Ligand for the generation of chromium-assisted 1-octene and method for ethylene oligomerization using the same

Abstract

A catalyst composition and a method for oligomerizing ethylene into 1-octene are described. The catalyst composition comprises a triaminobisphosphino (NPNPN) ligand system having specific phosphorus and nitrogen ligands. The terminal nitrogen atoms comprise linear alkyl hydrocarbons differing by three carbon atoms.

Description

Technology Field

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 758,783 filed November 12, 2018, and all contents of this application are incorporated herein by reference into all of those applications.

[0002] The present invention generally relates to a catalyst for a reaction that oligomerizes ethylene into 1-octene. The catalyst comprises a chromium (III) species and a ligand that enhances the oligomerization selectivity of 1-octene to 1-hexene. Background Technology

[0003] Conventional methods for producing linear alpha-olefins (LAOs), including comonomer-grade 1-butene, 1-hexene, and 1-octene, rely on the oligomerization reaction of ethylene and can yield mixtures of ethylene-derived oligomers with chain lengths of 4, 6, and 8. While not intended to be limited to theory, the chemical mechanism is believed to be dominated primarily by competitive chain growth and displacement reaction steps, resulting in a Schulz-Flory or Poisson distribution. From a commercial perspective, this product distribution presents challenges to full-range LAO producers, as each market segment exhibits different behaviors in terms of market size and growth, geographical location, and market fragmentation. Consequently, within a given economic context, while there is high demand for parts of the product spectrum, other parts may be completely unmarketable or marketable only in negligible niches, making it difficult for LAO producers to adapt to market demands. For example, some grades of polyethylene material require improved physical properties such as superior tensile strength and crack resistance, which require that 1-octene be present but other ethylene-derived oligomers not be present.

[0004] The oligomerization of ethylene usually proceeds in the presence of a suitable catalyst. In some conventional ethylene oligomerizations, namely dimerization, trimerization, or tetramerization, the catalyst has one or more disadvantages. These disadvantages may include: 1) low selectivity for the desired substance (e.g., 1-octene); 2) low selectivity for LAO isomers within the C8 cut (e.g., isomerization, branched olefin formation, etc.); 3) wax formation (e.g., formation of heavy, long-chain (high carbon number) products); 4) polymer formation (including polyethylene containing branched and / or cross-linked polyethylene) which can lead to equipment contamination as well as a loss of yield of a significant amount of LAO products; 5) insufficient turnover / catalytic activity resulting in an increased production cost per kilogram; 6) high catalyst- or ligand costs; 7) complex multi-step ligand synthesis resulting in limited catalyst availability and high catalyst costs; 8) sensitivity of the catalytic role to both activity and selectivity for tracking impurities (e.g., leading to loss or degradation of the catalyst); 9) difficult handling of catalyst components in mechanical / commercial environments (e.g., synthesis, premixing, inactivation, catalyst recovery, or ligand recovery of catalyst complexes); 10) harsh reaction conditions, such as high temperature and pressure, resulting in the need for specialized equipment (increasing investment, maintenance, and energy costs); 11) high co-catalyst / activator costs or consumption; and / or 12) sensitivity to various co-catalyst qualities, which often occur when using large quantities of relatively obscure compounds (e.g., specific methylaluminoxane (MAO)-deriveds) as activators.

[0005] An attempt to produce LAO is described. As an exemplary method, Al-Hazmi et al. U.S. Patent Application No. 2017 / 0203288 describes a chromium compound and R 1 , R 2 , R 3 , R4 , R 5 , R 6 , and R 7 Each of these independently consists of hydrogen, halogen, amino, trimethylsilyl, or C1 to C 20 Hydrocarbyl of, preferably straight-chain or branched C1 to C 10 Alkyl, phenyl, C6 to 7 C 20- aryl or C6 to C 20 Alkyl-substituted phenyl, (R 1 ) (R 2 )N―P(R 3 )―N(R 4 )―P(R 5 )―N(R 6 )(R 7 The use of a catalyst composition that may include a functionalized triaminodiphosphine (NPNPN) ligand having the formula ) is described. The catalyst is C 10+ There is a problem in that it generates more than 8 wt% and the weight percentage ratio of 1-hexene to approximately 1-octene is about 50:50. When increasing the ratio to favor C6 over C8, C 10+ The amount of also increases, lowering the total amount of the desired product. In other subsequent examples, Peulecke ( Dalton Transactions , 2016 45; 8869-8874) is (R 1 )(R 2 )N―P(Ph)―N(R 3 )―P(PH)―N(R 4 )(R 5 We describe the production of a mixture of 1-hexene and 1-octene using an NPNPN ligand having the chemical formula ). The present catalyst system contains C greater than 11 wt% 10+ Produces, and when the yield of 1-octene increases according to the yield of 1-hexene, C 10+ There is a problem in that the production of hydrocarbons increases.

[0006] For this reason, there remains a need in the field of technology for a catalyst system for the oligomerization of ethylene that can obtain 1-octene with high selectivity and purity.

