example 10 was carried out with the molar amount of OH equal to 0.6 times {(the molar amount of aluminum in the aluminoxane) + (the molar amount of aluminum in the alkylaluminum) + (the molar amount of aluminum in the alkylaluminum)}. Note that no alkylaluminum cocatalyst was present in the catalyst systems of Examples 6-10. Examples 6-10 are summarized in Table 2 below.

[0066] As shown by the data in Table 2, Example 6 had significant 1-dodecene isomerization and dimerization, as expected in the absence of a cocatalyst deactivator. However, in the presence of the cocatalyst deactivator, Examples 8-10 behaved the same as the control Example 7 (1-dodecene control). No isomerization or dimerization was found in Examples 8-10. The GC data for Examples 6-10 were also confirmed using NMR, which showed that Examples 7-10 each contained the same amount of alpha olefins and internal olefins (no isomerization).

[0067] Surprisingly, using 1.0 and 0.8 molar amounts in Examples 8 and 9, respectively, completely suppressed isomerization / dimerization. However, even more unexpectedly, a similar effect was also obtained using an effective OH quenching amount equal to 0.6 in Example 10. These data demonstrate that much lower amounts of cocatalyst deactivator can be used to successfully deactivate the catalyst system without introducing an excessive amount of OH into the oligomerization reactor system, thereby avoiding associated cost and performance drawbacks.

[0068] Table 2

[0069]

[0070] *The OH molar amount of the cocatalyst deactivator is based on {(moles of aluminum in the aluminoxane)+(moles of aluminum in the alkylaluminum)+(moles of aluminum in the alkylaluminum)}.

[0071] The present invention has been described with reference to many aspects and specific embodiments. Those skilled in the art will envision many variations in light of the detailed description. All such apparent variations are within the full scope of the appended claims. Other aspects of the invention may include, but are not limited to, the following aspects (which are described as "comprising", but alternatively may "consist essentially of" or "consist of"):

[0072] Aspect 1. A method for deactivating a transition metal-based catalyst system (e.g., a residual catalyst system), the catalyst system comprising a cocatalyst comprising an aluminoxane and optionally an alkylaluminum, the method comprising:

[0073] contacting the catalyst system with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times {(moles of aluminum in the aluminoxane)+(moles of aluminum in the alkylaluminum)+(moles of aluminum in the alkylaluminum)}.

[0074] Aspect 2. A method for deactivating a residual transition metal-based catalyst system in an effluent stream from an oligomerization reactor, the catalyst system comprising a cocatalyst comprising an aluminoxane and optionally an alkylaluminum, the method comprising:

[0075] contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the effluent stream comprising unreacted ethylene, oligomer products, the residual transition metal-based catalyst system comprising the cocatalyst comprising the aluminoxane and optionally the alkylaluminum, and an organic reaction medium, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times {(moles of aluminum in the aluminoxane)+(moles of aluminum in the alkylaluminum)+(moles of aluminum in the alkylaluminum)}.

[0076] Aspect 3. An oligomerization process, comprising:

[0077] A) introducing ethylene, a transition metal-based catalyst system or catalyst system component, an organic reaction medium, and optionally hydrogen into an oligomerization reactor, wherein the transition metal-based catalyst system or catalyst system component contains a cocatalyst comprising aluminoxane and optionally alkylaluminum;

[0078] B) forming an oligomer product in the oligomerization reactor, the oligomer product comprising hexene and octene;

[0079] C) discharging an effluent stream from the oligomerization reactor, the effluent stream comprising unreacted ethylene, the oligomer product, a residual transition metal-based catalyst system (containing the cocatalyst comprising the aluminoxane and optionally the alkylaluminum), and the organic reaction medium; and

[0080] D) contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}.

[0081] Aspect 4. The method or process as defined in Aspect 2 or 3, wherein after contacting the effluent stream with the cocatalyst deactivator, the effluent stream is introduced into a separator to remove at least a portion of the unreacted ethylene.

[0082] Aspect 5. The method or process as defined in Aspect 2 or 3, wherein after removing at least a portion of the unreacted ethylene from the effluent stream in a separator, the effluent stream is contacted with the cocatalyst deactivator.

[0083] Aspect 6. The method or process as defined in any one of the preceding aspects, wherein the alkylaluminum comprises trimethylaluminum (TMA), triethylaluminum (TEA), tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum, or any combination thereof.

