Continuous solution polymerization process

Abstract

A continuous solution polymerization process according to an embodiment of the present application comprises: producing a product comprising a polymer subjected to the polymerization process in a reactor; separating the product in a liquid-liquid separator (L / L separator) into a first solution comprising a polymer and a second solution comprising a polymer; supplying the first solution to a devolatilizer and supplying the second solution to a solid-liquid separator (S / L separator); separating the first solution in a devolatilizer into a polymer-containing vapor and a liquid polymer; separating the second solution and the polymer-containing vapor into a solvent capable of being introduced into the reactor and a polymer-containing solid in a solid-liquid separator (S / L separator); and introducing a solvent capable of being introduced into the reactor into the reactor and recycling the solvent.

Description

Technical Field

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0022474 filed in the Korean Intellectual Property Office on February 20, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to a continuous solution polymerization process. Background Art

[0003] In a polymer continuous solution polymerization process, the reactor effluent is usually subjected to one or more separation steps, and during the process, a process of recycling the separated solvent and monomer to the polymerization reactor is included.

[0004] However, physical entrainment of oligomers, low-density materials, and products may occur in the devolatilizer corresponding to the back end of the reaction of a continuous solution polymerization process of a polymer, thereby interfering with the recycling process.

[0005] Specifically, when oligomers, low-density materials, and products are physically entrained into the devolatilizer, fouling occurs during recycling of the separated solvent, which is contamination of the above-mentioned physically entrained materials into units such as condensers, pumps, and heat exchangers.

[0006] Fouling as described above leads to instability in the recycling process, which will hinder the long-term operability of the entire polymer continuous solution polymerization process and aggravate the problem of product productivity loss.

[0007] Therefore, there is a need for a method for preventing physical carryover of oligomers, low density materials, and products to prevent fouling and to efficiently recycle only the materials needed for a continuous solution polymerization process of a polymer. Summary of the invention

[0008] Technical issues

[0009] The present application aims to provide a continuous solution polymerization process including a recycling system capable of effectively preventing scaling.

[0010] Technical Solution

[0011] An exemplary embodiment of the present application provides a continuous solution polymerization process, which includes:

[0012] producing a product comprising a polymer subjected to a polymerization process in a reactor;

[0013] supplying the product to a liquid-liquid separator (L / L separator);

[0014] separating the supplied product into a first solution containing the polymer and a second solution containing the polymer in the liquid-liquid separator;

[0015] supplying the first solution separated from the liquid-liquid separator to a devolatilizer;

[0016] supplying the second solution separated from the liquid-liquid separator to a solid-liquid separator (S / L separator);

[0017] separating the first solution into a vapor comprising a polymer and a liquid polymer in the devolatilizer;

[0018] supplying the vapor containing the polymer separated from the devolatilizer to the solid-liquid separator (S / L separator);

[0019] separating the supplied second solution and the vapor containing the polymer into a solvent capable of being introduced into the reactor and a solid containing the polymer in the solid-liquid separator; and

[0020] introducing the solvent separated from the solid-liquid separator and capable of being introduced into the reactor into the reactor and recycling it,

[0021] Wherein, the first solution and the second solution satisfy the following formula 1.

[0022] [Formula 1]

[0023] M a >M b

[0024] In equation 1,

[0025] M a refers to the content of the polymer in the first solution, and

[0026] M b represents the content of the polymer in the second solution.

[0027] Technical Effects

[0028] The continuous solution polymerization process according to the present application has a recycling system, and thus energy efficiency can be improved.

[0029] Since the continuous solution polymerization process according to the present application can prevent scaling, the efficiency of the recycling system can be improved, so that the continuous solution polymerization process can be performed for a long time, thereby improving productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a block diagram illustrating a continuous solution polymerization process according to the present application.

[0031] Figure 2 is a block diagram illustrating an existing continuous solution polymerization process.

[0032] [Explanation of Reference Numerals]

[0033] 100: Feed supply container

[0034] 150: Supply pump

[0035] 160: Eighth heat exchanger

[0036] 200: Reactor

[0037] 230: First heat exchanger

[0038] 240: Liquid-Liquid Separator

[0039] 250: Third heat exchanger

[0040] 260: Solid-liquid separator

[0041] 270: Seventh heat exchanger

[0042] 330: Second heat exchanger

[0043] 340: Devolatilizer

[0044] 350: Fourth heat exchanger

[0045] 360: Can

[0046] 380: Sixth heat exchanger DETAILED DESCRIPTION

[0047] Hereinafter, the present invention will be described in detail so that those skilled in the art to which the present application belongs can easily implement the present invention. However, the present application can be implemented in various different forms and is not limited to the configuration described herein.

