Separation system

Abstract

The present invention relates to a separation system comprising a distillation column with a separation wall, a reboiler, and a condenser, and more particularly to a separation system in which the circulation system is improved and separation efficiency is enhanced by changing the structure of the bottom region of the distillation column in the oligomerization process.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0088159, filed on July 7, 2023, and all the contents disclosed in the document of the corresponding Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a separation system used in an oligomerization process using ethylene, and more particularly, to a separation system that improves separation efficiency by changing the sump structure in a distillation column.

Background Art

[0003] Alpha-olefin is widely used commercially as an important substance used in comonomers, detergents, lubricants, plasticizers, etc. In particular, 1-hexene and 1-octene are widely used as comonomers for adjusting the density of polyethylene during the production of linear low density polyethylene (LLDPE).

[0004] The alpha-olefin is typically produced by an oligomerization reaction of ethylene, and a polymer is also generated as a by-product in such a production process. The polymer generated by the side reaction is contained in the reactor effluent and is introduced into the distillation column in the subsequent process. Here, if the reactor effluent is immediately introduced into the tray at the feed stage, there is a very high risk of a plugging phenomenon due to by-products such as polymers. Therefore, conventionally, a method of directly introducing the reactor effluent into the reboiler section has been considered.

[0005] However, reactor effluent contains unreacted ethylene in addition to by-products, and the feed stage becomes a reboiler area, significantly reducing the efficiency of separating unreacted ethylene. As a result, not all of the unreacted ethylene can be recovered into the reactor, and some leaks out as bottom (BTM) products. Furthermore, such raw material losses result in financial losses.

[0006] Therefore, in order to solve the above-mentioned problems, research is needed to prevent polymer blockage and minimize leakage of unreacted ethylene in the separation system after the ethylene reaction. [Overview of the project] [Problems that the invention aims to solve]

[0007] The problem that this invention aims to solve is to provide a separation system that, in order to solve the problems mentioned in the background art of the invention above, prevents blockage by polymers in subsequent processes by improving the sump structure at the bottom of the distillation column, and allows unreacted ethylene to be recovered into the reactor without leakage.

[0008] However, the problems that this application seeks to solve are not limited to those mentioned above, and other problems not mentioned can be clearly understood by an ordinary engineer from the following description. [Means for solving the problem]

[0009] According to one embodiment of the present invention for solving the above problems, the present invention provides a separation system including a distillation column having a separation wall, a reboiler, and a condenser, wherein the distillation column includes a column bottom region including a first region and a second region partitioned by a first separation wall, an intermediate region including a plurality of trays, and a column top region connected to the condenser.

[0010] Furthermore, the bottom region of the tower includes a raw material supply port located at the top of the first region through which reactor effluent containing ethylene and oligomers is supplied to the first region; a first outlet located at the bottom of the first region through which a first stream containing the reactor effluent is discharged; a first reflux inlet located at the top of the second region through which the first stream passes the reboiler and refluxes to the second region; and a second outlet located at the bottom of the second region through which a second stream containing oligomers is discharged.

[0011] Furthermore, the first separation wall includes an opening with a plurality of holes having different diameters. [Effects of the Invention]

[0012] According to the separation system of the present invention, the sump at the bottom of the distillation column is divided into a low-temperature liquid phase region and a high-temperature liquid phase region by a structure in which a separation wall is installed, and since the separation wall includes openings with multiple holes, fluidity can be formed by the temperature difference between the low-temperature liquid phase region and the high-temperature liquid phase region, thereby making the recirculation of the reboiler smoother.

[0013] Furthermore, according to the separation system of the present invention, by designing the sump structure at the bottom of the distillation column so that the reactor discharge and the solution (dropping liquid) falling from the bottom tray always pass through the reboiler, it is possible to prevent unreacted ethylene from leaking directly to the product outlet without passing through the reboiler, thereby improving economic efficiency in terms of raw material loss.

[0014] Furthermore, according to the separation system of the present invention, if an auxiliary separation structure including an auxiliary tray is provided at the reflux inlet into which the first stream that has passed through the reboiler flows, unreacted gases such as unreacted ethylene remaining in the first stream can be further separated.

[0015] The effects obtained in the present application are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those with ordinary knowledge in the technical field to which the present invention belongs from the following description.

