Separation system

Abstract

The present disclosure relates to a separation system including a distillation column with a partition wall, a reboiler, and a condenser, and more particularly, to a separation system which improves a circulation system to improve separation efficiency by changing a structure of a bottom region of a distillation column in an oligomerization process.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0088159, filed on Jul. 7, 2023, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to a separation system used in an ethylene oligomerization process, and more particularly, to a separation system that improves separation efficiency by changing a sump structure in a distillation column. Background Art

[0004] Alpha-olefins are widely used commercially as important raw materials for comonomers, detergents, lubricants, plasticizers, etc. In particular, 1-hexene and 1-octene are widely used as comonomers to control the density of polyethylene in the production of linear low-density polyethylene (LLDPE).

[0005] α-olefins are generally produced by oligomerization of ethylene, and polymers are produced as byproducts in this production process. The polymers produced by the by-reaction are contained in the reactor effluent and injected into the distillation column of the post-treatment process. In this case, when the reactor effluent is directly injected into the feed tray, the risk of clogging due to by-products such as polymers is very high. Therefore, conventionally, a method of directly injecting the reactor effluent into the reboiler section has been considered.

[0006] However, the reactor effluent contains unreacted ethylene in addition to by-products, and when the feed tray becomes the reboiler part, the separation efficiency of unreacted ethylene will be greatly reduced. Therefore, there is a problem that the unreacted ethylene cannot be fully recovered into the reactor, and part of the unreacted ethylene leaks with the bottom (BTM) product. In addition, this raw material loss will cause economic losses.

[0007] Therefore, in order to solve the above problems, it is necessary to study how to prevent the blockage caused by polymers in the separation system of the ethylene reaction post-treatment process, while minimizing the loss of unreacted ethylene. Summary of the invention

[0008]

Technical issues

[0009] The problem to be solved by the present disclosure is to solve the problems mentioned in the above-mentioned background technology of the invention, and the purpose of the present disclosure is to provide a separation system, which can prevent the blockage caused by polymer in the post-treatment process by improving the liquid collecting tank structure at the bottom of the distillation tower, and recover the unreacted ethylene without causing the loss of unreacted ethylene.

[0010] However, the problem to be solved by the present disclosure is not limited to the above aspects. That is, those skilled in the art can obviously understand other aspects not described from the following description.

[0011]

Technical solution

[0012] In order to solve the above problems, according to one embodiment of the present disclosure, a separation system includes: a distillation tower with a partition wall, a reboiler and a condenser, wherein the distillation tower includes: a bottom area, which includes a first area and a second area separated by a first partition wall; a middle area, which includes a plurality of tower plates; and a top area, which is connected to the condenser.

[0013] In addition, the bottom area includes: a raw material supply port, which is arranged at the upper part of the first area, and the reactor effluent containing ethylene and oligomers is transported to the first area through the raw material supply port; a first outlet, which is arranged at the lower part of the first area, and the first stream containing the reactor effluent is discharged through the first outlet; a first reflux inlet, which is arranged at the upper part of the second area, so that the first stream passing through the reboiler is refluxed to the second area; and a second outlet, which is arranged at the lower part of the second area, and the second stream containing the oligomers is discharged through the second outlet.

[0014] Furthermore, the first partition wall includes an opening provided with a plurality of holes having different diameters.

[0015]

Beneficial Effects

[0016] According to the separation system of the present disclosure, since a partition wall is installed in the liquid collecting tank at the lower part of the distillation tower and the partition wall includes a structure with an opening of multiple holes, a low-temperature liquid zone and a high-temperature liquid zone are separated. Therefore, fluidity can be formed by the temperature difference between the low-temperature liquid zone and the high-temperature liquid zone, so that reboiler recycling can be performed more smoothly.

[0017] In addition, according to the separation system disclosed in the present invention, by designing the liquid collecting tank structure at the bottom of the distillation tower so that the reactor effluent or the solution (dripping liquid) dripping from the lowest tower plate must pass through the reboiler, it is possible to avoid the unreacted ethylene being lost directly to the product outlet without passing through the reboiler, thereby improving the economic benefits caused by raw material loss.

[0018] Furthermore, according to the separation system of the present disclosure, when an auxiliary separation structure including an auxiliary tray is provided at the reflux inlet into which the first stream flows through the reboiler, unreacted gas such as unreacted ethylene remaining in the first stream can be additionally separated.