[0048] In the present specification, when a component “comprises” a constituent element, unless otherwise specifically stated, this does not mean that other constituent elements are excluded but means that other constituent elements may be further included.

[0049] In this specification, "p to q" means "p or more and q or less".

[0050] In the present specification, "polymerization process" may also be expressed as "polymerization method" or "method of preparing a polymer by a polymerization process".

[0051] In this specification, “the” is used to distinguish devices or schemes with the same name and does not mean a specific order.

[0052] In the present specification, the reactor may be used in the form of a CSTR (autoclave), a solution loop reactor, and a PFR, but is not limited thereto, and various types of reactors may be used as long as they can withstand the conditions for conducting the polymerization reaction.

[0053] Herein, "a product including a polymer subjected to a polymerization process" may refer to a product including the polymer that will become a final product and other materials.

[0054] Furthermore, in describing the present application, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present application will be omitted.

[0055] An exemplary embodiment of the present application provides a continuous solution polymerization process, which includes: producing a product containing a polymer subjected to a polymerization process in a reactor; supplying the product to a liquid-liquid separator (L / L separator); separating the supplied product into a first solution containing the polymer and a second solution containing the polymer in the liquid-liquid separator; supplying the first solution separated from the liquid-liquid separator to a devolatilizer; supplying the second solution separated from the liquid-liquid separator to a solid-liquid separator (S / L separator); separating the first solution into a vapor containing the polymer and a liquid polymer in the devolatilizer; supplying the vapor containing the polymer separated from the devolatilizer to the solid-liquid separator (S / L separator); separating the supplied second solution and the vapor containing the polymer into a solvent capable of being introduced into a reactor and a solid comprising the polymer in the solid-liquid separator; and introducing the solvent capable of being introduced into the reactor separated from the solid-liquid separator into the reactor and recycling, wherein the first solution and the second solution satisfy the following formula 1.

[0056] [Formula 1]

[0057] M a >M b

[0058] In equation 1,

[0059] M a refers to the content of the polymer in the first solution, and

[0060] M b represents the content of the polymer in the second solution.

[0061] The continuous solution polymerization process according to the present application has a recirculation system, so that energy efficiency can be improved. In addition, since the recirculation system of the present application can reduce the processing flow of the devolatilizer by introducing a liquid-liquid separator, the energy required for the heat exchange process generated in the process of supplying materials to the devolatilizer can be reduced. In addition, by introducing a liquid-liquid separator, physical entrainment of oligomers, low-density materials and products in the devolatilizer can be prevented, thereby improving the efficiency of the recirculation system. That is, the continuous solution polymerization process according to the present application can prevent scaling.

[0062] Therefore, the continuous solution polymerization process according to the present application can improve the efficiency of the recycling system, thereby allowing the continuous solution polymerization process to be performed for a long time, thereby improving productivity.

[0063] In this specification, "a first solution containing a polymer" refers to a solution containing a large amount of polymer (polymer-rich solution), and "a second solution containing a polymer" refers to a solution containing a small amount of polymer (polymer-lean solution). That is, in the above equation 1, M a The weight of the polymer in the first solution, M b The weight of the polymer in the second solution may be expressed.

[0064] Furthermore, in the present specification, “vapor containing a polymer” contains a relatively smaller amount of the polymer than the content of the polymer contained in the solution, and may be expressed as vapor containing a small amount of the polymer.

[0065] Herein, “a product including a polymer subjected to a polymerization process” may mean including the polymer that will become a final product and other materials.

[0066] In an exemplary embodiment of the present application, the liquid polymer separated from the devolatilizer may be extruded. By extruding the liquid polymer, a product prepared by a continuous solution polymerization process may be prepared.

[0067] In an exemplary embodiment of the present application, supplying a product to a liquid-liquid separator (L / L separator) may include heating the product using a first heat exchanger; decompressing the heated product using a first pressure reducing valve; and supplying the heated and decompressed product to the liquid-liquid separator.

