CN1310969C - Polymerizing method for olefine - Google Patents

Abstract

The invention provides a method for the polymerization of olefin CH ₂ =CHR, wherein R is hydrogen or an alkyl group, cycloalkyl group or aryl group containing 1-12 carbon atoms, the method comprises the presence of a catalyst and under polymerization reaction conditions, The CH ₂ =CHR polymerization reaction is carried out in a series gas-phase fluidized bed polymerization reaction zone, characterized in that the series gas-phase fluidized bed polymerization reaction zone includes at least one slow fluidized reaction zone and at least A fast fluidized reaction zone, the polymer or mixture generated in the slow fluidized reaction zone is continuously or intermittently sent to the connected fast fluidized reaction zone, the fluidization of the fast fluidized reaction zone and the slow fluidized reaction zone The speed ratio is 2-50.

Description

A kind of polymerization method of olefin

technical field

The present invention relates to a polymerization process for the preparation of _CH2 =CHR olefin polymers, wherein R is hydrogen or an alkyl, cycloalkyl or aryl group containing 1-12 carbon atoms, the process comprising at least two fluidization speeds Olefin polymers with broad molecular weight distribution can be prepared in different polymerization reaction zones.

technical background

It is well known that olefin polymers or copolymers with wide molecular weight distribution (MWD) can be obtained by controlling each reactor or reaction zone to carry out polymerization reaction under different polymerization conditions in multiple reactors or multiple reaction zones in series. Different methods can be used to control the molecular weight of each reactor or reaction zone, such as by appropriately selecting the polymerization conditions, changing the nature or concentration of the catalyst, the type and concentration of the monomers to be polymerized, the concentration of the molecular weight regulator, and the form of the polymerization reaction wait.

The known method is usually in two or more polymerization reactors in series, the catalyst is continuously introduced into the first reactor, after the polymerization reaction, the polymer enters the second reactor, and the formed polymer is discharged from the reaction outside the device. In each reactor, the molecular weight is controlled by a molecular weight regulator such as hydrogen. In this type of polymerization process, the problem generally encountered is that due to the long process flow, the transfer of polymer between different reactors is complicated and the residence time is long, which will cause the loss of catalyst activity.

It has now been found that a new gas phase polymerization process for the preparation of polymers or copolymers of olefin CH ₂ =CHR, by controlling the fluidization velocity in different reaction zones (or in different reactors) in the same reactor, And by selecting suitable polymerization conditions according to different fluidization speeds, the purpose of producing polyolefin resins with a wider molecular weight distribution can be achieved, and the polymerization method has a short process flow and low production costs.

Contents of the invention

A method for the polymerization of olefin CH ₂ =CHR, wherein R is hydrogen or an alkyl group, cycloalkyl group or aryl group containing 1-12 carbon atoms. The polymerization reaction of CH ₂ =CHR is carried out in the gas-phase fluidized-bed polymerization reaction zone, and it is characterized in that, the gas-phase fluidized-bed polymerization reaction zone in series comprises at least one slow fluidized reaction zone and at least one fast fluidized reaction zone In the reaction zone, the polymer or mixture generated in the slow fluidization reaction zone is continuously or intermittently sent to the connected fast fluidization reaction zone, and the ratio of the fluidization velocity of the fast fluidization reaction zone to the slow fluidization reaction zone is 2~50.

In the polymerization method of the present invention, the gas phase polymerization reaction of olefin CH ₂ =CHR is carried out in at least two interconnected fluidized bed reaction zones with different fluidization velocities. Usually the slow fluidized reaction zone (first reaction zone) is in front, and the fast fluidized reaction zone (second reaction zone) is behind. The catalyst is introduced at the front end of the first reaction zone. Under the slow fluidization state, all or most of the generated polymer particles flow through the reaction zone, and enter the second reaction zone after flowing out. Under the action of gravity and rapid fluidization The resulting polymer is discharged continuously or intermittently. The fluidization velocity ratio of the fast fluidization reaction zone and the slow fluidization reaction zone is 2-50, preferably 3-20. Generally, the superficial gas velocity of the gas in the slow fluidization zone ranges from 0.01 to 0.3m/s.

