Synthesis of Normal Alpha Olefins Using Decarbonylative Olefination

Abstract

The alpha olefin synthesis process includes (i) subjecting a first normal alpha olefin to hydroformylation in the presence of carbon monoxide and hydrogen to form a first linear aldehyde, (ii) subjecting the first linear aldehyde to decarbonylative olefination to form a linear internal olefin, (iii) subjecting the linear internal olefin to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form a second linear aldehyde, and (iv) subjecting the second linear aldehyde to hydrogenation to form a linear alcohol, followed by dehydration to form a second normal alpha olefin, or subjecting the second linear aldehyde to a combined hydrogenation-dehydration in a single step to form a second normal alpha olefin. Using this process, for example, ethylene can be converted to 1-hexene, and 1-butene can be converted to 1-decene.

Description

Technical Field

[0001] The present invention generally relates to a process for producing normal alpha olefins in a multi-step synthesis scheme that may include a hydroformylation step, a decarbonylative olefination step, an isomerization-hydroformylation step, a hydrogenation step, and a dehydration step.

Background Art

[0002] The synthesis of normal alpha olefins with a specific number of carbon atoms, particularly 1-hexene, 1-octene, and 1-decene, is very important in the chemical industry. However, with current catalysts and reaction processes, it is difficult to selectively produce only the alpha olefin fraction with the desired number of carbon atoms rather than a complex mixture of olefin products. It would be beneficial to develop a new method for producing a specific normal alpha olefin having a specific number of carbon atoms. Accordingly, the present invention generally aims at these objectives.

Summary of the Invention

[0003] This summary is provided to introduce, in a simplified form, certain concepts that are further described herein. This summary is not intended to identify essential or indispensable features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0004] The processes disclosed and described herein are: (i) subjecting a first normal alpha olefin having the structure (C) n -C=C to hydroformylation in the presence of carbon monoxide and hydrogen to form a first composition comprising a first linear aldehyde having the structure C(C) n+1 CH(=O), (ii) subjecting the first linear aldehyde to decarbonylative olefination to form C 2n+5forming a second composition comprising linear internal olefins, (iii) subjecting the linear internal olefins to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form a third composition comprising a second linear aldehyde having the structure C(C) 2n+4 CH(=O), and (iv-a) subjecting the second linear aldehyde to hydrogenation-dehydration to form a resulting composition comprising a second normal alpha olefin having the structure (C) 2n+4 -C=C, or (iv-b1) subjecting the second linear aldehyde to hydrogenation to form a fourth composition comprising a linear alcohol having the structure C(C) 2n+4 C(OH), and (iv-b2) subjecting the linear alcohol to dehydration to form a resulting composition comprising a second normal alpha olefin having the structure (C) 2n+4 -C=C. In this process, n can be an integer ranging from 0 to 30.

[0005] In one aspect of the process of the present disclosure, the first normal alpha olefin can include ethylene, and the second normal alpha olefin can include 1-hexene. In another aspect, the first normal alpha olefin can include propylene, and the second normal alpha olefin can include 1-octene. In yet another aspect, the first normal alpha olefin can include 1-butene, and the second normal alpha olefin can include 1-decene.

[0006] Both the foregoing summary and the following detailed description are provided by way of example and are merely illustrative. Accordingly, the foregoing summary and the following detailed description should not be regarded as limiting. Further, features or variations may be provided in addition to those described herein. For example, certain aspects may be directed to various combinations and sub-combinations of the features described in the detailed description.

[0007] The following drawings form a part of this specification and are included to further illustrate certain aspects of the present invention. The present invention can be better understood by referring to these drawings in combination with the detailed description below.

Brief Description of the Drawings

[0008]

Figure 1

Modes for Carrying Out the Invention

[0009] The present invention disclosed herein may admit of various modifications and alternative forms, but only a few specific aspects are shown by way of example in the drawings and described in detail below. The drawings and detailed description of these specific aspects are not intended to limit the concept of the present invention or the scope or range of the appended claims in any way. Rather, the drawings and detailed description are provided to illustrate the concept of the present invention to those skilled in the art and to enable such skilled artisans to make and use the concept of the present invention.

[0010] Definitions To more clearly define the terms used herein, the following definitions are provided. Unless otherwise indicated, 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 the IUPAC Compendium of Chemical Terminology, 2nd Ed (1997) may apply, provided that the definition does not conflict with any other disclosure or definition applied herein or render any of the claims to which it applies unclear or impossible. In the event of any conflict between any definition or usage provided by any document incorporated herein by reference and the definition or usage provided herein, the definition or usage provided herein shall prevail.

[0011] In this specification, the features of the subject matter are described such that combinations of different features may be envisioned in certain aspects. For any and all aspects and / or features disclosed herein, all combinations that do not adversely affect the designs, compositions, processes, and / or methods described herein are contemplated, whether or not there is an explicit recitation of a particular combination. Additionally, unless otherwise specified, any aspect and / or feature disclosed herein may be combined to explain inventive features that are consistent with the present disclosure.

[0012] In the present disclosure, processes are described from the perspective of "comprising" various steps, but the processes can also "consist essentially of" or "consist of" various steps, unless otherwise stated. The terms "a", "an", and "the" are intended to include plural alternatives, e.g., at least one, unless otherwise specified. For example, the disclosure of "a first normal alpha olefin" means, unless otherwise specified, one first normal alpha olefin or a combination of two or more.

[0013] Generally, groups of elements are indicated using the numbering scheme shown in the version of the periodic table of the elements published in Chemical and Engineering News, 63(5), 27, 1985. In some cases, groups of elements may be indicated using the common names assigned to the groups, e.g., alkali metals for Group 1 elements, alkaline earth metals for Group 2 elements, transition metals for Groups 3 - 12 elements, and halogens or halides for Group 17 elements.

[0014] For any particular compound or group disclosed herein, any name or structure presented is intended to encompass all conformational isomers, positional isomers, stereoisomers, and mixtures thereof that can result from a particular set of substituents, unless otherwise specified. The name or structure is also intended to encompass all enantiomeric forms, whether enantiomorphic or racemic, all enantiomers, diastereomers, and other optical isomers (if any), and mixtures of stereoisomers, as would be recognized by one of ordinary skill in the art, unless otherwise specified. For example, a general reference to 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-methyl-butane, and 2,2-dimethylpropane, and a general reference to a butyl group includes an n-butyl group, a sec-butyl group, an iso-butyl group, and a t-butyl group.

