Equipment for the preparation of polyolefin elastomers

Abstract

The present invention relates to an apparatus for preparing a polyolefin elastomer. The apparatus for preparing a polyolefin elastomer according to the present invention may include: a reactor to which a solvent and a raw material are supplied; a primary devolatilizer, which devolatilizes a product discharged from the reactor to remove unreacted materials (primary devolatilization recovery stream) and discharges the remaining portion thereof (primary devolatilization preparation stream); a secondary devolatilizer, which re-devolatilizes the primary devolatilization preparation stream discharged from the primary devolatilizer to further remove unreacted materials (secondary devolatilization recovery stream) and discharges the remaining portion thereof (secondary devolatilization preparation stream); a finisher, which washes the secondary devolatilization preparation stream discharged from the secondary devolatilizer with water so that unreacted materials and water are vaporized and a polymer product is left; and a flash tank, which removes low molecular weight materials (impurity removal stream) in the primary devolatilization recovery stream removed from the primary devolatilizer and recovers the remaining portion to the reactor.

Description

Technical Field

[0001] The present invention relates to an apparatus for preparing a polyolefin elastomer, and more particularly, to a process for recovering a solvent and unreacted materials in the apparatus for preparing a polyolefin elastomer. Background Art

[0002] Polyolefin elastomer (POE) is a copolymer of ethylene and α-olefin with low density among polyolefin-based products, and exhibits properties such as differentiated impact reinforcement, high elasticity, and low heat-sealing temperature, and is therefore used in automotive interior and exterior materials, sound insulation materials, footwear products, food films, packaging materials, etc.

[0003] In order to prepare POE as described above, metallocene catalysts are mainly used, and in addition, research has been conducted to improve the yield or efficiency of the POE preparation process by developing Ziegler-Natta based catalysts or by expanding the plant, but there is still room for improvement in the cost of raw materials and process operations and the efficiency of using raw materials.

[0004] During the preparation of POE, the separation process of the solvent and the unreacted material is mainly composed of two devolatilizers and a finisher (or extruder), and although the solvent and the unreacted material are vaporized and discharged by temperature increase and pressure reduction in the process, the largest amount of the solvent and the unreacted material are separated and discharged in the first primary devolatilizer, which has a higher pressure in the above process and shows a high component of materials with relatively low boiling points (such as ethylene). In addition, by stripping, in which vaporized water is discharged together with residual hydrocarbon gas, the final residue is discharged from the finisher together with water, and the residue is introduced in the recovery process by being included in the recycling stream after removing water.

[0005] Generally, POE is mainly prepared from 1-octene or 1-butene, and is mainly prepared by alternating the two feeds. That is, in the POE preparation process, it is necessary to consider the situation when 1-butene is injected instead of 1-octene.

[0006] In addition, as a solvent used in the above-mentioned POE process, high-purity n-hexane or high-purity methylcyclohexane is used. Typically, there are problems in that since the entire stream discharged from the first primary devolatilizer is recovered, light materials having a low molecular weight and thus a low boiling point and a high vapor pressure (such as ethane contained in ethylene) are concentrated, since n-hexane is separated from the upper end of the primary distillation column in the primary distillation column, a large amount of energy is consumed, since 1-octene is separated from the upper end of the tertiary distillation column, a large amount of energy is consumed, and materials having a boiling point lower than 1-octene and higher than n-hexane contained in the raw material as a solvent cannot be removed. Summary of the invention

[0007] Technical issues

[0008] An object of the present invention is to provide a solvent recovery unit (SRU) for solving the above-mentioned problems occurring in a typical POE production process, the SRU being capable of improving the recovery rate of ethylene as an unreacted monomer and 1-octene or 1-butene as an unreacted comonomer and minimizing the energy used in the process while not using 99% or higher purity n-hexane as a solvent but using a mixture of materials having no double bonds among hydrocarbon compounds having 5 to 7 carbon atoms so as not to affect the reaction and having a boiling point in the range of 60 to 100° C. at atmospheric pressure (hereinafter referred to as C6 compounds, such as a mixture having an n-hexane content of 63% by weight).

