Separating device

Abstract

The present disclosure relates to a separation device comprising a distillation column having double partition walls, a first reboiler, a second reboiler, and a condenser, and more specifically, to a separation device which can improve the separation efficiency of an oligomerization process by improving the bottom region structure and circulation system of the distillation column in the oligomerization process. The problem of blockage caused by byproducts is prevented, and the recovery rate of unreacted monomers is improved.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0103230, filed on August 8, 2023, which is hereby incorporated by reference in its entirety. [Technical field]

[0003] The present disclosure relates to a separation device for an ethylene monomer oligomerization process, and more particularly, to a separation device capable of preventing clogging problems caused by polymer byproducts and improving the recovery rate of unreacted ethylene by changing the interior of a distillation tower sump to a double partition wall structure and improving a circulation system. [Background technology]

[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-reactions are present in the reactor effluent in an amount of about 1 wt% or less, and are 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 byproducts such as polymers is very high. Therefore, a method of directly injecting the reactor effluent into the reboiler section has been considered.

[0006] However, the reactor effluent contains unreacted ethylene monomer in addition to by-products, and when the feed position is changed to the reboiler part, the separation efficiency of the unreacted ethylene monomer will be greatly reduced. Therefore, there is a problem that all unreacted ethylene monomer cannot be recovered from the reactor, and part of the unreacted ethylene monomer will leak with the bottom (BTM) product, and this raw material loss will also cause economic losses.

[0007] Therefore, in order to solve the above problems, it is necessary to study how to prevent the blockage caused by polymer by-products in the separation process after the ethylene reaction in the post-treatment process, while minimizing the loss of unreacted ethylene monomer. [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. The purpose of the present disclosure is to provide a separation device. By improving the liquid collecting tank structure and the circulation system at the bottom of the distillation tower, the separation device can prevent the blockage caused by polymer by-products in the post-treatment process of the oligomerization reaction process, and at the same time can recover the unreacted ethylene monomer without losing it to the bottom of the distillation tower.

[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] To solve the above problems, according to an embodiment of the present disclosure, a separation device includes a distillation column having a double partition wall, a first reboiler, a second reboiler and a condenser. The interior of the distillation column can be divided into a bottom area, a middle area and a top area.

[0013] The bottom region of the distillation column may include: a first region to a third region, the first region to the third region being partitioned by a first partition wall and a second partition wall extending from the bottom of the distillation column to a predetermined height and spaced apart from each other; a raw material supply port, the raw material supply port being provided at one side of the first region and allowing a reactor effluent containing monomers and oligomers to be transferred to the first region through the raw material supply port; a first outlet, the first outlet being provided at a lower portion of the first region and connected to one side of a first reboiler through a first flow path; a first reflux inlet, the first reflux inlet being provided at an upper portion of the first region and connected to the other side of the first reboiler through a second flow path; a second outlet, the second outlet being provided at a lower portion of the second region between the first partition wall and the second partition wall and connected to one side of the second reboiler through a third flow path; and a second reflux inlet, the second reflux inlet being provided at one side of the third region and connected to the other side of the second reboiler through a fourth flow path.

[0014]

Beneficial Effects

[0015] According to the separation device disclosed in the present invention, by improving the structure of the distillation tower sump and the circulation system, the risk of clogging (scaling) of the tower internal structure that may occur due to the polymer by-products contained in the reactor effluent can be minimized, and all unreacted monomers dissolved in the solution can be recovered into the reactor without being lost to the lower part.

[0016] More specifically, by providing a double dividing wall at the lower portion of the distillation column, dividing the sump into a total of 3 areas, and using two reboilers with different flow rates, it is possible to function as a complete first stage of the distillation column.

[0017] The effects that can be achieved by the present disclosure are not limited to the above-mentioned effects, that is, those skilled in the art to which the present disclosure belongs can obviously understand other effects that are not described from the following description.

Brief Description of the Drawings

[0018] Figure 1 is a process flow diagram of a separation device according to one embodiment.

[0019] Figure 2 A diagram for illustrating in detail the structure of the bottom region of the distillation column in the separation device according to the embodiment.

[0020] Figure 3 This is a diagram illustrating a conventional separation system as a comparative example. [Specific implementation method]

[0021] The terms and words used in this specification and claims should not be interpreted as general meanings or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical ideas of the present disclosure based on the principle that the inventor can appropriately define the concepts of the terms in order to describe his own disclosure in the best manner.

