Trimerization of olefin

Abstract

To provide a method for producing olefin trimers from olefin monomers with high selectivity.SOLUTION: A method for producing olefin trimers comprises: feeding into a reactor containing a dimerization catalyst olefin monomer feed and at least one oxygen-containing moderator; operating the reactor at 40-140°C and 10-40 bar for carrying out catalytic dimerization reactions and addition reactions between olefin monomers and dimers; and distilling a reactor outlet stream to separate a bottom product containing olefin trimers, in which a lighter product is recycled into the reactor, olefin monomers are fed into the reactor, amounts of the olefin monomer feed and the recycled feed fed into the reactor are controlled such that a mass ratio of olefin monomers to olefin dimers entering the reactor is selected from a range of 1:8-1:15.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the treatment of olefins, particularly to the production of olefin trimers from olefin monomers with high selectivity.

Background Art

[0002] Current methods used to polymerize olefins typically produce a mixture of olefin polymers and have low selectivity for a particular polymer. The production of the desired polymer species from such polymer mixtures requires the use of complex separation techniques. Thus, it would be beneficial to find a method for producing the desired olefin polymer with high selectivity instead of a mixture of polymers, and a process in which the olefin monomer is efficiently converted to the desired polymer.

[0003] <00​​​​​​​​Acid-catalyzed isobutene oligomerization generally results in a broader oligomer distribution as the conversion of isobutene increases. Therefore, previous processes were not efficient in producing isobutene trimers, i.e., isododecene. This disclosure relates to a process that achieves high olefin conversion and, at the same time, a number of trimer products with selectivity even higher than 90%.

[0006] The purpose of this disclosure is therefore to provide products, processes, and systems for mitigating the aforementioned disadvantages. In particular, the disclosure aims to provide processes and manufacturing units that can be used to produce olefin trimers from olefin monomers with high selectivity. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 4,544,791 [Overview of the Initiative]

[0008] The scope of protection required by the various embodiments of the present invention is defined by the appended claims.

[0009] This specification discloses a method for producing an olefin trimer, the method being described herein. Feeding an olefin monomer feed and at least one oxygen-containing moderator into a reactor containing a dimerization catalyst, To carry out catalytic dimerization reactions between olefin monomers and addition reactions between olefin monomers and olefin dimers, the reactor is operated at a temperature selected from the range of 40 to 140°C and a pressure selected from the range of 10 to 40 bar. Extracting the reactor outlet flow from the reactor, and Distilling the reactor outlet stream to separate at least one lighter product containing an olefin dimer and a heavier bottom product containing an olefin trimer. Including, here, At least a portion of the lighter products is recycled into the reactor to provide a recycled feed. Olefin monomers are fed into the reactor, mainly as fresh olefin monomer feed. The amount of fresh olefin monomer feed and recycled feed fed into the reactor is controlled so that the mass ratio of olefin monomers to olefin dimers entering the reactor is selected from the range of 1:8 to 1:15, and The catalytic reaction is carried out under operating conditions in which the olefin remains in the liquid phase.

[0010] An advantage of the process of the present invention is the selectivity of the polymerization reaction (dimerization and addition reaction) for olefin trimers. Another advantage is that the process of the present invention makes it possible to produce olefin trimers even in a single reactor system. The dimers produced in the reactor can be recycled by being returned to the reactor along with other lighter components after distillation, so further separation techniques are not required to remove lighter components, such as dimers, from the olefin trimer product. Thus, the process of the present invention simultaneously achieves the recovery of olefin trimers and the recycling of reaction species.

[0011] Alternatively, multiple reactor vessels may be used instead of a single reactor unit, which even allows for further control to optimize the process selectivity for trimer production. The use of multiple reactor vessels is also compatible with the single-step distillation described above. Furthermore, the process is flexible and allows for the recovery of olefin dimers and olefin trimers as separate product streams. As will be described later, the present invention can also be carried out using two distillation columns.

[0012] In this specification, a manufacturing unit suitable for and configured to carry out the above-described process is disclosed, a. At least one reactor unit configured to accept an acid catalyst, b. At least one distillation column configured to separate isododecene from isooctene, c. A reactor unit or multiple reactor units and at least one reservoir and at least one reactor feed line connected to the liquid for olefin monomers. d. A reactor unit or multiple reactor units and at least one reactor outlet flow line connected to a distillation column and liquid. e. A distillation column and reactor unit or at least one recycling line liquid-connected to multiple reactor units, and f. The distillation column and the bottom product line, which is fluidly connected to the bottom product reservoir. It is equipped with.

[0013] The present invention will be described in more detail by non-limiting preferred embodiments with reference to the following drawings. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows the composition of the bottom product obtained by the process of the present invention using recycled olefin dimers. [Figure 2] Figure 2 shows the composition of the bottom product for comparison obtained using a "through-flow" experimental design, i.e., without recycling the olefin dimer. [Figure 3] Figure 3 shows an embodiment of the manufacturing unit 100. [Figure 4] Figure 4 shows another embodiment of the manufacturing unit 100. [Modes for carrying out the invention]

[0015] The term "oxygen containing moderator" means a compound containing oxygen, such as an oxide or a compound containing oxygen, carbon and hydrogen.

[0016] As used herein, the term "comprising" includes the broader meanings of "including", "containing", and "comprehending", as well as the narrower expressions of "consisting of" and "consisting only of".