Brief Description of the Drawings

[0016] [Figure 1] It is a diagram showing the process flow of a separation system according to an embodiment. [Figure 2] It is a diagram illustrating the bottom region structure of a separation system according to an embodiment. [Figure 3] It is a diagram illustrating the front of a first separation wall according to an embodiment. [Figure 4] As a comparative example, it is a diagram illustrating a conventional separation system.

Modes for Carrying Out the Invention

[0017] The terms and words used in the description of the present invention and the claims should not be construed as limited to their ordinary or dictionary meanings. The inventors should interpret them in accordance with the meaning and concept consistent with the technical idea of the present invention in accordance with the principle that they can appropriately define the concept of the terms in order to explain their invention in the best way.

[0018] In connection with the description of the drawings, similar reference numerals can be used for similar or related components.

[0019] The singular form of the noun corresponding to an item can include one or more of the said items unless clearly indicated to have a different meaning in the relevant context.

[0020] In the present disclosure, phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" can each include any one of the items listed together in the corresponding phrase of the phrase, or all possible combinations thereof.

[0021] The term "and / or" includes combinations of a plurality of related described components or any of the plurality of related described components.

[0022] Terms such as "first", "second", or "first" or "second" can simply be used to distinguish the component from other such components and do not limit the component in other aspects (e.g., importance or order).

[0023] Also, terms such as "front", "rear", "top", "bottom", "side", "left side", "right side", "upper part", "lower part", etc. used in the present application are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0024] Terms such as "comprising" or "having" specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the present disclosure, and do not preclude in advance the presence or addition possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0025] When a certain component is "connected", "coupled", "supported", or "contacted" to another component, this includes not only the case where the components are directly connected, coupled, supported, or contacted, but also the case where they are indirectly connected, coupled, supported, or contacted via a third component.

[0026] When we say that one component is located "on top of" another component, this includes not only cases where one component is in contact with another, but also cases where yet another component exists between the two components.

[0027] Furthermore, the terms "approximately" and "substantially" used in this application are used either numerically or in a sense close to numerically when manufacturing and material tolerances specific to the meaning referred to are presented, and are used to facilitate understanding of the present invention and to prevent unscrupulous infringers from unfairly exploiting disclosures that refer to precise or absolute numerical values.

[0028] As used in this application, the term "stream" may mean the flow of fluid within a process, or it may mean the fluid itself flowing through piping. Specifically, the stream may simultaneously mean the fluid itself and the flow of fluid through piping connecting each device. Furthermore, the fluid may contain one or more components of gas, liquid, and solid.

[0029] In the following sections, various embodiments of the separation system will be described in detail with reference to the attached drawings.

[0030] Figure 1 illustrates the overall structure and process flow of a separation system according to one embodiment, and Figure 2 illustrates the detailed structure of the column bottom region of the separation system according to one embodiment.

[0031] A separation system according to one embodiment of the present invention is for efficiently separating oligomer products and unreacted monomers contained in reactor effluent discharged from reactor 1 after the oligomerization process of ethylene monomers, and for minimizing the risk of plugging by by-products such as polymers, and as shown in Figure 1, includes a distillation column 2, a reboiler 3, and a condenser 4.

[0032] Referring to Figure 1, the interior of the distillation column 2 can be divided into a column base region A, an intermediate region B, and a column top region C.

[0033] In this specification, the term "bottom region A" means the relatively lower part of the structure of the distillation column 2, and may mean, for example, the lowest of the three regions divided in the height direction of the distillation column, and more specifically, the region below the lowest tray, i.e., the lower region.

[0034] Furthermore, in this specification, the term "top region C" means the relatively upper part of the structure of the distillation column 2, and may mean, for example, the uppermost of the three regions divided in the height direction of the distillation column, and more specifically, the upper region of the top tray, i.e., the upper region.

[0035] Furthermore, in this specification, "intermediate region B" means the relatively central part of the structure of the distillation column 2, for example, the central region of the three regions divided in the height direction of the distillation column, and more specifically, the region between the bottom region and the top region of the distillation column, that is, the region between the lowest tray and the uppermost tray.

[0036] Tower bottom area A In one embodiment, the bottom region A of the distillation column 2 includes a first region D1 and a second region D2, which are separated by a first separation wall 10 from a sump where liquid-phase reactor waste is collected. Here, the sump may mean the region at the bottom of the distillation column where the solution is collected. The bottom region A can also be divided into a liquid phase region and a gas phase region based on the liquid level of the solution.