[0007] A discovery has been made that provides a solution to at least some of the problems associated with the reaction of oligomerizing ethylene to 1-octene. The solution is based on the use of an NPN(CH3)PN ligand system having a specific terminal amine alkyl substituent and a phosphorus. In particular, the phosphorus substituent is limited to an aromatic group and / or an aromatic group substituted with an alkyl group, and the terminal amine comprises linear alkyl groups that differ by three carbon atoms. As illustrated, but not limited to, in the examples, a surprising discovery is that limiting the phosphorus atom substituent to an aromatic group or a substituted aromatic group, and limiting the length of the hydrocarbon chain bonded to the terminal nitrogen atom, produces at least 60 weight% of C8 hydrocarbons, while having a selectivity for 1-octene of 99% or more and less than 2 weight% of the solvent-insoluble material (e.g., polymer).

[0008] In one aspect of the present invention, the present invention describes a catalyst composition for oligomerizing ethylene into 1-octene. The catalyst composition comprises a chromium (III) species and a ligand having the following chemical formula:

[0009]

[0010] Here, Ar 1 and Ar 2 is each independently an aromatic group or a substituted aromatic group, n is 0 or 1, and m is n+3. In some embodiments, Ar 1 and Ar 2 Each is a phenyl group or a phenyl group substituted with an alkyl group, preferably both are phenyl groups. As one example, n is 0 and the catalyst is (CH3)( n-C4H9)NP(C6H5)N(CH3)NP(C6H5)N(CH3)( n- It is represented by the following structural formula as C4H9:

[0011] .

[0012] As another example, n is 1 and the catalyst is (CH3CH2)( n- C5H 11 )NP(C6H5)N(CH3)NP(C6H5)N(CH2CH3)( n- C5H 11 It is expressed by the following structural formula as ):

[0013] .

[0014] The above catalyst composition comprises an activator or a co-catalyst (e.g., a methylaluminoxane compound, preferably methyl Iso It may include a butyl aluminum oxide compound. The chromium (III) species may include any inorganic or organic chromium compound in which the chromium has a valence of +3. Non-limiting examples of the chromium (III) species may include chromium (III) acetylacetonate, chromium (2,2,6,6,-tetramethyl-3,5-heptadionate)3, chromium (III)2-ethylhexanoate, chromium trichloride tris-tetrahydrofuran, chromium (III) octanoate, or chromium (III) naphthenate, or any combination thereof.

[0015] The present invention describes a process for producing 1-octene using a catalyst composition of the present invention. The process for synthesizing 1-octene may include contacting a reactant stream consisting of an olefin source with a solution composed of the catalyst composition of the present invention to synthesize an oligomer composition containing 1-octene. The catalyst composition may also include a solvent (e.g., a saturated hydrocarbon or an aromatic hydrocarbon, preferably n-hexane, methylcyclohexane, toluene, or a mixture thereof). The contacting step may include a temperature of 15 to 100°C, preferably 40 to 70°C, and / or a pressure of at least 2 MPa or 2 to 20 MPa, preferably 2 to 7 MPa. During the process, a material insoluble in the solvent (e.g., a polymeric material) may be produced in an amount less than 2 wt%, preferably less than 1 wt%, more preferably less than 0.5 wt%, or not produced at all. In some examples, the catalyst composition It may include chromium(III) species, and an activator or co-catalyst. In another example, the catalyst composition is , the chromium (III) species, and the activator or the co-catalyst may be included. In some embodiments, the product stream may contain 1-hexene. In these embodiments, the reaction selectivity of 1-octene may be greater than 99% and / or the weight ratio of 1-hexene to 1-octene may be less than 0.3.

[0016] At least 20 embodiments are described below within the context of the present invention. Embodiment 1 is a catalyst composition for oligomerizing ethylene into 1-octene. The catalyst composition comprises a chromium (III) species and a ligand having the following chemical formula:

[0017]

[0018] Here, Ar 1 and Ar 2Each is independently an aromatic group or a substituted aromatic group, n is 0 or 1, and m is n+3. Example 2 is a modified version of Example 1 in which Ar 1 and Ar 2 Each is a catalyst composition comprising an aromatic group independently comprising a phenyl group, a substituted phenyl group, or two or more conjugated rings. Example 3 is a modified version of Example 2 in which Ar 1 and Ar 2 Both are catalyst compositions having a phenyl group. Example 4 is a catalyst composition in which n is 0 in Example 3 and the catalyst has the following chemical formula:

[0019] .

[0020] Example 5 is a catalyst composition in which n is 1 in Example 2 and the catalyst has the following structure:

[0021] .