[0019] The effects that can be achieved by the present disclosure are not limited to the above effects. That is, those skilled in the art to which the present disclosure belongs can clearly understand other effects that are not described from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a process flow diagram of a separation system according to an embodiment.

[0021] Figure 2 2 is a diagram showing a structure of a bottom region of a separation system according to an embodiment.

[0022] Figure 3 is a diagram showing a front view of a first partition wall according to an embodiment.

[0023] Figure 4 It is a diagram showing a conventional separation system as a comparative example. DETAILED DESCRIPTION

[0024] The terms and words used in this specification and claims should not be understood as general or dictionary meanings, but should be understood as meanings and concepts consistent with the technical ideas of the present disclosure based on the principle that inventors can appropriately define term concepts in order to describe their own inventions in the best manner.

[0025] Throughout the drawings, similar or related components will be denoted by like reference numerals.

[0026] Unless the relevant context clearly indicates otherwise, a singular form of a noun corresponding to an item may include one or more of that item.

[0027] In the present disclosure, each phrase 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" may include any one of the items listed together in the corresponding one of these phrases, or all possible combinations thereof.

[0028] The term "and / or" includes a combination of a plurality of related described components or any one of a plurality of related described components.

[0029] Terms such as “first” or “second” may be used only to distinguish one component from another component, and do not limit these components in other aspects (for example, importance or order).

[0030] In addition, terms such as "front", "rear", "top", "bottom", "side", "left", "right", "up", "down", etc. used in this document are defined based on the drawings, and the shape and position of each component are not limited by the terms.

[0031] It should be understood that the terms "including" or "having" used in the present disclosure specify the presence of the features, numbers, steps, operations, components, parts or their combinations mentioned in the present specification, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or their combinations.

[0032] When one component is “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only the case where these components are directly connected, coupled, supported, or in contact with each other, but also the case where these components are indirectly connected, coupled, supported, or in contact with each other through a third component.

[0033] When a component is "on" another component, this includes not only a case where one component is in contact with the other component, but also a case where another component exists between the two components.

[0034] The terms "approximately", "substantially" and the like used in this specification represent numerical values ​​corresponding to manufacturing and material tolerances for the stated meaning and numerical values ​​close thereto, and are used to prevent unreasonable abusers from unfairly using the disclosure of accurate or absolutely described numerical values ​​to help understand the present disclosure.

[0035] The term "flow" used herein may refer to the flow of a fluid in a process or the fluid itself flowing in a pipeline. Specifically, a flow may refer to the fluid itself or the flow of a fluid flowing in a pipeline connecting each device. In addition, a fluid may include at least one component of a gas, a liquid, and a solid.

[0036] Hereinafter, a separation system according to various embodiments will be described in detail with reference to the accompanying drawings.

[0037] Figure 1 The overall structure and process flow of the separation system according to the embodiment are shown. Figure 2 The detailed structure of the bottom area of ​​the separation system according to the embodiment is shown.

[0038] The separation system according to the embodiment of the present disclosure is intended to minimize the risk of blockage caused by byproducts such as polymers after the ethylene monomer oligomerization process, while effectively separating the oligomer products and unreacted monomers contained in the reactor effluent discharged from the reactor 1, see Figure 1 , including a distillation tower 2, a reboiler 3 and a condenser 4.

[0039] refer to Figure 1 The interior of the distillation tower 2 can be divided into a bottom region A, a middle region B and a top region C.

[0040] In this specification, the term "bottom area A" refers to the relatively lower part of the structure of the distillation tower 2, for example, it may refer to the lowest part of the three areas divided in the height direction of the distillation tower, and more specifically refers to the area below the lowest tower tray, that is, the lower area.

[0041] In this specification, the term "top region C" refers to a relatively upper portion in the structure of the distillation tower 2, for example, it may refer to the uppermost portion of three regions divided in the height direction of the distillation tower, more specifically, it refers to the region above the uppermost tray, i.e., the upper region.

[0042] In addition, the "middle region B" in the present specification refers to a relatively middle portion in the structure of the distillation tower 2, and may refer to, for example, a middle region among three regions divided in the height direction of the distillation tower, and more specifically, to a region between the bottom region and the top region of the distillation tower, that is, a region between the lowest tray and the highest tray.