[0037] Referring to Figure 2, the bottom region A of the distillation column 2 is equipped with a raw material supply port 30, a first outlet port 40, a first reflux inlet 50, and a second outlet port 60, and a second reflux inlet 70 may be provided as well.

[0038] In one embodiment of the separation system, by modifying the sump structure of the distillation column 2 using a separation wall, the risk of column plugging by polymers contained in the reactor discharge is minimized, and unreacted ethylene can be recovered to the reactor 1 in its entirety without leaking to the bottom.

[0039] As illustrated in Figures 1 and 2, the first separation wall 10 can be provided in a direction perpendicular to the cross-section of the distillation column 2. Furthermore, the first separation wall 10 can extend from the bottom of the distillation column 2 and be provided to have a predetermined height, and can be provided so as not to be in contact with the lowest tray among the multiple trays 20 described later.

[0040] Figure 4 illustrates a conventional separation system in which the distillation column sump is not equipped with a separation wall, as an example. Referring to Figure 4, when reactor effluent is introduced into the column bottom region where there is no separation wall, the stream that is discharged to the reboiler and the stream that is discharged with the product are not separated. As a result, the entire amount of reactor effluent cannot pass through a reboiler such as a heat exchanger, and unreacted ethylene can be immediately discharged to the bottom along with the product.

[0041] However, as illustrated in Figures 1 and 2, the separation system according to the present invention is designed such that the bottom region A of the distillation column 2 is divided by a first separation wall 10 into a first region D1 equipped with a first outlet 40 for discharging reactor effluent to the reboiler 3, and a second region D2 equipped with a second outlet 60 for discharging product P, and the raw material supply port 30 is located in the first region D1, so that the entire amount of reactor effluent passes through the reboiler 3, thereby further improving the separation efficiency of unreacted monomers.

[0042] Furthermore, by ensuring that the first separation wall 10 does not come into contact with the lowest tray among the multiple trays 20, the gas in the gas phase region of the tower base region A can move between the first region D1 and the second region D2.

[0043] In one embodiment, the first separation wall 10 can have an opening 11 formed in one region. Referring to Figures 1 and 2, the opening 11 is located below the liquid level of the solution, and a flow can be generated between the first region D1 and the second region D2 through the opening 11 due to the difference in flow rates between the solution in the first region D1 and the solution in the second region D2, thereby maintaining the same level of the solution inside each region.

[0044] Specifically, since the flow rates into and out of the first region D1 and the second region D2, respectively, after excluding the flow of solution through the opening 11, are different, the amounts of solution remaining in the first region D1 and the second region D2 can be substantially different, without considering the flow of solution through the opening 11. In this case, a flow occurs through the opening 11, causing the solution to move from the region with a large amount of solution to the region with a small flow rate, thereby maintaining the same level of solution. If the first separation wall 10 were not provided with the opening 11, the levels of solution in the first region D1 and the second region D2 would be different, and mixing of the solution in the first region D1 and the solution in the second region D2 could not be expected.

[0045] The opening 11 can compensate for the incomplete system caused by the excessive difference between the first stream flow rate and the second stream flow rate, which will be described later, discharged from the lower parts of the first region D1 and the second region D2, respectively. More specifically, if we define the amount obtained by subtracting the first stream flow rate F2 discharged from the first region D1 from the flow rate F1 flowing into the first region D1 as the flow rate F1-F2 substantially remaining in the first region D1, and the amount obtained by subtracting the second stream flow rate F4 discharged from the second region D2 from the flow rate F3 flowing into the second region D2 as the flow rate F3-F4 substantially remaining in the second region D2, then the flow rate F3-F4 substantially remaining in the second region D2 can be greater than the flow rate F1-F2 substantially remaining in the first region D1 [(F1-F2)<(F3-F4)], in which case a flow can occur in which the solution in the second region D2 moves to the first region D1 through the opening 11. Here, the flow rate F1 flowing into the first region D1 may include, for example, reactor discharge flowing in from the raw material supply port 30, and may further include the solution that drops from the bottom tray 20, which will be described later, i.e., the descending liquid.

[0046] Furthermore, the flow of solution from the second region D2 to the first region D1, as described above, can contribute to the driving force of the distillation column sump, and even if instability occurs in the reboiler head due to changes in the solution level, the recirculation of the reboiler can be made smoother.