In the polymerization method of the present invention, the slow fluidized reaction zone (the first reaction zone) both can be positioned at the inside of the fast fluidized reaction zone (the second reaction zone), also can be positioned at the rapid fluidized reaction zone (the second reaction zone) ) outside.

In the slow fluidized reaction zone, a gas mixture is continuously introduced from below the polymer bed by means of a gas distributor, the gas mixture generally comprising polymerizable monomers, molecular weight regulator (hydrogen) and optionally inert gas. In the first reaction zone, the polymer-containing mixture is wholly or mostly drawn from above the polymerization zone (or polymer bed) and introduced into the second polymerization zone by gravity or gas flow. At least 75% of the total amount of catalyst is introduced into the slow fluidized reaction zone, and the adding position of various catalyst components is preferably introduced in any place of the slow fluidized reaction zone, more preferably in the slow fluidized reaction zone (the first reaction zone ) is introduced at the front end (bottom end), and a small amount of catalyst can also be added anywhere in the fast fluidized reaction zone (second reaction zone).

The polymer and gas mixture flowing from the first reaction zone flows entirely into the second reaction zone either continuously or intermittently. The mixed gas containing freshly polymerized monomers can be introduced at any position in the second reaction zone, and a small amount of catalyst can also be introduced. The unreacted gas mixture in the second polymerization reaction zone is separated from the entrained solid in the upper expansion section of the reactor, and the gas flows out of the reactor for external circulation. The gas mixture exiting the reactor is cooled by a heat exchanger and then returned to the reactor after cooling. Usually the gas mixture is cooled to a temperature below the dew point in the heat exchanger, wherein the condensate is returned to the slow fluidized reaction zone and/or the fast fluidized reaction zone, and all non-condensable gases are returned to the bottom of the fast fluidized reaction zone. The polymer produced in the second reaction zone is discharged continuously or intermittently.

In the polymerization method of the present invention, the working pressure of the gas-phase fluidized bed polymerization reaction zone is 0.5～10MPa, preferably 1.5～6MPa, wherein the pressure of the slow fluidized reaction zone should be slightly higher than the fast fluidized reaction zone, and the pressure balance is determined by the material The flow resistance is self-controlled.

Due to different polymerization stages, catalysts exhibit different polymerization kinetics. In the initial stage of the reaction, the activity of the catalyst is higher, and more polymers can be obtained in a shorter time. Therefore, in the polymerization method of the present invention, since the residence time in the first reaction zone (slow fluidization reaction zone) can be shorter, and the polymer particles are also smaller in the initial stage of the reaction, the first reaction zone can be designed Smaller, in the reaction zone, the polymerized monomer contacts with the catalyst to undergo a polymerization reaction, and the heat of reaction is removed by external heat removal or condensate volatilization, and the entire reaction section can be similar to a plug-flow reactor. The superficial gas velocity of the gas in the fluidized reaction zone can be controlled within the range of 0.01-0.3 m/s, preferably 0.05-0.2. All or most of the mixture containing the polymer is drawn from the top of the first polymerization reaction zone (or polymer bed) and then enters the second reaction zone for further polymerization. Due to the decrease in the reaction rate, the reaction kinetics tends to be relaxed, and the reaction The device can be designed larger. The gas superficial gas velocity in this fluidized reaction zone is 2 to 50 times that of the slow fluidized zone, preferably 3 to 20 times, generally controlled at 0.1 to 1.0m/s, and only by circulating gas Most of the heat can be withdrawn.

Any type of catalyst used in the polymerization of olefins can be used in the polymerization process of the present invention. For example, a large number of titanium, chromium, vanadium or zirconium based catalysts disclosed in the prior art can be used in supported or unsupported form. Specific examples of available catalysts of this type are disclosed in Chinese patents CN85100997A, CN1258680A, CN1258683A, CN1258684A, CN1091748A, CN1330086A, CN1268520A, CN1491618A, CN1463991A. The catalyst can be used directly or added after prepolymerization.