[0043] Bottom Area A

[0044] In one embodiment, the bottom region A of the distillation tower 2 is a first region D1 and a second region D2 separated by a first partition wall 10 in a sump where the liquid reactor effluent is collected. Here, the sump may refer to a region where the solution is collected at the bottom of the distillation tower. In addition, the bottom region A may be divided into a liquid region and a gas phase region based on the liquid level of the solution.

[0045] In addition, see Figure 2 The bottom region A of the distillation column 2 may include a raw material supply port 30 , a first outlet 40 , a first reflux inlet 50 , and a second outlet 60 , and may further include a second reflux inlet 70 .

[0046] The separation system according to the embodiment allows all unreacted ethylene to be recovered to the reactor 1 without being lost to the bottom by changing the sump structure of the distillation column 2 using a dividing wall, while minimizing the risk of clogging in the column due to polymers contained in the reactor effluent.

[0047] like Figure 1 and 2 As shown, the first partition wall 10 may be disposed in a direction perpendicular to the cross section of the distillation tower 2. In addition, the first partition wall 10 may extend from the bottom of the distillation tower 2 to a predetermined height and may be disposed so as not to contact the lowest tray among the plurality of trays 20, which will be described later.

[0048] Figure 4 A conventional separation system in which no dividing wall is provided in the sump of the distillation column is shown as a comparative example. Figure 4 When the reactor effluent is injected into the bottom area where no dividing wall is provided, since the area of ​​the flow discharged from the reboiler and the flow discharged from the product is not separated, the reactor effluent does not all pass through the reboiler (e.g., a heat exchanger), and there is a problem that unreacted ethylene may be directly discharged to the lower part with the product.

[0049] However, in the separation system according to the present disclosure, if Figure 1 and 2 As shown, the bottom area A of the distillation tower 2 is divided into a first area D1 and a second area D2. The first area D1 is provided with a first outlet 40, and the reactor effluent is discharged to the reboiler 3 through the first outlet 40. The second area D2 is provided with a second outlet 60, and the product P is discharged through the second outlet 60. It is designed that the raw material supply port 30 is located in the first area D1, so that the reactor effluent can all pass through the reboiler 3, thereby further improving the separation efficiency of the unreacted monomers.

[0050] In addition, since the first partition wall 10 is disposed so as not to contact the lowermost tray among the plurality of trays 20 , the gas in the gas phase region of the bottom region A can move between the first region D1 and the second region D2 .

[0051] In one embodiment, an area of ​​the first partition wall 10 may be provided with an opening 11, see Figure 1 and 2 The opening 11 is located below the liquid surface of the solution, and the difference in flow rate between the solution in the first area D1 and the solution in the second area D2 causes flow between the first area D1 and the second area D2 through the opening 11, thereby maintaining the same solution level in each area.

[0052] Specifically, since the flow rates flowing into and out of the first region D1 and the second region D2 (excluding the flow of the solution through the opening 11) are different from each other, the amounts of the solutions respectively remaining in the first region D1 and the second region D2 may be significantly different from each other without considering the flow of the solution through the opening 11. In this case, the flow of the solution moving from the region with a large amount of solution to the region with a low flow rate occurs through the opening 11, and therefore, the solution level can be kept the same. When the opening 11 is not provided in the first partition wall 10, the solution levels in the first region D1 and the second region D2 will be different from each other, and mixing between the solution in the first region D1 and the solution in the second region D2 cannot be expected to occur.

[0053] It is possible to compensate for the system imperfection caused by the excessive difference between the first flow rate and the second flow rate discharged from the lower parts of each of the first region D1 and the second region D2 through the opening 11 (which will be described later). More specifically, the amount obtained by subtracting the first flow rate F2 discharged from the first region D1 from the flow rate F1 flowing into the first region D1 is roughly defined as the flow rate F1-F2 retained in the first region D1, and the amount obtained by subtracting the second flow rate F4 discharged from the second region D2 from the flow rate F3 flowing into the second region D2 is roughly defined as the flow rate F3-F4 retained in the second region D2, and the flow rate F3-F4 retained in the second region D2 may be significantly greater than the flow rate F1-F2 retained in the first region D1 [(F1-F2)<(F3-F4)]. In this case, a flow in which the solution in the second region D2 moves to the first region D1 through the opening 11 may occur. Here, the flow rate F1 flowing into the first region D1 includes, for example, a reactor effluent flowing out from the raw material supply port 30, and may also include a solution dripping from the lowermost tray 20 (which will be described later), ie, a dripping solution.

