Method for producing linear alpha olefins using parallel reactors

Abstract

A system and method for producing linear alpha olefins is disclosed. The system includes two or more reaction units arranged in parallel. The system includes a wash unit configured to flash one or more of the reaction units that are offstream while the remaining reaction units are onstream to produce linear alpha olefins.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 076,172, filed September 9, 2020, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION The present invention relates generally to systems and processes for the oligomerization of olefins. More specifically, the present invention relates to systems and processes for producing linear alpha olefins (LAO) via the oligomerization of ethylene. [Background technology]

[0003] Linear alpha olefins (LAOs) are important chemicals used as intermediates in various chemical processes. For example, C4-C8 LAOs are used as comonomers in the production of polyethylene. C4-C8 LAOs can also be used to produce linear aldehydes, which are intermediates for short-chain fatty acids and linear alcohols.

[0004] Conventionally, linear alpha olefins can be produced by the oligomerization of ethylene. However, there are several drawbacks associated with the production of linear alpha olefins using this method. First, the oligomerization of ethylene inherently produces polymer, which can lead to the formation of polymer deposits within the oligomerization unit, including the reactor, heat exchangers, pipes, and pumps. Polymer accumulation on these equipment and reactor surfaces can reduce heat transfer to and from the equipment and cause fouling. Therefore, the oligomerization reactor must be periodically shut down to clean the polymer deposits, resulting in lost production time and reduced linear alpha olefin production efficiency. Second, the oligomerization system, particularly the reactor, is highly sensitive to the presence of moisture and oxygen, which further increases polymer formation during the production process.

[0005] Overall, while systems and processes exist for producing linear alpha olefins via the oligomerization of ethylene, there is a continuing need for improvements in this area, at least in light of the above-mentioned shortcomings of conventional systems and processes. Summary of the Invention [Means for solving the problem]

[0006] A solution to at least some of the above-mentioned problems associated with systems and methods for producing LAO has been discovered. This solution resides in a system and method for producing LAO that includes two or more reaction units operated in parallel. Each reaction unit can include a reactor, a heat exchanger, a pump, and optionally a polymer filter. This is beneficial for at least avoiding shutting down the entire system when one or more reaction units are being cleaned to remove polymer deposits, thereby improving the production time and production efficiency of the LAO production system. Furthermore, the disclosed method can include passivating the reaction units of the LAO production system using an inert gas, solvent, and aluminum alkyl mixture before flowing the feedstock into the oligomerization reactor to remove moisture and oxygen from the reaction system, thereby reducing polymer formation during the LAO production process. Thus, the disclosed method can reduce the frequency of cleaning the reaction units of the system, resulting in improved production efficiency. Furthermore, the disclosed method can include adding an optimized amount of a polymer inhibitor additive to the reactor, thereby further reducing the formation of polymer deposits in the LAO production system and improving LAO production efficiency. Thus, the systems and methods of the present invention provide technical solutions to at least some of the problems associated with conventional systems and methods for producing LAOs.

[0007] An embodiment of the present invention includes a system for producing linear alpha olefins. The system comprises two or more reaction units configured to react ethylene in the presence of a catalyst to produce one or more linear alpha olefins. The two or more reaction units are operated in parallel. Each of the two or more reaction units comprises a reactor and a heat exchanger configured to cool at least a portion of an effluent stream from the reactor. The system also comprises a scrubbing unit in fluid communication with the two or more reaction units and configured to remove at least some polymer deposits within the two or more reaction units. The scrubbing unit is configured to remove polymer deposits from at least one of the reaction units while the remaining reaction units are on-stream to produce linear alpha olefins.

[0008] An embodiment of the present invention includes a method for producing linear alpha olefins. The method includes flowing a feed stream containing ethylene to one or more reactors of one or more reaction units. Each reaction unit includes a reactor and a heat exchanger configured to cool at least a portion of the effluent stream from the reactor, the reaction units being operated in parallel. The method includes reacting ethylene in the one or more reactors in the presence of a catalyst and, optionally, a solvent, under reaction conditions sufficient to produce one or more linear alpha olefins. The method includes recycling at least a portion of the effluent stream flowing from each of the one or more reactors to the one or more reactors. The effluent stream includes one or more linear alpha olefins, unreacted ethylene, the catalyst, and, optionally, the solvent. The method includes separating at least a portion of the effluent stream from each of the one or more reactors in a separation unit to produce an ethylene recycle stream containing primarily ethylene, optionally a recycle solvent stream, and one or more product streams containing linear alpha olefins.