[0047] The average temperature of the solution in the bottom region A of the distillation column 2 (i.e., the liquid phase region) can be in the range of approximately 200 to 210°C.

[0048] More specifically, the solution in the first region D1 may have a relatively lower average temperature than the solution in the second region D2. More specifically, the difference in average temperature between the solution in the first region D1 and the solution in the second region D2 may be about 3 to 10°C. For example, the average temperature of the solution in the first region D1 may be in the range of about 200 to 207°C, and the average temperature of the solution in the second region D2 may be in the range of about 203 to 210°C. This difference in average temperature between the solutions in the two regions improves the fluidity of the solution contained in the relatively hotter second region D2 moving through the opening 11 to the relatively colder first region D1, which can further contribute to the driving force of the distillation column sump and make the recirculation of the reboiler smoother. It also allows for the effect of transferring the temperature of the solution in the second region D2 that refluxes through the reboiler 3 to the first region D1.

[0049] In other words, the relatively high-temperature fluid present in the second region D2 moves to the first region D1 where the relatively low-temperature fluid is present and mixes, thereby increasing the temperature of the stream (first stream) introduced into the reboiler 3, preventing fouling of piping and other components by the first stream, and enabling more efficient operation of the reboiler. Furthermore, as will be described later, the multiple holes provided in the first separation wall 10 and their structure allow for smoother mixing of the fluid in the first region D1.

[0050] In one embodiment, the opening 11 of the first separation wall 10 may be provided with a plurality of holes having different diameters.

[0051] Figure 3 shows the front view of the first separation wall 10, which is provided with an opening 11 according to one embodiment.

[0052] Referring to Figure 3, the opening 11 can be configured such that the diameter of the holes located below it becomes progressively smaller than the diameter of the holes located above it. For example, the diameter R of the hole 11a in the top row a Based on this, the diameter of the holes in the next row can be progressively reduced in a ratio of approximately 0.5 to 0.9 times, but is not limited to this. Therefore, among the holes provided in the opening 11, the diameter R of the hole 11b provided in the bottom row b The holes can be provided with a diameter that is smallest at the top row and gradually increases in diameter towards the top row, with the diameter of the hole R at the top row being the smallest. a This can be maximized. Preferably, the diameter of the lower hole is provided to be progressively smaller than the diameter of the upper hole, so that progressively faster flow velocities can be formed towards the bottom of the opening 11, thereby greatly improving the mixing efficiency of the solution inside the sump.

[0053] More specifically, as described above, a flow occurs through the opening 11, moving the solution from the second region D2 to the first region D1. Here, the upper part of the opening 11, which has a larger diameter hole, has a relatively slow flow velocity for the solution moving from the second region D2 to the first region D1, while the lower part of the opening 11, which has a smaller diameter hole, has a relatively fast flow velocity for the solution moving from the second region D2 to the first region D1. Thus, the fast flow velocity generated in the lower part causes a swirling flow in the solution within the first region D1, which helps to smoothly mix the reactor effluent flowing into the relatively low-temperature environment, the descending liquid in the bottom tray (described later), and the solution inside the existing sump within the first region D1.

[0054] In one embodiment, the diameters of the plurality of holes can be in the range of approximately 10 to 50 mm. More specifically, the diameter R of the hole located at the top of the opening 11, i.e., the topmost hole 11a. aThe diameter R can be in the range of approximately 40-50 mm, and the hole located at the bottom of the opening 11, i.e., the bottom hole 11b. b The diameter can be in the range of approximately 10 to 15 mm. When the diameter is within this range, the relatively large diameter of the uppermost hole 11a allows the water levels in the first region D1 and the second region D2 to be maintained similarly without generating a large differential pressure between them. Furthermore, by setting the diameter of the lowermost hole 11b to at least 10 mm or more, the possibility of hole fouling due to by-products such as polymers can be eliminated, and a stable flow of the solution can be ensured.

[0055] Furthermore, the diameter R of the lowest hole 11b b The diameter R of the uppermost hole 11a a The ratio can satisfy a range of 1:3 to 1:5. When the ratio is within this range, a difference in flow velocity occurs between the upper and lower parts of the opening 11, enabling smooth mixing of the solution in the first region D1 and the solution in the second region D2.