[0022] Example 6 is a catalyst composition in any one of Examples 1 to 5, wherein the composition further comprises an activator or a co-catalyst. Example 7 is a catalyst composition in Example 6, wherein the activator or co-catalyst is a methylaluminoxan compound. Example 8 is a catalyst composition in Example 6, wherein the activator or co-catalyst is methyl Iso - It is a catalyst composition that is a butyl aluminum oxide compound. Example 9 is a catalyst composition in which the chromium (III) species in Example 8 is chromium (III) acetylacetonate, chromium (2,2,6,6-tetramethyl-3,5-heptadioneate)3, chromium (III)2-ethylhexanoate, chromium trichloride tris-tetrahydrofuran, chromium (III) octanoate, or chromium (III) naphthenate.

[0023] Example 10 is a method for producing 1-octene from ethylene. The method comprises the step of contacting a reactant stream containing an olefin source with a solution containing the catalyst composition described in any one of Examples 1 to 9 to produce an oligomer composition containing 1-octene. Example 11 is a method in which the solution in Example 10 contains a solvent. Example 12 is a method in which the solvent in Example 11 is a saturated hydrocarbon or an aromatic hydrocarbon. Example 13 is a method in which the solvent in Example 12 is n-hexane, methylcyclohexane, toluene, or a mixture thereof. Example 14 is a method in which, in any one of Examples 10 to 13, the product stream further contains 1-hexene, the selectivity for 1-octene is greater than 60 wt%, and the weight ratio of 1-hexene to 1-octene is less than 0.3. Example 15 is a method in which the amount of a substance insoluble in a solvent is formed in any one of Examples 10 to 14 in an amount less than 2 weight percent. Example 16 is a method in which the catalyst composition in Example 15 comprises the following substances:

[0024] .

[0025] Example 17 is a method comprising additionally including a chromium (III) species, an activator, or a co-catalyst in either Example 15 or Example 16. Example 18 is a method comprising, in any one of Examples 10 to 17, that the catalyst composition comprises the chromium (III) species, the activator, the co-catalyst, and the following substances:

[0026] .

[0027] Example 19 is a method comprising, in any one of Examples 10 to 18, that the contact is made at a temperature of 15 to 100°C, preferably at a temperature of 40 to 70°C. Example 20 is a method comprising, in any one of Examples 10 to 19, that the contact is made at a pressure of at least 2 MPa or 2 to 20 MPa, preferably at a pressure of 2 to 7 MPa.

[0028] Other embodiments of the invention are discussed in this application. Any embodiment discussed regarding one aspect of the invention applies to other aspects of the invention, and vice versa. Each embodiment described herein is understood to be an embodiment of the invention that may also be applied to other aspects of the invention. Any embodiment discussed herein is considered to be embodied in any method or composition of the invention, and vice versa. Furthermore, compositions of the invention may be used to realize the method of the invention.

[0029] The following includes definitions of various terms and phrases used throughout this specification.

[0030] The term "alkyl group" means a linear or branched saturated hydrocarbon. Non-limiting examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl groups, etc.

[0031] The "aryl" or "aromatic" group is a substituted or unsubstituted single or polycyclic hydrocarbon in which single and double bonds alternate in each ring structure. Non-limiting examples of aryl group substituents include alkyl, substituted alkyl groups, linear or branched unsaturated hydrocarbons, halogen, hydroxyl, alkoxy, haloalkyl, haloalkoxy, carboxylic acid, ester, amine, nitro, amide, nitrile, acyl, alkyl silane, thiol, and thioether substituents. Non-limiting examples of alkyl groups include linear or branched C1 to C5 hydrocarbons. Non-limiting examples of unsaturated hydrocarbons include C2 to C5 hydrocarbons having at least one double bond (e.g., vinyl). The above aryl or alkyl group may be substituted with halogen, hydroxyl, alkoxy, haloalkyl, haloalkoxy, carboxylic acid, ester, ether, amine, nitro(-NO2), amide, nitrile(-CN), acyl, alkyl silane, thiol, and thiol ester substituents. Non-limiting examples of halogens include chloro(-Cl), bromo(-Br), or fluoro(-F) substituents. Non-limiting examples of haloalkyl substituents include -CX3, -CH2X, -CH2CH2X, -CHXCH2X, -CX2CHX2, -CX2CX2, where X is F, Cl, Br, or a combination thereof. Non-limiting examples of amine substituents include -NH2, -CH2NH2, -CHCH2NH2, and -C(NH2)CH3. Non-limiting examples of alkoxy groups include -OCH3, -OCH2CH3, and their analogs. Non-limiting examples of alkyl silane substituents include Si(CH3)3, -Si(CH2CH3)3, and their analogs. Non-limiting examples of polycyclic groups include two or more conjugated rings (e.g., conjugated aromatic rings) and substituted conjugated rings, such as -C 10 It includes a conjugated ring system having H7 and 10 substituted carbons.

[0032] The phrase "insoluble in solvent" refers to hydrocarbon substances with a molecular weight of 400 g / mol and greater (30 or more carbon atoms) that do not form a homogeneous solution in the reaction solvent under reaction conditions. For example, said substances precipitate or form a second phase during the reaction. Such substances are present in an amount less than 2 wt%, preferably less than 1 wt%, and more preferably less than 0.5 wt%, as determined by gravitational measurement.