[0054] Furthermore, since the solution flows from the second region D2 to the first region D1 as described above, this can contribute to the driving force of the distillation column sump, so there is an advantage that reboiler recirculation can be performed more smoothly even if reboiler head instability occurs due to solution level changes.

[0055] The average temperature of the solution in the bottom region A of the distillation column 2 (ie, the liquid region) may be about 200 to 210°C.

[0056] 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 average temperature difference 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 about 200 to 207°C, while the average temperature of the solution in the second region D2 may be about 203 to 210°C. Due to the average temperature difference between the solutions in the two regions, the fluidity of the solution contained in the second region D2 with a relatively high temperature flowing to the first region D1 with a relatively low temperature through the opening 11 can be improved, which can additionally contribute to the driving force of the distillation tower sump. Therefore, the reboiler recirculation can be further stabilized. In addition, the effect of transferring the temperature of the solution in the second region D2 refluxed through the reboiler 3 to the first region D1 can also be achieved.

[0057] That is, the relatively high temperature fluid existing in the second region D2 moves to the first region D1 where the relatively low temperature fluid exists and mixes to increase the temperature of the flow (first flow) introduced into the reboiler 3, thereby preventing the pipe clogging (scaling) caused by the first flow, etc., and making the reboiler operate efficiently. In addition, as described later, by providing a plurality of holes and a structure thereof on the first partition wall 10, the mixing of the fluids in the first region D1 can be achieved more smoothly.

[0058] In one embodiment, the opening 11 of the first partition wall 10 may be provided with a plurality of holes having different diameters.

[0059] Figure 3 A front view of a first partition wall 10 provided with an opening 11 according to an embodiment is shown.

[0060] See also Figure 3 , the diameter of the hole located at the upper part of the opening 11 may be gradually smaller than the diameter of the hole located at the lower part of the opening 11. For example, based on the diameter Ra of the hole 11a arranged in the uppermost row, the diameter of the hole in the next row may be gradually reduced at a ratio of about 0.5 to 0.9 times, but is not limited thereto. Therefore, among the holes arranged in the opening 11, the diameter Rb of the hole 11b arranged in the lowermost row is the smallest, and holes with gradually increasing diameters may be arranged toward the upper row, while the diameter Ra of the hole arranged in the uppermost row is the largest. Preferably, the diameter of the lower hole may be gradually smaller than the diameter of the upper hole, so that a gradually faster flow rate may be formed toward the lower part of the opening 11. Thereby, the mixing efficiency of the solution in the sump may be greatly improved.

[0061] More specifically, as described above, the flow of the solution from the second region D2 to the first region D1 occurs through the opening 11. In this case, the flow rate of the solution moving from the second region D2 to the first region D1 is relatively slow in the upper portion of the opening 11 provided with the larger diameter hole, and the flow rate of the solution moving from the second region D2 to the first region D1 is relatively fast in the lower portion of the opening 11 provided with the smaller diameter hole. In this way, due to the fast flow rate generated in the lower portion, the solution in the first region D1 swirls upward, which can help the reactor effluent flowing in at a relatively low temperature, the dripping liquid of the lowermost tray described later, and the solution in the sump to be smoothly mixed in the first region D1.

[0062] In one embodiment, the diameter range of the plurality of holes may be about 10 to 50 mm. More specifically, the diameter Ra of the hole located at the top of the opening 11 (i.e., the top hole 11a) may range from about 40 to 50 mm, and the diameter Rb of the hole located at the bottom of the opening 11 (i.e., the bottom hole 11b) may range from about 10 to 15 mm. When the above diameter range is met, since the diameter of the top hole 11a is relatively large, the water levels in the first region D1 and the second region D2 can remain the same without generating a large pressure difference between the two regions. In addition, by setting the diameter of the bottom hole 11b to at least 10 mm, a stable solution flow can be ensured by eliminating the possibility of pore clogging (scaling) caused by byproducts such as polymers.

[0063] In addition, the ratio of the aperture Ra of the uppermost hole 11a to the aperture Rb of the lowermost hole 11b can satisfy the range of 1:3 to 1:5. When the above ratio range is satisfied, a flow rate difference will be generated between the upper and lower parts of the opening 11, so that the solution in the first area D1 and the solution in the second area D2 can be mixed smoothly.

