WO2012005519A2

WO2012005519A2 - Method for polymerizing alpha-olefins with utilizing three-phase system, using three-phase fluidized-bed reactor

Info

Publication number: WO2012005519A2
Application number: PCT/KR2011/004962
Authority: WO
Inventors: 강성우; 전용재; 김만중; 김길수
Original assignee: 대림산업 주식회사
Priority date: 2010-07-09
Filing date: 2011-07-07
Publication date: 2012-01-12
Also published as: WO2012005519A3; KR100999555B1

Abstract

Disclosed is a method for polymerizing alpha-olefins with utilizing a three-phase system, using a three-phase fluidized bed reactor, wherein alpha-olefins are efficiently and economically polymerized by agitating multiphase reaction media comprising solid, liquid and gas phases (three phases) with a three-phase fluidized bed reactor comprising an agitation means by bubbles. The method for polymerizing alpha-olefins utilizing the three-phase system is by agitating the bubbles in a gas stream comprising of one or more types of alpha-olefins and an inert gas, in the form of bubbles in a liquid stream comprising a catalyst which is a liquid hydrocarbon solvent and one or more types of alpha-olefins, to form multiphase (three phases of solid phase, liquid phase and gas phase) reaction media, and polymerizes the alpha-olefins into a polyolefin in the formed multiphase reaction media.

Description

Three-Phase Polymerization of Alpha-Olefin Using Three-Phase Fluidized Bed Reactor

The present invention relates to a three-phase polymerization method of alpha-olefin, and more particularly, by using a three-phase fluidized bed reactor including agitation means by bubbles, by shaking the solid, liquid and gas phase of the multi-phase (three-phase) reaction medium, A three-phase polymerization process of alpha-olefins using a three-phase fluidized bed reactor, which economically polymerizes alpha-olefins.

The slurry polymerization reactor used in the commercial slurry polymerization process may be a continuous tank reactor (CSTR) and a loop reactor. Philips has developed a slurry polymerization process using a loop reactor (US Pat. No. 4,121,029, etc.), and Mitsui et al. Have developed a slurry polymerization process using a CSTR. In general slurry polymerization reactors such as CSTR and loop reactors, agitation means for mixing a multiphase reaction medium is provided. The agitation means promotes dissolution of gaseous reaction medium ethylene, hydrogen, etc. in the liquid reaction medium, maintains the concentration of the reactants dissolved in the liquid reaction medium relatively uniformly, and maintains the concentration of the polymerizable olefin relatively. In order to maintain uniformity, the reaction medium is shaken. For example, a continuous stirred tank reactor (CSTR) uses mechanical shaking means to shake the reaction medium to be liquid phase polymerized. CSTRs comprising such mechanical agitation means can completely mix (shake) the reaction medium, but require relatively high equipment costs due to the need for expensive motors, fluid-sealed bearings and drive shafts and / or complex stirring mechanisms. It is not preferable to have a and to use alone. In addition, the rotating and / or vibrating mechanical components of the CSTR require regular maintenance and, due to the effort and downtime associated with the maintenance, increase the operating cost of the CSTR. Moreover, despite regular maintenance, mechanical shaking means (systems) used in CSTRs are prone to mechanical failure and may require replacement over a relatively short period of time.

Compared to slurry polymerization reactors (mechanical shaking polymerization reactors) using mechanical shaking means such as CSTR, three-phase fluidized bed reactors can shake the reaction medium without expensive and unreliable mechanical shaking means. The three-phase fluidized bed reactor includes an elongated, upright reaction zone into which the reaction medium is introduced, and by the natural buoyancy of the bubbles (gas phase reaction medium (gas stream) supplied to the bottom of the reaction zone) rising through the liquid reaction medium, The entire reaction medium in the reaction zone is shaken. Thus, the three-phase fluidized bed reactor does not have the equipment and maintenance costs associated with mechanical shake reactors, and less worry about machine failure.

It is an object of the present invention to provide a three-phase polymerization method of alpha-olefins, which eliminates the disadvantages of slurry polymerization using only conventional mechanical shaking means, and which is efficient and economical.

In order to achieve the above object, the present invention provides a gas stream comprising at least one alpha-olefin and an inert gas in the form of a bubble in a liquid stream comprising a catalyst, a liquid hydrocarbon solvent and at least one alpha-olefin. By forming a multi-phase (solid, liquid, gaseous three-phase) reaction medium by agitating the bubble, and in the formed multi-phase reaction medium, the alpha-olefin is polymerized to a polyolefin, to provide a three-phase polymerization method of alpha-olefin do.