[0022] Throughout the drawings, similar or related components will be denoted by like reference numerals.

[0023] A singular form of a noun corresponding to an item may include one or more of that item unless the relevant context clearly dictates otherwise.

[0024] In the present disclosure, each term 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 corresponding ones of these terms listed together, or all possible combinations thereof.

[0025] The term "and / or" includes a combination of a plurality of related described components or any one of a plurality of related described components.

[0026] Terms such as “first”, “second” and the like 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).

[0027] In addition, the terms "front", "rear", "top", "bottom", "side", "left", "right", "upper", "lower", 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.

[0028] 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.

[0029] When a component is “connected,” “coupled,” “supported,” or “contacted” with another component, this includes not only the case where the components are directly connected, coupled, supported, or contacted, but also the case where the components are indirectly connected, coupled, supported, or contacted via a third component.

[0030] 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.

[0031] The terms "approximately", "substantially" and the like used in this specification represent numerical values ​​corresponding to manufacturing and material tolerances specific to the stated meanings 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.

[0032] 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.

[0033] The separation device of the present disclosure will be described below in conjunction with the accompanying drawings, but the accompanying drawings are only exemplary and the scope of the separation device is not limited thereto.

[0034] Figure 1 For illustrating a separation device and a process flow according to an embodiment, Figure 2 2 is a diagram illustrating a detailed structure of a bottom region A of a distillation column according to an embodiment.

[0035] See also Figure 1 The separation device according to an embodiment of the present disclosure includes a distillation tower 2, a first reboiler 3, a second reboiler 4 and a condenser 5.

[0036] The distillation tower 2 is a device that can separate multi-component substances contained in the raw material based on the difference in boiling points. In consideration of the boiling points of the inflowing raw material components, the components to be separated, etc., a distillation tower equipped with various types of trays 30 can be used in the separation device of the present disclosure. In addition, after the oligomerization process of the ethylene monomer, in order to minimize the risk of clogging due to by-products such as polymers, while effectively separating and recovering the oligomer products and unreacted ethylene monomer contained in the reactor effluent discharged from the reactor 1, a distillation tower equipped with double partition walls 10 and 20 in the bottom area A of the distillation tower can be used in the separation device of the present disclosure.

[0037] For example, Figure 1 As shown, the interior of the distillation column 2 can be divided into a bottom region A, a middle region B and a top region C.

[0038] 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 in which the distillation tower is divided in the height direction, and more specifically, it may refer to the area below the lowest tower tray, that is, the lower area.

[0039] In the present 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 the three regions into which the distillation tower is divided in the height direction, more specifically, it may refer to the region above the uppermost tray, i.e., the upper region.

[0040] In addition, in the present specification, "middle region B" refers to a relatively middle portion in the structure of the distillation tower 2, and for example, may refer to a middle region among three regions into which the distillation tower is divided in the height direction, and more specifically, may refer 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.

[0041] In one embodiment, the bottom area A of the distillation tower 2 is provided with a first partition wall 10, a second partition wall 20, a raw material supply port 40, a first outlet 51, a first reflux inlet 61, a second outlet 53, a second reflux inlet 63, and may also be provided with a third outlet 55 and / or a third reflux inlet 65.

[0042] According to one embodiment of the separation device, by setting a raw material supply port 40 in the bottom area A, the risk of clogging in the tower due to polymer by-products contained in the reactor effluent can be minimized, and by changing the structure of the sump of the distillation tower 2 using a double dividing wall, all unreacted ethylene monomers can be recovered into the reactor 1 without being lost to the bottom.

[0043] In one embodiment, the bottom region A of the distillation tower 2 is provided with double partition walls 10 and 20 in a sump for collecting the liquid reactor effluent. Here, the sump may refer to an area for collecting the solution at the lower part 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.

[0044] More specifically, see Figure 1 , the bottom region A of the distillation column 2 has a first region D1, a second region D2, and a third region D3 divided by a first partition wall 10 and a second partition wall 20, and the first partition wall 10 and the second partition wall 20 extend from the bottom of the distillation column 2 to a predetermined height and are spaced apart from each other. For example, the first region D1 and the second region D2 are divided by the first partition wall 10 therebetween, and the second region D2 and the third region D3 may be divided by the second partition wall 20 disposed therebetween. In addition, the second region D2 may be located between the first partition wall 10 and the second partition wall 20. In addition, it is preferred that the first region D1, the second region D2, and the third region D3 divided by the first partition wall 10 and the second partition wall 20 are equally divided.