[0009] Technical Solution

[0010] The apparatus for preparing a polyolefin elastomer according to the present invention may include an apparatus for preparing a polyolefin elastomer, wherein the apparatus includes a reactor to which a solvent and a raw material are supplied, a primary devolatilizer, which devolatilizes a product discharged from the reactor to remove unreacted materials (primary devolatilization recovery stream) and discharges the remaining portion thereof (primary devolatilization preparation stream), and a secondary devolatilizer, which re-devolatilizes the primary devolatilization preparation stream discharged from the primary devolatilizer to further remove unreacted materials (secondary devolatilization recovery stream) and discharges the remaining portion thereof ( a secondary devolatilization preparation stream), a finisher which uses water to strip the secondary devolatilization preparation stream discharged from the secondary devolatilizer so that unreacted materials and water are vaporized and a polymer product is left, a water removal process in which water in the unreacted materials and water removed from the finisher are removed and the remainder (a finisher reaction process stream) is discharged; and a primary distillation column which distills the secondary devolatilization recycle stream removed from the secondary devolatilizer and the finisher reaction process stream discharged from the water removal process so as to recover the stream separated therefrom to the reactor.

[0011] In addition, the middle portion of the primary distillation column (17) may be a point corresponding to 10% to 50% from the upper end of the primary distillation column (17).

[0012] In addition, the apparatus may further include a flash tank for removing low molecular weight materials (impurity removal stream) from the primary devolatilizer recovery stream removed from the primary devolatilizer and recycling the remainder to the reactor, and a secondary distillation tower for distilling the impurity removal stream removed from the flash tank and a stream separated from an upper portion of the primary distillation tower to recycling the stream separated from a lower portion thereof to the reactor.

[0013] Furthermore, the feedstock may include a material with a boiling point lower than the boiling points of ethylene and the solvent.

[0014] Additionally, the feedstock may include 1-butene.

[0015] Furthermore, the mass flow rate of the stream separated from the upper portion of the primary distillation column may be maintained at most 9 times the mass flow rate of the stream separated from the middle portion of the primary distillation column.

[0016] Furthermore, the stream separated from the upper portion of the primary distillation column may be maintained at 35 to 140° C. and 2 to 10 bar.

[0017] In addition, the apparatus may further include a tertiary distillation column which distills the stream separated from the lower portion of the primary distillation column to recover the stream separated therefrom to the reactor.

[0018] Furthermore, the middle portion of the three-stage distillation column may be a point corresponding to 30 to 70% from the upper end of the three-stage distillation column.

[0019] Furthermore, the feedstock may include a material with a boiling point higher than the boiling points of ethylene and the solvent.

[0020] Additionally, the feedstock may include 1-octene.

[0021] In addition, the solvent may include a mixture containing a material having no double bond in a hydrocarbon compound having 5 to 7 carbon atoms and having a boiling point of 60 to 100° C. at atmospheric pressure.

[0022] Beneficial Effects

[0023] As described above, the process for recovering solvent and unreacted materials in an apparatus for preparing polyolefin elastomer according to the present invention is intended to improve the method for recovering solvent and unreacted materials in a typical POE process, wherein

[0024] (1) When the unreacted material discharged from the primary devolatilizer is recovered, a step of removing the material having a high vapor pressure and a low boiling point is added, thereby preventing the concentration of the material,

[0025] (2) separating C6 compounds from the middle of the primary distillation column, thereby reducing the energy loss of the entire POE process, and

[0026] (3) Both impurities having a boiling point lower than 1-octene and impurities having a boiling point higher than 1-octene can be removed from the recycle stream by a three-stage distillation column, which is a distillation column for 1-octene. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a polyolefin elastomer production apparatus according to an embodiment of the present invention.

[0028] Figure 2is a schematic diagram of a polyolefin elastomer preparation apparatus according to another embodiment of the present invention.

[0029] Figure 3 is a schematic diagram of a polyolefin elastomer preparation apparatus according to a comparative example of the present invention. DETAILED DESCRIPTION

[0030] Referring to the accompanying drawings, a polyolefin elastomer production apparatus ( 10 , 10 ′) according to an embodiment of the present invention will be described in detail.

[0031] Figure 1 is a schematic diagram of a polyolefin elastomer production apparatus (10) according to an embodiment of the present invention.