In the slow fluidized reaction zone and the fast fluidized reaction zone described in the polymerization method of the present invention, it is favorable to keep one or more inert gases, and the amount kept is preferably such that the sum of the partial pressures of various inert gases is 5-80% of the total gas pressure. The inert gas may be nitrogen or paraffin containing 2-6 carbon atoms, preferably propane.

In order to obtain a polymer with a wide molecular weight distribution or a bimodal distribution, different gas compositions can be controlled in the two reaction zones, such as controlling the concentration ratio of different molecular weight modifiers to polymerized monomers in the two reaction zones to broaden the obtained Polymer molecular weight distribution. When preparing the impact copolymer, the concentration of different comonomers can be controlled in different polymerization reaction zones, so that the impact copolymer (rubber phase) can be very well dispersed in the matrix phase.

In the polymerization method of the present invention, the polymerization temperature is 0-150°C, preferably 40-100°C.

Detailed ways

The present invention will be further described by referring to two specific embodiments of the present invention with reference to the accompanying drawings, which are only for explaining but not limiting the present invention.

Specific implementation 1

Figure 1 Polymerization reaction device with slow fluidized bed inside fast fluidized bed

As shown in Figure 1, at least two reaction zones are included in a multi-zone fluidized bed reactor, a first reaction zone (1) and a second reaction zone (2), and the first reaction zone is a diameter relatively Small barrel-shaped fluidized bed reactor, its top can have expansion section or without expansion section, the bottom is a straight barrel section, and the bottom of the straight barrel section is a gas feed distributor (12); the second reaction The zone is a cylindrical fluidized bed reactor with a larger diameter, with an enlarged section (3) on the upper part, a polymer discharge system (14) in the straight barrel section, and a gas circulation distributor in the lower part of the second reaction zone (13);

The first reaction zone is located inside the second reaction zone, and the first reaction zone is directly opened in the expansion section of the second reaction zone.

The first reaction zone is equipped with gas feeding means (10), which is located somewhere below the gas distribution means (12). The catalyst is added to a certain position in the upper straight barrel section of the distribution device (12) through the feeding device (9).

Wherein the enlarged section at the upper end of the first reaction zone (1) is an inverted cone or vertical cylindrical shape, and the upper end of the enlarged section is completely open.

The top of the second reaction zone (2) is provided with a gas mixture circulation pipeline (4), which connects the compressor (7), the cooling system (8) and the system (5) for introducing the monomer and the system (5) for introducing the molecular weight regulator system (6).

Specific implementation 2

Figure 2 Polymerization reaction device with slow fluidized bed outside the fast fluidized bed

As shown in Fig. 2, it comprises first reactor (1) and second reactor (2), and described first reactor is the cylinder shape fluidized-bed reactor that a diameter is less, and its top is enlarged section, the bottom is a straight barrel section, and the bottom of the straight barrel section is a gas feed distributor (12); the second reactor is a larger diameter cylindrical fluidized bed reactor, and its top is a The expansion section (3), the lower part is a straight barrel section, a polymer discharge system (14) is installed in a certain part of the straight barrel section, and a gas circulation distributor (13) is installed in the lower part of the second reactor;

The first reactor is located outside the second reactor, and the expansion section of the first reactor is connected with the expansion section of the second reactor through a pipeline.

As in Fig. 1, the first reactor is equipped with gas feeding means (10), which is located somewhere below the gas distribution means (12). A catalyst feeding device (9) is connected to a certain position on the upper part of the gas distribution device (12) through a pipeline (11).

The top of the second reactor (2) is provided with a gas mixture circulation pipeline (4), which connects the compressor (7), the cooling system (8) and the system (5) for introducing the monomer and the system (5) for introducing the molecular weight regulator system (6).

In Fig. 1 and Fig. 2, preferably, the inclination angle of the expansion section of the first reaction zone is 0-60°, and the inclination angle of the expansion section of the second reaction zone is 5-25°.

The diameter ratio of the straight barrel section in the first reaction zone to the straight barrel section in the second reaction zone is 1/10˜1/2.

The diameter ratio of the straight barrel section and the expanding section in the first reaction zone and the second reaction zone is 1/3˜1/1.