[0064] In one embodiment, Figure 3 As shown, the holes 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, when the number of holes at the lower portion is relatively small, the solution flow is concentrated in the upper portion, which limits the smooth mixing, and when the number of holes at the upper portion is relatively small, a pressure difference is generated between the first region and the second region, thereby accelerating the clogging phenomenon caused by the by-product. Therefore, in a separation system according to one embodiment, the holes at the same height (row) in the opening 11 may have the same diameter, and the number of holes in each row may also be the same, so that the solution flow is concentrated in some areas of the upper and lower portions of the opening 11, thereby preventing the smooth mixing from being restricted. In addition, by preventing the pressure difference between the first region D1 and the second region D2, the clogging phenomenon caused by the by-product can be prevented.

[0065] In one embodiment, the lowermost hole 11b may be located at a height h of about 150 to 300 mm from the bottom of the distillation tower 2. When the height h range is satisfied, the second flow may be prevented from being affected by the first flow, thereby preventing the second flow from having an unstable flow rate. Specifically, when the second flow (i.e., the discharge flow of the second region D2) is affected by the first flow (i.e., the discharge flow of the first region D1), the opening and closing range of the water level control valve may change significantly, and thus an unstable flow rate of the second flow may occur.

[0066] The raw material supply port 30 is connected to the reactor 1, located at the upper portion of the first region D1, and is provided at the side of the distillation column 2. The reactor effluent containing ethylene and oligomers may be supplied to the first region D1 through the raw material supply port 30. More specifically, the raw material supply port 30 may be located at a height between the upper end of the first partition wall 10 and the liquid level of the solution in the first region D1, but is not limited thereto.

[0067] In the prior art, when the reactor effluent is injected into the feed end tray corresponding to the middle area, there is a risk of blockage due to the polymer. However, in the present disclosure, the raw material supply port 30 is located in the bottom area A to avoid blockage of the distillation column.

[0068] Here, the reactor effluent includes oligomer products (α-olefin, P) produced by the oligomerization reaction of the ethylene monomer performed in the reactor 1 and ethylene as an unreacted monomer, and may further include a polymer as a by-product.

[0069] Oligomerization refers to the polymerization of monomers. Depending on the number of monomers polymerized, it is called trimerization or tetramerization, and these trimerization and tetramerization reactions are collectively called polymerization reactions.

[0070] Alpha-olefins are widely used commercially as important materials such as comonomers, detergents, lubricants, plasticizers, etc. In particular, 1-hexene and 1-octene are widely used as comonomers for controlling 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 of ethylene.

[0071] The first outlet 40 is provided at the bottom of the lower portion of the first region D1 of the distillation tower 2 and is connected to one side of the reboiler 3, and the first stream containing the reactor effluent can be discharged to the reboiler 3 through the first outlet 40. As described above, since the reactor effluent containing unreacted monomers and the dripping liquid of the lowermost tray both flow into the first region D1, the unreacted monomers can all be discharged through the first outlet 40 located at the lower portion of the first region D1 and guided through the reboiler 3.

[0072] The second outlet 60 is provided at the bottom of the lower portion of the second region D2 of the distillation column 2. A second stream containing the oligomer product P may be discharged through the second outlet 60.

[0073] See also Figure 4 , which shows a conventional separation system in which no partition wall is provided in the sump of a distillation column, when the reactor effluent is injected into the bottom region without the partition wall, the region of the stream discharged from the reboiler and the stream discharged with the product are not separated, so the reactor effluent does not all pass through the reboiler (heat exchanger). As a result, there is a problem in that the separation efficiency is reduced because unreacted ethylene is discharged to the bottom together with the product.

[0074] Meanwhile, in the separation system according to the present disclosure, the bottom region A of the distillation tower 2 is partitioned into a first region D1 and a second region D2 by the first partition wall 10, the first region D1 is provided with a first outlet 40 through which the reactor effluent is discharged to the reboiler 3, the second region D2 is provided with a second outlet 60 through which the product P is discharged, and the bottom region A of the distillation tower 2 is designed so that the raw material supply port 30 is located in the first region D1 so that the reactor effluent all passes through the reboiler 3, thereby maximizing the separation efficiency.