[0033] The terms “about” or “nearly” are defined as understood by a person skilled in the art. In one non-limiting embodiment, the terms are defined as approximately 10%, preferably approximately 5%, more preferably approximately 1%, and most preferably approximately 0.5%.

[0034] The terms “weight%”, “volume%”, or “mole%” each mean the weight percentage, volume percentage, and mole percentage of a component relative to the total weight, total volume, or total mole of a substance containing the component. In one non-limiting example, 10 grams of a component in 100 grams of a substance is 10 weight% of the component.

[0035] The term "substantially" and its derivatives are defined as including a range of approximately 10%, a range of approximately 5%, a range of approximately 1%, or a range of approximately 0.5%.

[0036] "Repressing," "reducing," "preventing," or "avoiding," or any derivatives of these terms, when used in claims and / or specifications, include any measurable reduction or complete inhibition to obtain a desired result.

[0037] The term "effective," when used in specifications and / or claims, means sufficient to achieve the desired, expected, or intended result.

[0038] When the word "one" is used in conjunction with terms such as "composing," "including," "containing," or "having," its usage may mean "one," but it also corresponds to the meanings of "one or more," "at least one," and "one or more than one."

[0039] The words "constituting" (and any other form such as "constitut"), "having" (and any other form such as "have"), "including" (and any other form such as "include"), or "containing" (and any other form such as "containing") are inclusive and unrestricted and do not exclude additional and unlisted composition or method steps.

[0040] The catalytic composition of the present invention may “comprise,” “consist essentially of,” or “consist of” specific materials, elements, compositions, etc. disclosed in the specification. With respect to the transition “consist essentially of,” in one non-limiting aspect, a fundamental and novel feature of the catalytic composition of the present invention is its ability to promote the reaction of oligomerizing ethylene to 1-octene with greater selectivity than 60%, with the production of a minimal amount of solvent-insoluble material (e.g., less than 2 weight%) and the resulting 1-octene having a purity of at least 99%.

[0041] Other embodiments, characteristics, and advantages of the present invention will become apparent from the following drawings, detailed description, and examples. However, the drawings, detailed description, and examples should be understood as being provided only by illustration and not intended to be limiting when illustrating specific embodiments of the present invention. Additionally, any variation or modification within the spirit and scope of the invention should be considered obvious to those skilled in the art from this detailed description. In additional embodiments, characteristics of a specific embodiment may be combined with characteristics of other embodiments. For example, characteristics of one embodiment may be combined with characteristics from some of the other embodiments. In additional embodiments, additional characteristics may be added to the specific embodiments described herein. Brief explanation of the drawing

[0042] The advantages of the present invention will become apparent to those skilled in the art from the benefit of the following detailed description and reference to the attached drawings. Drawing 1 This is an illustration schematically showing a system for producing 1-octene from the oligomerization of ethylene. While the above invention is sensitive to various modifications and alternative forms, specific embodiments thereof are illustrated by the methods exemplified in the drawings. The drawings may not be limited to their scale. Specific details for implementing the invention

[0043] It has been discovered that 1-octene is produced from the oligomerization of ethylene with an acceptable yield, high selectivity, and without producing a significant amount of solvent-soluble material. This discovery is based on the use of an NPNPN ligand system. In particular, and as illustrated, but not limitedly, in the examples, the oligomerization product stream may contain at least 60 wt% 1-octene, less than 25 wt% 1-hexene, and less than 2 wt% of solvent-insoluble material (e.g., polymeric material). This contrasts with ligands of the prior art that produce more than 2 wt% of polymeric material. Important variables include the selection of phosphorus and nitrogen substituents. The phosphorus substituent comprises an aromatic group or an aromatic group substituted with an alkyl group, the intermediate nitrogen substituent comprises a methyl substituent, and the terminal nitrogen substituent comprises different linear alkyl hydrocarbons differing by three carbon atoms. This combination of substituents provides an excellent and simple ligand system that produces 1-octene with high purity and selectivity of over 60 wt%.

[0044] These and other non-limiting aspects of the invention are discussed in additional details in the following sections.

[0045] A. Catalytic composition

[0046] The catalyst composition may comprise the ligand of the present invention, a chromium(III) species, and an activator or co-catalyst. The ligand of the present invention may be prepared as described in the specification and examples. The catalyst composition may be provided as a solution in an aliphatic or aromatic hydrocarbon solvent. Aliphatic hydrocarbon solvents include hexane, methylcyclohexane, cyclohexane, n- It may include heptane, toluene, and analogs thereof.