[0045] Meanwhile, the heights of the first partition wall 10 and the second partition wall 20 may be appropriately changed according to the structure or size of the distillation column. Figure 1 As shown, it can be arranged not to contact the lowest tray among the plurality of trays 30 described later. Here, the predetermined height may refer to the height at which the first partition wall 10 and / or the second partition wall 20 are spaced apart so as not to contact the lowest tray. For example, the first partition wall 10 and the second partition wall 20 may preferably have the same height, but the height is not limited thereto.

[0046] In addition, since the upper ends of the first partition wall 10 and the second partition wall 20 are set not to contact the lowermost tray among the plurality of trays 30 described later, the gas in the gas phase region of the bottom region A can move between the first region D1, the second region D2 and the third region D3.

[0047] Also, see Figure 2 , an auxiliary tray 11 may be further provided at the upper end of the first partition wall 10, which has a predetermined slope toward the second region D2. The auxiliary tray 11 is provided to compensate for the phenomenon that the solution injected into the first region D1 does not pass through the first reboiler 3 but detours to the second region D2. For example, the auxiliary tray 11 is inclined at an angle of less than 90°, more specifically, about 40° to about 80°, relative to the first partition wall 10 in the direction toward the second region D2, but is not limited thereto. In addition, when the first partition wall 10 is provided with the auxiliary tray 11, the overall height including the auxiliary tray may be the same as the height of the second partition wall 20, but is not limited thereto.

[0048] In one embodiment, a region of the second partition wall 20 may be provided with an opening 21. Figure 2 , the opening 21 is located below the liquid surface of the solution in the second area D2 and the third area D3, so that the solution flows from the third area D3 to the second area D2, so that the liquid level in the two areas can be kept the same. The shape and / or size of the opening 21 may not be particularly limited, as long as it can make the solution flow from the third area D3 to the second area D2. For example, the opening 21 may include one or more holes, or may include multiple holes with different diameters. The shape, size and / or number of the holes are not particularly limited, as long as the liquid levels in the second area D2 and the third area D3 can be kept the same.

[0049] See also Figure 1 According to one embodiment, the raw material supply port 40, the first outlet 51 and the first reflux inlet 61 are arranged in the first region D1 of the separation device.

[0050] In one embodiment, the raw material supply port 40 is connected to the reactor 1 and is disposed at one side of the first region D1, so that the reactor effluent containing ethylene monomer and oligomer discharged from the reactor 1 can be supplied to the first region D1. More specifically, the raw material supply port 40 can be located at one side of the first region D1 of the distillation column 2, and its height is adjacent to the height of the first partition wall 10, and is preferably disposed at a height higher than the liquid level of the solution in the first region D1.

[0051] Here, the reactor effluent includes oligomer products (α-olefins, P) produced by the oligomerization reaction of ethylene monomers carried out in the reactor 1 and ethylene as unreacted monomers, and may also include polymers as by-products. As in the prior art, when the reactor effluent is injected into the feed tray located in the middle area of ​​the tower, there is a risk of clogging due to polymer by-products. However, in the present disclosure, the raw material supply port 40 is located in the bottom area A to prevent the tower from clogging.

[0052] Oligomerization refers to the reaction of monomer polymerization. According to the number of monomers to be polymerized, it is called trimerization and tetramerization, and these trimerization and tetramerization are collectively referred to as polymerization. Alpha-olefins are widely used as important materials for comonomers, detergents, lubricants, plasticizers, etc. in business. Specifically, 1-hexene and 1-octene have been 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.

[0053] Meanwhile, in one embodiment, the first outlet 51 may be disposed at the bottom of the lower portion of the first region D1 and connected to one side of the first reboiler 3 through the first flow path 110. The lower discharge flow of the first region D1 containing the reactor effluent, i.e., the first flow, may be transmitted to the first reboiler 3 for primary heat exchange through the first outlet 51. Since the reactor effluent containing unreacted monomers and the liquid dripping from the lowermost tray both enter the first region D1, more than about 80% by volume, preferably more than about 90% by volume of the flow rate may be discharged through the first outlet 51 located at the lower portion of the first region D1 and guided through the first reboiler 3.