[0075] The first reflux inlet 50 is located at the upper portion of the second region D2, connected to the other side of the reboiler 3, and provided at the side of the distillation tower 2. More specifically, the first reflux inlet 50 may be located at a height between the upper end of the first partition wall 10 and the liquid level of the solution in the second region D2, or may be located at a lower height than the raw material supply port 30, but is not limited thereto.

[0076] The first stream passing through the reboiler 3 may flow back to the second region D2 through the first reflux inlet 50. The first stream flowing into the second region D2 through the first reflux inlet 50 is heated while passing through the reboiler 3, so the average temperature of the second region D2 is higher than that of the first region D1.

[0077] In one embodiment, the bottom region A may also be provided with an auxiliary separation structure for separating unreacted gas (light gas), such as ethylene, remaining in the first flow passing through the reboiler 3 .

[0078] See also Figure 2 The auxiliary separation structure includes an auxiliary tower tray 51 and a second dividing wall 52 .

[0079] The auxiliary tray 51 may have a structure provided with a side wall and a bottom to accommodate the first flow flowing in from the first reflux inlet 50 through the reboiler 3. In addition, the side wall of the auxiliary tray 51 may be spaced apart to be parallel to the first partition wall 10. In addition, the upper end of the side wall of the auxiliary tray 51 may be located at a height lower than the upper end of the first partition wall 10.

[0080] In one embodiment, the second partition wall 52 may be located inside the auxiliary tray 51 and may partition it into the third area D3 and the fourth area D4. The second partition wall 52 may be spaced apart to be parallel to the side wall of the auxiliary tray 51, and the lower portion of the second partition wall 52 may be arranged to be spaced apart to not contact the bottom of the auxiliary tray 51. In addition, the upper end of the second partition wall 52 may be located at a higher height than the upper end of the side wall of the auxiliary tray 51, and may be located at a lower height than the upper end of the first partition wall 10.

[0081] See also Figure 2, when the area based on the second partition wall 52 located toward the center of the distillation column 2 is the third area D3, and the area where the first reflux inlet 50 is located is the fourth area D4, the solution of the first flow passing through the reboiler 3 flows into the fourth area D4 from the first reflux inlet 50, and the gas moves upward. Subsequently, the solution moves to the third area D3 through the separation space between the second partition wall and the bottom of the auxiliary tray 51, and the remaining gas (unreacted gas) dissolved in the solution in the third area D3 is further separated and moves upward, while the liquid moves to the lower part of the second area D2. In this case, the solution levels in the third area D3 and the fourth area D4 may be the same.

[0082] As described above, the remaining unreacted gas dissolved in the liquid flow passing through the reboiler 3 is separated again by the auxiliary separation structure, and the stable operation of the distillation column can be achieved. More specifically, when the gas-liquid mixed flow passing through the reboiler 3 is excessive and a sufficient residence time cannot be ensured in the process of reaching the second region D2 through the auxiliary tray 51, the remaining unreacted gas dissolved in the solution may be discharged into the second region D2 together, but by including the second partition wall 52, the residence time of the remaining unreacted gas in the solution can be ensured, thereby compensating for the problem of the remaining unreacted gas flowing into the second region D2.

[0083] See also Figure 2 The second reflux inlet 70 may be connected to the second outlet 60, located at the lower portion of the second region D2, and disposed at the side of the distillation tower 2. Part of the second stream may be refluxed to the second region D2 through the second reflux inlet 70. More specifically, the second reflux inlet 70 is located below the first reflux inlet 50 and may be located below the liquid level of the solution in the second region D2, but is not limited thereto.

[0084] Central Area B

[0085] According to one embodiment of the present disclosure, the middle region B of the distillation tower 2 includes a plurality of trays 20 , which are arranged horizontally with the cross section of the distillation tower 2 and are disposed to be spaced apart from each other.

[0086] The gas flow containing the unreacted gas generated in the bottom region A passes through a plurality of trays 20 provided in the middle region B, and moves toward a top region C which will be described later.

[0087] In the separation system according to an embodiment of the present disclosure, one end of the lowest tray 20 among the plurality of trays is located at the upper portion of the first region D1, and the separation system may further include a guide partition wall 21 extending downward from one end of the lowest tray 20. One end of the lowest tray 20 may be open so as not to contact the side of the distillation column 2.