[0056] In one embodiment, as illustrated in Figure 3, holes located at the same height (row) in the opening 11 may have the same diameter, and the number of holes in each row may be the same. For example, if the number of holes located at the bottom is relatively small, the flow of solution may concentrate at the top, limiting smooth mixing. If the number of holes located at the top is relatively small, a differential pressure may occur between the first and second regions, accelerating the blockage phenomenon caused by by-products. Therefore, in the separation system according to one embodiment, by having holes located at the same height (row) in the opening 11 with the same diameter and the same number of holes in each row, it is possible to prevent the flow of solution from concentrating in a part of the upper or lower part of the opening 11, thereby limiting smooth mixing. Furthermore, by preventing the occurrence of a differential pressure between the first region D1 and the second region D2, it is possible to prevent the blockage phenomenon caused by by-products.

[0057] In one embodiment, the lowest hole 11b can be located at a height h of approximately 150 to 300 mm from the bottom of the distillation column 2. When the height h is within this range, it is possible to prevent the second stream from being affected by the first stream and to prevent the occurrence of flow rate instability in the second stream. Specifically, if the second stream, which is the discharge flow of the second region D2, is affected by the first stream, which is the discharge flow of the first region D1, the opening and closing range of the water level control valve may fluctuate significantly, which can cause flow rate instability in the second stream.

[0058] The raw material supply port 30 is connected to the reactor 1 and located at the top of the first region D1, and is provided on the side of the distillation column 2. Reactor effluent containing ethylene and oligomers can be supplied to the first region D1 through the raw material supply port 30. More specifically, the raw material supply port 30 may, but is not limited to, be located at a height between the upper end of the first separation wall 10 and the liquid level of the solution in the first region D1.

[0059] Conventionally, when reactor waste is introduced into the feed tray in the intermediate region, there is a risk of blockage by polymers. However, in the present invention, since the raw material supply port 30 is located in the column bottom region A, column blockage can be prevented.

[0060] Here, the reactor discharge includes oligomer products (alpha-olefins) produced by the oligomerization reaction of ethylene monomers carried out in reactor 1, as well as unreacted monomers such as ethylene, and may further include polymers as by-products.

[0061] The aforementioned oligomerization reaction may refer to a reaction in which monomers undergo small-scale polymerization. Depending on the number of monomers polymerized, this is called trimerization or tetramerization, and collectively referred to as multimerization.

[0062] The aforementioned alpha-olefins are widely used commercially as important substances in the form of comonomers, detergents, lubricants, and plasticizers. In particular, 1-hexene and 1-octene are frequently used as comonomers to adjust the density of polyethylene in the production of linear low-density polyethylene (LLDPE). Alpha-olefins such as 1-hexene and 1-octene can be produced, for example, by trimerization or tetramerization reactions of ethylene.

[0063] The first outlet 40 is located at the bottom of the first region D1 of the distillation column 2 and is connected to one side of the reboiler 3. The first stream, including the reactor effluent, can be discharged to the reboiler 3 via the first outlet 40. As described above, since both the reactor effluent containing unreacted monomers and the descending liquid from the bottom tray flow into the first region D1, the entire amount of unreacted monomers can be discharged through the first outlet 40 located at the bottom of the first region D1 and guided to pass through the reboiler 3.

[0064] The second outlet 60 is located at the bottom of the second region D2 of the distillation column 2. The second stream containing the oligomer product P can be discharged through the second outlet 60.

[0065] Referring to Figure 4, which illustrates a conventional separation system in which the distillation column sump is not equipped with a separation wall, when reactor effluent is introduced into the column bottom region where there is no separation wall, the stream that is discharged to the reboiler and the stream that is discharged with the product are not separated. As a result, the reactor effluent cannot pass through the reboiler (heat exchanger) completely, and unreacted ethylene is discharged to the bottom along with the product, leading to a problem of reduced separation efficiency.

[0066] On the other hand, in the separation system according to the present invention, the bottom region A of the distillation column 2 is divided by a first separation wall 10 into a first region D1 equipped with a first outlet 40 for discharging reactor effluent to the reboiler 3, and a second region D2 equipped with a second outlet 60 for discharging product P. The raw material supply port 30 is located in the first region D1, so that the entire amount of reactor effluent passes through the reboiler 3, thereby maximizing the separation efficiency.