[0015] The term "subjecting" is used herein, unless otherwise specified, to describe a process step of contacting or combining a plurality of substances in any order, in any manner, and for any length of time. For example, the plurality of substances can be contacted or combined by blending, mixing, slurrying, dissolving, reacting, treating, impregnating, formulating, or in some other manner, or by any suitable method or technique.

[0016] The term "hydrocarbon" as used herein and in the claims always means a compound containing only carbon and hydrogen. Other identifiers may be used to indicate the presence of particular groups in the hydrocarbon (e.g., a halogenated hydrocarbon indicates the presence of one or more halogen atoms that replace an equal number of hydrogen atoms in the hydrocarbon). Similarly, the term "alkane" refers to a saturated hydrocarbon compound.

[0017] 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. 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, unless otherwise specified. Olefins having only one, only two, only three, etc. carbon-carbon double bonds can be identified by using terms such as "mono", "di", "tri", etc. in the name of the olefin. Olefins can be further identified by the position of the carbon-carbon double bond(s). The term "alpha olefin" refers to an olefin having a carbon-carbon double bond between the first and second carbon atoms of the longest continuous chain of carbon atoms. The term "alpha olefin" includes linear and branched alpha olefins, and alpha olefins that may have two or more non-aromatic carbon-carbon double bonds, unless otherwise specified. The term "normal alpha olefin" refers to a linear aliphatic hydrocarbon monoolefin having a carbon-carbon double bond between the first and second carbon atoms. The term "linear internal olefin" refers to a linear aliphatic hydrocarbon monoolefin having a double bond that is not between the first and second carbon atoms.

[0018] Various numerical ranges are disclosed herein. When any kind of range is disclosed or claimed, the intention is, unless otherwise specified, to individually disclose or claim each of the possible numbers that such a range could reasonably encompass, including the endpoints of the range as well as any sub-ranges and combinations of sub-ranges contained therein. As a representative example, the present disclosure details that the molar ratio of carbon monoxide to hydrogen in step (i) or step (iii) of the process can be within a specific range. The disclosure that the molar ratio can be in the range of 5:1 to 1:5 is intended to detail that the molar ratio can be any ratio within that range and can include any range or combination of ranges within 5:1 to 1:5, such as, for example, 2:1 to 1:2, or 1.5:1 to 1:1.5. Similarly, all other ranges disclosed herein should be interpreted in the same manner as this example.

[0019] Generally, amounts, sizes, formulations, parameters, ranges, or other quantities or characteristics are "about" or "approximately", whether or not so stated. Whether or not modified by the term "about" or "approximately", the claims include equivalents of that quantity or characteristic.

[0020] Any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, but representative methods and materials are described herein.

[0021] All publications and patents mentioned herein are hereby incorporated by reference in their entirety for the purpose of describing and disclosing the structures and methodologies described in the publications and patents, which can be used, for example, in connection with the invention described herein.

[0022] Detailed Description of the Invention This specification discloses processes for producing normal alpha-olefins, particularly atom-efficient processes for converting normal alpha-olefins to higher carbon number normal alpha-olefins. Advantageously, these processes result in high carbon conservation and low by-product formation and can utilize syngas as a reactant in two separate steps of the process.

[0023] Synthesis of Normal Alpha-Olefins Aspects of the invention include (i) subjecting a first normal alpha-olefin having the structure (C) n -C=C to hydroformylation in the presence of carbon monoxide and hydrogen to form a first composition comprising a first linear aldehyde having the structure C(C) n+1 CH(=O), (ii) subjecting the first linear aldehyde to decarbonylative olefination to form a second composition comprising a C 2n+5 linear internal olefin, (iii) subjecting the linear internal olefin to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form a third composition comprising a second linear aldehyde having the structure C(C) 2n+4 CH(=O), and (iv-a) subjecting the second linear aldehyde to hydrogenation-dehydration to form a product composition comprising a second normal alpha-olefin having the structure (C) 2n+4 -C=C, or (iv-b1) subjecting the second linear aldehyde to hydrogenation to form a fourth composition comprising a linear alcohol having the structure C(C) 2n+4 C(OH), and (iv-b2) subjecting the linear alcohol to dehydration to form a product composition comprising a second normal alpha-olefin having the structure (C) 2n+4 -C=C. In this process, n can be an integer ranging from 0 to 30.

[0024] Generally, the features of this process (for example, among a number of features, especially the hydroformylation step, the decarbonylative olefination step, the isomerization-hydroformylation step, the combined hydrogenation-dehydration step, the hydrogenation step, and the dehydration step) are described herein independently, and these features can be combined in any combination to further illustrate the normal alpha olefin synthesis process. Further, unless otherwise stated, additional process steps can be carried out before, during, and / or after any of the steps of this process.

[0025] As described herein, n can be an integer ranging from 0 to 30. In one aspect consistent with the present invention, n can be an integer from 0 to 18, in another aspect, n can be an integer from 0 to 12. Further, in another aspect, n can be an integer from 0 to 8, and in yet another aspect, n can be an integer from 0 to 6. For example, n can be equal to 0, 1, 2, 3, 4, 5, 6, etc.

[0026] In some embodiments of the present invention, the first normal alpha olefin can include (or consist essentially of or consist of) ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, or any combination thereof. For example, the first normal alpha olefin can include (or consist essentially of or consist of) ethylene, alternatively propylene, alternatively 1-butene, alternatively 1-pentene, alternatively 1-hexene, alternatively 1-heptene, alternatively 1-octene, alternatively 1-nonene, alternatively 1-decene, alternatively 1-dodecene, alternatively 1-tetradecene, alternatively 1-hexadecene, or alternatively 1-octadecene. In other embodiments, the first normal alpha olefin can include (or consist essentially of or consist of) ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, or any combination thereof.

[0027] In one aspect of the present invention, the first normal alpha olefin can comprise (or consist essentially of or consist of) ethylene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-hexene. In another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) propylene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-octene. In another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) 1-butene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-decene. In another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) 1-pentene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-dodecene. In another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) 1-hexene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-tetradecene. In yet another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) 1-heptene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-hexadecene. In still another aspect, the first normal alpha olefin can comprise (or consist essentially of or consist of) 1-octene, and the second normal alpha olefin can comprise (or consist essentially of or consist of) 1-octadecene.