[0084] Aspect 7. The method or process as defined in any one of the preceding aspects, wherein the aluminoxane comprises methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, tert-butylaluminoxane, sec-butylaluminoxane, isobutylaluminoxane, 1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane, isopentylaluminoxane, neopentylaluminoxane, or any combination thereof.

[0085] Aspect 8. A method or process as defined in any of the foregoing aspects, wherein the molar ratio of the aluminum-based aluminoxane:alkylaluminum is within any of the ranges disclosed herein, such as 100:1 to 1:100, 20:1 to 1:20, 10:1 to 1:10, 5:1 to 1:5, 10:1 to 1:1, or 8:1 to 2:1.

[0086] Aspect 9. A method or process as defined in any of the foregoing aspects, wherein the transition metal-based catalyst system comprises chromium, iron, cobalt, vanadium, titanium, zirconium, hafnium, or a combination thereof.

[0087] Aspect 10. A method or process as defined in any of the foregoing aspects, wherein the cocatalyst deactivator comprises a monoalcohol compound, a diol compound, a polyol compound (alternatively, a monoalcohol compound), and the cocatalyst deactivator comprises a C4-C 18 alcohol, a C6-C 16 alcohol, or a C8-C 12 alcohol.

[0088] Aspect 11. A method or process as defined in any of the foregoing aspects, wherein the cocatalyst deactivator comprises butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, or a mixture thereof.

[0089] Aspect 12. A method or process as defined in any of the foregoing aspects, wherein the cocatalyst deactivator comprises 1-butanol, 2-butanol, isobutanol, sec-butanol, tert-butanol, 1-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, cyclohexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2-methyl-3-heptanol, 1-nonanol, 1-decanol, 2-decanol, 3-decanol, 4-decanol, 5-decanol, 1-undecanol, 2-undecanol, 7-methyl-2-decanol, 1-dodecanol, 2-dodecanol, 2-ethyl-1-decanol, or a mixture thereof.

[0090] Aspect 13. A method or process as defined in any of the foregoing aspects, wherein the cocatalyst deactivator comprises 2-ethylhexanol.

[0091] Aspect 14. A method or process as defined in any of the foregoing aspects, wherein the boiling point (at 1 atmosphere) of the cocatalyst deactivator is within any of the ranges disclosed herein, such as at least 130 °C, at least 140 °C, at least 150 °C, at least 160 °C, or at least 170 °C, and less than or equal to 300 °C, less than or equal to 280 °C, less than or equal to 250 °C, or less than or equal to 220 °C.

[0092] Aspect 15. A method or process as defined in any one of Aspects 2 to 14, wherein contacting with the cocatalyst deactivator forms a deactivated catalyst system component (such as an alkoxide), and the deactivated catalyst system component is soluble in the effluent stream (such as an organic reaction medium, a hydrocarbon) at any temperature disclosed herein, the temperature being for example at least 130 °C, at least 140 °C, at least 150 °C, at least 160 °C or at least 170 °C, and less than or equal to 300 °C, less than or equal to 280 °C, less than or equal to 250 °C or less than or equal to 220 °C.

[0093] Aspect 16. A method or process as defined in any one of the preceding aspects, wherein the contacting with the cocatalyst deactivator is a single addition that both deactivates the cocatalyst (e.g., stops the oligomerization of ethylene to hexene and / or octene and / or the isomerization of hexene and / or octene) and stops the spontaneous combustion activity of the cocatalyst (e.g., stops the air and moisture reactivity).

[0094] Aspect 17. A method or process as defined in any one of the preceding aspects, wherein the method or process is carried out continuously.

[0095] Aspect 18. A method or process as defined in any one of the preceding aspects, wherein the transition metal-based catalyst system or catalyst system component comprises (i) a heteroatom ligand transition metal compound complex and a cocatalyst, or (ii) a heteroatom ligand, a transition metal compound and a cocatalyst.

[0096] Aspect 19. A method or process as defined in any one of the preceding aspects, wherein the transition metal-based catalyst system or catalyst system component comprises (i) a heteroatom ligand chromium compound complex and a cocatalyst, or (ii) a heteroatom ligand, a chromium compound and a cocatalyst.