[0067] The first reflux inlet 50 is located at the top of the second region D2 and is connected to the other side of the reboiler 3 and provided on the side of the distillation column 2. More specifically, the first reflux inlet 50 may be located at a height between the upper end of the first separation wall 10 and the liquid level of the solution in the second region D2, and may also be located at a height lower than the raw material supply inlet 30, but is not limited thereto.

[0068] The first stream that has passed through the reboiler 3 via the first reflux inlet 50 can reflux into the second region D2. As the first stream flowing into the second region D2 via the first reflux inlet 50 is heated as it passes through the reboiler 3, the second region D2 comes to have a higher average temperature than the first region D1.

[0069] In one embodiment, the bottom region A of the tower may be further provided with an auxiliary separation structure for separating unreacted gases (light gases) such as ethylene that remain in the first stream after passing through the reboiler 3.

[0070] Referring to Figure 2, the auxiliary separation structure includes an auxiliary tray 51 and a second separation wall 52.

[0071] The auxiliary tray 51 may have a structure with side walls and a bottom to accommodate the first stream that flows in from the first reflux inlet 50 and has passed through the reboiler 3. The side walls of the auxiliary tray 51 may be spaced parallel to the first separation wall 10. The upper end of the side wall of the auxiliary tray 51 may be located at a lower height than the upper end of the first separation wall 10.

[0072] In one embodiment, the second separation wall 52 is located inside the auxiliary tray 51 and can be divided into a third region D3 and a fourth region D4. The second separation wall 52 can be spaced parallel to the side wall of the auxiliary tray 51, and the lower end of the second separation wall 52 can be positioned so as not to come into contact with the bottom of the auxiliary tray 51. Furthermore, the upper end of the second separation wall 52 can be positioned at a height higher than the upper end of the side wall of the auxiliary tray 51 and at a height lower than the upper end of the first separation wall 10.

[0073] Referring to Figure 2, with respect to the second separation wall 52, the region located towards the center of the distillation column 2 is defined as the third region D3, and the region where the first reflux inlet 50 is located is defined as the fourth region D4. Then, the solution of the first stream that has passed through the reboiler 3 flows into the fourth region D4 from the first reflux inlet 50, and the gas moves upward. Next, the solution moves to the third region D3 through the separated space between the second separation wall and the bottom of the auxiliary tray 51, where the gas (unreacted gas) dissolved and remaining in the solution is further separated and moves upward, and the liquid moves to the bottom of the second region D2. Here, the water level of the solution inside the third region D3 and the fourth region D4 can be the same.

[0074] As described above, stable column operation is possible by separating the unreacted gas dissolved and remaining in the liquid phase stream after passing through the reboiler 3 using the auxiliary separation structure. More specifically, if sufficient residence time cannot be ensured in the process where the excess gas-liquid mixed flow that has passed through the reboiler 3 goes to the second region D2 via the auxiliary tray 51, the unreacted gas dissolved and remaining in the solution may be discharged together with the second region D2. However, by providing the second separation wall 52, it is possible to ensure a residence time in which the residual unreacted gas in the solution is separated, thereby compensating for the problem of residual unreacted gas flowing into the second region D2.

[0075] Referring to Figure 2, the second reflux inlet 70 is connected to the second outlet 60 and located below the second region D2, and can be provided on the side of the distillation column 2. A portion of the second stream can reflux into the second region D2 through the second reflux inlet 70. More specifically, the second reflux inlet 70 may be located below the first reflux inlet 50 and below the liquid level of the solution in the second region D2, but is not limited thereto.

[0076] Intermediate area B According to one embodiment of the present invention, the intermediate region B of the distillation column 2 includes a plurality of trays 20. The plurality of trays 20 are arranged horizontally with respect to the cross-section of the distillation column 2 and are spaced apart from each other.

[0077] The gas phase stream containing unreacted gas generated in the column bottom region A moves to the column top region C, which will be described later, via a plurality of trays 20 provided in the intermediate region B.

[0078] A separation system according to one embodiment of the present invention may further include a guide partition 21 extending downward from the one end of the bottom tray 20 of the plurality of trays, with one end of the bottom tray 20 located above the first region D1. The one end of the bottom tray 20 may be left open so as not to come into contact with the side of the distillation column 2.