[0068] In an exemplary embodiment of the present application, heating the product using the first heat exchanger may be performed at a temperature equal to or lower than a bubble point temperature of the product.

[0069] In an exemplary embodiment of the present application, the pressure of the heated product may be reduced by reducing the pressure using the first pressure reducing valve so that the pressure of the product is equal to or lower than the cloud point pressure. The pressure may be a measured pressure.

[0070] When the above temperature and pressure ranges are satisfied, the product can be more efficiently separated into a first solution containing a polymer (a solution containing a large amount of the polymer) and a second solution containing a polymer (a solution containing a small amount of the polymer) in a liquid-liquid separator.

[0071] In the exemplary embodiment of the present application, when only the below-described solid-liquid separator is applied without applying the liquid-liquid separator, the effect of the continuous solution polymerization process as described in the present application cannot be obtained due to the absence of a lean-phase.

[0072] In an exemplary embodiment of the present application, supplying the first solution separated from the liquid-liquid separator to the devolatilizer may include: heating the first solution using a second heat exchanger; decompressing the heated first solution using a second decompression valve; and supplying the heated and decompressed first solution to the devolatilizer.

[0073] In an exemplary embodiment of the present application, heating the first solution using the second heat exchanger may be performed at a temperature lower than a bubble point temperature of the first solution.

[0074] In an exemplary embodiment of the present application, the pressure of the first solution may be reduced by using the second pressure reducing valve to reduce the pressure so that the pressure of the first solution is equal to or lower than the bubble point pressure. The pressure may be a measured pressure.

[0075] When the above temperature and pressure ranges are satisfied, the first solution can be more efficiently separated into vapor containing the polymer and the liquid polymer in the devolatilizer.

[0076] In an exemplary embodiment of the present application, supplying the second solution separated from the liquid-liquid separator to a solid-liquid separator (S / L separator) may include cooling the second solution using a third heat exchanger; and supplying the cooled second solution to the solid-liquid separator.

[0077] In the exemplary embodiment of the present application, cooling the second solution using the third heat exchanger may be performed at a temperature equal to or higher than the melting point of the second solution.

[0078] In an exemplary embodiment of the present application, supplying the vapor containing the polymer separated from the devolatilizer to a solid-liquid separator (S / L separator) may include: cooling the vapor containing the polymer using a fourth heat exchanger; and supplying the cooled vapor containing the polymer to the solid-liquid separator.

[0079] In the exemplary embodiment of the present application, cooling the vapor including the polymer using the fourth heat exchanger may cool the vapor including the polymer at a temperature equal to or higher than the melting point temperature of the polymer and lower than the bubble point temperature of the vapor including the polymer.

[0080] When the above temperature range is satisfied, the second solution and the vapor containing the polymer in the solid-liquid separator can be more efficiently separated into the solvent and the solid containing the polymer, which can be introduced into the reactor.

[0081] In an exemplary embodiment of the present application, extruding the solid polymer separated from the solid-liquid separator may be further included. The description of the above extrusion step may be applicable to the extrusion of the solid polymer separated from the solid-liquid separator.

[0082] In an exemplary embodiment of the present application, when only the above-mentioned liquid-liquid separator is applied without a solid-liquid separator, scaling may occur as the temperature of the lean phase condensate of the liquid-liquid separator decreases, and thus the operation may not be able to be performed, and then the effect of the continuous solution polymerization process in the present application cannot be obtained.

[0083] In an exemplary embodiment of the present application, introducing and recycling the solvent separated from the solid-liquid separator and capable of being introduced into the reactor may include: adjusting the solvent to a reaction temperature range of the continuous solution polymerization process using a fifth heat exchanger; and introducing the solvent into the reactor.

[0084] The polymerization method according to the exemplary embodiment of the present application may further include a part of the solvent that will be separated from the solid-liquid separator and can be introduced into the reactor and reintroduced into the solid-liquid separator. The temperature of the solid-liquid separator can be regulated by a process (recycling) in which a part of the solvent that will be separated from the solid-liquid separator and can be introduced into the reactor is reintroduced into the solid-liquid separator. As mentioned above, the solid-liquid separator needs to be operated at a temperature below the melting point of the polymer. In this case, a part of the solvent that can be separated from the solid-liquid separator and can be introduced into the reactor can be used to effectively regulate the temperature within the operating temperature range of the solid-liquid separator.