Here, the three-phase polymerization method of the alpha-olefin, (a) feeding the liquid stream to the reaction zone (fluid bed) of the three-phase fluidized bed reactor; (b) feeding said gas stream to the bottom of said three phase fluidized bed reactor; (c) introducing the gas stream into a liquid stream of the reaction zone to form a multiphase (three phase) reaction medium and polymerizing the alpha-olefin into a polyolefin; And (d) discharging the resulting polyolefin polymer from the three phase fluidized bed reactor.

In the three-phase polymerization method of the alpha-olefin according to the present invention, since the turbulent mixing occurs between the catalyst and the reactant in the multiphase (three phase) reaction medium by bubble shaking, etc., the reaction rate is high, and a multiphase reaction medium is used. Even in the case of high fluid volume, the pressure drop is not severe and heat transfer is uniform through the entire reactor. In addition, the high liquid retention of the polyphase reaction medium acts as a heat sink, and if necessary, by recycling the reaction medium, it is easy to control the temperature of the polyphase reaction medium, and the liquid phase serves as a cushion of solid particles. Therefore, the wear of the resulting polyolefin particles is not severe. In addition, since the bubble shaking is mainly used, the overall equipment is simple and economically advantageous.

1 is a schematic diagram of a three-phase fluidized bed reactor to which a three-phase polymerization method of alpha-olefins according to one embodiment of the present invention can be applied.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

The three-phase polymerization process of alpha-olefins according to the invention comprises at least one alpha-olefin and an inert gas, having a bubble form, in a liquid stream comprising a catalyst, a liquid hydrocarbon solvent and at least one alpha-olefin. Bubble agitation of the gas stream to form a multiphase (solid, liquid, gaseous three phase) reaction medium, and polymerize the alpha-olefin into a polyolefin in the formed polyphase reaction medium, preferably in the bubble. Using a three-phase fluidized bed reactor comprising agitation means by: (a) feeding the liquid stream to the reaction zone (fluidized bed) of the three-phase fluidized bed reactor, (b) feeding the gas stream to the bottom of the three-phase fluidized bed reactor (C) introducing the gas stream into a liquid stream of the reaction zone to form a multiphase (three phase) reaction medium and - it is a step of polymerizing an olefin in the polyolefin, and (d) generating the polyolefin polymer may comprise the step of discharging from a three-phase fluidized bed reactor.

In the present invention, the three-phase fluidized bed reactor means a reactor capable of promoting a chemical reaction in a liquid phase of a multiphase (eg, three phase, solid, liquid, and gaseous phase) reaction medium, preferably, a multiphase reaction medium by shaking. In this case, the shaking refers to an operation of dispersing the reaction medium to flow and / or mix the fluid. Here, the shaking may be by bubble shaking, mechanical shaking, flow shaking, or the like. The bubble shaking refers to the shaking of the reaction medium caused by upward movement of the bubbles, and the mechanical shaking refers to the reaction caused by the physical movement of the rigid or flexible element (s) to or within the reaction medium. Means shaking of the medium. For example, the mechanical agitation can be provided by rotation, vibration and / or vibration of an internal stirrer, paddle, vibrator or acoustic reflector located within the reaction medium. The fluid shaking means shaking of the reaction medium caused by the high speed injection and / or recycle of one or more fluids in the reaction medium. For example, the flow shake can be provided by nozzles, ejectors and / or extractors. The three-phase fluidized bed reactor according to the present invention mainly promotes the chemical reaction of the multiphase reaction medium by using bubble shaking, for example, 5 to 60% of the shaking, preferably 20 to 50%, more preferably 30 to 50. % May be provided by mechanical shaking and / or flow shaking and the remainder may be provided by bubble shaking.

The liquid stream used in the present invention comprises a catalyst, a liquid hydrocarbon solvent and a mixture of one or more alpha-olefins and, if necessary, in separate inlets, the catalyst, liquid hydrocarbon solvent and one or more alpha-olefins. The mixture may be added separately to each other. As the catalyst, a conventional olefin polymerization catalyst can be used without limitation, for example, a chromium (Cr) catalyst, a Ziegler-Natta catalyst, a metallocene catalyst supported on silica (for example, (n-BuCp ) _₂ ZrCl ₂₎ it may be used, such as a metallocene catalyst, may be preferably used a metallocene catalyst. The liquid hydrocarbon solvent is a low vapor pressure hydrocarbon having high solubility in gaseous lower hydrocarbons. For example, a liquid hydrocarbon having 2 to 7 carbon atoms, preferably liquid ethane, propane, normal butane, and isobutane. Tertiary butane, pentane, hexane, heptane, more preferably propane, normal butane and isobutane. The alpha-olefin is a compound represented by CH ₂ = CHR, wherein R is hydrogen or a hydrocarbon radical having 1 to 12 carbon atoms, for example, ethylene, 1- Butene, 1-hexene, 1-octene, mixtures thereof and the like.