[0028] An integer n, a first normal alpha-olefin, and a second normal alpha-olefin are described herein, and their features can be used without limitation to further illustrate the normal alpha-olefin synthesis process disclosed herein. Other suitable values for the integer n, as well as the selection of the first normal alpha-olefin and the second normal alpha-olefin, can be readily understood from the present disclosure.

[0029] Step (i) of the process disclosed herein is often referred to as the hydroformylation step, in which a first normal alpha-olefin having the structure (C) n -C=C is subjected to hydroformylation in the presence of carbon monoxide and hydrogen to form a first composition comprising a first linear aldehyde having the structure C(C) n+1 CH(=O). Thus, in one aspect, this hydroformylation step can convert a first normal alpha-olefin such as ethylene or 1-butene into a first linear aldehyde such as propanal or 1-pentanal, respectively. Those skilled in the art will recognize that any suitable hydroformylation catalyst system for step (i) and any suitable conditions for the hydroformylation reaction in step (i) can be used, considering the present disclosure and, for example, Behr at al., Journal of Molecular Catalysis A: Chemical 206 (2003), 179-184, Vogl at al., Journal of Molecular Catalysis A: Chemical 232 (2005), 41-44, Jorke et al., Chemical Engineering Journal, December 12, 2016, 1-34, Peng et al., U.S. Patent No. 7,196,230, and Yan et al., JACS 2006, 128, 16058-16061.

[0030] Although not limited, the hydroformylation in step (i) can utilize a rhodium-based catalyst system. In such an embodiment, the rhodium-based catalyst system may include rhodium and a phosphorus-containing ligand, and the elemental ratio of Rh:P can often range from 1:1 to 1:15, and more often, the elemental ratio of Rh:P falls within a range such as 1:2 to 1:10, or 1:2 to 1:6. The specific phosphorus-containing ligand is not particularly limited, but BiPhePhos (CAS number 121627-17-6) is well-suited for use in a rhodium-based catalyst system used in the hydroformylation reaction.

[0031] In one embodiment, the molar ratio of the first normal alpha-olefin in step (i) to rhodium in the rhodium-based catalyst system can fall within the range of 100:1 to 500,000:1. In another embodiment, the molar ratio of the first normal alpha-olefin to rhodium can range from 100:1 to 10,000:1. In yet another embodiment, the molar ratio of the first normal alpha-olefin to rhodium can range from 100:1 to 1000:1. As those skilled in the art will readily recognize, the molar ratio of alpha-olefin to rhodium can change as the hydroformylation reaction proceeds. Therefore, these ranges of molar ratios mean that they include not only the molar ratio of the first normal alpha-olefin to rhodium that occurs as the hydroformylation reaction proceeds but also the initial ratio.

[0032] In addition, carbon monoxide and hydrogen (H 2) The molar ratio to [substance] is often in the range of 5:1 to 1:5, or in some embodiments in the range of 2:1 to 1:2, and in other embodiments in the range of 1.5:1 to 1:1.5 or 1.1:1 to 1:1.1. The sources of carbon monoxide and hydrogen used in step (i) are not limited, but in certain embodiments of the present invention, the sources of carbon monoxide and hydrogen in step (i) can be synthesis gas. As will be recognized by those skilled in the art, synthesis gas is a mixture mainly containing carbon monoxide and hydrogen. Synthesis gas may also contain carbon dioxide and methane in smaller amounts.

[0033] The temperature and pressure conditions used in the hydroformylation step are not particularly limited. However, generally, the hydroformylation temperature can be in the range of 80 to 200 °C, alternatively 80 to 160 °C, or alternatively 100 to 130 °C. The hydroformylation pressure can be in the range of 5 to 70 bar, alternatively 10 to 50 bar, or alternatively 20 to 45 bar. These ranges of temperature and pressure also mean that step (i) is carried out at a series of different temperatures and pressures rather than a single fixed temperature and a single fixed pressure, and at least one temperature and pressure fall within their respective ranges.

[0034] If desired, and among other considerations, especially depending on the first normal alpha-olefin (e.g., its carbon number), the hydroformylation temperature, and the hydroformylation pressure, the hydroformylation reaction in step (i) can be carried out in a diluent as appropriate. Exemplary and non-limiting examples of diluents that can be used include toluene, propylene carbonate, dimethylformamide, dodecane, etc., and mixtures or combinations thereof (see, for example, Stein, Molecular Catalysis 503, 2021, 111429). Any suitable amount of diluent can be used relative to the amount of the first normal alpha-olefin.

[0035] Typically, by using hydroformylation in step (i), both linear and branched aldehydes are produced, but mainly linear aldehydes are produced. Thus, the first composition produced via the hydroformylation of step (i) has the structure C(C) n+1 may include a first linear aldehyde having CH(=O), a small amount of branched aldehyde, and, if used, a diluent. Optionally, this step may further include isolating from the first composition an aldehyde composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the first linear aldehyde prior to step (ii). Any suitable technique such as extraction, filtration, evaporation, distillation, etc., and any combination thereof may be used.

[0036] Referring now to step (ii) of this process, the first linear aldehyde formed in step (i) is subjected to decarbonylative olefination to form a second composition containing a C 2n+5 linear internal olefin. Step (ii) of this process is often referred to as a decarbonylative olefination step. Thus, in step (ii), by decarbonylative olefination, a first linear aldehyde such as propanal or 1-pentanal can be converted to a linear internal olefin such as 2-pentene or 4-nonene, respectively. Those skilled in the art will recognize, considering the present disclosure and, for example, Ainembabazi at al., Journal of the American Chemical Society 2020, 142, 696 - 699, that any suitable decarbonylative olefination catalyst system for step (ii) and any suitable conditions for the decarbonylative olefination reaction in step (ii) can be used.