[0009] An embodiment of the present invention includes a method for producing linear alpha olefins. The method includes passivating one or more reaction units of a linear alpha olefin production system by removing moisture and oxygen therefrom. Each reaction unit includes a reactor and a heat exchanger configured to cool at least a portion of an effluent stream from the reactor, the reaction units being operated in parallel. The method includes flowing a feed stream containing ethylene to one or more reactors of the one or more reaction units. The method includes reacting ethylene in the one or more reactors in the presence of a catalyst and, optionally, a solvent, under reaction conditions sufficient to produce one or more linear alpha olefins. The method includes recycling at least a portion of the effluent stream flowing from each of the one or more reactors to the one or more reactors. The effluent stream contains one or more linear alpha olefins, unreacted ethylene, optionally the solvent, and the catalyst. The method includes separating at least a portion of the effluent stream from each of the one or more reactors in a separation unit to produce a recycle stream containing primarily ethylene, optionally a recycle solvent stream, and one or more product streams containing linear alpha olefins. The method includes flushing at least one of the reaction units with a solvent to remove polymer deposits formed in the reaction unit during the reaction step while the remaining reaction units are on-stream to produce linear alpha olefins. The polymer is then removed from the flashing solvent in a separation unit to produce clean flashing solvent that can be recycled to the wash unit.

[0010] The following contains definitions of various terms and phrases used throughout this specification.

[0011] The terms "about" or "approximately" are defined as close to what would be understood by one of ordinary skill in the art. In one non-limiting embodiment, these terms are defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0012] The terms "wt. %, "vol. %, or "mole %" refer to the weight, volume, or mole percentage, respectively, of a component based on the total weight, volume, or moles of the material containing that component. As a non-limiting example, 10 moles of a component in 100 moles of a material is 10 mole % of the component.

[0013] The term "substantially" and variations thereof are defined to include ranges of within 10%, within 5%, within 1%, or within 0.5%.

[0014] When used in the claims and / or specification, the terms "inhibit" or "reduce" or "prevent" or "avoid" or any variation of these terms includes any measurable decrease or complete inhibition to achieve a desired result.

[0015] The term "effective," as that term is used in the specification and / or claims, means sufficient to accomplish a desired, expected, or intended result.

[0016] The use of the words "a" or "an" when used in conjunction with the words "comprising," "including," "containing," or "having" in any claim or specification may mean "one," but is also consistent with the meanings of "one or more," "at least one," and "one or more than one."

[0017] The terms "comprising" (and any of its forms such as "comprise" and "comprises"), "having" (and any of its forms such as "have" and "has"), "including" (and any of its forms such as "includes" and "include") or "containing" (and any of its forms such as "contains" and "contain") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0018] The methods of the present invention may "comprise," "consist essentially of," or "consist of" certain ingredients, components, compositions, etc. disclosed throughout this specification.

[0019] The term "predominantly," as that term is used in this specification and / or claims, means greater than 50% by weight, 50% by mole, and 50% by volume. For example, "predominantly" can include 50.1% by weight to 100% by weight and all values ​​and ranges therebetween, 50.1% by mole to 100% by mole and all values ​​and ranges therebetween, or 50.1% by volume to 100% by volume and all values ​​and ranges therebetween.

[0020] Other objects, features, and advantages of the present invention will become apparent from the following drawings, detailed description, and examples. It should be understood, however, that the drawings, detailed description, and examples, while indicating specific embodiments of the present invention, are given by way of illustration only and are not intended to be limiting. Furthermore, changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments can be combined with features from other embodiments. For example, features from one embodiment can be combined with features from any of the other embodiments. In further embodiments, additional features can be added to the specific embodiments described herein.

[0021] For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0022] [Figure 1] 1 illustrates a system for producing linear alpha olefins according to an embodiment of the present invention. [Figure 2] 1 illustrates a process for producing linear alpha olefins according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Currently, LAO can be produced by the oligomerization of ethylene. However, conventional methods for producing LAO have relatively low efficiency due to several factors. Because the oligomerization of ethylene inevitably produces polymer, polymer deposits gradually form in reactors, heat exchangers, pipes, and / or pumps, resulting in fouling of LAO production system equipment. Generally, LAO production systems must be shut down to clean the polymer deposits therefrom, resulting in reduced production time (on-stream time). Furthermore, conventional LAO production systems can experience high concentrations of moisture and oxygen intrusion due to frequent shutdowns, which enhances polymer formation in the LAO production system. The present invention provides a solution to at least some of these problems. This solution is premised on a system and method including two or more reaction units operating in parallel such that when one or more reaction units are taken off-stream, another reaction unit is on-stream to produce LAO, thereby mitigating the reduced production time of conventional systems and methods. The disclosed systems and methods further include passivating the reaction unit by purging the feed stream with an inert gas and circulating a solvent and aluminum alkyl mixture through the reaction unit prior to flowing the feed stream into the reaction unit, thereby significantly reducing the moisture and oxygen content within the reaction unit. Additionally, the disclosed methods include adding a polymer inhibitor additive to the reaction unit to inhibit polymer formation during the LAO production process, thereby increasing LAO production efficiency and reducing the frequency of cleaning polymer deposits. These and other non-limiting aspects of the invention are described in further detail in the following sections.