[0032] The polyolefin elastomer production apparatus (10) according to an embodiment of the present invention is used to produce ethylene-butene rubber (EBR), see Figure 1 The polyolefin elastomer preparation equipment (10) comprises a reactor (11), a primary devolatilizer (12), a secondary devolatilizer (13), a post-condensation device (14), a water removal process (15) including a gas-liquid separator and an adsorption tower, a flash tank (16), a primary distillation tower (17) and a secondary distillation tower (18).

[0033] Reactor (11) receives solvent and raw material to produce polymer reactant. Here, solvent can include the mixture of material without double bond in hydrocarbon compound, and this hydrocarbon compound has 5 to 7 carbon atoms so that reaction is not affected, and has the boiling point of 60 to 100 ℃ under atmospheric pressure, for example, this mixture can include normal hexane, more specifically about 63 to 71.2 weight % normal hexane, about 0.016 to 0.63 weight % cyclohexane, about 6 to 28.7 weight % methylcyclopentane, about 0.57 to 5.7 weight % 2-methylpentane, about 5.4 to 22.3 weight % 3-methylpentane etc. In addition, for example, raw material can include ethylene and the material with boiling point lower than ethylene and solvent, for example, 1-butene.

[0034] The primary devolatilizer (12) devolatilizes the product discharged from the reactor (11) (i.e., the polymerization reactant and the solvent, monomer, comonomer, etc. as unreacted materials) to remove the unreacted materials. Hereinafter, the stream (102) as the unreacted materials removed from the primary devolatilizer (12) is referred to as the 'primary devolatilization circulation stream (102)', and the stream (103) as the remainder thereof discharged from the primary devolatilizer (12) is referred to as the 'primary devolatilization preparation stream (103)'.

[0035] The secondary devolatilizer (13) re-devolatilizes the primary devolatilizer preparation stream (103) discharged from the primary devolatilizer (12) to further remove unreacted materials. Hereinafter, the stream (104) as the unreacted materials removed from the secondary devolatilizer (13) is referred to as the 'secondary devolatilization circulation stream (104)', and the stream (105) as the remaining part thereof discharged from the secondary devolatilizer (13) is referred to as the 'secondary devolatilization preparation stream (105)'. Generally, the secondary devolatilization preparation stream (105) may contain, for example, about 90 to 95% by weight of polymer and other unreacted materials.

[0036] The finisher (14) strips the secondary devolatilization preparation stream (105) discharged from the secondary devolatilizer (13) with water. As a result, unreacted materials and water in the secondary devolatilization preparation stream (105) are vaporized, and finally a polymer product is left.

[0037] The water removal process (15) removes water in the stream (106) removed as unreacted material and water from the finisher (14). Hereinafter, for ease of description, the resulting stream (107) is referred to as 'finisher reaction treated stream (107)'.

[0038] The reactor (11), the primary devolatilizer (12), the secondary devolatilizer (13), the finisher (14) and the water removal process (15) themselves are substantially the same as those known in the art or can be easily obtained by those skilled in the art, so further description thereof will be omitted.

[0039] The flash tank (16) removes low molecular weight materials (more specifically, containing ethane) having a relatively low boiling point and a high vapor pressure from the primary devolatilization circulation stream (102) removed from the primary devolatilizer (12). Hereinafter, the stream (108) as the low molecular weight materials containing ethane removed from the flash tank (16) is referred to as 'impurity removal stream (108)'. Meanwhile, the flash tank (16) recovers the stream (109) as the remainder thereof discharged from the flash tank (16) to the reactor (11).

[0040] The primary distillation tower (17) distills the secondary devolatilization circulation stream (104) discharged from the secondary devolatilizer (13) and the finisher reaction treatment stream (107) discharged from the water removal process (15) to recover the stream (110) separated from the middle thereof (more specifically, containing n-hexane) to the reactor (11), and discharges the stream (111) separated from the lower portion thereof as a heavy substance to the outside. Here, the middle portion of the primary distillation tower (17) may be, for example, a point corresponding to about 30% to 70% from the upper end thereof. In addition, the mass flow rate of the stream (112) separated from the upper portion of the primary distillation tower (17) (more specifically, including C6 compounds and 1-butene) may be maintained at least 0.1 times and at most 9 times the mass flow rate of the stream (110) separated from the middle portion of the primary distillation tower (17). Preferably, the stream (112) separated from the upper portion of the primary distillation column (17) may be maintained at 35 to 140° C. and 2 to 10 bar. Particularly preferably, the stream (112) separated from the upper portion of the primary distillation column (17) may be maintained at, for example, about 50° C. Here, when the temperature rises to 50° C. or higher, n-hexane is separated from the upper portion, thereby consuming more energy, and when the temperature is equal to or lower than 50° C., it is necessary to use a refrigerant other than cooling water, so that there may be an increase in cost, but since the basic function of the equipment is not impaired, changing the temperature does not harm the present invention.