[0037] Although not limited thereto, a palladium-based catalyst system can be utilized for the decarbonylative olefination in step (ii). In such an embodiment, the palladium-based catalyst system may be a supported palladium catalyst, and non-limiting examples thereof may include Pd / hydrotalcite, Pd / alumina, Pd / gamma-alumina, Pd / silica, Pd / carbon, or Pd / magnesia, etc., and combinations thereof. Any suitable amount of palladium, such as, for example, 0.01 to 10 mol%, more often 0.05 to 5 mol%, or 0.05 to 1 mol%, etc., can be used.

[0038] The reaction conditions used in the decarbonylative olefination step are not particularly limited. However, in one embodiment, the decarbonylative olefination reaction temperature can be in the range of 80 to 200 °C, in another embodiment, the reaction temperature can be in the range of 100 to 190 °C, and in yet another embodiment, the reaction temperature can be in the range of 150 to 180 °C. These temperature ranges also mean that step (ii) is carried out at a series of different temperatures rather than a single fixed temperature, and at least one temperature falls within each temperature range.

[0039] The decarbonylative olefination in step (ii) produces the desired linear internal olefin, but may also produce carbon monoxide, water, or both. Accordingly, the second composition obtained from step (ii) may contain a linear internal olefin, carbon monoxide, and water. Thus, this step may further include a step of isolating, as appropriate, an internal olefin composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of linear internal olefin from the second composition before step (iii). As described above, any suitable techniques, such as extraction, filtration, evaporation, distillation, etc., and any combination thereof, can be used.

[0040] Referring now to step (iii) of this process, the linear internal olefin formed in step (ii) is subjected to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to give a third composition containing a second linear aldehyde having structure C(C) 2n+4 CH(=O). A third composition is formed which contains a second linear aldehyde having structure C(C)CH(=O). Step (iii) of this process is often referred to as the isomerization-hydroformylation step. In step (iii), linear internal olefins such as 2-pentene or 4-nonene can be converted by isomerization-hydroformylation into second linear aldehydes such as 1-hexanal or 1-decanal, respectively.

[0041] In the isomerization-hydroformylation step (iii) of this process, the hydroformylation step (i) of this process is disclosed herein, and any of the catalyst systems and reaction conditions disclosed in the references of Behr, Vogl, Jorke, Peng, and Yan may be utilized. Thus, for the isomerization-hydroformylation in step (iii), a rhodium-based catalyst system can be utilized, which can contain rhodium and a phosphorus-containing ligand (such as BiPhePhos) in any elemental ratio of Rh:P from 1:1 to 1:15.

[0042] Also, similar to step (i), the molar ratio of carbon monoxide to hydrogen (H 2 ) in the isomerization-hydroformylation reaction of step (iii) can be any molar ratio from 5:1 to 1:5, and the sources of carbon monoxide and hydrogen used in step (iii) can be, but are not limited to, synthesis gas. Similarly, the temperature and pressure conditions utilized in the isomerization-hydroformylation step can include the same temperature and pressure conditions as in step (i), and any temperature in the range of 80 to 200 °C and any pressure in the range of 5 to 70 bar can be utilized. Further, the isomerization-hydroformylation reaction of step (iii) can be carried out, similar to step (i), in any suitable diluent and using any amount of diluent.

[0043] In one aspect, the molar ratio of the linear internal olefin in step (iii) to rhodium in the rhodium-based catalyst system can fall within the range of 100:1 to 500,000:1. In another aspect, the molar ratio of the linear internal olefin to rhodium can be in the range of 100:1 to 10,000:1. In yet another aspect, the molar ratio of the linear internal olefin to rhodium can be in the range of 100:1 to 1000:1. As those skilled in the art will readily recognize, the molar ratio of linear internal olefin to rhodium can change as the isomerization-hydroformylation reaction proceeds. Therefore, these ranges of molar ratios mean that they include not only the molar ratio of linear internal olefin to rhodium that occurs as the isomerization-hydroformylation reaction proceeds but also the initial ratio.

[0044] By the isomerization-hydroformylation in step (iii), both linear and branched aldehydes are produced, but mainly linear aldehydes are produced. Therefore, the third composition produced via the isomerization-hydroformylation of step (iii) has the structure C(C) 2n+4 It may contain a second linear aldehyde having CH(=O), a small amount of branched aldehyde, and, when used, a diluent. Optionally, this step may further include a step of isolating from the third composition a second aldehyde composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the second linear aldehyde before step (iv-a) or (iv-b1). This can be achieved via any suitable technique, and non-limiting examples include extraction, filtration, evaporation, distillation, etc. Combinations of two or more techniques may also be used.

[0045] Once the second linear aldehyde (having the structure C(C) 2n+4 with CH(=O)) is formed, in the normal alpha olefin synthesis process disclosed herein, a second normal alpha olefin (having the structure (C) 2n+4There are two alternative routes to form (having -C=C). In one route (via step (iv-a)), the second straight-chain aldehyde is subjected to hydrodehydration (a combined type of hydrogenation and dehydration in a single combined step) to give structure (C). 2n+4 An outcome composition containing a second normal alpha-olefin having -C=C is formed. In the other route, the second straight-chain aldehyde is subjected to (iv-b1) hydrogenation to give a fourth composition containing a straight-chain alcohol having C(C). 2n+4 C(OH), and then the straight-chain alcohol is subjected to (iv-b2) dehydration to give structure (C). 2n+4 An outcome composition containing a second normal alpha-olefin having -C=C is formed.

[0046] Referring now to the latter route of this step as well as steps (iv-b1) and (iv-b2), step (iv-b1) of this step is often referred to as the hydrogenation step, and step (iv-b2) is often referred to as the dehydration step. Thus, in step (iv-b1), by hydrogenation, a second straight-chain aldehyde such as 1-hexanal or 1-decanal can be converted to a straight-chain alcohol such as 1-hexanol or 1-decanol, respectively. Next, in step (iv-b2), by dehydration, a straight-chain alcohol such as 1-hexanol or 1-decanol can be converted to a second normal alpha-olefin such as 1-hexene or 1-decene, respectively.

[0047] Referring first to step (iv-b1), those skilled in the art will recognize that any suitable hydrogenation catalyst system for step (iv-b1) and any suitable conditions for the hydrogenation reaction in step (iv-b1) can be used, considering the present disclosure and, for example, Chetty et al., American Chemical Society Omega 2018, 3, 7911-7924 and U.S. Patent No. 5,093,535.