[0085] In an exemplary embodiment of the present application, the content of the solvent reintroduced into the solid-liquid separator can be adjusted so that the solid-liquid separator can be operated even at a temperature equal to or lower than the melting point of the polymer. That is, the solid-liquid separation efficiency of the solid-liquid separator can be improved by adjusting the content of the solvent reintroduced into the solid-liquid separator.

[0086] In the exemplary embodiment of the present application, the polymer of the polymer-containing product may be a polyolefin. Even in the case where the polymer is a polyolefin, the continuous solution polymerization process (polymerization method) of the present invention may be used.

[0087] In the exemplary embodiment of the present application, when the polymer of the polymer-containing product is polyolefin, the above-mentioned heating, cooling and pressurizing conditions may be more specifically stated as follows.

[0088] In the exemplary embodiment of the present application, when the polymer of the polymer-containing product is polyolefin, heating the product using the first heat exchanger may heat the product at 120°C to 220°C, preferably 130°C to 210°C.

[0089] In an exemplary embodiment of the present application, when the polymer of the polymer-containing product is a polyolefin, the pressure of the heated product can be reduced by reducing the pressure using the first pressure reducing valve so that the pressure of the product becomes 20 bar to 90 bar, preferably 30 bar to 80 bar. The pressure may be the measured pressure.

[0090] In an exemplary embodiment of the present application, when the polymer of the polymer-containing product is polyolefin, heating the first solution containing the polymer using the second heat exchanger can heat the first solution containing the polymer so that the temperature of the first solution is 220°C to 300°C, preferably 220°C to 280°C.

[0091] In an exemplary embodiment of the present application, when the polymer of the product containing the polymer is a polyolefin, the pressure of the first solution containing the heated polymer can be reduced by decompressing the first solution containing the polymer using the second pressure reducing valve so that the pressure of the first solution containing the polymer becomes 1 bar to 40 bar. The pressure may be the measured pressure.

[0092] In an exemplary embodiment of the present application, when the polymer of the polymer-containing product is polyolefin, cooling the second solution containing the polymer using the third heat exchanger can cool the second solution so that the temperature of the second solution containing the polymer is 40°C to 160°C, preferably 50°C to 100°C.

[0093] When the above conditions are met while using polyolefin in the continuous polymerization process (polymerization method) of the present invention, the efficiency of the process can be further improved.

[0094] Figure 1 2 is a block diagram showing a continuous solution polymerization process according to the present application, and an embodiment of the present invention will be described based on the block diagram. A product containing a polymer is produced by a polymerization method in a reactor 200. The product containing a polymer produced in the reactor 200 is heated using a first heat exchanger 230 through a path 210-211, and is supplied to a liquid-liquid separator 240 through a path 231-232. In this case, a first pressure reducing valve disposed between paths 231-232 may be used to perform a process of reducing the pressure on the heated product.

[0095] Then, the product supplied from the liquid-liquid separator 240 is separated into a solution containing a large amount of the polymer (polymer-rich solution, first solution) and a solution containing a small amount of the polymer (polymer-poor solution, second solution).

[0096] The solution containing a large amount of polymer separated from the liquid-liquid separator 240 is supplied to the second heat exchanger 330 through the path 242-311, wherein the solution containing a large amount of polymer is heated in the second heat exchanger 330. The heated solution containing a large amount of polymer is depressurized using a second depressurizing valve, and the heated and depressurized solution containing a large amount of polymer is supplied to the devolatilizer 340 through the path 332.

[0097] The solution containing a large amount of polymer is separated into vapor containing a small amount of polymer (polymer-lean vapor) and molten polymer (polymer melt) in the devolatilizer 340. The molten polymer can be supplied to another devolatilizer or an extruder and a pelletizer through a path 342 to be processed into a final product.

[0098] The vapor containing a small amount of polymer is supplied to the fourth heat exchanger 350 through the path 341, and the vapor containing a small amount of polymer is cooled in the fourth heat exchanger 350 and supplied to the tank 360 through the path 351. In this case, if necessary, a portion of the cooled vapor containing a small amount of polymer supplied to the tank 360 may be supplied to the feed supply container 100 through the path 362-130. During this process, an additional cooling process may be performed in the sixth heat exchanger 380.

[0099] Furthermore, the cooled vapor containing a small amount of polymer moving from the tank 360 through the path 362 may be additionally cooled using the sixth heat exchanger 380 and supplied to the tank 360 again through the path 381 , and thereby may be supplied to the solid-liquid separator 260 .