[0088] More specifically, the dripping liquid separated from the lowermost tray 20 after contacting with the gas and the liquid can be guided to the first region D1 through the guide partition wall 21. Since unreacted ethylene may be dissolved in the solution (dripping liquid) dripping from the tray, the guide partition wall 21 is provided at the end of the lowermost tray so that the solution dripping from the tray flows only into the first region D1, thereby preventing the product from being directly lost to the second outlet 60 as the product outlet without passing through the reboiler 3.

[0089] The number and type of the plurality of trays 20 may be appropriately selected in consideration of the type of the distillation column 2 and the desired separation efficiency, and the type of tray that can be used is not particularly limited as long as it is a tray commonly used in a distillation column for gas-liquid separation.

[0090] Top Area C

[0091] According to one embodiment of the present disclosure, the top region C is connected to the condenser 4. More specifically, the upper gas stream containing unreacted ethylene passing through the plurality of trays of the middle region B may be discharged to the condenser 4. The upper gas stream discharged to the condenser may be condensed and recycled to the reactor 1, but is not limited thereto.

[0092] Exemplary embodiments of separation systems according to the present disclosure have been described above and illustrated in the accompanying drawings. However, the above description and the illustrations of the accompanying drawings only illustrate core components for understanding the present disclosure. In addition to the processes and devices shown in the description and the accompanying drawings, processes and devices that are not separately described or shown may be appropriately applied and used to implement separation systems according to the present disclosure.

[0093] Furthermore, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the concept and scope of the claims.

[0094] [Explanation of Reference Numerals]

[0095] 1: Reactor 2: Distillation tower

[0096] 3: Reboiler 4: Condenser

[0097] A: Bottom area B: Middle area C: Top area

[0098] 10: First partition wall 11: Opening

[0099] 20: tray 21: guide partition wall

[0100] 30: Raw material supply port 40: First outlet 50: First reflux inlet

[0101] 51: auxiliary tray 52: second dividing wall

[0102] 60: Second outlet 70: Second reflux inlet

[0103] D1: first area D2: second area D3: third area D4: fourth area

Claims

1. A separation system comprising: Distillation columns with dividing walls, reboilers and condensers, The distillation tower comprises: a bottom region, which comprises a first region and a second region separated by a first dividing wall; a middle region, which comprises a plurality of trays; a top region, which is connected to a condenser, and The bottom area includes: a raw material supply port, which is disposed at an upper portion of the first zone and through which a reactor effluent containing ethylene and oligomers is transported to the first zone; a first outlet disposed at a lower portion of the first zone through which a first stream containing a reactor effluent is discharged; A first reflux inlet is disposed at an upper portion of the second region to reflux the first stream passing through the reboiler to the second region; and a second outlet disposed at a lower portion of the second zone through which a second stream containing oligomers is discharged, and The first partition wall includes an opening provided with a plurality of holes having different diameters.

2. The separation system according to claim 1, wherein: Among the plurality of holes, diameters of holes located at a lower portion of the opening gradually become smaller than diameters of holes located at an upper portion of the opening.

3. The separation system according to claim 2, wherein: The ratio of the diameter of the hole located at the uppermost portion of the opening to the diameter of the hole located at the lowermost portion of the opening is 1:3 to 1:

5.

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

5. The separation system according to claim 1, wherein: The hole located at the lowermost 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 average temperature of the solution in the first region is relatively lower than that of the solution in the second region.

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

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

9. The separation system according to claim 1, wherein: The bottom area also includes: an auxiliary tray having a side wall and a bottom for receiving the first stream refluxed from the first reflux inlet; and a second dividing wall, which is located inside the auxiliary tray and is divided into a third area and a fourth area, and A lower portion of the second partition wall is spaced apart from the bottom of the auxiliary tray so as not to contact the bottom of the auxiliary tray.

10. The separation system according to claim 1, further comprising: A guide partition wall is located at an upper portion of the first region and extends downward from an end of a lowermost tray among the plurality of trays.

11. The separation system according to claim 1, wherein: The dripping liquid of the lowermost tray flows into the first area through the guide partition wall.

12. The separation system according to claim 1, wherein: The bottom region further includes a second reflux inlet connected to the second outlet, disposed at a side of the second region, and causing a portion of the second flow to reflux to the second region.

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