The gas stream used in the present invention comprises at least one alpha-olefin which is a reactant and an inert gas (dispersion medium), for example 50-90 mole% of the alpha-olefin, preferably 55-80 It may comprise mole%, more preferably 60 to 70 mole% and the remaining inert gas and is introduced at a flow rate that can form a bubble layer (gas bubble) through the liquid stream introduced into the reaction zone. The alpha-olefin may be the same as the alpha-olefin contained in the liquid stream, the inert gas, to prevent the melting of the polyolefin particles by rapid polymerization reaction around the inlet or gas bubble of the gas stream It serves as heat dilution of the multiphase reaction medium and as a diluent for gaseous reactants. The inert gas is, for example, selected from the group consisting of nitrogen and aliphatic hydrocarbons having 1 to 6 carbon atoms, preferably 2 to 6 carbon atoms, and may be used alone or in combination of two or more, preferably nitrogen, Ethane, propane, mixtures thereof, and the like, more preferably nitrogen, ethane, mixtures thereof, and the like. In the gas stream, if the content of the alpha-olefin is too low (if the content of inert gas is too high), the amount of inert gas dissolved in the liquid stream increases, so that the content of alpha-olefin dissolved in the liquid stream is increased. Decreases and the reaction activity is sharply lowered, which may lead to a decrease in production, and when the content of alpha-olefin is too high (the content of inert gas is too low), the polyolefin is produced by rapid polymerization at the inlet of the gas stream or around the gas bubble. Melt phenomenon of the particles may occur, there is a fear that the operation is stopped.

Injecting the gaseous stream in the form of bubbles into the liquid stream (including the solid catalyst) in the reaction zone forms a solid phase (catalyst), liquid and gaseous multiphase (three phase) reaction medium, and polymerizes the alpha-olefins. As the reaction proceeds, the resulting solid polyolefin polymer is produced, forming a solid phase (catalyst and polyolefin polymer), liquid and gaseous polyphase (three phase) reaction medium in the reaction zone. Here, the bubbles of the gas stream shake the polyphase reaction medium (bubble shake) to further promote the polymerization reaction of the alpha-olefin in the polyphase reaction medium (mainly in the liquid phase of the polyphase reaction medium), and to obtain a polyolefin polymer to obtain more efficiently. To form. Depending on the properties of the polyolefin polymer to be obtained (eg polymer density), the content of the alpha-olefin relative to the multiphase reaction medium is 1 to 20% by weight, preferably 3 to 15% by weight, More preferably, it is 5 to 15% by weight, the content of the catalyst may vary depending on the activity of the catalyst used, but 0.01 to 0.15 parts by weight, preferably 0.015 to 0.1 with respect to 100 parts by weight of the alpha-olefin. The amount of the inert gas may be 10 to 200 parts by weight, preferably 30 to 150 parts by weight, more preferably 50 to 120 parts by weight, based on 100 parts by weight of the alpha-olefin. The content of the polyolefin polymer (polyolefin polymer included in the polyphase reaction medium except the discharged polyolefin polymer (product)) is in 10 to 500 based on 100 parts by weight of the alpha-olefin. A portion, preferably from 50 to 450 parts by weight, more preferably from 100 to 300 parts by weight, the remainder being hydrocarbon solvent in the liquid phase.