[0097] Aspect 20. A method or process as defined in any one of Aspects 2 to 19, wherein the oligomer product comprises any amount of octene disclosed herein, for example at least 20, 30 or 40 wt% based on the total amount of oligomers in the oligomer product; at most 99, 95, 92.5, 90, 87.5 or 85 wt%; or 20 to 99 wt%, 30 to 95 wt%, 40 to 95 wt%, 40 to 90 wt%, 20 to 90 wt%, 30 to 87.5 wt%, 30 to 85 wt%, 40 to 87.5 wt%, 40 to 85 wt%, 20 to 60 wt%, 30 to 55 wt% or 40 to 55 wt% of octene.

[0098] Aspect 21. The method or process as defined in any one of Aspects 2 to 20, wherein the oligomer product comprises any amount of hexene disclosed herein, for example, at least 15, 20, 25, 30 or 35 wt% based on the total amount of oligomers in the oligomer product; at most 75, 65, 60, 55 or 50 wt%; or 20 to 60 wt%, 25 to 55 wt% or 30 to 50 wt% of hexene.

[0099] Aspect 22. The process as defined in any one of Aspects 3 to 21, wherein the oligomerization reactor has any ethylene conversion rate disclosed herein, for example, at least 20, 30, 35, 40, 45 or 50 wt% based on the amount of ethylene entering the reactor and the amount of ethylene in the effluent stream; at most 99, 95, 90, 80, 75, 70 or 65 wt%; or a conversion rate of 20 to 95 wt%, 30 to 90 wt%, 40 to 80 wt%, 50 to 70 wt% or 55 to 65 wt%.

[0100] Aspect 23. The process as defined in any one of Aspects 3 to 22, wherein hydrogen is present in step A).

[0101] Aspect 24. The method or process as defined in any one of the foregoing aspects, further comprising the following steps:

[0102] (i) determining the amount of catalytic activity remaining after adding the cocatalyst deactivator (e.g., testing the isomerization of the oligomer product of the product, such as 1-octene isomerization); and

[0103] (ii) adjusting the amount of the cocatalyst deactivator based on the catalytic activity.

[0104] Aspect 25. The method or process as defined in any one of the foregoing aspects, wherein the molar amount of OH is within any range disclosed herein, for example, at least 0.6 times, at least 0.7 times, at least 0.8 times, at least 0.9 times, at least 1 time or at least 1.1 times of {(the number of moles of aluminum in aluminoxane)+(the number of moles of aluminum in alkylaluminum)+(the number of moles of aluminum in alkylaluminum)}, and less than or equal to 1.5 times, less than or equal to 1.4 times, less than or equal to 1.3 times or less than or equal to 1.2 times.

[0105] Aspect 26. The method or process as defined in any one of the foregoing aspects, wherein the cocatalyst comprises the aluminoxane and the alkylaluminum (alternatively, comprises the aluminoxane but does not comprise the alkylaluminum).

Claims

1. A method for deactivating a transition metal-based catalyst system, the catalyst system containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum, the method comprising: Contact the catalyst system with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the molar amount of aluminum in the aluminoxane)+(the molar amount of aluminum in the alkylaluminum)+(the molar amount of aluminum in the alkylaluminum)}.

2. A method for deactivating a residual transition metal-based catalyst system in an effluent stream from an oligomerization reactor, the catalyst system containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum, the method comprising: Contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the effluent stream comprising unreacted ethylene, oligomerization products, the residual transition metal-based catalyst system containing the cocatalyst comprising the aluminoxane and optionally the alkylaluminum, and an organic reaction medium, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times of {(the number of moles of aluminum of the aluminoxane)+(the number of moles of aluminum of the alkylaluminum)+(the number of moles of aluminum of the alkylaluminum)}.

3. An oligomerization process, which comprises: A) introducing ethylene, a transition metal-based catalyst system or catalyst system components, an organic reaction medium, and optionally hydrogen into an oligomerization reactor, the transition metal-based catalyst system or catalyst system components containing a cocatalyst comprising aluminoxane and optionally an alkylaluminum; B) forming an oligomer product in the oligomerization reactor, the oligomer product comprising hexene and octene; C) discharging an effluent stream from the oligomerization reactor, the effluent stream containing unreacted ethylene, the oligomer product, a residual transition metal-based catalyst system, and the organic reaction medium; and D) contacting the effluent stream with a C4-C 18 alcohol cocatalyst deactivator, the OH molar amount of the cocatalyst deactivator being in the range of 0.5 to 1.5 times {(the molar amount of aluminum in the aluminoxane)+(the molar amount of aluminum in the alkylaluminum)+(the molar amount of aluminum in the alkylaluminum)}.