[0047] The ligand of the present invention can be represented by the following chemical formula:

[0048]

[0049] Here, Ar 1 and Ar 2 Each is independently an aromatic group or a substituted aromatic group, n is 0 or 1, and m is n+3. The aromatic group or substituted aromatic group is phenyl (Ph), C6 to C 11 aryl or C6 to C 20 It includes a substituted aryl group. C6 to C 11 Non-limiting examples of aryl groups include methylbenzyl, dimethylbenzyl (substituted at ortho, meta, and para positions), ethylbenzyl, propylbenzyl, and analogs thereof. Substituted C6 to C 20Non-limiting examples of substituents of the aryl group include alkyl, substituted alkyl groups, linear or branched alkyl groups, linear or branched unsaturated hydrocarbons, halogens, hydroxyl, alkoxy, haloalkyl, haloalkoxy, carboxylic acids, esters, amines, nitro, amides, nitriles, acyl, alkyl silanes, thiols, and thioether substituents. Non-limiting examples of the alkyl group include linear and branched C1 to C5 hydrocarbons. Non-limiting examples of the unsaturated hydrocarbon include C2 to C5 hydrocarbons containing at least one double bond (e.g., vinyl). The above aryl or alkyl group may be substituted with halogen, hydroxyl, alkoxy, haloalkyl, haloalkoxy, carboxylic acid, ester, ether, amine, nitro(-NO2), amide, nitrile(-CN), acyl, alkyl silane, thiol, and thioether substituents. Non-limiting examples of halogens include chloro(-Cl), bromo(-Br), or fluoro(-F) substituents. Non-limiting examples of haloalkyl substituents include -CX3, -CH2X, -CH2CH2X, -CHXCH2X, -CX2CHX2, -CX2CX2, where X is F, Cl, Br, or a combination thereof. Non-limiting examples of amine substituents include -NH2, -CH2NH2, -CHCH2NH2, and -C(NH2)CH3. Non-limiting examples of alkoxy groups include -OCH3, -OCH2CH3, and their analogs. Non-limiting examples of alkyl silane substituents include -Si(CH3)3, -Si(CH2CH3)3, and their analogs. Non-limiting examples of polycyclic groups include conjugated aromatic rings and substituted conjugated aromatic rings, e.g., -C 10 It includes a conjugated aromatic ring system having H7 and 10 substituted carbons. In some embodiments, the C6 to C 20 The aryl group is chlorobenzene, bromobenzene, trifluorotoluene, phenylamine, nitrobenzene, dichlorotoluene, benzonitrile, trimethylbenzylsilane, benzylmethyl ether, or a conjugated aromatic ring (C 10H7). The above ligand is (CH3)( n- C4H9)NP(Ar 1 )N(CH3)NP(Ar 2 )N(CH3)( n- C4H9) and (CH3CH2)( n- C5H 11 )NP(Ar 1 )N(CH3)NP(Ar 2 )N(CH2CH3)( n- C5H 11 ) (CH3)( n- C4H9)NP(C6H5)N(CH3)NP(C6H5)N(CH3)( n- C4H9) and (CH3CH2)( n- C5H 11 )NP(C6H5)N(CH3)NP(C6H5)N(CH2CH3)( n- C5H 11 ) may be. The structures of the above ligands are exemplified as follows:

[0050]

[0051]

[0052]

[0053]

[0054] Here, R1 and R2 are alkyl groups, e.g., methyl, ethyl, propyl, isopropyl, butyl, tersiery - Represents butyl and pentyl and their analogs.

[0055] The above NPNPN ligand system can be produced by a synthetic approach known to those skilled in the art. In some embodiments, the ligand (1) is available by the reaction pathway shown in Schematic I.

[0056]

[0057] Here, Ar 1 and Ar 2 R3 is defined earlier, R3 is methyl or ethyl, and R4 is butyl when R3 is methyl and pentyl when R3 is ethyl.

[0058] The chromium species may be an organic salt, an inorganic salt, a coordination complex, or an organometallic complex of chromium (III). In one embodiment, the chromium species is an organometallic chromium (III) species. Non-limiting examples of chromium species include chromium (III) acetylacetonate, chromium (III) octanoate, CrCl3 (tetrahydrofuran)3, chromium (III)-2-ethylhexanoate, chromium (III) chloride, or any combination thereof. The molar ratio of ligand to chromium may be about 0.5 to 50, about 0.5 to 5, about 0.8 to about 2.0, about 1.0 to 5.0, or preferably about 1.0 to about 1.5.

[0059] The activator (also known as a co-catalyst in the art) may be an aluminum compound. Non-limiting examples of aluminum compounds include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, methylaluminoxane, or mixtures thereof. In some embodiments, the activator may be a modified methylaluminoxane, more preferably MMAO-3A (CAS No. 146905-79-5), which is a modified methylaluminoxane type 3A available from Akzo Nobel, a toluene solution containing 7% aluminum corresponding to a concentration of about 18% MMAO-3A. The aluminum / chromium molar ratio may be about 1 to about 1000, about 10 to about 1000, about 1 to 500, about 10 to 500, about 10 to about 300, about 20 to about 300, or preferably 50 to about 300.