[0048] Although not limited, the hydrogenation in step (iv-b1) can utilize a copper-based catalyst system. One such copper-based catalyst system can include Cu / alumina containing any suitable amount of copper, such as 1 to 35 wt% copper based on the weight of the supported catalyst. In some embodiments, the amount of copper in the Cu / alumina catalyst falls within a range such as 2 to 30 wt%, or 5 to 25 wt%.

[0049] The temperature and pressure conditions used in the hydrogenation step are not particularly limited. However, generally, the hydrogenation temperature can be in the range of 80 to 200 °C, alternatively 90 to 190 °C, or alternatively 100 to 180 °C. The hydrogenation pressure can be in the range of 10 to 70 bar, alternatively 20 to 50 bar, or alternatively 25 to 45 bar. These temperature and pressure ranges also mean that step (iv-b1) is carried out at a series of different temperatures and pressures rather than a single fixed temperature and a single fixed pressure, with at least one temperature and pressure falling within their respective ranges.

[0050] In one embodiment, the molar ratio of hydrogen (H 2 ) to the second linear aldehyde in step (iv-b1) can fall within the range of 0.5:1 to 5:1. In another embodiment, the molar ratio of hydrogen to the second linear aldehyde can range from 0.75:1 to 3:1. In yet another embodiment, the molar ratio of hydrogen to the second linear aldehyde can range from 1:1 to 2:1. As those skilled in the art will readily recognize, the molar ratio of hydrogen (H 2 ) to the second linear aldehyde can change as the hydrogenation reaction progresses. Therefore, these ranges of molar ratios mean that they include not only the molar ratio of hydrogen to the second linear aldehyde that occurs as the hydrogenation reaction progresses but also the initial ratio.

[0051] The hydrogenation in step (iv-b1) mainly produces the desired linear alcohol, but other by-products of the hydrogenation reaction may also be formed. Therefore, optionally, this step may further include isolating from the fourth composition an alcohol composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of linear alcohol prior to step (iv-b2). As described herein, this can be achieved via any suitable technique, and non-limiting examples include extraction, filtration, evaporation, distillation, etc., and any combination thereof.

[0052] Referring now to step (iv-b2), those skilled in the art will recognize that any suitable dehydration catalyst system for step (iv-b2) and any suitable conditions for the dehydration reaction in step (iv-b2) can be used in view of the present disclosure and, for example, Kim et al., Fuel 256 (2019), 115957, 1-8 and Millet et al., U.S. Patent No. 10,071,937 (2018).

[0053] Without limitation, in one aspect, the dehydration in step (iv-b2) can utilize an alumina-based catalyst system, and in another aspect, the dehydration in step (iv-b2) can utilize a metal phosphate-based catalyst system. When an alumina-based catalyst system is utilized, the alumina can be calcined at any suitable temperature prior to step (iv-b2). Typical ranges of the calcination temperature include, for example, 100-1200 °C, 250-1000 °C, or 400-600 °C, etc. When a metal phosphate-based catalyst system is utilized, suitable metals include, inter alia, lanthanum, neodymium, gadolinium, samarium, etc.

[0054] The reaction conditions used in the dehydration step are not particularly limited. However, in one aspect, the dehydration reaction temperature can be in the range of 200 to 500 °C, in another aspect, the reaction temperature can be in the range of 250 to 450 °C, and in yet another aspect, the reaction temperature can be in the range of 300 to 400 °C. These temperature ranges also mean that step (iv-b2) is carried out at a series of different temperatures rather than a single fixed temperature, with at least one temperature falling within each temperature range.

[0055] The dehydration in step (iv-b2) produces the desired second normal alpha-olefin but can also produce water. Therefore, the resulting product composition from step (iv-b2) can contain the second normal alpha-olefin and water. Thus, this step can further include a step of purifying the product composition to isolate an alpha-olefin composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the second normal alpha-olefin. Suitable techniques include, for example, extraction, filtration, evaporation, distillation, etc., and combinations thereof.

[0056] Referring now to the route through step (iv-a), the second linear aldehyde is subjected to a combined (single-step) hydrogenation-dehydration to form a product composition containing the second normal alpha-olefin having structure (C) 2n+4 -C=C. Step (iv-a) of this process is often referred to as the hydrogenation-dehydration step. In step (iv-a), by hydrogenation-dehydration, a second linear aldehyde such as 1-hexanal or 1-decanal can be converted into a second normal alpha-olefin such as 1-hexene or 1-decene, respectively.

[0057] As will be appreciated by those skilled in the art considering the present disclosure and the associated hydrogenation process and catalyst system and dehydration process and catalyst system described above, any suitable hydrogenation-dehydration catalyst system for step (iv-a) and any suitable conditions for the hydrogenation-dehydration reaction in step (iv-a) can be used. Since this step is disadvantageous for complete hydrogenation, it is advantageous to form a product composition containing less than 10 wt%, or less than 5 wt% of an alkane (such as n-alkane). Thus, the unsaturated second normal alpha olefin is produced in high yield.

[0058] Each step of the process of the present disclosure for synthesizing a normal alpha olefin can be independently carried out in any suitable reactor or vessel, non-limiting examples of which include fixed bed reactors, stirred tank reactors, plug flow reactors, annular reactors, and tubular reactors, including two or more reactors in series or parallel, and any combination of reactor types and arrangements. Each step can be independently carried out batchwise or continuously.

[0059] Referring now to the figures, the first reaction scheme shows the conversion of 1-butene to 1-decene according to the processes of the present disclosure, and the second reaction scheme shows the conversion of ethylene to 1-hexene according to the processes of the present disclosure. In the first reaction scheme, 1-butene is subjected to hydroformylation in the presence of carbon monoxide and hydrogen to form 1-pentanal, which is subsequently subjected to decarbonylative olefination to form 4-nonene. Next, 4-nonene is subjected to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form 1-decanal, which is hydrogenated to form 1-decanol, and finally 1-decanol is dehydrated to form 1-decene. Similarly, in the second reaction scheme, ethylene is subjected to hydroformylation in the presence of carbon monoxide and hydrogen to form propanal, which is subsequently subjected to decarbonylative olefination to form 2-pentene. Next, 2-pentene is subjected to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form 1-hexanal, which is hydrogenated to form 1-hexanol, and finally 1-hexanol is dehydrated to form 1-hexene.