[0017] In certain embodiments, the process is carried out on an industrial scale, preferably as a continuous process.

[0018] In certain embodiments, the process steps are carried out in the order defined in any aspect, embodiment, or claim. In another embodiment, any process step specified to be carried out on a product or intermediate obtained in a previous step is carried out directly on the product or intermediate, i.e., without any additional, optional, or ancillary treatment steps that would chemically or physically change the product or intermediate between the two consecutive steps.

[0019] In the context of the present invention, the term reactor feed means any feed entering the reactor. For the sake of brevity, when at least one identical component, such as an olefin monomer, is fed to the reactor via multiple feeds, the reactor feed of the olefin monomer or the olefin monomer reactor feed means the total amount of the olefin monomer to the reactor in such cases.

[0020] The terms fresh olefin monomer feed and fresh olefin monomers refer to olefin monomers that are fresh, i.e., not recycled, and that are fed into the reactor to provide a source of olefin monomers to replenish the amount of olefin monomers that are consumed during the catalytic reaction in the reactor and are primarily removed as dimer or trimer products that are recovered or consumed. The fresh olefin monomers are fed in an amount sufficient to maintain the monomer-to-dimer mass ratio at the desired level. Thus, when olefin trimer production is carried out as a continuous process, fresh monomers that have not previously entered the reactor are fed into the reactor through the reactor feed line, and the olefin trimers are removed from the process as reaction products.

[0021] In one embodiment, olefin monomers are fed into the reactor primarily as fresh olefin feed, i.e., fresh olefin monomers constituting more than 50 wt-% of the total olefin monomers entering the reactor. In another embodiment, at least 55 wt-%, 60 wt-%, 70 wt-%, 80 wt-%, or 90 wt-% of the olefin monomers entering the reactor are fresh.

[0022] In one embodiment, the recycled feed contains unreacted olefin monomers.

[0023] The term reactor refers to a reactor, such as at least one reactor unit or at least one reactor vessel, where a catalytic reaction takes place. The reactor may have at least one catalyst bed and openings for introducing fluid into and removing fluid from the reactor.

[0024] Olefins are compounds composed of at least hydrogen and carbon, and contain at least one double bond between two carbon atoms. Olefins suitable for the process of the present invention contain two or more carbon atoms and may have a linear or branched structure. A preferred olefin in the present invention is isobutene.

[0025] For example, olefin mixtures, such as mixtures of olefin monomers, olefin dimers and heavier polymers, or mixtures containing olefins having various numbers of carbon atoms and double bonds, may also be used in the process of the present invention and fed into the reactor. In one embodiment, a feed containing an olefin mixture is fed into the reactor as a mixed feed.

[0026] In the context of the present invention, a mixed feed or mixed monomer feed means a mixture of olefins having various numbers of carbon atoms or olefin isomers having the same number of carbon atoms, and combinations thereof. In one embodiment, the mixed feed contains C4-C5 olefins. In another embodiment, the mixed feed contains olefins having C4+ / -1 carbon atoms. In one embodiment, reactive components that are lighter than the C4 olefin are removed from the feed entering the reactor to allow distillation of the reaction product.

[0027] In one embodiment, the olefin monomer feed is at least one of the following: C4 oleic acid, C5 olefins, mixed feeds of C4 and C5 olefins, isobutene, 1-butene, cis-2-butene, trans-2-butene, and optionally at least one inert substance, n-butane, i-butane, butadiene, distillation fractions, or any mixture thereof. Includes.

[0028] In one embodiment, the olefin monomer feed, or mixed feed, comprises or essentially consists of at least one of isobutene, as well as C4 olefins, C5 olefins, mixed feeds of C4 and C5 olefins, isobutene, 1-butene, cis-2-butene, trans-2-butene, inerts, n-butane, i-butane, butadiene, distillation fractions, or any mixture thereof. In a preferred embodiment, isobutene is the main component of the mixed feed.

[0029] In one embodiment, the amount of unreactive components such as inerts, n-butane, and i-butane in the reactor outlet stream leaving the reactor is very small, and therefore they do not significantly hinder the separation of olefin dimers and olefin trimers in the distillation step.

[0030] The advantage of using a mixed feed in the process of the present invention is that the removal of inert substances present in the mixed feed is efficient, and the removal of inert substances does not significantly affect the product yield. When a mixed feed is used in the process of the present invention, due to the high monomer conversion rate per cycle, only a small amount of reactive monomer remains in the reactor outlet stream leaving the reactor, and as a result, almost no monomer is lost in the inert substance removal step.

[0031] The reactor outlet flow drawn from the reactor contains at least olefin dimers and olefin trimers, and optionally smaller amounts of olefin monomers, moderators, and inerts.

[0032] An embodiment of a manufacturing unit 100 for carrying out the process of the present invention is shown in Figure 3. The manufacturing unit 100 comprises a reactor unit 110 and a distillation column 210. Olefin monomers are fed from a reservoir 410 into the reactor through a reactor feed line 420, which is fluidly connected to a first recycle feed 220 and a second recycle feed 230 in Figure 3. From the reactor unit 110, the reaction products are moved to the distillation column 210 through a reactor outlet stream 120. From the distillation column 210, the first recycle line 220 returns the lighter product, which includes at least one of the olefin monomer, diluent, and moderator, to the reactor unit 110. The second recycle line 230 returns the stream, which mainly consists of olefin dimers, to the reactor unit 110. The heavier bottom product, which includes olefin trimers, is carried from the distillation column to the bottom product reservoir 510 via a bottom product line 250. Inert materials can optionally be removed by investing in an inert material removal line 240.