[0041] The secondary distillation column (18) distills the impurity-removed stream (108) removed from the flash tank (16) and the stream (112) separated from the upper portion of the primary distillation column (17) to recover the stream (113) separated from the lower portion thereof (more specifically, comprising C6 compounds and 1-butene) to the reactor (11), and discharges the stream (114) separated from the upper portion thereof as ethylene and 1-butene purge to the outside.

[0042] In the polyolefin elastomer production apparatus according to an embodiment of the present invention, the temperature, pressure, and flow rate for each stream may be as shown in the following Table 1 (Example 1).

[0043] [Table 1]

[0044] Stream Symbols temperature pressure Flow rate 101 -18.4℃ 90 bar 240 tons / hour 102 169℃ 9.6 bar 182 tons / hour 104 180℃ 3 bar 14.6 tons / hour 106 200℃ 50 pallets 7.1 tons / hour 107 45℃ 4.5 bar 3 to 3.6 tons / hour 108 94 to 102°C 9.1 bar 0.9 to 1.7 tons / hour 110 96℃ 2.2 bar 14.8 tons / hour 112 50℃ 2 bar 3 tons / hour 113 155℃ 8.4 bar 3.1 to 3.5 tons / hour 114 50℃ 8 bar 0.7 to 1.2 tons / hour 115 -14.2℃ 90 bar 18 tons / hour

[0045] Figure 2 is a schematic diagram of a polyolefin elastomer preparation apparatus (10') according to another embodiment of the present invention.

[0046] The polyolefin elastomer preparation apparatus according to another embodiment of the present invention is used to prepare ethylene-octene rubber (EOR), see Figure 2The polyolefin elastomer preparation equipment comprises a reactor (11'), a primary devolatilizer (12'), a secondary devolatilizer (13'), a post-condensation device (14'), a water removal process (15'), a flash tank (16'), a primary distillation tower (17'), a secondary distillation tower (18') and a tertiary distillation tower (19').

[0047] Reactor (11 ') receives solvent and raw material to produce polymer reactant. Here, solvent can include the mixture of material without double bond in hydrocarbon compound, and this hydrocarbon compound has 5 to 7 carbon atoms so that reaction is not affected, and has the boiling point of 60 to 100 ℃ under atmospheric pressure, for example, this mixture can include normal hexane, more specifically about 63 to 71.2 weight % normal hexane, about 0.016 to 0.63 weight % cyclohexane, about 6 to 28.7 weight % methylcyclopentane, about 0.57 to 5.7 weight % 2-methylpentane, about 5.4 to 22.3 weight % 3-methylpentane etc. In addition, for example, raw material can include ethylene and the material with boiling point higher than ethylene and solvent, for example 1-octene.

[0048] The primary devolatilizer (12'), the secondary devolatilizer (13'), the finisher (14'), the water removal process (15') and the flash tank (16') are substantially the same as those of the polyolefin elastomer production apparatus (10) according to an embodiment of the present invention, or are expected to be naturally changed by those skilled in the art according to the difference in EBR / EOR ​​characteristics, and thus a repeated description thereof will be omitted.