If the content of the alpha-olefin is less than 1% by weight, the amount of polyolefins produced is not economical, and if the content of the alpha-olefin is more than 20% by weight, the amount of the unreacted alpha-olefin that does not dissolve in the liquid phase of the polyphase reaction medium and passes through the reaction zone is As the amount increases, the pressure of the reactor overhead (separation zone) increases rapidly, and there is a concern that the energy loss of the compressor that introduces the gas stream increases due to an increase in the gas stream passing through without polymerization by dissolving in the liquid stream. When the content of the catalyst is less than 0.01 part by weight, the productivity is lowered due to low catalyst activity, which is not economical. When the content of the catalyst is less than 0.01 part by weight, excessive heat of reaction (polymerization heat) is generated. , Heat removal of the reactor by an inert gas, etc., is impossible, and there is a fear that a polyolefin in the form of agglomerate is produced. If the content of the gaseous gas is less than 10 parts by weight, solid polyolefin may be deposited around a hole (inlet) through which the gas stream is introduced into the liquid stream, which may make it difficult to introduce a uniform bubble gas stream. If the weight part is exceeded, the alpha-olefin in the gas stream may not be dissolved in the liquid phase of the polyphase reaction medium, thereby decreasing the content of the alpha-olefin in the liquid phase and lowering the yield of the polyolefin polymer. If less than parts, the residence time of the polyolefin polymer is shortened, productivity is not economical, and if it is more than 500 parts by weight, a part of the polyolefin reaction medium may be free of motion due to friction between the solid polyolefin polymer and the reactor wall. This may cause reactor fouling, which may cause the operation to stop. There is.

In the three-phase polymerization process of alpha-olefins according to the present invention, the polymerization reaction of the alpha-olefin takes place mainly in the liquid phase of the polyphase reaction medium, and the liquid phase of the polyphase reaction medium is the liquid hydrocarbon solvent of the liquid stream and the alpha-olefin dissolved in the solvent. And inert gases. However, the liquid hydrocarbon solvent (e.g., propane, isobutane) is partially boiled / vaporized due to the exothermic properties of the polymerization reaction, and the gas phase of the polyphase reaction medium is a vaporized solvent, an inert gas (e.g., a gas stream). For example, it consists of unresolved, unreacted portions of nitrogen, ethane) and alpha-olefins. Therefore, the three-phase polymerization method of the alpha-olefin according to the present invention, in order to prevent excessive vaporization of the polyphase reaction medium by the heat of polymerization, and to maintain the liquid content of the polyphase reaction medium in which the polymerization reaction takes place, the step (c) and ( Between steps d), (e) may further comprise the step of discharging and cooling a part of the multiphase (three phase) reaction medium from the top of the reaction zone to remove the heat of polymerization, and then recycle to the bottom of the reaction zone. In this case, the polyphase reaction medium is formed by the liquid stream, the gas stream, the solid polyolefin polymer and the recycled stream (polyphase reaction medium) from which the heat of polymerization is removed.

1 is a schematic diagram of a three-phase fluidized bed reactor to which the three-phase polymerization method of alpha-olefin according to an embodiment of the present invention can be applied. As shown in FIG. 1, the three-phase fluidized bed reactor 100 according to an embodiment of the present invention is connected to the reaction zone 110 and the reactor bottom 130 by a gas dispersion plate (sparger) 120. At the top of the reaction zone 110, there is a separation zone 140 for collecting the unreacted gas stream passing through the reaction zone (fluid bed 110). Also, a liquid stream inlet 112 for supplying the liquid stream to the reaction zone 110, a gas stream inlet 132 for supplying the gas stream to the reactor bottom 130, and the separation zone 140. A gas outlet (not shown) for discharging the collected unreacted gas stream to the outside of the reactor, a polyolefin outlet (not shown) for discharging the produced polyolefin polymer, and the like. , The double pipe 200, the double pipe discharge part 210, the double pipe introduction part 220, and a recirculation pump 300 may be further included. Here, the double pipe 200 is a conventional concentric double pipe (inner pipe and outer pipe), the reaction medium is circulated to the inner pipe of the double pipe 200, the cooling water (heating water when heated through the outer (inlet) pipe) ) Is circulated to maximize the heat transfer area.

The reaction zone (fluid layer 110) is a liquid stream supplied from the liquid stream inlet 112 and a gas stream supplied from the gas stream inlet 132 and converted into a small bubble form by the gas dispersion plate 120. Etc., a space in which a polyphase reaction medium is formed, in which a polyphase reaction medium is shaken (bubble shaken) by a gas stream in the form of a bubble, in which a polymerization reaction of an alpha-olefin occurs. Typically, the reaction zone 110 may have a cylindrical shape, and the L / D value obtained by dividing the height L of the reaction zone 110 by the diameter D is maintained at 4 to 10, preferably 5 to 9. do. If the L / D value is out of the above range, the residence time of the gas stream in the reaction zone cannot be sufficiently secured, and there is a fear that the alpha-olefin of the gas stream cannot be sufficiently dissolved in the liquid phase of the multiphase dispersion medium.