[0060] The catalyst composition may further comprise a solvent. Non-limiting examples of solvents are straight-chain and cyclic aliphatic hydrocarbons, straight-chain olefins, ethers, aromatic hydrocarbons, and analogs thereof. Combinations comprising at least one of the aforementioned solvents may also be used. Preferably, the solvent is toluene,n - It is heptane or methylcyclohexane or any mixture thereof.

[0061] The concentration of the chromium compound in the above solvent depends on the specific compound used and the desired reaction rate. In some embodiments, the concentration of the chromium compound is about 0.01 to about 100 mmol / 1, about 0.01 to about 10 mmol / 1, about 0.01 to about 1 mmol / 1, about 0.1 to about 100 mmol / 1, about 0.1 to about 10 mmol / 1, about 0.1 to about 10 mmol / 1, about 1 to about 10 mmol / 1, and about 1 to about 100 mmol / 1 per liter. Preferably, the concentration of the chromium compound is about 0.1 to about 1.0 mmol / 1.

[0062] In some embodiments, the catalyst composition is chromium(III) acetylacetonate as a chromium compound, and Et as an NPNPN ligand. n- pentyl)N—P(Ph)-N(Me)-P(Ph)-N( n- It includes pentyl)Et and MMAO-3A as an activator. In another embodiment, the catalyst composition comprises chromium(III) acetylacetonate as a chromium compound and Me as an NPNPN ligand. n- butyl)N—P(Ph)-N(Me)-P(Ph)-N( n- butyl)Me, includes MMAO-3A as an activator.

[0063] B. System for the oligomerization of 1-octene

[0064] The catalyst composition of the present invention can be used in a method for oligomerizing ethylene into 1-octene. In one embodiment, the method comprises contacting ethylene with the catalyst composition under ethylene oligomerization conditions effective for producing 1-octene. A person skilled in the art will understand that ethylene oligomerization for the production of 1-octene is by ethylene tetramerization.

[0065] FIG. 1 illustrates a schematic diagram of a system for producing 1-octene. The system (100) may include an inlet (102) for a reactant feed containing ethylene, a reaction zone (104) configured to deliver fluid to the inlet, and an outlet (106) configured to deliver fluid to the reaction zone (104) and remove a product stream from the reaction zone. The reaction zone (104) may contain a catalyst composition of the present invention. The ethylene reactant feed is provided through the inlet (102). through It may enter the reaction zone (104). In some embodiments, the ethylene reactant feed may be used to maintain pressure inside the reaction zone (104). In some embodiments, the reactant feed stream contains an inert gas (e.g., nitrogen or argon). After a sufficient amount of time has elapsed, the product stream exits the product outlet (106). through The product stream can be removed from the reaction zone (104). The product stream can be sent to another process unit and / or stored and / or transported.

[0066] The system (100) may include one or more heating and / or cooling devices (e.g., insulation in a wall, electric heater, covered heat exchanger) or controllers (e.g., computer, fluid valve, automated valve, etc.) necessary to control the reaction temperature or pressure of the reactant mixture. Although only one reactor is shown, it should be understood that multiple reactors may be grouped into one unit, or multiple reactors may be grouped into one heat exchange unit.

[0067] As previously described, the method and catalyst composition of the present invention enable the production of 1-octene with high selectivity, limiting the distribution of LAO products to 1-hexene and 1-octene. High selectivity for 1-octene is an advantageous characteristic, considering that it leads to high product purity, thereby avoiding the need for additional purification steps in the separation process. Additional advantageous characteristics of the catalyst composition and method include the suppression of ethylene polymerization reactions that lead to the formation of unwanted polymers, mild reaction conditions, and consequently, a reduction in operating and energy costs as well as capital for equipment. Additionally, a relatively simple and intuitive process design is possible. The selectivity for 1-octene is greater than 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, or about 100 wt% or any range or value in between. The purity of 1-octene can be at least about 99% or 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, or 99.9%. A purity of at least 99.1% is preferred. In one embodiment, when 1-hexene is produced, the weight ratio of 1-hexene to 1-octene may be less than 0.3 or 0 to 0.3 or 0.1, 0.15, 0.2, 0.25, or 0.3 or any range or value in between.

[0068] Examples

[0069] The present invention is further elaborated by the methods of specific embodiments. The following embodiments are provided for illustrative purposes only and are not intended to limit the invention in any way. A person skilled in the art will readily recognize various non-essential variables to which changes or modifications may be made to yield essentially the same result.

[0070] Example 1

[0071] (Synthesis of Ligand 2, Ligand 3, and Comparison Ligand)

[0072] Two methodologies can be used to prepare ligands having the above structural formulas (2) and (3). The comparison ligand has the following structural formula, where the amino functionality includes a methyl group and an ethyl group (i.e., n is less than 3).