The aspect ratio of the straight barrel section in the first reaction zone is 1/20-1/5.

The aspect ratio of the straight barrel section in the second reaction zone is 1/10-1/2.

The preparation of embodiment 1 bimodal polyethylene

The polymerization device shown in Figure 3 and the polymerization process flow shown in Figure 4 were used.

The polymerization reaction device is shown in Figure 3. The slow fluidized bed (first reaction zone, small fluidized bed) is located inside the fast fluidized bed (second reaction zone, large fluidized bed), the diameter of the small fluidized bed is 100mm, and the height of the straight barrel section is 1300mm. The small fluidized bed is directly opened to the enlarged section on the upper part of the large fluidized bed. There is an outwardly expanded inclination at the opening, the angle is 11°, and the height of the enlarged section is 100mm. The diameter of the large fluidized bed is 350mm, the height of the straight barrel section is 1000mm, the inclination angle of the enlarged section of the large fluidized bed is also 11°, and the height of the enlarged section is 900mm. The height of the settling section is 700mm, and the height of the settling section is 100mm. On the upper part of the settling section is a 1/2 elliptical head with a hole in the center of the head, through which the unreacted monomer circulates to cool the heat exchanger.

The polymerization process flow is shown in Figure 4. The catalyst is added from above the gas distributor in the lower part of the small fluidized bed. The catalyst is the BCG catalyst developed by Beijing Research Institute of Chemical Industry of China Petroleum & Chemical Corporation and produced by Beijing Aoda Petrochemical New Technology Development Center. The batch number of the catalyst used in this example is BCG- 04-01. The catalyst is added as a dry powder. Fresh reaction monomers are added to the gas mixing chamber at the lower part of the small fluidized bed distributor, and the addition ratio of polymerized monomers, molecular weight modifiers and comonomers is adjusted according to different products. The concentration of each component is measured by online gas chromatography, and the reaction gas The composition is shown in Table 1. The reaction gas enters the reaction section (small fluidized bed) through the gas distributor, and the polymerization reaction occurs in contact with the catalyst in the reaction section. The small fluidized bed is fluidized at a slow speed, the gas superficial velocity is controlled at 0.09m/s, the polymerization temperature is controlled at about 80°C, and the polymerization pressure is 2.35MPa. The polymerization reaction is relatively violent, and the heat of polymerization reaction is mainly removed by liquid volatilization. The liquid used for heat removal is directly sprayed into the reaction section (straight barrel section) of the small fluidized bed. In order to disperse the polymer-reaction gas-coolant evenly, a stirring can be added in the reaction section. The rotational speed is 15 rev/min. The unreacted monomer and cooling liquid volatile gas enter the large fluidized bed to participate in the circulation, and the movement of the polymer in the small fluidized bed is similar to a plug-flow reactor or a series connection of several fully mixed tanks. After a period of reaction, they polymerize The material enters the large fluidized bed.

The polymer, unreacted monomer and fresh monomer from the small fluidized bed are mixed in the large fluidized bed (the second reaction zone) to continue the reaction. In order to obtain bimodal or broadly distributed polyethylene, the gas in the two reaction zones is controlled Composition is different, in the present embodiment the material ratio of small fluidized bed (first reaction zone) is hydrogen/ethylene/butene mol ratio equals 0.86/100/32.3, and large fluidized bed (second reaction zone) material ratio hydrogen/ The ethylene/butene molar ratio is equal to 19.1/100/26.6. The large fluidized bed (the second reaction zone) is a fast fluidized zone, the gas superficial gas velocity range is 0.61m/s, and the polymerization reaction heat is mainly removed by the circulating gas. In order to maintain the bed temperature, a large amount of gas must be involved in the circulation to remove heat, the polymerization temperature is controlled at 85°C, and the reaction pressure is slightly lower than that of the small fluidized bed, which is 2.34MPa. The unreacted monomer and the gas from the small fluidized bed The volatile gas of the cooling liquid flows out of the large fluidized bed and enters the cooling heat exchanger. The condensed part is pumped back to the small fluidized bed to remove heat, and the uncondensed part of the gas is returned to the large fluidized bed through a circulating fan to circulate and remove heat.