[0100] The cooled vapor containing a small amount of polymer supplied to the tank 360 is substantially in liquid form, which can be supplied to the solid-liquid separator 260 through a path 361 .

[0101] Not only the cooled vapor containing a small amount of polymer supplied through the path 361, but also the solution containing a small amount of polymer separated from the liquid-liquid separator 240 is supplied to the solid-liquid separator 260. In this case, the solution containing a small amount of polymer separated from the liquid-liquid separator 240 is subjected to a cooling process using the third heat exchanger 250 and then supplied to the solid-liquid separator 260. The path for supplying the solution containing a small amount of polymer to the solid-liquid separator 260 corresponds to the paths 241-251.

[0102] In the solid-liquid separator 260, a process of separating a solution containing a small amount of polymer into a solvent (recovery solvent) that can be introduced into the reactor 200 and a solid containing the polymer is performed. In this case, the solid containing the polymer can be supplied to an extruder, a pelletizer, or a devolatilizer, and thereby produced as a final product.

[0103] Most of the solvent that can be introduced into the reactor 200 is supplied to the feed supply container 100, but a part of the solvent is reintroduced into the solid-liquid separator 260, and thus can be used in the process of adjusting the operating temperature of the solid-liquid separator 260. In this case, the path of the reintroduced solvent is the path 262-271-272, and in this process, the temperature of the solvent can be adjusted by the seventh heat exchanger 270, and whether to reintroduce the solvent can be regulated by a valve provided between the paths 271-272.

[0104] As described above, most of the solvent that can be introduced into the reactor 200 is supplied to the feed container 100 through the path 262 - 271 - 120 (recycling process), and even in this process, the temperature of the solvent can be adjusted by the seventh heat exchanger 270 .

[0105] The feed supply container 100 can supply the comonomer for the polymerization reaction in the reactor 200 through the path 140, and as described above, the feed supply container 100 can supply the solvent (recovery solvent) that can be introduced into the reactor 200 and a portion of the cooling vapor (unreacted monomer) containing a small amount of polymer through the paths 120 and 130, respectively. In addition, if necessary, the solvent can also be additionally supplied through the path 110. In addition, the path 111 corresponds to a ventilation / purging line.

[0106] Finally, the feed containing the solvent (recovery solvent) etc. that can be introduced into the reactor 200 in the feed supply container 100 is supplied to the reactor 200 by the feed pump 150 through the paths 151-161, and the above process is repeated. More specifically, the feed can be a mixture containing comonomers and solvents etc.

[0107] In this case, the comonomer used for the polymerization reaction may be additionally supplied through a separate path 141, and the feed may be cooled through the eighth heat exchanger 160. In this case, the additionally supplied comonomer is Figure 1 1 is shown as being supplied before the feed pump 150, but is not limited thereto, and may also be additionally supplied before and after the eighth heat exchanger 160. In addition, the eighth heat exchanger 160 may also be referred to as a feed cooler.

[0108] In addition, a polymerization catalyst may be introduced. Figure 1 The illustration of the part related to the introduction of the catalyst is omitted.

[0109] Figure 2 FIG. 1 is a block diagram showing a conventional continuous solution polymerization process, and a comparative example of the present invention is described based on the block diagram. Figure 2 In the case of Figure 1 In addition to the process using the liquid-liquid separator 240 and the solid-liquid separator 260, it is also possible to Figure 1 That is, the paths 210-211-231-232-241-251 and 210-211-231-232-242 are not used, and the product including the polymer produced by the polymerization reaction in the reactor 200 is transferred to the devolatilizer 340 through the path 210-212-311. In addition, it is applicable Figure 1 Description.

[0110] Example

[0111] The present application will be described in detail below with reference to the embodiments for specifically illustrating the present application. However, the embodiments according to the present application can be modified in various forms, and should not be interpreted as the scope of the present application being limited to the embodiments described in detail below. The embodiments of the present application are provided to more completely explain the present application to those of ordinary skill in the art.

[0112] Example 1

[0113] The conditions of the devolatilization and solid-liquid separator are assumed as follows (assumption conditions 1) to 5)), and the conditions shown in Table 1 below are applied to the above Figure 1 The continuous solution polymerization process (polymerization method) of the present invention shown was simulated using the Aspen Plus program (manufacturer: Aspen Technology Inc.) to simulate the process of making the final polymer product.