[0049] The primary distillation tower (17') distills the secondary devolatilization circulation stream (104') discharged from the secondary devolatilizer (13') and the finisher reaction treatment stream (107') discharged from the water removal process (15') to recover the stream (110') separated therefrom (more specifically, containing hexane) to the reactor (11'). Here, for example, the middle of the primary distillation tower (17') may be a point corresponding to about 10 to 50% from the upper end thereof. In addition, the mass flow rate of the stream (112') separated from the upper portion of the primary distillation tower (17') may be maintained at least 0.1 times and at most 9 times the mass flow rate of the stream (110') separated from the middle portion of the primary distillation tower (17'). Preferably, the stream (112') separated from the upper portion of the primary distillation tower (17') may be maintained at 35 to 80° C. and 5 to 10 bar. Particularly preferably, for example, the stream (112') separated from the upper portion of the primary distillation column (17') may be maintained at about 50° C. Here, when the temperature rises to 50° C. or higher, n-hexane is separated from the upper portion, thereby consuming more energy, and when the temperature is equal to or lower than 50° C., it is necessary to use a refrigerant other than cooling water, so that there may be an increase in cost, but since the basic function of the equipment is not impaired, changing the temperature does not harm the present invention.

[0050] The secondary distillation column (18') distills the impurity-removed stream (108') removed from the flash tank (16') and the stream (112') separated from the upper portion of the primary distillation column (17') to recover the stream (113') separated from the lower portion thereof (more specifically, containing C6 compounds) to the reactor (11'), and discharges the stream (114') separated from the upper portion thereof as ethylene purge to the outside.

[0051] The tertiary distillation column (19') distills the stream (111') separated from the lower portion of the primary distillation column (17') to recover the stream (116') separated therefrom (more specifically, containing 1-octene) to the reactor (11'), and discharges the stream (117') separated from the lower portion thereof as a heavy substance and the stream (118') separated from the upper portion thereof as a purge to the outside. Here, for example, the middle portion of the tertiary distillation column (19') may be a point corresponding to about 30 to 70% from the upper end thereof.

[0052] In the polyolefin elastomer production apparatus (10') according to another embodiment of the present invention, the temperature, pressure and flow rate for each stream may be as shown in the following Table 2 (Example 2).

[0053] [Table 2]

[0054] Stream Symbols temperature pressure Flow rate 101 -18.5℃ 90 bar 240 tons / hour 102 180℃ 9.6 bar 182 tons / hour 104 200℃ 3 bar 13.6 to 14.3 tons / hour 106 200℃ 50 pallets 7 to 7.6 tons / hour 107 45℃ 4.5 bar 3 to 3.6 tons / hour 108 50 to 70°C 9.1 bar 0.07 to 0.08 ton / hour 110 95℃ 2.1 bar 9.8 to 11.4 t / h 111 152℃ 2.2 bar 2.4 to 4.9 t / h 112 50℃ 2 bar 2.6 to 3.4 tons / hour 113 154℃ 8.4 bar 2.5 to 3.2 tons / hour 114 92 to 106°C 8 bar 0.2 to 0.3 ton / hour 115 -14℃ 90 bar 12.2 to 14.6 t / h 116 -15℃ 90 bar 2.1 to 4.7 tons / hour 117 161℃ 2.7 bar 0.2 to 1.5 tons / hour 118 157℃ 2.5 bar 0.15t / h

[0055] Figure 3 is a schematic diagram of a polyolefin elastomer preparation apparatus (10") according to a comparative example of the present invention.

[0056] The polyolefin elastomer preparation apparatus according to the comparative example of the present invention is used to prepare ethylene-octene rubber (EOR), see Figure 3 The polyolefin elastomer preparation equipment includes a reactor (11"), a primary devolatilizer (12"), a secondary devolatilizer (13"), a post-condensation reactor (14"), a water removal process (15"), a primary distillation tower (17"), a secondary distillation tower (18") and a tertiary distillation tower (19").

[0057] The polyolefin elastomer production apparatus (10") according to the comparative example of the present invention is different from the polyolefin elastomer production apparatus (10') according to another embodiment of the present invention in that the flash tank (16') is omitted, so that the primary devolatilization circulation stream (102") is recovered to the reactor (11") as it is.

[0058] Furthermore, there is a difference in that, in the polyolefin elastomer producing apparatus (10') according to another embodiment of the present invention, the stream (112') separated from the upper portion of the primary distillation tower (17') includes a part of the C6 compounds, and the stream (116') separated therefrom includes the remaining part of the C6 compounds, while in the polyolefin elastomer producing apparatus (10") according to the comparative example of the present invention, the stream (112") separated from the upper portion of the primary distillation tower (17"), in other words, the stream (112") injected into the secondary distillation tower (18") includes all of the C6 compounds. Here, the temperature of the stream (112") separated from the upper portion of the primary distillation tower (17") may be, for example, about 70 to 150°C.