[0024] A. System for Producing Linear Alpha Olefins In an embodiment of the present invention, a system for producing linear alpha olefins (LAO) includes a reaction system, a washing unit, a separation unit, and a passivation unit. Referring to Figure 1, a schematic diagram of a system 100 used to produce LAO via ethylene oligomerization is shown.

[0025] According to an embodiment of the present invention, system 100 includes a reaction system 101 configured to receive a feed stream 11 containing ethylene and react the ethylene to produce one or more LAOs. In an embodiment of the present invention, reaction system 101 includes two or more reaction units 110 arranged in parallel. In an embodiment of the present invention, feed stream 11 may further include a solvent, a polymer inhibitor additive, and a catalyst configured to catalyze the oligomerization of ethylene. The catalyst may include any catalyst known in the art capable of catalyzing ethylene oligomerization. In an embodiment of the present invention, the catalyst includes a metal compound, a ligand, optionally a modifier including a quaternary ammonium salt, a quaternary phosphonium solvent, a sulfonate, or a combination thereof, and an aluminum alkyl or a combination thereof as a cocatalyst. The catalyst may further include a solvent including an aromatic, paraffinic, or olefinic solvent, which may include decalin, toluene, hexane, heptane, octane, xylene, iso-pentane, cyclohexane, or a combination thereof. The metal compound may include chromium. Exemplary metal compounds include CrCl3(tetrahydrofuran)3, Cr(III) acetylacetonate, Cr(III) octanoate, Cr-hexacarbonyl, Cr(III)-2-ethylhexanoate, (benzene)tricarbonylchromium, or combinations thereof. The aluminum alkyl in the catalyst can scavenge moisture, oxygen, and / or other impurities. Exemplary aluminum alkyl cocatalysts include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, ethylaluminum sesquichloride, diethylaluminum chloride, ethylaluminum dichloride, methylaluminoxane [MAO], modified methylaluminoxane [MMAO], or combinations thereof.Exemplary ligands include organic compounds based on a PNPNH skeleton, where each P and N may independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and such substituents may contain other heteroatoms including N, S, and P, for example, (Ph)P-N(i-Pr)-P(Ph)-N(i-Pr)-H; or the ligand may be an NPNPN skeleton-based organic compound, where each P and N may independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and such substituents may contain other heteroatoms including N, S, and P, for example, (n-Bu)(Me)NP(Cy)-N(Me)-P(Cy)-N(n-Bu)(Me), where Cy is a cyclohexyl group, Me is a methyl group, and n-Bu is a normal butyl group.

[0026] In an embodiment of the invention, each reaction unit 110 comprises a reactor 102 configured to react ethylene in the presence of a catalyst to form one or more LAOs in effluent stream 12. In an embodiment of the invention, reactor 102 comprises a liquid-gas phase reactor. Each reaction unit 110 may further comprise a heat exchanger 103 in fluid communication with an outlet of reactor 102. Heat exchanger 103 is configured to cool a portion of effluent stream 12 to form recycled effluent stream 13. In an embodiment of the invention, effluent stream 12 further comprises catalyst, unreacted ethylene, optionally solvent (from feed stream 11), polymer, or a combination thereof.

[0027] In an embodiment of the present invention, each reaction unit 110 further comprises a pump 104 configured to pass at least a portion of the effluent stream 12 through a heat exchanger 103. Each reaction unit 110 may further comprise a filter 105 in fluid communication with the heat exchanger 103. The filter 105 may be configured to remove polymer from the recycle effluent stream 13.

[0028] According to an embodiment of the present invention, the system 100 further comprises a washing unit 120 in fluid communication with the reaction system 101. The washing unit 120 may be in fluid communication with each reaction unit 110 of the reaction system 101. In certain embodiments of the present invention, each reaction unit 110 has a different washing unit 120, or different sets of reaction units 110 have different washing units 120. In embodiments of the present invention, the washing unit 120 is configured to flush one or more reaction units 110 using a solvent to remove polymer deposits therefrom. At least a portion of the solvent flushed through the one or more reaction units 110 may be passed to a separation unit configured to separate the polymer dissolved in the solvent and produce a regenerated solvent. The regenerated solvent may be returned to the washing unit 120. In an embodiment of the present invention, the washing unit 120 comprises a flashing drum 121 configured to store the solvent and a heat exchanger 122 configured to heat or cool the solvent. Exemplary solvents used in the scrubbing unit 120 include aromatics, paraffins, and olefins, which may include decalin, toluene, hexane, heptane, octane, xylene, iso-pentane, cyclohexane, or combinations thereof. In an embodiment of the invention, the reaction system 101 and the scrubbing unit 120 are configured to operate such that one or more off-stream reaction units 110 are flashed while the remaining reaction units 110 of the reaction system 101 are on-stream to produce LAO.