The gas dispersion plate 120 is to disperse the gas stream supplied to the reactor bottom 130 in the form of bubbles, and may have various forms capable of dispersing the gas stream into bubbles having a uniform and sufficiently small size. Specifically, they may have various shapes such as perforated plates, bubble caps or nozzles, sparsers, conical grids, and pierced sheet grids. Can be.

The reactor bottom 130 is a space in which a gas stream is supplied first, and the pressure of the reactor bottom 130 by the gas stream supplied is controlled by the reaction zone so that the multiphase reaction medium does not flow from the reaction zone 110. 110) 0.5 to 1.0 bar, preferably 0.7 to 0.95 bar, more preferably 0.8 to 0.9 bar higher than the pressure of the bottom.

The separation zone 140 is a space for collecting the unreacted and undissolved gas stream passing through the reaction zone 110, that is, the multiphase reaction medium, and the upper portion of the reaction zone 110 (the curved line in FIG. 1). Polyphase reaction medium). In the separation zone 140, polyolefin microparticles and droplets entrained due to breakage of bubbles in the reaction zone 110, which are included in the unreacted and undissolved gas stream, may be removed, The gas stream from which the microparticles and droplets have been removed may be discharged through a gas outlet (not shown), and then purified in a refining apparatus (not shown) and fed back to the reactor bottom 130. In order to remove the polyolefin microparticles and droplets, the diameter of the separation zone 140 may be designed to be 1.5 to 3 times, preferably 1.7 to 2 times the diameter of the reaction zone 110, wherein the separation zone The height of the 140 may be 2 to 5 times, preferably 2.5 to 3 times the diameter of the reactor (reaction zone 110). In addition, the separation zone 140 is designed such that the gas flow rate in the separation zone 140 is lower than the particle termination speed so that the polyolefin fine particles and the droplets can return to the reaction zone 110 by gravity. If the diameter size of the separation zone 140 exceeds three times the diameter size of the reaction zone 110, there is a fear that the energy of the compressor (compressor) for supplying the gas stream is excessively necessary, less than 1.5 times , The flow rates of the entrained polyolefin microparticles and droplets are maintained above the particle end velocity, so that they do not drop into the reaction zone 110 by gravity and the polyolefin microparticles and droplets cannot be removed from the unreacted (undissolved) gas stream. There is concern.

Conventional slurry polymerization reactors use a jacket-type reactor or install a heat exchange coil in the reactor to heat or cool the reaction medium. However, this type of heat exchange is not preferred for the three phase fluidized bed reactor and the three phase polymerization process according to the present invention. Therefore, in the three-phase polymerization method of the present invention, heat removal such as heat of polymerization of the multiphase reaction medium is performed by removing and cooling a part of the polyphase reaction medium from the upper portion of the reaction zone 110 to remove the heat of polymerization, and then the reaction zone. A method of recycling to the bottom of 110 is used. The discharge and recirculation of the multiphase reaction medium is preferably by a loop reactor structure, that is, a part of the polyphase reaction medium is supplied from the double pipe discharge part 210 using the recirculation pump 300. Heat may be removed from the double tube 200 using a method of removing heat such as polymerization heat and recycling the cooled polyphase reaction medium to the double tube introduction unit 220. At this time, the heat removal in the double pipe 200, a method of maximizing the heat transfer area by circulating the cooling water (heating water when heated) through the external input pipe of the double pipe (200). In addition, the three-phase polymerization method of the present invention can increase the heat removal efficiency by using the latent heat of evaporation of the multiphase reaction medium by the inert gas of the gas stream.

The position, size, and the like of the polyolefin outlet (not shown) for discharging a portion of the polyolefin generated in the three-phase fluidized bed reactor 100 may be adjusted as needed, and, for example, the reaction zone of the reactor 100 ( 110 may be formed at the bottom or the lower portion of the double pipe 200 located between the recirculation pump 300 and the double pipe introduction portion 220.

In order to polymerize the alpha-olefin in the three-phase fluidized bed reactor 100, it may vary depending on the properties of the polyolefin polymer (for example, polymer density) to be obtained, for example, the temperature of the polyphase reaction medium is 30 to 250 C, preferably 50 to 150 ° C., more preferably 50 to 120 ° C., and the overhead pressure (separation zone 140 pressure) on the multiphase reaction medium is from 1 to 100 bar, preferably It is preferable to keep it at 10 to 60 bar, more preferably 15 to 45 bar. Further, the pressure difference between the top of the multiphase reaction medium (top of the reaction zone 110) and the bottom of the multiphase reaction medium (bottom of the reaction zone 110) is 0.4 to 5 bar, preferably 0.7 to 3 bar, more preferably 1 to 2, it is preferable that the bottom pressure of the multiphase reaction medium is maintained higher than the top pressure. The overhead pressure on the multiphase reaction medium is typically preferably maintained at a relatively constant value.