[0059] Furthermore, the polyolefin elastomer production apparatus (10") according to the comparative example of the present invention is different in that a stream (118") (more specifically, containing 1-octene) separated from the upper portion of the tertiary distillation column (19") is recovered to the reactor (11").

[0060] Other matters are substantially the same as those of the polyolefin elastomer producing apparatus ( 10 ′) according to another embodiment of the present invention, or are expected to be naturally changed by those skilled in the art according to the differences, and thus detailed descriptions thereof will be omitted.

[0061] In the polyolefin elastomer production apparatus (10") according to the comparative example of the present invention, the temperature, pressure and flow rate for each stream may be as shown in the following Table 3 (Comparative Example).

[0062] [Table 3]

[0063] Stream Symbols temperature pressure Flow rate 101" -18.5℃ 90 bar 240 tons / hour 102" 182℃ 9.6 bar 182 tons / hour 104" 200℃ 3 bar 13.8 to 14.4 t / h 106" 200℃ 50 pallets 6.9 to 7.6 tons / hour 107" 45℃ 4.5 bar 2.9 to 3.6 tons / hour 111" 150℃ 2.2 bar 2.6 to 5.1 tons / hour 112" 91℃ 2 bar 12.3 to 14.7 tons / hour 113" -14℃ 90 bar 11.6 to 14 tons / hour 114" 131℃ 8 bar 0.7 to 0.8 ton / hour 117" 161℃ 2.7 bar 0.2 to 1.3 tons / hour

[0064] For the above-mentioned comparative example and Example 2, when the sum of the contents of the solvent (n-hexane), the monomer (ethylene) and the comonomer (1-octene) is set to be the same, the sum of the replenishment amounts of the raw materials of the distillation towers (17', 18', 19'; and 17", 18", 19") and the sum of the heat loads are compared. Here, the replenishment amount of the raw materials refers to the amount of raw materials consumed by synthesizing the polymer product from the amount of raw materials to be replenished to the reactor (11'; 11") in order to drive the corresponding process under a stable state, in addition to the amount of raw materials recycled to the reactor (11'; 11").

[0065] [Table 4]

[0066] Comparative Example

[0067]

[0068] [Table 5]

[0069] (Example 2)

[0070]

[0071] Tables 4 and 5 show the mass balance as the result of ASPENPLUS simulation when 1-octene is 15 wt%, 24 wt% and 35 wt%, respectively. At this time, as a basic example, the total of the contents of the solvent, monomer and comonomer in the streams (101') and (101") injected into the reactors (11') and (11") is set to 92.2 wt%.

[0072] In the comparative example, the entire amount of n-hexane was recovered through the upper portion of the primary distillation column (17"), whereas in Example 2, n-hexane was recovered through the middle portion of the primary distillation column (17'), and thus it has been confirmed that the solvent and unreacted materials can be recovered more efficiently (this is the same as in Example 1).

[0073] Furthermore, in Comparative Example, 1-octene was extracted through the upper portion of the tertiary distillation column (19"), and thus it was impossible to remove impurities (methylcyclohexane, etc.) having a boiling point higher than that of n-hexane and a boiling point lower than that of 1-octene. However, in Example 2, 1-octene was extracted through the middle portion of the tertiary distillation column (19'), and thus it was possible to remove impurities having a boiling point lower than that of 1-octene through the upper portion of the tertiary distillation column (19').

[0074] Furthermore, in the comparative example, the primary devolatilization circulation stream (102") removed from the primary devolatilizer (12") is recovered to the reactor (11") as it is, so that when a material having a very low boiling point, such as ethane, is concentrated, it is impossible to remove the material, and since n-hexane is separated through the upper end of the primary distillation column (17"), more energy is consumed. In contrast, in Example 2, when the unreacted material discharged from the primary devolatilizer (12') is recovered, the concentration of the above-mentioned material can be prevented by removing the material having a low boiling point, and separation of C6 compounds through the middle part of the primary distillation column (17') can also reduce energy consumption (this is also the same for Example 1). In addition, both impurities having a boiling point lower than 1-octene and impurities having a boiling point higher than 1-octene are removed through the tertiary distillation column (19'), so that process efficiency can be improved.