[0079] More specifically, the descending liquid separated after gas-liquid contact from the bottom tray 20 can be guided to the first region D1 via the guide partition 21. Since unreacted ethylene may be dissolved in the solution (descending liquid) falling from the tray, the guide partition 21 is provided at the end of the bottom tray, and the system is designed so that the solution falling from the tray flows only into the first region D1. This prevents the solution from leaking directly to the second outlet 60, which is the product outlet, without passing through the reboiler 3.

[0080] The number and type of the aforementioned trays 20 can be appropriately selected considering the type of distillation column 2 and the desired separation efficiency, and the type of tray can be any tray that is normally used in distillation columns for gas-liquid separation without any particular restrictions.

[0081] Tower top area C According to one embodiment of the present invention, the top region C is connected to a condenser 4. More specifically, the upper gas phase stream containing unreacted ethylene that has passed through multiple trays in the intermediate region B can be discharged to the condenser 4. The upper gas phase stream discharged to the condenser can be condensed and recovered in the reactor 1, but is not limited to this.

[0082] An exemplary embodiment of the separation system according to the present invention has been described above and illustrated in the drawings. However, the above description and illustration in the drawings describe and illustrate only the core components necessary for understanding the present invention, and processes and apparatus not described or illustrated in the above description and drawings can be appropriately applied and used to carry out the separation system according to the present invention.

[0083] Furthermore, a person with ordinary skill in the relevant technical field will understand that various modifications and variations are possible, provided they do not deviate from the concepts and scope of the claims described below. [Explanation of symbols]

[0084] 1 Reactor 2 Distillation column 3 Reboiler 4. Condenser A Tower bottom area B Intermediate area C tower top area 10 1st separation wall 11 Opening 20 trays 21 Guide bulkhead 30 Raw material supply port 40 1st outlet 50 First return flow inlet 51 subsidy 52 Second Separation Wall 60 Second row exit 70 Second Recirculation Inlet D1, Domain 1 D2, Second Field D3, Third Domain D4, 4th Field

Claims

1. A separation system comprising a distillation column with a separation wall, a reboiler, and a condenser, The distillation column includes a bottom region containing a first region and a second region partitioned by a first separation wall, an intermediate region containing a plurality of trays, and a top region connected to the condenser. The aforementioned tower base region is A raw material supply port is provided at the top of the first region, through which reactor discharge containing ethylene and oligomers is supplied to the first region, A first outlet is provided at the lower part of the first region, through which the first stream containing the reactor waste is discharged, A first reflux inlet is provided at the top of the second region, through which the first stream passes the reboiler and refluxes into the second region, It includes a second outlet located at the bottom of the second region, from which a second stream containing oligomers is discharged, The separation system includes an opening in the first separation wall that is provided with a plurality of holes having different diameters.

2. The separation system according to claim 1, characterized in that the diameter of the plurality of holes is progressively smaller in the holes located below the opening than the diameter of the holes located above the opening.

3. The separation system according to claim 2, wherein the ratio of the diameter of the hole at the top to the diameter of the hole at the bottom of the opening is 1:3 to 1:

5.

4. The separation system according to claim 1, wherein the plurality of holes have a diameter of 10 to 50 mm.

5. The separation system according to claim 1, wherein the hole located at the lowest part of the opening is located at a height of 150 to 300 mm from the bottom of the distillation column.

6. The separation system according to claim 1, wherein the solution in the first region has a relatively lower average temperature than the solution in the second region.

7. The average temperature of the solution in the first region is 200 to 207°C. The separation system according to claim 1, wherein the average temperature of the solution in the second region is 203 to 210°C.

8. The separation system according to claim 1, wherein a portion of the solution in the second region moves to the first region through the opening.

9. The aforementioned tower base region is An auxiliary tray is provided with side walls and a bottom, and contains the first stream that flows back in from the first recirculation inlet, It further includes a second separating wall located inside the auxiliary tray, which divides it into a third region and a fourth region. The separation system according to any one of claims 1 to 8, wherein the lower part of the second separation wall is separated from the bottom of the auxiliary tray so as not to come into contact with it.

10. The separation system according to claim 1, further comprising a guide partition located above the first region and extending downward from the end of the lowest tray among the plurality of trays.

11. The separation system according to claim 10, wherein the descending liquid from the lowest tray flows into the first region via the guide partition.

12. The separation system according to claim 1, wherein the column bottom region is connected to the second outlet and provided on the side of the second region, further including a second recirculation inlet through which a portion of the second stream recirculates back into the second region.

Images