[0054] In addition, if Figure 2 As shown, the first flow path 110 may also be provided with a valve 111 that can be opened and closed as needed.

[0055] In the present application, the reboilers 3 and 4 are heating devices separately installed outside the distillation tower 2, and may refer to devices for reheating and evaporating the high-boiling-point component flow discharged from the bottom of the distillation tower.

[0056] In one embodiment, the first reboiler 3 may be a device for heating the first stream discharged from the lower part of the first region D1 of the distillation tower 2 through the first flow path 110 by primary heat exchange. For example, a thermosyphon reboiler may be preferably used as the first reboiler 3. The thermosyphon reboiler operates by continuously supplying the liquid at the lower part of the distillation tower to the reboiler without a pump and power, and may be designed to provide heat in the form of gas and liquid two-phases due to the evaporation of gas from the reboiler, and due to the presence of gas, the density is greatly reduced compared to the liquid at the inlet, so that the natural circulation of the liquid continues to be stable due to the density difference and liquid head pressure in the distillation tower. A certain proportion of polymer by-products may exist in the sump of the distillation tower, but it can be determined that the amount of polymer by-products is not only extremely small, but also that the polymer by-products are in a liquefied state under high temperature conditions. Therefore, the primary heat exchange by the thermosyphon recirculation system that can be installed and operated at low cost has the advantage of being able to operate a large amount of circulating streams economically and efficiently without additional equipment such as pumps.

[0057] at the same time, Figure 3 A conventional separation device without a partition wall in the sump of a distillation tower is shown as a comparative example. As shown in FIG4 , when the reactor effluent is injected into the bottom region where the partition wall is not provided, the region for the liquid stream discharged to the reboiler and the liquid stream discharged to the product is not separated. Therefore, there is a problem that the reactor effluent does not all pass through the reboiler, and unreacted monomers may be directly discharged to the bottom together with the product.

[0058] On the other hand, as described above, in the separation device according to the embodiment of the present disclosure, the solution discharged from the reactor 1, the two-phase fluid passing through the first reboiler 3, and the liquid separated and dripped after heat exchange in the lowermost tray 30 of the tower all flow into the first region D1 and overflow and enter the second region D2 at a flow rate exceeding the amount discharged to the lower part of the first region D1. Here, the lower discharge flow (first flow) of the first region D1 is subjected to primary heat exchange by the thermosiphon recirculation system of the first reboiler 3. In this case, about 80% by volume or more, preferably 90% by volume or more of the total flow rate can be circulated to the first reboiler 3. As a result, there is an advantage of improving the recovery rate of the unreacted ethylene monomer.

[0059] In addition, the lower discharge stream (first stream) of the first zone D1 may be heated to a temperature of about 200° C. to 205° C. by the primary heat exchange in the first reboiler 3. Heating the first stream to the above temperature range by the primary heat exchange may prevent the pipeline clogging phenomenon due to the polymer by-products, while converting the unreacted ethylene monomer dissolved in the solution into a gas phase.

[0060] In one embodiment, the first reflux inlet 61 is located at the upper portion of the first region D1, and may be connected to the other side of the first reboiler 3 through the second flow path 120, and may be disposed at the side of the distillation tower 2. The first stream having passed through the first reboiler 3 may be refluxed back to the first region D1 through the first reflux inlet 61.

[0061] More specifically, the first reflux inlet 61 may be located at a height between the lowermost tray among the plurality of trays 30 described later and the raw material supply port 40. The reactor effluent flowing out from the reactor 1 through the raw material supply port 40, the first stream discharged to the first outlet 51, passing through the first reboiler 3, and then recycled through the first reflux inlet 61, and / or the liquid separated and dripped from the lowermost tray 30 described later, flows into the first region D1. In this way, when the flow rate flowing into the first region D1 exceeds the capacity that the first region D1 can accommodate, the solution in the first region D1 passes through the first partition wall 10 and moves to the second region D2. In this case, since the first reflux inlet 61 is located at a higher height than the raw material supply port 40, the solution of the first stream after the first heat exchange that refluxes through the first reflux inlet 61 preferentially enters the second region D2.

[0062] See also Figure 1 According to one embodiment, the second outlet 53 is disposed in the second region D2, and the second reflux inlet 63 is disposed in the third region D3. Figure 2 As shown, the third outlet 55 and / or the third return inlet 65 may also be additionally provided in the third region D3 .