[0075] The above-mentioned polyolefin elastomer preparation processes (10) and (10') are only one example of the polyolefin elastomer preparation process according to various embodiments of the present invention. The technical spirit of the present invention is not limited to the above-mentioned embodiments, and as described in the claims, the technical spirit of the present invention includes all ranges that can be easily changed by those skilled in the art to which the present invention belongs.

[0076] Description of the symbol

[0077] 10, 10', 10": Preparation process of polyolefin elastomers

[0078] 11, 11', 11": Reactor

[0079] 12, 12', 12": Primary Devolatilizer

[0080] 13, 13', 13": Secondary devolatilizer

[0081] 14, 14', 14": Finisher

[0082] 15, 15', 15": Water removal process

[0083] 16, 16': Flash tank

[0084] 17, 17', 17": Primary distillation column

[0085] 18, 18', 18": Secondary distillation column

[0086] 19', 19": Three-stage distillation column

Claims

1. A device for preparing a polyolefin elastomer, the device comprising: a reactor to which a solvent and a raw material are supplied; a primary devolatilizer that devolatilizes the product discharged from the reactor to remove unreacted material, i.e., a primary devolatilization recovery stream, and discharges the remainder thereof, i.e., a primary devolatilization preparation stream; a secondary devolatilizer for re-devolatilizing the primary devolatilization preparation stream discharged from the primary devolatilizer to further remove unreacted materials, i.e., a secondary devolatilization recovery stream, and discharging the remaining portion thereof, i.e., a secondary devolatilization preparation stream; a finisher that washes the secondary devolatilization preparation stream discharged from the secondary devolatilizer with water to vaporize unreacted materials and water and leave behind a polymer product; a water removal process in which water in the unreacted material and water removed from the finisher are removed and the remainder, i.e., a finisher reaction process stream, is discharged; and a primary distillation column which distills a secondary devolatilization recycle stream removed from the secondary devolatilizer and the finisher reaction process stream discharged from the water removal process so as to recycle a stream separated therefrom to the reactor; a flash tank which removes low molecular weight materials, i.e., an impurity removal stream, from the primary devolatilization recovery stream removed from the primary devolatilizer and recycles the remainder to the reactor; and A secondary distillation column distills the impurity-removed stream removed from the flash tank and a stream separated from an upper portion of the primary distillation column to recover a stream separated from a lower portion thereof to the reactor. 2 . The apparatus according to claim 1 , wherein the middle portion of the primary distillation column is a point corresponding to 10 to 50% from an upper end of the primary distillation column.

3. The apparatus according to claim 1, wherein the feedstock comprises a material having double or triple bonds among hydrocarbons having a boiling point lower than the boiling points of ethylene and the solvent, and thus capable of forming a polymer by copolymerization with the ethylene.

4. The apparatus of claim 1, wherein the feedstock comprises 1-butene.

5. The apparatus according to claim 1, wherein the mass flow rate of the stream separated from the upper portion of the primary distillation column is maintained at least 0.1 times and at most 9 times the mass flow rate of the stream separated from the middle portion of the primary distillation column.

6. The apparatus according to claim 1, wherein the stream separated from the upper portion of the primary distillation column is maintained at 35 to 140°C and 2 to 10 bar.

7. The apparatus according to claim 1, further comprising a tertiary distillation column which distills the stream separated from the lower portion of the primary distillation column to recover the stream separated from the upper or middle portion thereof to the reactor. 8 . The apparatus according to claim 7 , wherein the middle portion of the three-stage distillation column is a point corresponding to 30 to 70% from an upper end of the three-stage distillation column.

9. The apparatus according to claim 7, wherein the feedstock includes a material having double bonds or triple bonds among hydrocarbons having a boiling point higher than that of the solvent, and thus capable of forming a polymer by copolymerization with ethylene.

10. The apparatus of claim 7, wherein the feedstock comprises 1-octene.

11. The apparatus according to claim 1, wherein the solvent comprises a mixture containing a material having no double bond in a hydrocarbon compound having 5 to 7 carbon atoms and having a boiling point of 60 to 100°C at atmospheric pressure.

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