[0029] According to an embodiment of the present invention, the system 100 includes a passivation unit 130 in fluid communication with the reaction system 101. In this embodiment, the passivation unit 130 is configured to remove moisture and / or oxygen from the reaction units 110. The passivation unit 130 includes an inert gas module configured to supply an inert gas to one or more reaction units 110 to reduce the moisture and oxygen concentrations in the reaction units 110 to a first level. The inert gas may include nitrogen, helium, argon, or a combination thereof. The passivation unit 130 may further include a solvent module configured to circulate a mixture including a solvent and an aluminum alkyl through each of the two or more reaction units 110 to reduce the moisture and oxygen concentrations in the reaction units 110 to a second level. In this embodiment, the first level is 500 to 1000 ppm, and the second level is approximately 1 to 10 ppm.

[0030] According to an embodiment of the present invention, reaction system 101 includes a polymer inhibiting additive unit 140 configured to add one or more polymer inhibiting additives to each reactor 102 of reaction units 110. An exemplary polymer inhibiting additive includes hydrogen. In an embodiment of the present invention, the polymer inhibiting additive may be added directly to reactor 102. Alternatively, or additionally, the polymer inhibiting additive may be mixed in feed stream 11. Alternatively, or additionally, the polymer inhibiting additive may be mixed with the catalyst.

[0031] According to an embodiment of the present invention, reaction system 101 comprises a separation unit 150 in fluid communication with an outlet of each reactor 102 such that at least a portion of effluent stream 12 from one or more of reactors 102 flows from the reactor 102 to separation unit 150. In an embodiment of the present invention, at least a portion of effluent stream 12 is mixed with a catalyst deactivator configured to deactivate catalyst in at least a portion of effluent stream 12 before being flowed to separation unit 150. In an embodiment of the present invention, the deactivator comprises an alcohol, an amine, water, caustic, air, or a combination thereof.

[0032] In an embodiment of the invention, the separation unit 150 is configured to separate at least a portion of the effluent stream 12 from the two or more reactors 102 to produce one or more product streams, including LAO, a solvent recycle stream, and an ethylene recycle stream 14 comprising primarily ethylene. In an embodiment of the invention, the separation unit 150 includes a series of distillation columns. The distillation columns of the separation unit 150 may include a C2 separation column configured to separate a portion of the effluent stream 12 to form the ethylene recycle stream 14 and a C3+ stream. The separation unit 150 may also include a C6 separation column configured to separate the C3+ stream to form a 1-hexene stream comprising primarily 1-hexene and a C7+ stream. The separation unit 150 may also include a C7 separation column configured to separate the C7+ stream to produce a C7 stream and form the solvent recycle stream 18 and a C8+ stream. The separation unit 150 may also include a C8 separation column configured to separate the C8+ stream to form a 1-octene stream and a C8+ stream. The separation unit 150 may further include a wash solvent separation column configured to separate the C stream to form a wash solvent stream and a heavies stream. In an embodiment of the invention, the wash solvent stream may be recycled as a solvent for the wash unit. In an embodiment of the invention, the heavies stream may include a catalyst, a deactivator, a polymer, or a combination thereof. In an embodiment of the invention, the separation unit 150 is further configured to separate the polymer from the solvent-polymer stream 15 from the wash unit 120 to produce a regenerated solvent stream 16 comprising regenerated solvent. The regenerated solvent stream 16 may be returned to the wash unit 120.

[0033] B. Oligomer Manufacturing Method A method for producing linear alpha olefins has been discovered. As shown in Figure 2, an embodiment of the present invention includes a method 200 for producing LAOs with improved production efficiency compared to conventional methods. Method 200 can be performed by system 100, as shown in Figure 1 and described above.

[0034] According to an embodiment of the present invention, as shown in block 201, method 200 includes passivating one or more reaction units 110 by removing moisture and oxygen therefrom using a passivation unit 130. In an embodiment of the present invention, passivating in block 201 can include purging one or more reaction units 110 with an inert gas to reduce the moisture and oxygen concentration in the reaction units 110 to a first level. The inert gas can include nitrogen, helium, argon, or a combination thereof. In an embodiment of the present invention, purging in block 201 is performed at an inert gas temperature higher than room temperature, preferably a temperature between 20°C and 300°C, and all ranges and values ​​therebetween. The first moisture and oxygen concentration levels can be in the range of 500 to 1000 ppm, and all ranges therebetween, including 500 to 600 ppm, 600 to 700 ppm, 700 to 800 ppm, 800 to 900 ppm, and 900 to 1000 ppm.