[0073]

[0074] Route A, general procedure (see Schematic 1). All operations were performed under an inert atmosphere. Bis(chlorophosphino)amine (PhP(Cl)N(CH3)P(Cl)Ph, 4.42 g, 14 mmol) was dissolved in 20 mL of anhydrous toluene. Appropriate secondary amines (29.4 mmol) and NET3 (35 mmol) were mixed with 30 mL of anhydrous toluene and then cooled to -10°C. The toluene solution of bis(chlorophosphino)amine was added dropwise to the reaction mixture under vigorous stirring under an inert atmosphere. The addition of the reactants resulted in the precipitation of a white gel-like substance. With continuous stirring, the solution was heated to 25°C over 3 hours, then heated to 75°C, and stirred at that temperature for an additional 12 hours. After all volatile compounds were vaporized under vacuum, the residual material was removed in anhydrous high-temperature n-heptane, and the insoluble material was separated by filtration. The vaporization of the solvent yielded a white oil. The purity of the product is 1 H, 13 C and 31 It was confirmed using P NMR. If desired, the product can be recrystallized from n-hexane, cyclohexane, n-heptane, or n-pentane to increase purity.

[0075] Route B, general procedure (see Schematic 1). All operations were performed under an inert atmosphere. A suitable secondary amine (10 mmol) was dissolved in 20 mL of anhydrous n-heptane, cooled to -10°C, and treated with n-BuLi in excess of 5% molarity dissolved in n-hexane. The solution was then stirred for 3 hours while left to rise to 25°C, and a white precipitate formed. The solid was separated from the solution, washed with n-hexane, and transferred to a flask using 30 mL of anhydrous ether. The resulting suspension was cooled to -10°C, and a solution of bis(chlorophosphino)amine (PhP(Cl)N(CH3)P(Cl)Ph, 1.55 g, 4.9 mmol) dissolved in 30 mL of anhydrous ether was added dropwise to the reaction mixture under vigorous stirring. After the above addition, the reaction mixture was left to be heated to 25°C and continuously stirred for 12 hours. During the reaction process, a white solid was formed. The insoluble material was separated by filtration, washed with ether, and discarded. The solution and the washing solution were combined, and the solvent was removed under vacuum, producing a white viscous liquid. The purity of the product is 1 H, 13 C and 31 It was confirmed using P NMP. If desired, the product could be recrystallized from n-hexane, cyclohexane, n-heptane, or n-pentane to increase purity.

[0076] The precursor PhP(Cl)N(Me)P(Cl)Ph is Jefferson et al. (J. Chem. Soc. Dalton Trans It was prepared by the procedure of . 1973, 1414-1419).

[0077] Example 2

[0078] (Preparation of catalyst composition and ethylene oligomer)

[0079] The reactor, equipped with a dip tube, thermowell, mechanical paddle, stirrer, cooling coil, and a unit for controlling temperature, pressure, and stirrer speed (all connected to a data acquisition system), was heated to 130°C under vacuum conditions to inert it, and then cooled by ventilation with a 30°C dry nitrogen stream. An isobaric ethylene supply was maintained by a gas dosing control unit connected to the data acquisition system. Ethylene consumption was monitored via the pressure loss in the injection cylinder over time with the help of a computerized data acquisition system.

[0080] A suitable amount of stock toluene solution, in which the above ligand (ligand (2) of the present invention or a comparative ligand) and chromium (III) acetylacetonate as a chromium precursor are dissolved at a ratio of ligand to chromium of 1.20, was measured and filled into a Schlenk tube under an inert atmosphere. A volume of 30 mL of anhydrous n- Heptane was introduced into a stainless steel pressure reactor and heated to the reaction temperature. After the temperature of the reactor stabilized, the reactor was pressurized with ethylene to 30 bar and left for 0.5 hours under continuous mechanical stirring. Subsequently, the pressure was reduced to 0.2 bar (0.02 MPa), and a 0.3 M MMAO-3A stock solution dissolved in an appropriate amount of anhydrous n-heptane was introduced into the reactor through the filling port to achieve an Al-to-Cr ratio of 300. Stirring continued for 10 minutes. Subsequently, a mixture of chromium and ligand solution was introduced into the reactor through the filling port.

[0081] Immediately after the introduction of the catalyst into the reactor, the pressure was increased to 30 bar (3 MPa). Standard reaction conditions were as follows: ethylene at a pressure of 30 bar (3 MPa), a temperature of 45°C, and a stirring speed of 450 RPM. After 1 hour of catalyst operation, the ethylene supply was stopped, and the reactor temperature was lowered to 5°C. The ethylene in the reactor was vented at a pressure of 0.2 bar (0.02 MPa). The reaction was carried out with 0.3 M HCl / Iso- The reactor was quenched with a propanol mixture and stopped. The liquid product was analyzed using gas chromatography with a known amount of internal standard toluene. Any insoluble byproducts, namely wax and polyethylene, were filtered, dried, and weighed. Successive catalyst experiments were performed without cleaning the reactor with the components and amounts described above. Table 1 shows the results for Structural Formula 2 (first and second operations) and the control group ligand.