4. The method or process according to claim 2 or 3, wherein the effluent stream is introduced into a separator to remove at least a portion of the unreacted ethylene after contacting the effluent stream with the cocatalyst deactivator.

5. The method or process according to claim 2 or 3, wherein the effluent stream is contacted with the cocatalyst deactivator after removing at least a portion of the unreacted ethylene from the effluent stream in a separator.

6. The method or process according to any one of the preceding claims, wherein the alkylaluminum comprises trimethylaluminum (TMA), triethylaluminum (TEA), tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum, or any combination thereof.

7. The method or process according to any one of the preceding claims, wherein the aluminoxane comprises methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, tert-butylaluminoxane, sec-butylaluminoxane, isobutylaluminoxane, 1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane, isopentylaluminoxane, neopentylaluminoxane, or any combination thereof.

8. The method or process according to any one of the preceding claims, wherein the cocatalyst deactivator comprises butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, or a mixture thereof.

9. The method or process according to any one of the preceding claims, wherein the cocatalyst deactivator has a boiling point of at least 130 °C, at least 140 °C, at least 150 °C, at least 160 °C, or at least 170 °C and less than or equal to 300 °C, less than or equal to 280 °C, less than or equal to 250 °C, or less than or equal to 220 °C at 1 atmosphere.

10. The method or process according to any one of the preceding claims, wherein the cocatalyst deactivator comprises 2-ethyl-1-hexanol.

11. The method or process according to any one of the preceding claims, wherein the catalyst system comprises chromium, iron, cobalt, vanadium, titanium, zirconium, hafnium or a combination thereof.

12. The method or process according to any one of the preceding claims, wherein the transition metal-based catalyst system or catalyst system component comprises (i) a heteroatom ligand chromium compound complex and the cocatalyst, or (ii) a heteroatom ligand, a chromium compound and the cocatalyst.

13. The method or process according to any one of claims 1 to 12, wherein the cocatalyst comprises the aluminoxane and the alkylaluminum.

14. The method or process according to claim 13, wherein the molar ratio of aluminoxane:alkylaluminum (based on aluminum) is in the range of 100:1 to 1:100, 20:1 to 1:20, 10:1 to 1:10, 5:1 to 1:5, 10:1 to 1:1 or 8:1 to 2:

1.

15. The method or process according to any one of claims 1 to 12, wherein the cocatalyst comprises the aluminoxane but does not contain the alkylaluminum.

16. The method or process according to any one of the preceding claims, further comprising the steps of: (i) determining the amount of catalytic activity remaining after adding the cocatalyst deactivator; and (ii) adjusting the amount of the cocatalyst deactivator based on the catalytic activity.

17. The method or process according to any one of the preceding claims, wherein the molar amount of OH is at least 0.6 times, at least 0.7 times, at least 0.8 times, at least 0.9 times, at least 1 time or at least 1.1 times of {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}, and is less than or equal to 1.5 times, less than or equal to 1.4 times, less than or equal to 1.3 times or less than or equal to 1.2 times.

18. The method or process according to any one of the preceding claims, wherein: the molar amount of OH is 0.6 to 1.5 times of {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}; the molar amount of OH is 0.6 to 1.4 times of {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}; or the molar amount of OH is 0.6 to 1.3 times of {(the number of moles of aluminum in the aluminoxane)+(the number of moles of aluminum in the alkylaluminum)+(the number of moles of aluminum in the alkylaluminum)}.

19. The method or process according to any one of claims 2 to 18, wherein the oligomer product comprises: 20 to 99 wt%, 30 to 95 wt%, 40 to 95 wt%, 40 to 90 wt%, 20 to 90 wt%, 30 to 87.5 wt%, 30 to 85 wt%, 40 to 87.5 wt%, 40 to 85 wt%, 20 to 60 wt%, 30 to 55 wt% or 40 to 55 wt% of octene, based on the total amount of oligomers in the oligomer product; and Based on the total amount of oligomers in the oligomer product, 20 to 60% by weight, 25 to 55% by weight, or 30 to 50% by weight of hexene.

20. The method according to any one of claims 3 to 19, wherein: hydrogen is present in step A); and / or based on the amount of ethylene entering the reactor and the amount of ethylene in the effluent stream, the ethylene conversion of the oligomerization reactor is 20 to 95% by weight, 30 to 90% by weight, 40 to 80% by weight, 50 to 70% by weight, or 55 to 65% by weight.

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