[0033] In the embodiment shown in Figure 3, the recycle feed consists of two recycle feeds that lead to the reactor unit 110 through a first recycle line 220 and a second recycle line 230. In Figure 3, the recycle lines are depicted as being fluidly connected to a reactor feed line 420 that enters the reactor unit 110. Alternatively, the recycle lines may be led to the reactor unit 110 through a separate opening in the reactor unit 110.

[0034] Instead of the two recycling lines 220 and 230 described above, a single recycling feed line may also be used. In this embodiment, the single recycling line recycles both the olefin dimer and the olefin trimer, and optionally the moderator, back into the reactor.

[0035] In one embodiment, the olefin monomer reservoir 410 is configured to provide a mixed feed.

[0036] In another embodiment, the olefin monomer reservoir 410 is configured to provide fluid connections to a plurality of reaction units or reactor vessels. When a plurality of reactor vessels are provided in sequence, preferably the olefin monomer is fed to the first reactor vessel of the series, and optionally, subsequent reactor vessels receive only feed from the reactor outlet flow line of the preceding reactor vessel.

[0037] Another embodiment of the manufacturing unit 100 is shown in Figure 4, where a mixed feed is preferably used. In this embodiment, the manufacturing unit 100 comprises a reactor unit 110 and a distillation column 210. Fresh olefin is fed from the reservoir 410 to the reactor through the reactor feed line 420, which is fluidly connected in Figure 4 to a first recycle feed line 220, a second recycle feed 230, and an optional dimer feed line 430. The reaction product is moved from the reactor unit 110 to the distillation column 210 through the reactor outlet flow line 120. The first recycle line 220 returns the lighter product, which includes at least one of olefin monomers, diluents, and moderators, from the distillation column 210 to the reactor unit 110. The second recycle line 230 returns the stream, which mainly consists of olefin dimers, to the reactor unit 110. The heavier bottom product, containing olefin trimers, is led from the distillation column through the bottom product line 250 to the bottom product reservoir 510. Inerts may optionally be removed through the inerts removal line 240. Figure 4 also shows a heat exchanger 310 which may be used to remove heat from the outlet flow leaving the distillation column and to heat the reactor outlet flow line 120 before it enters the distillation column. In Figure 4, the olefin dimers are removed from the distillation column through a second recycle line 230 which is fluidly connected to the side of the distillation column to provide a side flow. Preferably, the side flow is taken out of the distillation column as a vapor outlet flow, which is condensed after heat recovery in the heat exchanger and before it enters the reactor unit 110 as a recycle feed.

[0038] As shown in Figure 4, the bottom product line 250 may be treated through an optional heat exchanger to heat the reactor outlet flow line 120 before the stream enters the distillation column.

[0039] In one embodiment, an olefin monomer feed, preferably a high-purity olefin monomer feed, is fed into a reactor unit, which is a single reactor vessel, in the embodiments shown in Figures 3 and 4. Alternatively, a reactor unit comprising multiple reactor vessels may be used.

[0040] The reactor unit 110 contains a dimerizing catalyst that catalyzes the formation of an olefin dimer in a dimerization reaction between two olefin monomers, and the formation of an olefin trimer in an addition reaction between the olefin monomers and the olefin dimer. In addition, a small amount of heavier olefin oligomers may be produced. The reaction products are led from the reactor as a reactor outlet stream 120 to a distillation column 210, which separates the unreacted inert material, olefin monomers, and olefin dimers from heavier bottom products containing at least olefin trimers and optionally compounds having higher boiling points than the olefin dimers. An optional heat exchanger 310 may be used to recover heat from the bottom products containing olefin trimers and to heat the reactor outlet stream before it enters the distillation column.

[0041] In the embodiments shown in Figures 3 and 4, the moderator may be added to the reactor along with the olefin monomer feed through the reactor feed line 420, along with the recycle feed which is led from the distillation column to the reactor unit as recycle lines 220, 239, or directly to the reactor through a separation inlet (not shown in the figure). To ensure good mixing, it is preferable to feed the moderator together with the reactor feed entering the reactor, for example, through the reactor feed line 420 or the recycle lines 220, 230.

[0042] In one embodiment, fresh monomers are fed to the reactor as a high-purity monomer feed. The high-purity olefin preferably has a purity of at least 95 wt-%. The use of high-purity olefin is particularly advantageous in a single-column system because it results in a reaction product feed that contains only small amounts of components having boiling points overlapping with the olefin dimer or trimer.

[0043] After the olefin stream passes through one or more reactor units, the resulting reactor outlet stream is led to a distillation column that separates unreacted olefins (primarily dimers) from olefin trimers, which are extracted as a lighter product at the bottom of the column. Preferably, the lighter product contains virtually no olefin monomers, which exhibits a high conversion rate. In one embodiment, process parameters are selected such that the pass-through conversion rate of olefin monomers is at least 96%, so that the lighter product contains primarily dimers and only small amounts of olefin monomers. Controlling the feed entering the reactor is simpler because monomers are added to the feed almost exclusively through a fresh olefin monomer feed, and only small amounts of monomers may be present in the recycled dimer feed, since monomers are consumed completely or almost completely in the catalytic conversion.