[0035] In embodiments of the invention, passivating in block 201 can further include circulating the solvent and aluminum alkyl mixture to one or more reactors 102 to further reduce the moisture and oxygen concentrations in the reaction unit 110 to a second level. In some embodiments, the solvent and aluminum alkyl mixture comprises 0.0001 to 7 wt. % aluminum alkyl and all ranges and values ​​therebetween. The second level of moisture and oxygen concentrations in the reaction unit 110 can be in the range of 1 to 10 ppm and all ranges and values ​​therebetween. The cycling in block 201 can be carried out at a solvent aluminum alkyl temperature in the range of 20-150°C and all ranges and values ​​therebetween, including 20-30°C, 30-40°C, 40-50°C, 50-60°C, 60-70°C, 70-80°C, 80-90°C, 90-100°C, 100-110°C, 110-120°C, 120-130°C, 130-140°C, and 140-150°C.

[0036] According to an embodiment of the present invention, as shown in block 202, the method 200 includes flowing a feed stream 11 containing ethylene to one or more reactors 102 of two or more reaction units 110. As shown in the system 100, each reaction unit 110 includes a reactor 102. The two or more reaction units 110 are operated in parallel. In an embodiment of the present invention, a feed stream 11 containing ethylene, a catalyst, and a solvent is introduced into each reactor 102, and an effluent stream 12 from each reactor 102 is combined together before being sent to a separation unit 150. In an embodiment of the present invention, the feed stream 11 includes a catalyst for the oligomerization of ethylene. The catalyst includes a metal compound, a ligand, a modifier, a solvent, and an aluminum alkyl cocatalyst. In an embodiment of the present invention, the feed stream 11 can be produced by a jet mixer for mixing ethylene, a catalyst, and / or a polymer inhibitor to form the feed stream 11. In an embodiment of the present invention, the polymer inhibitor can be added directly to the reactor 102 of each of the two or more reaction units 110, configured to reduce polymer formation in the reaction unit 110. The polymer inhibitor can include hydrogen. The hydrogen concentration in reactor 102 can be in the range of 0-12 wt % and all ranges and values ​​therebetween, including 0-2 wt %, 2-4 wt %, 4-6 wt %, 6-8 wt %, 8-10 wt %, and 10-12 wt %.

[0037] According to embodiments of the invention, as shown in block 203, process 200 comprises reacting ethylene in one or more reactors 102 in the presence of a catalyst and, optionally, a solvent, under reaction conditions sufficient to produce one or more linear alpha olefins in effluent stream 12. In embodiments of the invention, reaction conditions may include reaction temperatures ranging from 20 to 200°C and all ranges and values ​​therebetween, including 20 to 40°C, 40 to 60°C, 60 to 80°C, 80 to 100°C, 100 to 120°C, 120 to 140°C, 140 to 160°C, 160 to 180°C, and 180 to 200°C. Reaction conditions may include reaction pressures ranging from 5 to 100 bar and all ranges and values ​​therebetween. In embodiments of the invention, the linear alpha olefins produced in block 203 may be 1-butene, 1-hexene, 1-octene, C 10In an embodiment of the present invention, the effluent stream 12 comprises 0.1 to 75 wt. % 1-hexene and 0.1 to 75 wt. % 1-octene. The effluent stream 12 contains ethylene, polymer, catalyst, traces of butenes, C 10 + or combinations thereof.

[0038] According to an embodiment, as shown in block 204, the method 200 includes taking one or more reaction units 110 offstream. According to an embodiment of the present invention, as shown in block 205, the method 200 includes flushing at least one of the offstream reaction units 110 with a solvent using a scrubbing unit 120 to remove polymer deposited in the reaction units 110 while the remaining reaction units 110 are onstream to produce linear alpha olefins. In an embodiment of the present invention, the solvent comprises a flushing medium. In an embodiment of the present invention, the flushing in block 205 includes flushing with a solvent from upstream of the pump 104 through the heat exchanger 103 and withdrawing the solvent back into the flashing drum 121 of the scrubbing unit 120. The flashing in block 205 further includes simultaneously flushing the reactor 102 with a solvent through the jet mixer and the outlet of the reactor 102 and withdrawing the solvent from the bottom of the reactor 102 into the flashing drum 121 of the scrubbing unit 120. In an embodiment of the present invention, at least a portion of the solvent withdrawn from reactor 102 , pump 104 and / or heat exchanger 103 is separated in separation unit 150 to produce regenerated solvent stream 16 .

[0039] According to an embodiment of the invention, as shown in block 206, method 200 includes recycling at least a portion of effluent stream 12 back to one or more reactors 102 forming recycle stream 13. In an embodiment of the invention, recycle stream 13 may be cooled in heat exchanger 103 before being returned to reactor 102. Recycle stream 13 may be cooled from the reaction temperature by 1-15°C and all ranges and values ​​therebetween, including the ranges of 1-3°C, 3-6°C, 6-9°C, 9-12°C, and 12-15°C.