[0114] <Assumptions>

[0115] 1) Devolatilizer entrainment: 0.1 wt%

[0116] 2) Devolatilizer separation efficiency: polymer 70 wt%

[0117] 3) Solid-liquid separator hexane moisture content: 1 wt%

[0118] 4) Heat exchanger in front of the solid-liquid separator: Cooling is performed only at the reactor level and operates at a temperature and pressure equal to or higher than the melting point

[0119] 5) Polymer type: Polyolefin

[0120] In the hypothesis, entrainment refers to a phenomenon in which a liquid becomes small droplets and disperses into a gas or vapor and is carried by a gas flow, and is one of the elements that interfere with the process. "Devolatilizer entrainment: 0.1 wt%" means that a material corresponding to 0.1 wt% may experience the entrainment phenomenon based on the total amount of material (solution containing a large amount of polymer) introduced into the devolatilizer.

[0121] Furthermore, "devolatilizer separation efficiency: polymer 70 wt%" means that 70 wt% based on the total amount of the polymer contained in the solution is separated from a solution (first solution) containing a large amount of the polymer introduced into the devolatilizer.

[0122] The "solid-liquid separator hexane moisture content" refers to the hexane content contained in the solid component separated by the solid-liquid separator, and the hexane content is described as the solid-liquid separator hexane moisture content because the present polymer is assumed to be a polyolefin.

[0123] Finally, assumed case 4) corresponds to conditions for preventing fouling from occurring during operation.

[0124] Comparative Example 1

[0125] In Example 1, the conditions described in Table 1 below were applied to Figure 2 The conventional continuous solution polymerization process (polymerization method) in , except that, the production process of the final polymer product was simulated using Aspen Plus program (manufacturer: Aspen Technology Inc.) by applying the same assumptions as in Example 1.

[0126] Comparative Example 2

[0127] Without using a solid-liquid separator, dynamic simulation was performed under the same conditions as in Example 1. However, after starting the operation, as the temperature of the lean phase condensate in the liquid-liquid separator decreased, scaling occurred, and plugging occurred, thereby causing inability to operate.

[0128] [Table 1]

[0129]

[0130] The names of the conditions in Table 1 above can be used with routes and Figure 1 and Figure 2 The figures shown above are matched, and although not shown in the above Table 1, it is assumed that the pressure of the liquid-liquid separator 240 is 40 bar.

[0131] The number average molecular weight (Mn) and polymer polydispersity index (PDI) of the final products according to the simulation results of Examples 1 and 2 are shown in Table 2 below.

[0132] [Table 2]

[0133] Number average molecular weight (Mn, g / mol) Polydispersity Index (PDI) Example 1 94,645 1.84 Comparative Example 1 90,237 2.02

[0134] According to the results in Table 2 above, it can be confirmed that in Example 1, the number average molecular weight and polydispersity index of the polymer (polyolefin) corresponding to the final product are respectively greater than and less than those of Comparative Example 1. High PDI means that the molecular weight distribution of the polymer is broad and consists of molecules of different sizes, thus confirming that the number average molecular weight of Comparative Example 1 is less than that of Example 1.

[0135] In the process of extracting a low molecular weight polymer by a solid-liquid separator to produce a main product corresponding to a high molecular weight polymer, when a process using a liquid-liquid separator is included as in the continuous polymerization process according to the present application, it means that the efficiency can be further improved. For reference, the high molecular weight polymer can be expressed as having a low molecular weight distribution (MWD) or a low melt flow rate ratio (MFRR). In addition, it can be confirmed from the simulation results that the extraction of the low molecular weight polymer by a solid-liquid separator can prevent the scaling of the heat exchanger used in the recovery solvent supply process in Comparative Example 1 and the entire recovery process, thereby improving the operation stability and yield.

[0136] Furthermore, it was confirmed from the simulation results that the heating load in Example 1 was reduced by 15% and the cooling load was reduced by 11% compared to Comparative Example 1. That is, it was confirmed that the energy efficiency was high. By introducing the liquid-liquid separator, the temperature of the polymer solution state required for the devolatilizer can be lowered by first separating the solvent of the polymer solution, which is equivalent to the effect of saving as much heat as the latent heat generated in the process of condensing the steam.