[0063] In one embodiment, the second outlet 53 may be disposed at the bottom of the lower portion of the second region D2 between the first partition wall 10 and the second partition wall 20, and connected to one side of the second reboiler 4 through the third flow path 130. The lower exhaust flow (i.e., the second flow) of the second region D2 is transported to the second reboiler 4 through the second outlet 53 for secondary heat exchange. Figure 2 As shown, the third flow path 130 may also be provided with a valve 131 and / or a pump 133 that can be opened and closed as required.

[0064] The second reboiler 4 may be a device for heating the second stream flowing out from the lower part of the second region D2 of the distillation tower 2 through the third flow path 130. For example, the second reboiler is preferably a forced circulation reboiler. The forced circulation reboiler uses a pump 133 to force liquid to be supplied to the reboiler, and can be used in situations where forced circulation is required, such as situations where a fluid with a high viscosity or a fluid that is temperature sensitive and requires a fast reboiler cycle. When a forced circulation reboiler is used in the reboiler circulation in the second region D2, in the case where the efficiency of the thermosyphon reboiler in the first region D1 decreases over time due to the high viscosity of the polymer solution, etc., as the flow rate of the first stream discharged to the first outlet 51 decreases, the heat exchange capacity in the first reboiler 3 decreases, and thus the reflux flow rate of the entire distillation tower may also decrease. In this case, by adjusting the relative ratio of the circulation flow rates between the first reboiler 3 and the second reboiler 4, the second reboiler 4 compensates for the decrease in the efficiency of the first reboiler 3, so the second reboiler 4 can operate for a long time.

[0065] In addition, the lower discharge stream (second stream) of the second zone D2 may be heated to a temperature of about 205° C. to 210° C. by secondary heat exchange in the second reboiler 4. By heating to the above temperature range, the unreacted ethylene monomer remaining in the solution may be converted into a gas phase, and clogging due to polymer by-products may be prevented.

[0066] In one embodiment, the second reflux inlet 63 is provided at one side of the third region D3, and may be connected to the other side of the second reboiler 4 through the fourth flow path 140, and is provided at the side of the distillation tower 2. The second stream passing through the second reboiler 4 may flow back to the third region D3 through the second reflux inlet 63. More specifically, the second reflux inlet 63 may be located at a height between the upper end of the second partition wall 20 and the liquid level of the solution in the third region D3.

[0067] As described above, the liquid that flows into the second area D2 beyond the capacity of the first area D1 will flow through the first partition wall 10. In addition, the second flow is discharged to the second outlet 53 at the lower part of the second area D2, passes through the second reboiler 4, and then recirculates through the second reflux inlet 63, and flows into the third area D3, and part of the solution in the third area D3 flows back to the second area D2 through the opening 21 provided in the second partition wall 20. As a result, the solution levels in the second area D2 and the third area D3 remain the same. In addition, the average temperature of the solution in the second area D2 is increased by the solution flowing out of the third area D3, and therefore, the third flow path 130 through which the second flow, which is the discharge flow from the lower part of the second area D2, passes can prevent the problem of pipeline clogging due to polymer by-products.

[0068] In addition, the bottom area A of the distillation tower 2 is divided by the first partition wall 10 and the second partition wall 20 into a lower flow area of ​​the first area D1 for discharging the reactor effluent to the first reboiler 3, a lower flow area of ​​the second area D2 for discharging the solution overflowed from the liquid flow after the initial heat exchange through the first reboiler 3 to the second reboiler 4, and a lower flow area of ​​the third area D3 for discharging the product P, and the raw material supply port 40 is located in the first area D1, so it is designed that more than about 80 volume % of the flow rate of the reactor effluent, preferably about 90 volume % of the flow rate passes through the first reboiler 3, thereby further improving the separation efficiency of the unreacted monomers.

[0069] However, in the reaction device according to the present disclosure, in order to prevent the clogging of the tower structure due to the polymer by-products contained in the reactor effluent, the reactor effluent feed is directly injected into the sump of the distillation tower, so part of the unreacted ethylene monomer dissolved in the solution is still contained in the solution and may not be separated into vapor and may enter the second area D2. In order to compensate for this, the lower discharge flow (second flow) of the second area D2 is also subjected to secondary heat exchange through the forced circulation system of the second reboiler 4 to achieve the effect of the first stage of the full distillation tower that separates the unreacted ethylene monomer into the gas phase. Therefore, the unreacted reaction raw material ethylene monomer can be completely recovered to the upper part of the distillation tower, that is, the top, and the clogging (scaling) of the tower structure will not occur, so that a stable and economical separation process can be operated.