[0040] According to an embodiment of the invention, as shown in block 207, the method 200 includes separating at least a portion of the effluent stream 12 from each of the one or more reactors 102 in a separation unit 120 to produce an ethylene recycle stream 14 comprising primarily ethylene, one or more product streams comprising LAO, a recycle solvent stream comprising aliphatics, aromatics, or combinations thereof, and / or another solvent stream that is recycled to the wash unit 120. In an embodiment of the invention, prior to block 207, a catalyst deactivator is added to the effluent stream 12 to deactivate the catalyst. The deactivator may include an alcohol, an amine, water, caustic, air, or a combination thereof. Examples of alcohols include decanol and / or 2-ethylhexanol.

[0041] Although embodiments of the present invention have been described with reference to the blocks of Figure 2, it should be understood that the operation of the present invention is not limited to the specific blocks and / or the specific order of blocks shown in Figure 2. Thus, embodiments of the present invention may use various blocks in an order different from that of Figure 2 to provide the functionality described herein.

[0042] The systems and processes described herein may also include various equipment not shown that is known to those skilled in the art of chemical processing, such as some controls, piping, computers, valves, pumps, heaters, thermocouples, pressure gauges, mixers, heat exchangers, etc.

[0043] In the context of the present invention, at least the following 20 embodiments are described. Embodiment 1 is a system for producing linear alpha olefins. The system includes two or more reaction units configured to react ethylene in the presence of a catalyst and, optionally, a solvent to produce one or more linear alpha olefins, the two or more reaction units being arranged in parallel, and each of the two or more reaction units including a reactor. The system further includes a scrubbing unit in communication with the two or more reaction units and configured to flush polymer deposits from at least one off-stream reaction unit of the two or more reaction units while the remaining reaction units are on-stream to produce linear alpha olefins. Embodiment 2 is a system according to embodiment 1, wherein each of the reaction units further includes a heat exchanger configured to cool at least a portion of the effluent stream from the reactor, a pump, and / or a polymer removal filter in fluid communication with the reactor. Embodiment 3 is a system according to either embodiment 1 or 2, further including a passivation unit in fluid communication with each of the reaction units configured to remove moisture and oxygen from each of the reaction units. Embodiment 4 is the system of Embodiment 3, wherein the passivation unit includes an inert gas module configured to purge each of the reaction units with an inert gas to reduce moisture and oxygen, and a solvent module configured to circulate a mixture containing the solvent and the aluminum alkyl to each of the two or more reaction units.Embodiment 5 is the system of any of Embodiments 1-4, wherein a catalyst deactivator is added to a portion of the effluent stream to deactivate the catalyst and form a separated feed stream, and the system further includes a separation unit configured to separate at least a portion of the effluent stream from each reactor of each of the two or more reaction units to produce one or more of: (a) a recycled ethylene stream containing primarily ethylene; (b) one or more product streams containing one or more linear alpha-olefins; (c) a solvent recycle stream containing a solvent used as a process diluent; and (d) a heavy stream containing the catalyst, polymer, and / or catalyst deactivator.