[0137] That is, when the continuous solution polymerization process described in the present application is used to produce polymers, energy efficiency and process stability can be improved while increasing the yield of the desired product. In addition, as shown in Table 2 above, the physical properties (Mn, MWD) can also be adjusted according to the desired standards.

Claims

1. A continuous solution polymerization method, comprising: producing a product comprising a polymer subjected to a polymerization process in a reactor; supplying the product to a liquid-liquid separator (L / L separator); separating the supplied product into a first solution containing the polymer and a second solution containing the polymer in the liquid-liquid separator; supplying the first solution separated from the liquid-liquid separator to a devolatilizer; supplying the second solution separated from the liquid-liquid separator to a solid-liquid separator (S / L separator); separating the first solution into a vapor comprising the polymer and a liquid polymer in the devolatilizer; supplying the vapor containing the polymer separated from the devolatilizer to the solid-liquid separator (S / L separator); separating the supplied second solution and the vapor containing the polymer into a solvent capable of being introduced into the reactor and a solid containing the polymer in the solid-liquid separator; and introducing the solvent separated from the solid-liquid separator and capable of being introduced into the reactor into the reactor and recycling it, Wherein, the first solution and the second solution satisfy the following formula 1: [Formula 1] M a >M b In equation 1, M a refers to the content of the polymer in the first solution, and M b represents the content of the polymer in the second solution.

2. The continuous solution polymerization process according to claim 1, further comprising extruding the liquid polymer separated from the devolatilizer.

3. The continuous solution polymerization method according to claim 1, wherein The step of supplying the product to the liquid-liquid separator (L / L separator) comprises: heating the product using a first heat exchanger; reducing the pressure of the heated product using a first pressure reducing valve; and The heated and depressurized product is supplied to the liquid-liquid separator.

4. The continuous solution polymerization method according to claim 3, wherein The step of decompressing the heated product using the first pressure reducing valve reduces the pressure so that the pressure of the product becomes equal to or lower than the cloud point pressure.

5. The continuous solution polymerization method according to claim 1, wherein The step of supplying the first solution separated from the liquid-liquid separator to the devolatilizer comprises: heating the first solution using a second heat exchanger; Using a second pressure reducing valve to reduce the pressure of the heated first solution; and The heated and depressurized first solution is supplied to the devolatilizer.

6. The continuous solution polymerization method according to claim 5, wherein The step of heating the first solution using the second heat exchanger is performed at a temperature below the bubble point temperature of the first solution.

7. The continuous solution polymerization method according to claim 5, wherein The step of decompressing the heated first solution using the second pressure reducing valve reduces the pressure so that the pressure of the first solution becomes equal to or lower than the bubble point pressure.

8. The continuous solution polymerization method according to claim 1, wherein The step of supplying the second solution separated from the liquid-liquid separator to the solid-liquid separator (S / L separator) includes: cooling the second solution using a third heat exchanger; and The cooled second solution is supplied to the solid-liquid separator.

9. The continuous solution polymerization method according to claim 8, wherein The step of cooling the second solution using the third heat exchanger is performed at a temperature equal to or higher than the melting point of the second solution.

10. The continuous solution polymerization method according to claim 1, wherein The step of supplying the vapor containing the polymer separated from the devolatilizer to the solid-liquid separator (S / L separator) comprises: cooling the vapor comprising the polymer using a fourth heat exchanger; and The cooled vapor containing the polymer is supplied to the solid-liquid separator.

11. The continuous solution polymerization method according to claim 1, wherein The step of cooling the vapor containing the polymer using the fourth heat exchanger cools the vapor containing the polymer at a temperature equal to or higher than a melting point of the polymer and lower than a bubble point temperature of the vapor containing the polymer.

12. The continuous solution polymerization method according to claim 1, wherein The step of introducing the solvent separated from the solid-liquid separator and capable of being introduced into the reactor into the reactor and recycling it comprises a recycling system, the recycling system comprising: adjusting the solvent to a reaction temperature range of the continuous solution polymerization process using a fifth heat exchanger; and introducing the solvent into the reactor. 13 . The continuous solution polymerization method according to claim 1 , further comprising reintroducing into the solid-liquid separator a portion of the solvent separated from the solid-liquid separator and capable of being introduced into the reactor.

14. The continuous solution polymerization method according to claim 1, wherein The polymer is a polyolefin.

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