[0044] In one embodiment, the lighter product does not contain olefin trimers. The separation of olefin trimers can be controlled by distillation parameters. In the process of the present invention, olefin trimers are concentrated in the bottom product during distillation, and then they are removed from the process. As a result, the recycled feed contains olefin dimers, and olefin trimers are preferably not present in significant amounts in the recycled feed.

[0045] In one embodiment, the bottom product comprises less than 15 wt-% of olefin tetramers and optionally at least 80 wt-% of olefin trimers, based on the total weight of the bottom product. In another embodiment, the bottom product comprises less than 12 wt-% of olefin tetramers and optionally at least 80 wt-% of olefin trimers, based on the total weight of the bottom product. Instead of 80 wt-%, the amount of olefin trimers in the bottom product may also be at least 85 wt-%, or at least 88 wt-%.

[0046] In one embodiment, the transconversion rate of the olefin monomer is at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 96%, and optionally, the selectivity of the olefin trimer is at least 85%, at least 90%, expressed as weight-% of the olefin monomer.

[0047] In the context of the present invention, the term diluent means any inertant, or an agent less reactive than the olefin in the process of the present invention. The addition of a diluent to the reactor thus reduces the concentration of the olefin in the reactor, and the degree of catalytic conversion of the olefin in the process can be controlled by selecting an appropriate amount of diluent.

[0048] In one embodiment, the recycle feed may be withdrawn from the side of the first distillation column as a side recycle stream. In one embodiment, this recycle feed contains both olefin monomers and olefin dimers. In another embodiment, the recycle feed contains olefin dimers. The location from which the side recycle stream is withdrawn may be selected such that the dimers are at least partially removed from the distillation column, but the recycle feed does not contain significant amounts of heavier and lighter compounds.

[0049] In the embodiment shown in Figure 4, monomer-containing products and lighter dimer-containing products can be mixed with a fresh olefin stream before entering the reactor. The amount of recycled feed and the amount of fresh olefin can be controlled to maintain a desired mass ratio of olefin monomers to olefin dimers in the feed entering the reactor. An optional dimer feedline 430 can also be used to feed dimers into the reactor, thereby achieving further control of the process.

[0050] The embodiments described herein are suitable for the selective production of trimers from olefin monomers and allow for the control of the olefin feed and moderator so that the selectivity of the catalytic reaction promotes the formation of olefin trimers.

[0051] Moderators are applied to slightly slow the reaction rate and to ensure an extension of the catalyst lifetime. The preferred amount of moderator is specific to the main product of interest and can be selected by those skilled in the art by analyzing the reaction products and process conditions. For the production of olefin trimers, the preferred amount is significantly less than the amount used in the production of olefin dimers. The moderator can be recycled by returning it from the distillation column to the reactor along with the recycled feed containing the olefin monomers.

[0052] Surprisingly, unlike isooctene production, the inventors have found that in the present invention, which is optimized for producing olefin trimers, no separation solvent is required. Therefore, in some embodiments, the process of the present invention is carried out without additional solvents. In some embodiments, the olefin feed fed into the reactor includes isobutene and recycled olefin (mainly isooctene) recovered after the feed has passed through the reactor. The process of the present invention is advantageous because, in preferred embodiments, it can be carried out without diluents. Conventional processes, which are mainly designed for olefin dimers, require the use of diluents, which makes the process uneconomical, especially when high-purity and high-concentration feeds are used. Advantageously, the high conversion rate of olefin monomers in the process of the present invention means that the removal of inerts does not result in a significant loss of unreacted olefin monomers, which improves the efficiency of the process and enhances the removal of inerts.

[0053] Instead of using a single reactor unit, the reactor unit can be divided and distributed into separate vessels. By increasing the number of reactor vessels and reactor beds, reaction conditions become easier to control, and as a result, nearly complete pass-through conversion rates of olefin monomers, such as isobutene, can be achieved. Thermal control of adiabatic temperature rise also becomes easier than when a large number of reactor units are used.

[0054] In one embodiment, the reactor unit comprises a plurality of reactor vessels arranged as a continuous reactor, as parallel reactors, or as a combination thereof.

[0055] In one embodiment, the reactor comprises two or more reactor vessels, such as two, three, four, or five reactor vessels, each of which comprises at least one reactor bed. The use of two or more reactor vessels is advantageous because it allows for more precise temperature control and further allows for control of the amounts of moderator and catalyst in each individual reactor vessel. Between the reactor vessels, the feed temperature is controlled by a temperature control unit capable of cooling or heating the feed. In one embodiment, reaction conditions, such as temperature and pressure, are essentially the same in each individual reactor vessel.

[0056] When multiple reactor vessels are used as a reactor unit instead of a single reactor vessel, each reactor vessel contains a dimer catalyst, preferably an acidic ion exchange resin catalyst. Preferably, the same catalyst is used in each reactor vessel. Preferably, the amount of catalyst is kept low in the first reactor vessel and increased in subsequent reactor vessels downstream of the process. By limiting the amount of catalyst in the first reactor vessel, for example, the temperature becomes easier to control and the reaction conditions can be more easily maintained within a selected range. For example, when multiple reactor vessels are used, the olefin can be kept in the liquid phase, and the olefin flow is cooled between the reactor vessels, and the mass ratio of olefin monomers to olefin dimers can be more easily maintained at a desired level. Preferably, in addition to the reactor feed to the first reactor vessel, no further olefins are fed to subsequent reactor vessels during the process; i.e., the fed olefin mixture is not replenished by further olefins while the mixture flows through the reactor vessels. When multiple reactor vessels are used, each having a single reactor bed, the amount of catalyst can increase within the reactor vessels. In a multiple reactor configuration, the upstream reactor vessels contain more catalyst than the downstream reactor vessels. In one embodiment, the multiple reactor configuration includes three or four reactor vessels.