Example

[0060] The present invention will be further illustrated by the following examples, which should in no way be construed as limiting the scope of the present invention. Upon reading the description herein, various other aspects, modifications, and their equivalents will readily occur to those skilled in the art without departing from the spirit of the present invention or the scope of the appended claims.

[0061] Constructive Example 1 In accordance with the first reaction scheme of the processes and figures disclosed herein, Constructive Example 1 shows a representative and non-limiting example of the conversion of 1-butene to 1-decene. First, 1-butene is combined with a rhodium-BiPhePhos catalyst system in a reactor. The elemental ratio of Rh:P is 1:1.1, and the molar ratio of 1-butene to rhodium is 10,000:1. The total pressure is 30 bar, and carbon monoxide and hydrogen (H 2Add carbon monoxide and hydrogen to the reactor at a molar ratio of 1:1. Heat the reactor to 150 °C and stir the reactor contents for 1 hour to produce a first composition containing 1-pentanal. After cooling, an aldehyde composition containing 82 mol% of 1-pentanal is separated from the first composition by distillation.

[0062] Subject the aldehyde composition containing 1-pentanal to decarbonylative olefination by mixing the Pd / alumina catalyst containing 0.3 mol% of palladium and the aldehyde composition in the reactor at a temperature of 180 °C for 2 hours. A second composition containing 4-nonene, carbon monoxide, and water is produced. After cooling, carbon monoxide is discharged, and 4-nonene is separated from water by distillation or decantation to form an internal olefin composition containing 80 mol% of 4-nonene.

[0063] Using the rhodium-BiPhePhos catalyst system described above (although different catalysts may be used to improve selectivity), subject the internal olefin composition containing 4-nonene to isomerization-hydroformylation in a manner similar to the hydroformylation of 1-butene. A second aldehyde composition containing 82 mol% of 1-decanal is isolated by distillation.

[0064] In the reactor, mix the second aldehyde composition containing 1-decanal with a Cu / alumina catalyst containing 10 wt% of copper. Set the total pressure to 50 bar and add hydrogen to the reactor at a molar ratio of 1.5:1 of hydrogen (H 2 ) to 1-decanal. Heat the reactor to 140 °C and contact the reactor contents at a liquid hourly space velocity (LHSV) of 18 hr -1 to produce a fourth composition containing 1-decanol. After cooling, an alcohol composition containing 90 mol% of 1-decanol is separated from 1-decanal by distillation.

[0065] By mixing alumina pre-calcined at 300 °C for 2 hours with an alcohol composition, an alcohol composition containing 1-decanol is subjected to dehydration to form a resulting composition containing 1-decene. After cooling, the resulting composition is purified by distillation to isolate an alpha olefin composition containing at least 60 mol% of 1-decene.

[0066] Constructive Example 2 In Constructive Example 2, ethylene is converted to 1-hexene as shown in the second reaction scheme of the figure using a procedure similar to that of Constructive Example 1.

[0067] The present invention is described herein with reference to numerous aspects and specific examples. In view of the detailed description, many variations will readily occur to those skilled in the art. All such obvious variations are within the full intended scope of the appended claims. Other aspects of the present invention may include, but are not limited to, the following (the aspects are described as "comprising", but alternatively can be "consist essentially of" or "consist of").

[0068] Aspect 1. (i) Structure (C) n - A first normal alpha olefin having -C=C is subjected to hydroformylation in the presence of carbon monoxide and hydrogen to form a first composition containing a first linear aldehyde having C(C) n+1 CH(=O), (ii) Subjecting the first linear aldehyde to decarbonylative olefination to form a second composition containing C 2n+5 a linear internal olefin, (iii) Subjecting the linear internal olefin to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form a third composition containing a second linear aldehyde having C(C) 2n+4 CH(=O), and (iv-a) Subjecting the second linear aldehyde to hydrogenation-dehydration to form structure (C)2n+4 forming a resulting composition comprising a second normal alpha-olefin having -C=C, or (iv-b1) subjecting the second linear aldehyde to hydrogenation to form a fourth composition comprising a linear alcohol having C(C) 2n+4 C(OH), and (iv-b2) subjecting the linear alcohol to dehydration to form a resulting composition comprising a second normal alpha-olefin having structure (C) 2n+4 -C=C, comprising wherein n is an integer from 0 to 30, the process.

[0069] Aspect 2. The process defined in Aspect 1, wherein n is an integer from 0 to 18.

[0070] Aspect 3. The process defined in Aspect 1, wherein n is an integer from 0 to 6.

[0071] Aspect 4. The process defined in Aspect 1, wherein the first normal alpha-olefin comprises ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, or any combination thereof.

[0072] Aspect 5. The process defined in Aspect 1, wherein the first normal alpha-olefin comprises ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, or any combination thereof.

[0073] Aspect 6. The process defined in Aspect 1, wherein the first normal alpha-olefin comprises ethylene and the second normal alpha-olefin comprises 1-hexene.

[0074] Aspect 7. The process defined in Aspect 1, wherein the first normal alpha-olefin contains propylene and the second normal alpha-olefin contains 1-octene.

[0075] Aspect 8. The process defined in Aspect 1, wherein the first normal alpha-olefin contains 1-butene and the second normal alpha-olefin contains 1-decene.

[0076] Aspect 9. The process defined in Aspect 1, wherein the first normal alpha-olefin contains 1-pentene and the second normal alpha-olefin contains 1-dodecene.

[0077] Aspect 10. The process defined in Aspect 1, wherein the first normal alpha-olefin contains 1-hexene and the second normal alpha-olefin contains 1-tetradecene.

[0078] Aspect 11. The process defined in Aspect 1, wherein the first normal alpha-olefin contains 1-heptene and the second normal alpha-olefin contains 1-hexadecene.

[0079] Aspect 12. The process defined in Aspect 1, wherein the first normal alpha-olefin contains 1-octene and the second normal alpha-olefin contains 1-octadecene.

[0080] Aspect 13. The process defined in any one of Aspects 1 to 12, wherein the hydroformylation in step (i) utilizes a rhodium-based catalyst system.