[0070] Meanwhile, the flow ratio of the first stream flowing out through the first flow path 110 to the second stream flowing out through the third flow path 130 may be 7:3 to 9:1, preferably about 7.5:2.5 to 8.5:1.5. In this case, by satisfying the flow ratio, the sum of the heat of the first stream flowing out through the first flow path 110 and passing through the first reboiler 3 and the second stream flowing out through the third flow path 130 and passing through the second reboiler 4 may remain the same. Since the heat required for the entire separation process is fixed, even if two reboilers are used as in the present disclosure, the total heat may be the same as that of a conventional separation process using one reboiler. More specifically, by using different types of reboilers with different flow rates together, it can function as a complete first stage of a distillation column.

[0071] At the same time, the average temperature of the solution (i.e., the liquid area) in the bottom area A of the distillation tower 2 can be about 195°C to 210°C, preferably about 200°C to 205°C. When the above temperature range is met, appropriate heat exchange can be achieved through the first reboiler and the second reboiler, and an appropriate steam generation rate at the rear end of the reboiler can be maintained.

[0072] More specifically, the average temperature of the solution in the second region D2 may be relatively higher than the average temperature of the solution in the first region D1, and the average temperature of the solution in the third region D3 may be relatively higher than the average temperature of the solution in the second region D2. For example, the average temperature of the solution in the first region D1 of the distillation tower 2 may range from about 195° C. to 200° C., the average temperature of the solution in the second region D2 may range from about 200° C. to 205° C., and the average temperature of the solution in the third region D3 may range from about 205° C. to about 210° C. When each region satisfies the above temperature range, the steam dissolved in the solution can be properly separated and the two reboilers can be efficiently operated.

[0073] 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 5°C to 10°C, and the average temperature difference between the solution in the second region D2 and the solution in the third region D3 may be about 2°C to 5°C. Specifically, due to the average temperature difference between the solution in the second region D2 and the solution in the third region D3, the fluidity of the solution in the third region D3 with a relatively high temperature flowing to the second region D2 with a relatively low temperature through the opening 21 can be improved. In addition, the effect of transferring the temperature of the solution in the third region D3 refluxed through the second reboiler 4 to the second region D2 through the opening 21 can also be achieved. That is, the relatively high temperature fluid present in the third region D3 moves to the second region D2 where the relatively low temperature fluid is located and mixes to increase the temperature of the liquid flow introduced into the second reboiler 4, thereby preventing the polymer byproducts in the flow from clogging the pipeline (i.e., the third flow path).

[0074] At the same time, if Figure 2 As shown, the separation device according to one embodiment may further include a preparatory flow path 150 connecting the first flow path 110 and the third flow path 130. In addition, the preparatory flow path 150 may also be provided with one or more valves 151, 152 that can be opened and closed, and the first flow path 110 and / or the third flow path 130 may also be provided with one or more valves 111, 131 that can be opened and closed, respectively.

[0075] For example, when the valve 131 of the third flow path is opened, the valves 151 and 152 of the reserve flow path can be closed. In addition, when the valve 131 of the third flow path is closed, the valves 151 and 152 of the reserve flow path can be opened. In addition, when the valves 151 and 152 of the reserve flow path are opened, the valve 111 provided in the first flow path 110 can be closed. In addition, by switching the valves 111, 131, 151, and 152 of each flow path, when necessary, the first reboiler 3 with a larger capacity can be converted into a form of forced circulation by the pump 133 of the third flow path, and the second reboiler 4 can also be used in a non-operating modified form.

[0076] As described above, since the solution in the first region D1 has a relatively low average temperature, a pipe blockage problem may occur in the first flow path 110 due to the polymer byproducts in the first flow. In this way, when the efficiency of the thermosyphon reboiler (i.e., the first reboiler 3) is reduced due to the accumulation of polymer byproducts, the circulation flow rate is increased by mechanical stroke control of the forced circulation pump 133, and the efficiency reduction of the first reboiler 3 is compensated by increasing the steam heat supply from the second reboiler 4, thereby overcoming the problem caused by the reduced efficiency of the first reboiler 3.