[0057] In a reactor unit comprising multiple reactor vessels, the capacity of the reactor vessels can increase from the first reactor vessel downstream to subsequent reactor vessels. In one embodiment, the capacities of the first and second reactor vessels are essentially the same; in another embodiment, the capacities of the third and fourth reactor vessels are essentially the same.

[0058] In yet another embodiment, the capacities of the third and fourth reactor vessels are essentially the same as those of the first or second reactor vessel, where the first and second reactor vessels may have essentially the same capacity.

[0059] In one embodiment, the oxygen-containing moderator, or moderator, is an oxygenated substance such as demiwater (demineralized water) or tert-butyl alcohol (TBA). Alternatively or additionally, the moderator may include an alcohol produced in the reactor as a result of a reaction between water and an olefin. As a result, for example, 2-butanol may be produced from isobutene in the reactor.

[0060] After the olefin stream passes through the reactor unit, the resulting reactor outlet stream is led to a distillation column, which separates the unreacted olefins (mainly isooctene) and moderator components from the olefin trimer, which are removed as a bottom product. Olefin monomers may be present as small amounts of seeds in the lighter product, which is mainly composed of olefin dimers. Since monomers are consumed almost completely in the catalytic conversion, control of the feed composition inside the reactor becomes easier because monomers are added only through a fresh olefin monomer feed. If the lighter product contains dissolved gases, they can be separated from the lighter product by known methods.

[0061] The moderator may be circulated in a recycle-reactor loop with lighter compounds and replenished to maintain its quantity at a substantially constant level. The moderator may also preferably act as a source of oxygen in excess of the amount of water that may be present in the fresh olefin feed or recycled feed, but in amounts that are not sufficient in this invention. The moderator may be fed into the reactor by being mixed with the feed entering the reactor, such as a reactor feed containing fresh olefin monomers. Alternatively, the moderator may be mixed with the recycled olefin dimer stream before being mixed with the fresh olefin monomers. The use of additional moderators in the process of this invention is advantageous because it improves selectivity for trimer production.

[0062] At least a portion of the olefin dimers separated during distillation can be returned to the reactor for recycling. Alternatively or additionally, an external source of olefin dimers, preferably isooctene, is fed into the reactor along with the olefin monomers.

[0063] In one embodiment, the reactor outlet flow is distilled to separate the olefin dimers that are recycled back into the reactor.

[0064] In one embodiment, components that did not react in the reactor are separated as distillates in a distillation column. The distilled compounds can be removed from the process or recycled back into the reactor.

[0065] In one embodiment, the process of the present invention is a continuous process. Advantageously, the process of the present invention allows the process to continue for extended periods, even months, without interruption for maintenance. Prior art processes use laboratory-scale patch processes, which are unsuitable for industrial scale due to instability issues. In particular, when using multiple reactor vessels, the trimer production process can be effectively controlled in the process of the present invention, and the continuous process can be operated for extended periods.

[0066] The term “dimerization catalyst” or “catalyst” refers to a catalyst that catalyzes the dimerization of an olefin monomer to an olefin dimer, and the addition reaction between the olefin dimer and the olefin monomer to provide an olefin trimer. In one embodiment of the process of the present invention, the majority of the feed entering the reactor consists of olefin dimers, and the amount of olefin monomers is kept relatively low. As a result, the conditions in the reactor are selected in the present invention such that the dimerization catalyst catalyzes a reaction in which the olefin dimer formed in the reactor preferably reacts with an olefin monomer, thereby forming an olefin trimer.

[0067] In one preferred embodiment, the reactor comprises a single catalyst. Preferably, the reactor does not contain two different catalysts, such that a first catalyst is specific to the dimerization reaction between two monomers but does not catalyze the reaction between monomer and dimer, and a second catalyst is specific to the reaction between monomer and dimer but does not catalyze the dimerization reaction between two monomers. The process of the present invention therefore offers the advantage of being simpler compared to conventional systems that use multiple catalysts.

[0068] In one embodiment, water is not removed from the reactor or from the lighter product obtained from the distillation column.

[0069] In one embodiment, the catalytic reaction is carried out under operating conditions in which the olefin is maintained in the liquid phase, and optionally the moderator is also maintained in the liquid phase. Preferably, at least one of the reactor temperature and pressure is selected so that the olefin is in the liquid phase within the reactor. The advantage of maintaining at least the olefin in the liquid phase is that reactor control is easier to achieve than in processes involving gaseous olefins.

[0070] In one embodiment, fresh olefin monomers are fed into a reactor, and the fresh olefin monomers comprise an olefin having four carbon atoms, preferably isobutene.

[0071] In one embodiment, the olefin dimers are recycled into the reactor by mixing the recycled feed with fresh olefin monomers before feeding the mixed feed into the reactor. In another embodiment, the olefin dimers are mixed with the reactor feed before the combined mixture enters the reactor. Mixing the olefin dimers with the reactor feed is advantageous in ensuring effective mixing before it comes into contact with the first catalyst. Furthermore, potential temperature differences between the two feeds can be eliminated.