[0081] Aspect 14. The process defined in Aspect 13, wherein the rhodium-based catalyst system contains rhodium and a phosphorus-containing ligand in an Rh:P elemental ratio within any suitable range such as 1:1 to 1:15, 1:2 to 1:10, or 1:2 to 1:6.

[0082] Aspect 15. The step defined in any one of Aspects 13 to 15, wherein the phosphorus-containing ligand contains BiPhePhos.

[0083] Aspect 16. The step defined in any one of Aspects 13 to 15, wherein the molar ratio of the first normal alpha-olefin to rhodium is within any suitable range such as 100:1 to 500,000:1, 100:1 to 10,000:1, or 100:1 to 1000:1.

[0084] Aspect 17. The step defined in any one of Aspects 1 to 16, wherein the molar ratio of carbon monoxide to hydrogen in step (i) is within any suitable range such as 5:1 to 1:5, 2:1 to 1:2, or 1.5:1 to 1:1.5.

[0085] Aspect 18. The step defined in any one of Aspects 1 to 17, wherein the source of carbon monoxide and hydrogen in step (i) is synthesis gas.

[0086] Aspect 19. The step defined in any one of Aspects 1 to 18, wherein the hydroformylation in step (i) is carried out at any suitable pressure such as 5 to 70 bar, 10 to 50 bar, or 20 to 45 bar.

[0087] Aspect 20. The step defined in any one of Aspects 1 to 19, wherein the hydroformylation in step (i) is carried out at any suitable temperature such as 80 to 200 °C, 80 to 160 °C, or 100 to 130 °C.

[0088] Aspect 21. The step defined in any one of Aspects 1 to 20, wherein the hydroformylation in step (i) is carried out in any suitable diluent such as toluene, propylene carbonate, dimethylformamide, dodecane, or a combination thereof.

[0089] Aspect 22. The step defined by any one of Aspects 1 to 21, wherein the first composition further comprises a diluent.

[0090] Aspect 23. Before step (ii), isolating from the first composition an aldehyde composition comprising at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the first linear aldehyde via any suitable technique such as extraction, filtration, evaporation, distillation, or any combination thereof, or any technique disclosed herein; the step defined by any one of Aspects 1 to 22.

[0091] Aspect 24. The step defined by any one of Aspects 1 to 23, wherein the decarbonylative olefination in step (ii) utilizes a palladium-based catalyst system.

[0092] Aspect 25. The step defined in Aspect 24, wherein the palladium-based catalyst system comprises any suitable amount of palladium, such as 0.01 to 10 mol%, 0.05 to 5 mol%, or 0.05 to 1 mol%, and comprises Pd / hydrotalcite, Pd / alumina, Pd / gamma-alumina, Pd / silica, Pd / carbon, Pd / magnesia, or a combination thereof.

[0093] Aspect 26. The step defined by any one of Aspects 1 to 25, wherein the decarbonylative olefination in step (ii) is carried out at any suitable temperature, such as 80 to 200 °C, 100 to 190 °C, or 150 to 180 °C.

[0094] Aspect 27. The step defined by any one of Aspects 1 to 26, wherein the second composition further comprises carbon monoxide and / or water.

[0095] Aspect 28. Prior to step (iii), isolating an internal olefin composition comprising at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of said linear internal olefin from said second composition via any suitable technique such as extraction, filtration, evaporation, distillation, or any combination thereof, or any technique disclosed herein, the process defined in any one of aspects 1 to 27 further comprising this step.

[0096] Aspect 29. The isomerization-hydroformylation in step (iii) utilizes a rhodium-based catalyst system, the process defined in any one of aspects 1 to 28.

[0097] Aspect 30. The rhodium-based catalyst system contains rhodium and a phosphorus-containing ligand in an elemental ratio of Rh:P within any suitable range such as 1:1 to 1:15, 1:2 to 1:10, or 1:2 to 1:6, the process defined in aspect 29.

[0098] Aspect 31. The phosphorus-containing ligand contains BiPhePhos, the process defined in aspect 30.

[0099] Aspect 32. The molar ratio of said linear internal olefin to rhodium is within any suitable range such as 100:1 to 500,000:1, 100:1 to 10,000:1, or 100:1 to 1000:1, the process defined in any one of aspects 29 to 31.

[0100] Aspect 33. The molar ratio of carbon monoxide to hydrogen in step (iii) is within any suitable range such as 5:1 to 1:5, 2:1 to 1:2, or 1.5:1 to 1:1.5, the process defined in any one of aspects 1 to 32.

[0101] Aspect 34. The process defined in any one of Aspects 1 to 33, wherein the source of carbon monoxide and hydrogen in step (iii) is synthesis gas.

[0102] Aspect 35. The process defined in any one of Aspects 1 to 34, wherein the isomerization-hydroformylation in step (iii) is carried out at any suitable pressure such as 5 to 70 bar, 10 to 50 bar, or 20 to 45 bar.

[0103] Aspect 36. The process defined in any one of Aspects 1 to 35, wherein the isomerization-hydroformylation in step (iii) is carried out at any suitable temperature such as 80 to 200 °C, 80 to 160 °C, or 100 to 130 °C.

[0104] Aspect 37. The process defined in any one of Aspects 1 to 36, wherein the isomerization-hydroformylation in step (iii) is carried out in any suitable diluent such as toluene, propylene carbonate, dimethylformamide, dodecane, or a combination thereof.

[0105] Aspect 38. The process defined in any one of Aspects 1 to 37, wherein the third composition further comprises a diluent.

[0106] Aspect 39. The process defined in any one of Aspects 1 to 38, further comprising isolating a second aldehyde composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the second linear aldehyde from the third composition via any suitable technique such as extraction, filtration, evaporation, distillation, or any combination thereof, or any technique disclosed herein, prior to step (iv-a) or (iv-b1).

[0107] Aspect 40. The hydrogenation in step (iv-b1) is a process defined in any one of Aspects 1 to 39 that utilizes a copper-based catalyst system.

[0108] Aspect 41. The process defined in Aspect 40, wherein the copper-based catalyst system contains Cu / alumina with any suitable copper amount such as 1 to 35 wt%, 2 to 30 wt%, or 5 to 25 wt%.

[0109] Aspect 42. The process defined in any one of Aspects 1 to 41, wherein the hydrogenation in step (iv-b1) is carried out at any suitable temperature such as 80 to 200 °C, 90 to 190 °C, or 100 to 180 °C.