[0077] In one embodiment, the third outlet 55 is disposed at the bottom of the lower portion of the third region D3 of the distillation column 2. The third stream containing the oligomer product P can be discharged through the third outlet 55. Figure 2 , the third reflux inlet 65 may be connected to the third outlet 55, is located below the liquid surface of the solution in the third region D3, and is disposed at the side of the distillation tower 2. More specifically, a portion of the oligomer-containing liquid stream P discharged to the third outlet 55 is recovered, and the remaining stream may be branched through the third reflux inlet 65 and refluxed back to the third region (D3).

[0078] Also, see Figure 3 , which shows a conventional separation device using a distillation column without a partition wall in a sump, when the reactor effluent is injected into the bottom area without a partition wall, the area of ​​the stream discharged from the reboiler and the stream discharged from 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 of lowering the separation efficiency due to the unreacted ethylene monomer being discharged to the bottom together with the product.

[0079] In order to improve the above conventional problems, according to the separation device of the present disclosure, the bottom area A of the distillation tower 2 is divided into a first area D1, a second area D2 and a third area D3 by a first partition wall 10 and a second partition wall 20. In the first area D1, the bottom area A of the distillation tower 2 is provided with a first outlet 51, and the reactor effluent is discharged to the first reboiler 3 through the first outlet 51. The second area D2 is provided with a second outlet 53, and the solution overflowing from the first area D1 is discharged to the second reboiler 4 through the second outlet 53. The third area D3 is provided with a third outlet 55, and the oligomer product P with a relatively high boiling point is discharged through the third outlet 55. The raw material supply port 40 is located on the first area D1, so the entire reactor effluent is designed to necessarily pass through the first reboiler 3 and / or the second reboiler 4, thereby maximizing the separation efficiency of the unreacted monomers.

[0080] See also Figure 1 , the middle region B of the distillation column 2 includes a plurality of trays 30. The plurality of trays 30 are arranged in the vertical direction of the double partition walls 10, 20 and are spaced apart from each other. The gas stream containing the unreacted monomer gas generated in the bottom region A passes through the plurality of trays 30 arranged in the middle region B, is separated into gas and liquid, and moves to the top region C to be described later.

[0081] The number and type of the plurality of trays 30 may be appropriately selected in consideration of the type of the distillation column 2 and the desired separation efficiency, and the type of the tray may be used without particular limitation as long as it is a tray generally used in a distillation column for gas-liquid separation.

[0082] For example, the distillation tower 2 may be a distillation tower having 10 to 30 theoretical stages, wherein the theoretical number of stages refers to the number of stages divided by a virtual region or a plurality of trays in which two phases such as a gas phase and a liquid phase are in equilibrium with each other in the distillation tower 2 .

[0083] In the separation device according to an embodiment of the present disclosure, one end of the lowest tray 30 among the plurality of trays is located at the upper portion of the first region D1, and the separation device may further include a guide partition wall 31 extending downward from one end of the lowest tray 30. One end of the lowest tray 30 may be open so as not to contact the side of the distillation tower 2 on the first region D1.

[0084] More specifically, the dripping liquid separated from the bottom tray 30 after contacting with the gas-liquid can be guided to the first region D1 through the guide partition wall 31. Since the solution dripping from the tray (dripping liquid) may also dissolve unreacted ethylene monomer, the guide partition wall 31 is provided at the end of the bottom tray to ensure that the solution dripping from the tray only flows into the first region D1, thereby preventing the product from being directly lost to the third outlet 55 (i.e., the product P outlet) without passing through the first reboiler 3 and / or the second reboiler 4, thereby maximizing the recovery rate of the unreacted monomer.

[0085] See also Figure 1 A fourth outlet 57 connected to the condenser 5 is provided at the upper portion of the top region C of the distillation tower 2 .

[0086] The condenser 5 is a device installed separately outside the distillation tower 2, and is a device for cooling the fluid discharged from the top of the distillation tower by contacting it with cooling water flowing from the outside. For example, the condenser 5 may be a device for condensing the gaseous flow discharged upward from the top region C of the distillation tower 2 through the fourth outlet 57.