[0072] In one embodiment, the recycled feed contains at least 95 wt-% olefin dimers.

[0073] In one embodiment, the recycled feed contains less than 5 wt-%, preferably less than 3 wt-%, less than 2 wt-%, or less than 1 wt-% of olefin trimers. Maintaining a low amount of olefin trimers in the recycled feed further improves the selectivity of the process toward the production of olefin trimers and prevents the formation of olefin oligomers having more than three monomer units.

[0074] In a preferred embodiment, the mass ratio of olefin monomers to olefin dimers in the reactor feed is at least about 1:50, 1:40, 1:30, 1:20, 1:15, 1:14, 1:13, 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, or 1:2. In a more preferred embodiment, the feed mass ratio, expressed as the mass ratio of olefin monomers to olefin dimers in the feed entering the reactor, is selected from the range of 1:8 to 1:15 or 1:8 to 1:10. Using an excess amount of olefin dimers in the amounts specified above directs the catalytic reaction toward the formation of olefin trimers without significantly reducing the monomer conversion rate.

[0075] In one embodiment, the selectivity for olefin trimer production is expressed as weight-percentage (-%) based on the olefin monomer, and is at least about 85%, preferably about 90%. Depending on the process conditions, selectivity of even about 99% can be achieved. A selectivity of at least 85% means that at least 85% of the olefin monomer is used in the catalytic conversion when olefin dimers and olefin trimers are formed.

[0076] In one embodiment, the transconversion rate of the olefin monomer is at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 96%.

[0077] In one embodiment, the dimerization catalyst is an acid catalyst, preferably a strongly acidic ion exchange resin catalyst, and most preferably a macro-network acidic ion exchange resin catalyst.

[0078] In one embodiment, the catalyst is a solid.

[0079] In one embodiment, the catalyst catalyzes the dimerization reaction of two olefin monomers and the addition reaction between an olefin monomer and an olefin dimer.

[0080] Advantageously, the process of the present invention uses catalysts and moderators to improve the selectivity of the process for trimer formation. Preferably, it has been hypothesized that moderators such as t-butanol or alcohols promote dimer formation only, and that the presence of water in the reactor leads to the formation of alcohols or ethers, thereby inhibiting the formation of trimers and oligomers. As a result, polar compounds such as alcohols or ethers have previously been removed from the olefin feedstock before entering the reactor.

[0081] In one embodiment, the moderator comprises water, demiwater, alcohol, tert-butyl alcohol, or any combination thereof.

[0082] In one embodiment, the amount of moderator is selected from a range of 0.01 to 0.5 wt-% of the total feed to the reactor, preferably from a range of 0.1 to 0.4 wt-% and more preferably from a range of 0.2 to 0.3 wt-%. The total feed to the reactor includes all feed fed into the reactor.

[0083] In one embodiment, the temperature inside the reactor is selected from a range of 40 to 140°C, preferably from a range of 50 to 130°C, and more preferably from a range of 60 to 120°C.

[0084] In one preferred embodiment, the pressure inside the reactor is selected from a range of 15 to 35 bar, more preferably from a range of 20 to 30 bar.

[0085] In one preferred embodiment, the reactor is operated at 50–130°C and 13–35 bar, 50–130°C and 20–30 bar, 60–120°C and 15–35 bar, or 60–120°C and 20–30 bar, preferably. The reactor operating conditions are selected so that the olefin monomers and olefin dimers are in the liquid phase in the reactor. In one preferred embodiment, the residence time of the feed through the reactor is 0.25–2 1 / h, preferably 0.25–0.4 1 / h, expressed as gravitational space velocity per hour (WHSV).

[0086] The weight-to-space velocity per hour (WHSV) is defined as the weight of fresh feed flowing per unit weight of dry catalyst per unit weight per hour.

[0087] In one embodiment, distillation is carried out at a pressure selected from the range of 1.8 to 2 bar, and at 250°C. max It will be held at [location].

[0088] In one embodiment, the process further includes recovering heat from at least one feed obtained from a distillation column.

[0089] In one embodiment of the process of the present invention, the recovered heat is used to heat the reactor outlet flow before it enters the distillation column. In another embodiment, the heat is used to heat the reactor feed before it enters the reactor.

[0090] In one embodiment, the distillation column is a non-reactive distillation column that does not contain catalytic material or a reaction zone, and in which olefins do not react chemically to a significant degree. The non-reactive distillation column is therefore different from a reactive distillation column that has a reactive or catalytic zone that chemically converts, for example, the feed component, particularly olefin monomers, olefin dimers, or olefin trimers.

[0091] In one embodiment, distillation is carried out using two consecutive distillation columns. This embodiment may be particularly advantageous when using a mixed feed that contains components having a boiling point lower than that of the olefin dimer, or inerts having a boiling point lower than that of the olefin dimer. Thus, the inerts can be effectively removed by using a two-distillation-column configuration, and their condensation can be avoided.