[0044] Embodiment 6 is a method for producing linear alpha olefins. The method includes flowing a feedstream containing ethylene to one or more reactors of two or more reaction units, each reaction unit including a reactor, and the two or more reaction units being operated in parallel. The method further includes reacting ethylene in the one or more reactors in the presence of a catalyst and, optionally, a solvent, under reaction conditions sufficient to produce one or more linear alpha olefins. Embodiment 7 is the method of embodiment 6, wherein the reacting further produces a polymer, at least a portion of which is deposited in the reaction unit, and the method further includes flushing at least one of the reaction units with a solvent to remove the polymer deposited in the reaction unit while the remaining reaction units are on-stream to produce linear alpha olefins. Embodiment 8 is the method of embodiment 7, wherein the solvent includes an aromatic, paraffinic, and / or olefinic solvent, including decalin, toluene, hexane, heptane, octane, xylene, iso-pentane, cyclohexane, or a combination thereof. Embodiment 9 is the method of any of embodiments 6-8, wherein one or more reactors are liquid-gas phase reactors and the feed stream further contains a catalyst, a solvent, a polymer inhibitor additive, or a combination thereof.Embodiment 10 is the method of embodiment 9, wherein the catalyst contains a metal source, an aluminum alkyl, and optionally a modifier and a ligand.Embodiment 11 is the method of embodiment 9, wherein the metal source comprises a chromium-containing species including CrCl(tetrahydrofuran), Cr(III) acetylacetonate, Cr(III) octanoate, Cr-hexacarbonyl, Cr(III)-2-ethylhexanoate, (benzene)tricarbonylchromium, or a combination thereof; the aluminum alkyl comprises trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, ethylaluminum sesquichloride, diethylaluminum chloride, ethylaluminum dichloride, methylaluminoxane [MAO], modified methylaluminoxane [MMAO], or a combination thereof; and the modifier comprises a quaternary ammonium salt, ... The ligand may comprise an organic compound based on a PNPNH skeleton, wherein each P and N independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and the substituent may contain other heteroatoms including N, S, and P, such as (Ph)P-N(i-Pr)-P(Ph)-N(i-Pr)-H; or the ligand may comprise an organic compound based on a NPNPN skeleton, wherein each P and N independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and the substituent may contain other heteroatoms including N, S, and P, such as (n-Bu)(Me)NP(Cy)-N(Me)-P(Cy)-N(n-Bu)(Me), wherein Cy is a cyclohexyl group, Me is a methyl group, and n-Bu is a normal butyl group. Embodiment 12 is the method of any of embodiments 6-11, further comprising flowing a polymer inhibiting additive comprising hydrogen into the one or more reactors. Embodiment 13 is the method of embodiment 12, wherein hydrogen is mixed in the feed stream or injected directly into the reactor. Embodiment 14 is the method of any of embodiments 6-13, wherein each of the one or more reaction units further comprises a heat exchanger configured to cool at least a portion of the effluent stream from the reactor, and a pump. Embodiment 15 is the method of any of embodiments 6-14, further comprising passivating the one or more reaction units by removing moisture and oxygen therefrom prior to flowing the feed stream into the reactor.Embodiment 16 is the method of embodiment 15, wherein passivating comprises purging one or more reaction units with an inert gas to reduce the moisture and oxygen concentrations in the reaction units to a first level. The method further comprises circulating the solvent and aluminum alkyl mixture through the one or more reaction units to further reduce the moisture and oxygen concentrations in the reaction units to a second level. Embodiment 17 is the method of embodiment 16, wherein the first level is 500 to 1000 ppm, the second level is 1 ppm to 10 ppm, the inert gas is at a temperature of 20 to 300°C, and the solvent and aluminum alkyl mixture is at a temperature of 20 to 150°C. Embodiment 18 is the method of any of embodiments 6 to 16, further comprising recycling at least a portion of the effluent stream from each of the one or more reactors to the one or more reactors, the effluent stream containing one or more linear alpha olefins, unreacted ethylene, optionally solvent, and catalyst. The method further comprises deactivating the catalyst in at least a portion of the effluent stream from each reaction unit to produce a separate feed stream. The method further comprises separating the separated feed stream in a separation unit to produce an ethylene recycle stream containing primarily ethylene, a solvent recycle stream, and one or more product streams containing one or more linear alpha-olefins.Embodiment 19 is the method of any of embodiments 6-18, wherein the reaction conditions comprise a reaction temperature of 20 to 200°C and a reaction pressure of 5 to 100 bar.Embodiment 20 is the method of embodiment 19, wherein the effluent stream contains 0.1 to 75 wt% 1-hexene and / or 0.1 to 75 wt% 1-octene.

[0045] Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the embodiments, as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the processes, machines, manufacture, compositions of matter, means, methods, and steps described herein. As will be readily apparent from the above disclosure, those skilled in the art can utilize currently existing or later-developed processes, machines, manufacture, compositions of matter, means, methods, or steps that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. 1. A system for continuously producing linear alpha olefins, comprising: two or more reaction units configured to react ethylene in the presence of a catalyst and optionally a solvent to produce one or more linear alpha olefins, wherein the two or more reaction units are arranged in parallel, and each of the two or more reaction units comprises a reactor; and a wash unit in fluid communication with the two or more reaction units and a separator configured to flush polymer deposits from at least one off-stream reaction unit of the two or more reaction units and to allow the remaining reaction units to be on-stream to produce linear alpha olefins, the wash unit including a flashing drum containing a solvent, the solvent from the flashing drum being passed through the off-stream reaction unit and then treated in the separator to remove the polymer and produce a regenerated solvent, and the regenerated solvent being recycled from the separator to the flashing drum; and a passivation unit in fluid communication with each of the two or more reaction units configured to remove moisture and oxygen from at least one off-stream reaction unit of the two or more reaction units; Including, the system.

2. 10. The system of claim 1, wherein each of the reaction units further comprises a heat exchanger configured to cool at least a portion of an effluent stream from the reactor, a pump, and / or a polymer removal filter in fluid communication with the reactor.

3. The passivation unit an inert gas module configured to purge each of the reaction units with an inert gas to reduce moisture and oxygen; and a solvent module configured to circulate a mixture comprising a solvent and an aluminum alkyl to each of two or more reaction units; The system of claim 1 , comprising:

4. 3. The system of claim 2, wherein a catalyst deactivator is added to a portion of the effluent stream to deactivate the catalyst and form a separated feed stream, and the system further comprises a separation unit configured to separate at least a portion of the effluent stream from each reactor of each of the two or more reaction units to produce one or more of: (a) a recycle ethylene stream containing primarily ethylene; (b) one or more product streams comprising one or more linear alpha-olefins; (c) a solvent recycle stream containing a solvent used as a process diluent; and (d) a heavy stream comprising the catalyst, polymer, and / or catalyst deactivator.