[0087] More specifically, the gaseous stream containing the unreacted ethylene monomer may pass through the plurality of trays 30 of the middle region B, reach the top region C of the distillation tower 2, and then be discharged as an upper gaseous stream to the condenser 5 through the fourth outlet 57. The upper gaseous stream discharged from the condenser 5 may be condensed and returned to the reactor 1. In addition, a portion of the condensed top stream may be separated and recycled to the distillation tower 2, but is not limited thereto.

[0088] Above, exemplary embodiments of the separation device according to the present disclosure have been described and shown in the accompanying drawings. However, the above description and the illustrations of the accompanying drawings are only examples for understanding the core components of the present disclosure. In addition to the processes and equipment shown in the description and the accompanying drawings, processes and equipment that are not separately described or shown can be appropriately applied and used to implement the separation device according to the present disclosure.

[0089] 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.

[0090] [Explanation of Reference Numerals]

[0091] 1: Reactor 2: Distillation tower

[0092] 3, 4: Reboiler 5: Condenser

[0093] A: Bottom area B: Middle area

[0094] C: Top area D1, D2, D3: First to third area

[0095] 10: First partition wall

[0096] 11: Auxiliary tray 20: Second dividing wall

[0097] 21: Opening 30: Tray

[0098] 31: Guide divider wall

[0099] 40: Raw material supply port

[0100] 51, 53, 55, 57: Exit 1 to Exit 4

[0101] 61, 63, 65: First reflux inlet to third reflux inlet

[0102] 110, 120, 130, 140, 150: Flow path

[0103] 111, 131, 151, 152: valve

[0104] 133: Pump

Claims

1. A separation device, comprising: a distillation column having a double dividing wall, a first reboiler, a second reboiler and a condenser, wherein the interior of the distillation tower is divided into a bottom region, a middle region and a top region, and The bottom region of the distillation column comprises: first to third regions, the first to third regions being divided by a first dividing wall and a second dividing wall extending from the bottom of the distillation column to a predetermined height and spaced apart from each other; a raw material supply port, the raw material supply port being disposed at one side of the first zone and allowing the reactor effluent containing monomers and oligomers to be transferred to the first zone through the raw material supply port; a first outlet, the first outlet being disposed at a lower portion of the first region and connected to one side of the first reboiler through a first flow path; a first reflux inlet, which is disposed at an upper portion of the first region and connected to the other side of the first reboiler through a second flow path; a second outlet provided at a lower portion of the second region between the first partition wall and the second partition wall and connected to one side of the second reboiler through a third flow path; and A second reflux inlet is disposed at one side of the third region and connected to the other side of the second reboiler through a fourth flow path.

2. The separation device according to claim 1, wherein the second partition wall comprises an opening.

3. The separation device according to claim 1, further comprising: A third outlet is provided at a lower portion of the third zone and allows a liquid stream containing oligomers to be discharged therefrom.

4. The separation device according to claim 3, further comprising A third reflux inlet, through which part of the liquid flow discharged from the third outlet is split and returned to the third area.

5. The separation device according to claim 1, further comprising: A preliminary flow path connecting the first flow path and the third flow path.

6. The separation device according to claim 5, wherein The third flow path and the preparatory flow path are each provided with at least one valve which is opened and closed respectively. When the valve of the third flow path is opened, the valve of the preliminary flow path is closed, and when the valve of the third flow path is closed, the valve of the preliminary flow path is opened.

7. The separation device according to claim 1, wherein the first reboiler is a thermosyphon reboiler and the second reboiler is a forced circulation reboiler. 8 . The separation device according to claim 1 , wherein a flow ratio of the first flow flowing out through the first flow path to the second flow flowing out through the third flow path is 7:3 to 9:

1. 9 . The separation device according to claim 1 , wherein an average temperature of the solution in the second region is relatively lower than an average temperature of the solution in the third region.

10. The separation device according to claim 1, wherein the distillation column comprises a plurality of trays spaced apart in the vertical direction of the double dividing wall in the middle region, and The first reflux inlet is located at a height between the lowest tray among the plurality of trays and the raw material supply port.

11. The separation device according to claim 1, further comprising a guide partition wall extending downward from one end of a lowermost tray among the plurality of trays, One end of the lowest tray among the plurality of trays is open so as not to contact the side of the distillation column on the first zone.

12. The separation device according to claim 1, wherein: An auxiliary tray having a predetermined slope in the direction of the second region is provided at the upper end of the first dividing wall.

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