[0082] catalyst activity (kg / g Cr *h) % weight, C6 (1-Hexene, %) % weight, C8 (1-octene, %) % weight of a substance insoluble in solvent 2 (First operation) 179.15 21.55(79.20) 76.86(99.41) 0.32 2 (Second operation) 251.84 22.29(75.37) 75.88(99.40) 0.57 6 Comparison Group 95.45 40.10(76.78) 58.11(96.13) 1.09

[0083] Table 1 summarizes the results of ethylene oligomerization experiments conducted using a catalyst system prepared with standard conditions, a catalyst having the ligand shown by structural formula (2), and a control group catalyst having the ligand shown by structural formula (6). The table shows the selectivity in weight percent for hexene (C6), octene (C8), and solvent-insoluble substances in the liquid phase. The numbers in parentheses show the selectivity of each linear alpha-olefin in the total C6 / C8 fraction. This LAO purity is generally advantageously high. The control group catalyst (6) differs from catalyst (2) in that the ligand of the control group catalyst has a carbon chain that is two carbon atoms (i.e., ethyl) shorter than the carbon chain (i.e., butyl) of the ligand of catalyst 2. Both operations are shown in catalyst S2. The second consecutive operation is observed to typically show better performance than the first operation. As shown, the second consecutive operation has higher catalytic activity than the first catalyst operation. While not limited to theory, this rather typical behavior is believed to be due to the reactor being dried and cleaned during the first operational phase.

[0084] Although the embodiments of this application and their advantages are specifically described, it should be understood that various changes, substitutions, and modifications may be made to the embodiment without departing from the spirit and scope of the embodiment as defined by the appended claims. Furthermore, the intent of this application is not to limit it to the specific embodiments regarding the processes, apparatus, manufacture, composition of materials, manner, method, and step described in the specification. As any of the ordinary art in the relevant field can be readily recognized from the disclosure described above, processes, apparatus, manufacture, composition of materials, manner, method, or step corresponding to the embodiments described herein may be utilized to perform substantially the same function or achieve substantially the same result. For this reason, the appended claims are intended to include such processes, apparatus, manufacture, composition of materials, manner, method, or step in the spirit thereof.

Claims

Claim 1 A catalyst composition for the oligomerization of ethylene to 1-octene, wherein the catalyst composition comprises: a chromium(III) species; and a ligand of the following chemical formula: Here, Ar 1 and Ar 2 Each is independently an aromatic group or a substituted aromatic group, n is 0 or 1, and m is n+3. Claim 2 In paragraph 1, the above Ar 1 and Ar 2 A catalyst composition comprising, respectively, an aromatic group comprising a phenyl group, a substituted phenyl group, or two or more conjugated rings independently. Claim 3 In paragraph 2, the above Ar 1 and Ar 2 A catalyst composition in which both are phenyl groups. Claim 4 In paragraph 3, n is 0, and the catalyst is A catalyst composition having the structure of Claim 5 In paragraph 2, n is 1, and the catalyst is A catalyst composition having the structure of Claim 6 A catalyst composition according to any one of claims 1 to 5, wherein the composition further comprises an activator or a co-catalyst. Claim 7 A catalyst composition according to claim 6, wherein the activator or co-catalyst is a methylaluminoxan compound. Claim 8 In claim 6, the activator or co-catalyst is methyl Iso - A catalyst composition that is a butyl aluminum oxide compound. Claim 9 A catalyst composition according to claim 8, wherein the chromium (III) species is chromium (III) acetylacetonate, chromium (2,2,6,6-tetramethyl-3,5-heptadioneate)3, chromium (III)2-ethylhexanoate, chromium trichloride tris-tetrahydrofuran, chromium (III) octanoate or chromium (III) naphthenate. Claim 10 A method for producing 1-octene from ethylene, wherein the method comprises contacting a reactant stream containing an olefin source with a solution containing the catalyst composition of claim 1 to produce an oligomer composition containing 1-octene. Claim 11 In paragraph 10, the above solution comprises a solvent, a method. Claim 12 In claim 11, the method wherein the solvent is a saturated hydrocarbon or an aromatic hydrocarbon. Claim 13 In claim 12, the method wherein the solvent is n-hexane, methylcyclohexane, toluene, or a mixture thereof. Claim 14 A method according to any one of claims 10 to 13, wherein the oligomer composition further comprises 1-hexene, the selectivity for 1-octene is greater than 60 weight%, and the weight ratio of 1-hexene to 1-octene is less than 0.

3. Claim 15 A method according to any one of claims 10 to 13, wherein the amount of a substance insoluble in the solvent is formed in an amount less than 2 weight percent. Claim 16 In item 15, the catalyst composition is A method including Claim 17 In claim 15, the method wherein the catalyst composition further comprises an activator or a co-catalyst. Claim 18 In any one of claims 10 to 13, the catalyst composition comprises an activator or a co-catalyst and A method including Claim 19 A method according to any one of claims 10 to 13, wherein the contact is performed at 15 to 100°C. Claim 20 A method according to any one of claims 10 to 13, wherein the contact is made at a minimum of 2 MPa or 2 to 20 MPa.

Images