5. 10. The system of claim 1, further comprising a polymer inhibitor additive unit in fluid communication with each of the reaction units and configured to add hydrogen to each of the reaction units.

6. 1. A process for continuously producing linear alpha olefins, comprising: flowing a feed stream comprising ethylene to one or more of two or more reaction units, each reaction unit comprising a reactor, the two or more reaction units being operated in parallel; and reacting ethylene in the one or more reaction units in the presence of a catalyst and optionally a solvent under reaction conditions sufficient to produce one or more linear alpha olefins. Including, the reacting further produces a polymer, at least a portion of which is deposited within the reaction unit; passivating the one or more reaction units by removing moisture and oxygen therefrom prior to flowing the feed stream therethrough; flushing at least one of the reaction units with solvent from a flushing drum included in the washing unit to remove polymer deposited in one or more of the reaction units, while the remaining reaction units are on-stream to produce linear alpha olefins, the solvent from the flushing drum is then treated in a separator to remove the polymer and produce a regenerated solvent, and the regenerated solvent is recycled to the flushing drum; further comprising: method.

7. 7. The method of claim 6, wherein the solvent comprises an aromatic, paraffinic, and / or olefinic solvent including decalin, toluene, hexane, heptane, octane, xylene, isopentane, cyclohexane, or combinations thereof.

8. 8. The method of claim 6 or 7, wherein the one or more reactors are liquid-gas phase reactors and the feed stream further comprises a catalyst, a solvent, a polymer inhibiting additive, or a combination thereof.

9. 9. The method of claim 8, wherein the catalyst comprises a metal source, an aluminum alkyl, and optionally a modifier and a ligand.

10. The metal source is CrCl ３ chromium-containing species including chromium(tetrahydrofuran), Cr(III) acetylacetonate, Cr(III) octanoate, Cr-hexacarbonyl, Cr(III)-2-ethylhexanoate, (benzene)tricarbonylchromium, or combinations thereof; aluminum alkyls include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, ethylaluminum sesquichloride, diethylaluminum chloride, ethylaluminum dichloride, methylaluminoxane [MAO], modified methylaluminoxane [MMAO], or combinations thereof; and modifiers include quaternary ammonium salts, quaternary phosphonium salts, sulfonates, or combinations thereof.

10. The method of claim 9, wherein the ligand comprises an organic compound based on a PNPNH skeleton, wherein each P and N independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and such substituents may contain other heteroatoms including N, S, and P, for example, (Ph)P-N(i-Pr)-P(Ph)-N(i-Pr)-H; or wherein the ligand comprises an organic compound based on a NPNPN skeleton, wherein each P and N independently have an aromatic, aliphatic, straight-chain, or cyclic substituent, and such substituents may contain other heteroatoms including N, S, and P, for example, (n-Bu)(Me)N-P(Cy)-N(Me)-P(Cy)-N(n-Bu)(Me), wherein Cy is a cyclohexyl group, Me is a methyl group, and n-Bu is a normal butyl group.

11. 8. The method of claim 6 or 7, further comprising flowing a polymer inhibiting additive comprising hydrogen into the one or more reactors.

12. 12. The method of claim 11, wherein hydrogen is mixed in the feed stream or injected directly into the reactor.

13. 8. The method of claim 6 or 7, wherein each of the one or more reaction units further comprises a heat exchanger configured to cool at least a portion of the effluent stream from the reactor, and a pump.

14. The passivating step comprises: purging the one or more reaction units with an inert gas to reduce the concentration of moisture and oxygen in the reaction units to a first level; and circulating the solvent and aluminum alkyl mixture through the one or more reaction units to further reduce the moisture and oxygen in the reaction units to a second level lower than the first level. The method of claim 6, comprising:

15. 15. The method of claim 14, wherein the first level is from 500 to 1000 ppm, the second level is from 1 ppm to 10 ppm, the inert gas is at a temperature from 20 to 300°C, and the solvent and aluminum alkyl mixture is at a temperature from 20 to 150°C.

16. recycling at least a portion of an effluent stream from each of the one or more reaction units to the reactor, the effluent stream comprising one or more linear alpha olefins, unreacted ethylene, optionally a solvent and a catalyst; deactivating catalyst in at least a portion of the effluent stream from each reaction unit to produce a separate feed stream; and separating the separated feed stream in a separation unit to produce an ethylene recycle stream comprising primarily ethylene, a solvent recycle stream, and one or more product streams comprising one or more linear alpha olefins. The method of claim 6 or 7, further comprising:

17. 8. The process according to claim 6 or 7, wherein the reaction conditions comprise a reaction temperature of 20 to 200° C. and a reaction pressure of 5 to 100 bar.

18. 18. The process of claim 17, wherein the effluent comprises 0.1 to 75 wt. % 1-hexene and / or 0.1 to 75 wt. % 1-octene.

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