[0092] When two distillation columns are used, light inert materials are removed in the first distillation column, and optionally, at least one of the olefin monomer, diluent, and moderator is separated and returned to the reactor for recycling, while the olefin dimer and optional heavier compounds are removed as intermediate bottom products and fed to a second distillation column for separation for recycling, returning at least one of the olefin monomer, diluent, and moderator to the reactor, and the olefin trimer and optional heavier compounds are recovered as bottom products. In the two-distillation-column process, the olefin dimer may optionally be recovered from the recycled feed from the second distillation column.

[0093] In one embodiment, the chemical reaction takes place in a single reactor. In this embodiment, the recycled olefin dimer is led to the same reactor in which the olefin monomer is dimerized by a dimerization catalyst.

[0094] The olefin trimer obtained from the distillation column contains an olefin polymer formed by polymerizing two olefin monomers together. In some embodiments, the olefin monomer components forming the olefin trimer may be chemically identical olefin monomers, such as certain C4 olefins, such as isobutene, and the trimer may contain at least one lighter or heavier olefin monomer component having a different number of carbon atoms, or at least one olefin monomer having the same number of carbon atoms but with variations in the number of double bonds and / or degree of isomerization.

[0095] In one embodiment, the reactor is not a trickle bed reactor.

[0096] In one embodiment, the catalytic reaction takes place in a unit separate from where the distillation is performed. Therefore, in one embodiment, the reaction does not take place in the catalytic distillation column.

[0097] In one embodiment, the distillation column is operated in an environment in which olefin dimerization or oligomerization does not occur.

[0098] In one embodiment, the process of the present invention is carried out in the absence of further added solvents and / or further added inertants. Advantageously, the present invention allows the dimer itself to act as an agent controlling the rate of chemical conversion. Additionally, the moderator may be recycled into the reactor to control the rate of catalytic conversion in the reactor.

[0099] Embodiments of a manufacturing unit 100 suitable for carrying out the process of the first embodiment are provided in Figures 3 and 4.

[0100] The manufacturing unit optionally includes a heat recovery unit, a heat transfer unit, and / or a heater unit.

[0101] The heater unit may be positioned within the manufacturing unit to heat at least one of the following: the reactor feed line, the reactor outlet flow line before it enters the distillation column, and the distillation column reboiler.

[0102] When multiple reactor vessels are used, a heat recovery unit or cooling unit may be placed between the reactor vessels. The heat recovered from the feed moving from one reactor vessel to the next may preferably be used in a heating unit of the manufacturing unit to improve the economics of the process.

[0103] In one embodiment of the manufacturing unit, the reactor comprises multiple reactor vessels, where each downstream reactor unit contains a larger amount of acid catalyst compared to the preceding distillation reactor vessel.

[0104] In one embodiment, the production unit further comprises at least one heat exchanger configured to absorb heat from the bottom product containing the olefin trimer and to heat the reactor outlet flow before it enters the first distillation column.

[0105] In one embodiment, the manufacturing further includes a first recycling line configured to recycle olefin monomers, diluents, and moderators to at least one reactor through a first recycling line, and a second recycling line configured to recycle olefin dimers to at least one reactor unit.

[0106] Examples The following examples are provided to better illustrate the claimed invention and should not be understood as limiting the scope of the invention as defined by the claims. While certain materials are described to some extent, this is for illustrative purposes only and not intended to limit the invention. Those skilled in the art will be able to develop equivalent methods or reactants without exercising inventive capabilities and without departing from the present invention. It should be understood that many modifications can be made to the procedures described herein while remaining within the scope of the invention.

[0107] An exemplary embodiment of the present invention was carried out by performing a process in which the total feed to the reactor section had an isobutene:recycle feed ratio of 0.12 and a moderator TBA content of 0.37 wt-%. Three consecutive reactors with outlet temperatures of 90°C each were used. The catalyst was an acidic ion exchange resin (5.2 mmol gram equivalent of acid).

[0108] result Composition ratio of bottom products: Based on the total weight of bottom products, 0.0% dimers, 89.2% trimers, and 10.8% tetramers. The results are shown in Figure 1.

[0109] In comparative examples under conditions similar to those of the above experiment, the reaction section was carried out by flow through-flow using the same isobutene feed and isobutane solvent (50 wt-%) and similar moderator TBA content.

[0110] result Composition ratio of bottom products: Based on the total weight of bottom products, 68% dimers, 23% trimers, and 9% tetramers. The results are shown in Figure 2.

[0111] The dimer content in the once-through operation can be further minimized by reducing the volume of moderator TBA in the feed, but at the same time, the amount of tetramers will increase, and eventually larger oligomers will appear. Therefore, substantial trimer selectivity requires both a process configuration having the features described herein and an appropriate volume of moderator.

[0112] Different exemplary embodiments of the present invention are described above. The embodiments are used solely for the purpose of illustrating selected aspects or steps that may be used in carrying out the present invention. Some embodiments are shown herein solely for reference to specific aspects of the invention. It should be understood that embodiments may also be applicable to other aspects of the present invention. As a result, any suitable combination of embodiments and aspects may be formed. Any combination of aspects or embodiments described herein may also be made without the non-essential features described in the aspects, embodiments or examples.