Since the polyolefin produced in the three-phase fluidized bed reactor according to the present invention uses a multiphase reaction medium and bubble shaking, it has less physical external force by an impeller or stirrer than the conventional slurry reactor using only mechanical shaking means. It is possible to produce polyolefin products of lower density (eg 0.910 to 0.920) than polyolefins produced by conventional slurry reactors.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are intended to illustrate the invention, and the invention is not limited by the following examples.

[Examples 1-3] Three-Phase Polymerization of Alpha-olefins

₂ ZrCl ₂ metallocene catalyst (n-BuCp) supported on silica (ES70Y, manufactured by INEOS silica) using the three-phase fluidized bed reactor 100 shown in FIG. 1, ethylene and 1-hexene as alpha-olefins, and A three-phase copolymerization of alpha-olefins was carried out by feeding a liquid stream comprising liquid isobutane as solvent and a gas stream comprising ethylene and 1-hexene as alpha-olefins and ethane as inert gas. Here, the feed and residence time of the catalyst were adjusted to obtain the desired polymerization yield (polymer g per g solid catalyst component), and the flow rate of the recycled multiphase reaction medium was maintained at a residence time of 5 minutes. Other reaction conditions are shown in Table 1 below.

Table 1

In the polymerization production of low-density polyethylene using the three-phase polymerization method of the alpha-olefin according to the present invention, it is possible to increase the solid phase content in the polyphase reaction medium to obtain high productivity (g / g of polymer per g solid catalyst component per unit time).

The three-phase polymerization method of alpha-olefins according to the present invention is useful for preparing polyolefin polymers using solid, liquid and gaseous multiphase (three phase) reaction media.

Claims

The gaseous stream comprising at least one alpha-olefin and an inert gas, in the form of bubbles, in a liquid stream comprising a catalyst, a liquid hydrocarbon solvent and at least one alpha-olefin, is subjected to bubble agitation, thereby producing a multiphase (solid, liquid, Gas phase three-phase) reaction medium, and in the formed polyphase reaction medium, the alpha-olefin is polymerized to polyolefin,

The three-phase polymerization process of alpha-olefins comprises: (a) feeding the liquid stream to a reaction zone (fluid bed) of a three phase fluidized bed reactor; (b) feeding said gas stream to the bottom of said three phase fluidized bed reactor; (c) introducing the gas stream into a liquid stream of the reaction zone to form a multiphase (three phase) reaction medium and polymerizing the alpha-olefin into a polyolefin; And (d) withdrawing the resulting polyolefin polymer from the three phase fluidized bed reactor,

The three-phase fluidized bed reactor is partitioned into a reaction zone and a bottom of the reactor by a gas dispersion plate, and at the top of the reaction zone includes a separation zone for collecting the unreacted gas stream passing through the reaction zone. Three phase polymerization method.
The method of claim 1, wherein the catalyst is selected from the group consisting of chromium (Cr) catalyst, Ziegler-Natta catalyst and metallocene catalyst, the liquid hydrocarbon solvent is a liquid hydrocarbon having 2 to 7 carbon atoms, the alpha- The olefin is a compound represented by CH 2 = CHR, wherein R is hydrogen or a hydrocarbon radical of 1 to 12 carbon atoms, wherein the inert gas is selected from the group consisting of nitrogen and aliphatic hydrocarbons of 2 to 6 carbon atoms. 3-phase polymerization of olefins.
The method of claim 1, wherein the inert gas is selected from the group consisting of nitrogen, ethane, propane and mixtures thereof.
The method of claim 1, wherein the alpha-olefin is selected from the group consisting of ethylene, 1-butene, 1-hexene, 1-octene and mixtures thereof.
The process according to claim 1, wherein, between steps (c) and (d), (e) discharging and cooling a part of the polyphase reaction medium from the top of the reaction zone to remove heat of polymerization, and then to the bottom of the reaction zone. The method for three-phase polymerization of alpha-olefins further comprising the step of recycling.
The method of claim 5, wherein the discharge and recycle of the multiphase reaction medium is by a loop reactor structure.