[0110] Aspect 43. The process defined in any one of Aspects 1 to 42, wherein the hydrogenation in step (iv-b1) is carried out at any suitable pressure such as 10 to 70 bar, 20 to 50 bar, or 25 to 45 bar.

[0111] Aspect 44. The process defined in any one of Aspects 1 to 43, wherein the hydrogenation in step (iv-b1) is carried out at any suitable molar ratio of hydrogen to the second linear aldehyde such as 0.5:1 to 5:1, 0.75:1 to 3:1, or 1:1 to 2:1.

[0112] Aspect 45. Before step (iv-b2), further comprising the step of isolating from the fourth composition an alcohol composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the linear alcohol via any suitable technique such as extraction, filtration, evaporation, distillation, or any combination thereof, or any technique disclosed herein.

[0113] Aspect 46. The dehydration in step (iv-b2) is a process defined in any one of Aspects 1 to 45 that utilizes an alumina-based catalyst system.

[0114] Aspect 47. The process defined in Aspect 46, wherein the alumina is calcined at any suitable temperature such as 100 to 1200 °C, 250 to 1000 °C, or 400 to 600 °C before step (iv-b2).

[0115] Aspect 48. The dehydration in step (iv-b2) is a process defined in any one of Aspects 1 to 45 that utilizes a metal phosphate-based catalyst system.

[0116] Aspect 49. The process defined in any one of Aspects 1 to 48, wherein the dehydration in step (iv-b2) is carried out at any suitable temperature such as 200 to 500 °C, 250 to 450 °C, or 300 to 400 °C.

[0117] Aspect 50. The process defined in any one of Aspects 1 to 49, wherein the resulting composition further contains water.

[0118] Aspect 51. The process defined in any one of Aspects 1 to 50, further comprising the step of purifying the resulting composition via any suitable technique such as extraction, filtration, evaporation, distillation, or any combination thereof, or any technique disclosed herein, to isolate an alpha-olefin composition containing at least 85 mol%, at least 90 mol%, at least 93 mol%, or at least 96 mol% of the second normal alpha-olefin.

Claims

1. (i) Structure (C) ｎ - Subjecting a first normal alpha-olefin having -C=C to hydroformylation in the presence of carbon monoxide and hydrogen to obtain structure C(C) ｎ＋１ Forming a first composition containing a first linear aldehyde having CH(=O) (ii) subjecting the first linear aldehyde to decarbonylative olefination to form a second composition containing a linear internal olefin; ２ｎ＋５ ​ (iii) subjecting the linear internal olefin to isomerization-hydroformylation in the presence of carbon monoxide and hydrogen to form a third composition comprising a second linear aldehyde having the structure C(C) ２ｎ＋４ CH(=O), and (iv-a) subjecting the second linear aldehyde to hydrogenation-dehydration to form a resulting composition containing a second normal alpha olefin having -C=C, or ２ｎ＋４ forming a resulting composition containing a second normal alpha olefin having -C=C, or (iv-b1) subjecting the second linear aldehyde to hydrogenation to form a fourth composition comprising a linear alcohol having a structure C(OH), and ２ｎ＋４ and (iv-b2) subjecting the linear alcohol to dehydration to form a resulting composition containing a second normal alpha olefin having a structure (C) ２ｎ＋４ -C=C, A process wherein n is an integer from 0 to 30.

2. The process according to claim 1, wherein n is an integer from 0 to 6.

3. The process according to claim 1, wherein the first normal alpha-olefin contains ethylene and the second normal alpha-olefin contains 1-hexene.

4. The process according to claim 1, wherein the first normal alpha-olefin contains propylene and the second normal alpha-olefin contains 1-octene.

5. The process according to claim 1, wherein the first normal alpha-olefin contains 1-butene and the second normal alpha-olefin contains 1-decene.

6. The process according to claim 1, wherein the hydroformylation in step (i) utilizes a rhodium-based catalyst system.

7. The process according to claim 6, wherein the molar ratio of the first normal alpha-olefin to rhodium is in the range of 100:1 to 500,000:

1.

8. The process according to claim 1, wherein the source of carbon monoxide and hydrogen in step (i) is synthesis gas, and the hydroformylation in step (i) is carried out in a diluent.

9. The process according to claim 1, further comprising a step of isolating from the first composition an aldehyde composition containing at least 85 mol% of the first linear aldehyde before step (ii).

10. The process according to claim 1, wherein the decarbonylative olefination in step (ii) utilizes a palladium-based catalyst system.

11. The process according to claim 10, wherein the palladium-based catalyst system includes Pd / hydrotalcite, Pd / alumina, Pd / gamma-alumina, Pd / silica, Pd / carbon, Pd / magnesia, or a combination thereof.

12. The process according to claim 1, wherein the second composition further contains carbon monoxide and / or water, and the process further comprises a step of isolating from the second composition an internal olefin composition containing at least 85 mol% of the linear internal olefin before step (iii).

13. The process according to claim 1, wherein the isomerization-hydroformylation in step (iii) utilizes a rhodium-based catalyst system.

14. The process according to claim 13, wherein the rhodium-based catalyst system contains rhodium and a phosphorus-containing ligand in an element ratio of Rh:P in the range of 1:1 to 1:

15.

15. The process according to claim 14, wherein the phosphorus-containing ligand contains BiPhePhos.

16. The process according to claim 1, wherein the molar ratio of carbon monoxide to hydrogen in step (iii) is in the range of 5:1 to 1:

5.

17. The process according to claim 1, wherein the process includes step (iv-b1) and step (iv-b2).

18. The process according to claim 17, wherein the hydrogenation in step (iv-b1) utilizes a copper-based catalyst system.

19. The process according to claim 17, wherein the hydrogenation in step (iv-b1) is carried out at a molar ratio of hydrogen to the second linear aldehyde in the range of 0.5:1 to 5:

1.

20. The process according to claim 17, wherein the dehydration in step (iv-b2) utilizes an alumina-based catalyst system or a metal phosphate-based catalyst system.

21. The process according to claim 1, further comprising the step of purifying the resulting composition to isolate an alpha-olefin composition containing at least 85 mol% of the second normal alpha-olefin.

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