Claims

1. Feeding at least one of the following into a reactor containing a dimerization catalyst which is an acid catalyst: an olefin monomer feed including C4 olefin, C5 olefin, a mixed feed of C4 and C5 olefins, isobutene, 1-butene, cis-2-butene, trans-2-butene, and at least one oxygen-containing moderator including water, demiwater, alcohol, tert-butyl alcohol, or any combination thereof. To carry out catalytic dimerization reactions between olefin monomers and addition reactions between olefin monomers and olefin dimers, the reactor is operated at a temperature selected from the range of 40 to 140°C and a pressure selected from the range of 10 to 40 bar. To extract the reactor outlet flow from the reactor, and Distilling the reactor outlet stream to separate at least one lighter product containing an olefin dimer and a heavier bottom product containing an olefin trimer. A method for producing an olefin trimer, including At least a portion of the lighter product is recycled into the reactor to provide a recycled feed. Olefin monomers are fed into the reactor as fresh olefin monomer feed, where the fresh olefin monomer feed constitutes more than 50 wt-% of the total amount of olefin monomers entering the reactor. The amounts of fresh olefin monomer feed and recycled feed fed into the reactor are controlled so that the mass of olefin monomers to the mass of olefin dimers entering the reactor is selected from the range of 1:8 to 1:15, and A catalytic reaction is a method carried out under operating conditions in which the olefin remains in the liquid phase.

2. The method according to claim 1, wherein a fresh olefin monomer is fed into the reactor, and the fresh olefin monomer comprises an olefin having four carbon atoms.

3. The olefin monomer feed comprises at least one of the following: Inert substances, n-butane, i-butane, butadiene, distillation fractions, or any mixture thereof. The method according to claim 1 or 2, comprising:

4. The method according to any one of claims 1 to 3, wherein, before feeding fresh olefin monomers into the reactor, the recycled feed containing olefin dimers is mixed with the fresh olefin monomers to form a mixed feed, and the olefin dimers are recycled into the reactor by feeding the mixed feed into the reactor.

5. The method according to any one of claims 1 to 4, wherein the ratio of the mass of the olefin monomer to the mass of the olefin dimer is selected from the range of 1:8 to 1:

10.

6. The method according to any one of claims 1 to 5, wherein the selectivity for producing an olefin trimer is expressed as -% by weight based on the olefin monomer and is at least 85%.

7. The method according to any one of claims 1 to 6, wherein the translocation conversion rate of the olefin monomer is at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 96%.

8. The method according to any one of claims 1 to 7, wherein the dimerization catalyst is a strongly acidic ion exchange resin catalyst.

9. The method according to claim 1, wherein the amount of the moderator is selected from a range of 0.01 to 0.5 wt-% of the total amount fed to the reactor.

10. The method according to any one of claims 1 to 9, wherein the operating temperature of the reactor is selected from the range of 50 to 130°C.

11. The method according to any one of claims 1 to 10, wherein the operating pressure of the reactor is selected from the range of 15 to 35 bar.

12. The method according to any one of claims 1 to 11, wherein the residence time of the feed passing through the reactor is expressed as gravitational space velocity per hour (WHSV) and is 0.25 to 2 1 / h.

13. The distillation is carried out at a pressure selected from the range of 1.8 to 2 bar, and at 250°C. max The method according to any one of claims 1 to 12, which is carried out by [the present invention].

14. The method according to any one of claims 1 to 13, wherein the recycled feed comprises at least 95 wt-% of an olefin dimer.

15. a. At least one reactor unit configured to accept an acid catalyst, b. At least one distillation column configured to separate isooctene from isododecene, c. At least one reactor feed line liquid-connected to the reactor unit and reservoir for the olefin monomer, d. At least one reactor outlet flow line that is liquid-connected to the reactor unit and the distillation column, e. At least one recycling line that is liquid-connected to the distillation column and the reactor unit, and f. The bottom product line that is fluidly connected to the distillation column and the bottom product reservoir. A manufacturing unit comprising the above for use in performing the method according to any one of claims 1 to 14.

16. The use of the manufacturing unit according to claim 15, wherein the reactor unit comprises a plurality of reactor vessels, and each of the reactor vessels downstream of the plurality of reactor vessels contains a larger amount of acid catalyst compared to the reactor vessel upstream of the plurality of reactor vessels.

17. Use of the manufacturing unit according to claim 16, further comprising at least one heat exchanger configured to recover heat from at least one line from the distillation column.

18. Use of the manufacturing unit according to any one of claims 15 to 17, wherein the manufacturing unit comprises a first recycling line configured to recycle at least one of the olefin monomer, diluent, and moderator to the at least one reactor through a first recycling line, and a second recycling line configured to recycle the olefin dimer to the at least one reactor.

19. The method according to claim 2, wherein the fresh olefin monomer comprises isobutene.

20. The method according to claim 6, wherein the selectivity for producing an olefin trimer is expressed as -% by weight based on the olefin monomer and is at least 90%.

21. The method according to claim 8, wherein the strongly acidic ion exchange resin catalyst is a macro-network acidic ion exchange resin catalyst.

22. The method according to claim 1, wherein the amount of the moderator is selected from a range of 0.1 to 0.4 wt-% of the total amount fed to the reactor.

23. The method according to claim 1, wherein the amount of the moderator is selected from a range of 0.2 to 0.3 wt-% of the total amount fed to the reactor.

24. The method according to claim 10, wherein the operating temperature of the reactor is selected from the range of 60 to 120°C.

25. The method according to claim 11, wherein the operating pressure of the reactor is selected from the range of 20 to 30 bar.

26. The method according to claim 12, wherein the residence time of the feed passing through the reactor is expressed as gravitational space velocity per hour (WHSV) and is 0.25 to 0.4 1 / h.

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