The material ratio of the small fluidized bed (the first reaction zone): the molar ratio of hydrogen/ethylene/butene is 0.86/100/32.3, the gas superficial velocity is controlled at 0.09m/s, the polymerization temperature is controlled at 80°C, and the polymerization pressure is 2.35MPa.

The material ratio of the large fluidized bed (the second reaction zone): the molar ratio of hydrogen/ethylene/butene is 19.1/100/26.6, the gas superficial velocity is controlled at 0.61m/s, the polymerization temperature is controlled at 85°C, and the polymerization pressure is 2.34MPa.

By controlling the residence time ratio of the two reaction zones, the polymer obtained in the small fluidized bed (the first reaction zone) accounts for about 10% of the total yield, and the polymer obtained in the large fluidized bed (the second reaction zone) The polymer accounted for 90% of the total yield, and the molecular weight distribution of the obtained polyethylene was Mw/Mn=11.06.

Table 1 small fluidized bed large fluidized bed reactor: Fluidized bed diameter (mm) 100 350 Height of fluidized section (mm) 1300 1000 Height of expansion section(mm) 100 900 Angle of expansion section (°) 11 11 Height of settlement section (mm) - 100 Settlement section diameter (mm) - 700 Large/small fluidized bed position relationship The small fluidized bed is located inside the large fluidized bed Internals with stirring - Polymerization Conditions: Reactor temperature (°C) 80 85 Reactor pressure (MPa) 2.35 2.34 Stirring speed (rpm) 15 - Reactor superficial gas velocity (m/s) 0.09 0.61 Amount of liquid in gas stream (wt%) 29.5 6.5 Fluidized bulk density (kg/m ³ ) 355.5 307.5 Productivity (kg/hr) 0.5 4.5 Gas composition in the reactor: Ethylene (mol%) 46.5 32.0 Butene-1(mol%) 15.0 8.5 Hydrogen (mol%) 0.4 6.1 Nitrogen (mol%) 19.4 43.2 Propane (mol%) 18.5 10.0 Ethane (mol%) 0.2 0.2 Methane (mol%) - - Polymerization product characteristics: Melt index (g/10min) 1.90 Resin density (kg/m ³ ) 918.0 Average particle size (mm) 1.05 Bulk density(kg/m ³ ) 411.7

The preparation of embodiment 2 impact polypropylene

Same as Example 1, using the polymerization device shown in Figure 3 and the polymerization process flow shown in Figure 4.

The catalyst is an N-type catalyst developed by Beijing Research Institute of Chemical Industry, China Petroleum & Chemical Corporation, and produced by Beijing Aoda Petrochemical New Technology Development Center. The batch number of the catalyst used in this example is N-C-01-13. For the catalyst production method, see patent CN85100997A. The catalyst is first mixed with white oil into a certain proportion of paste, wherein the catalyst content is 30wt%, and the catalyst paste is injected into the catalyst feed port by a screw metering pump, and is entrained by a certain amount of liquid propylene into the reactor. Others are the same as in Example 1, and the reaction conditions and polymer characteristics are shown in Table 2.

The material ratio of the small fluidized bed (the first reaction zone): the molar ratio of hydrogen/ethylene/propylene is 0.61/0.12/100, the gas superficial velocity is controlled at 0.08m/s, the polymerization temperature is controlled at 66°C, and the polymerization pressure is 2.31 MPa.

The material ratio of the large fluidized bed (second reaction zone): the molar ratio of hydrogen/ethylene/propylene is 6.2/14.4/100, the gas superficial velocity is controlled at 0.59m/s, the polymerization temperature is controlled at 70°C, and the polymerization pressure is 2.30 MPa.

By controlling the residence time ratio of the two reaction zones, the polymer obtained in the small fluidized bed (the first reaction zone) accounts for about 19% of the total yield, and the polymer obtained in the large fluidized bed (the second reaction zone) The polymer accounted for 81% of the total yield, and the ethylene content in the obtained polymer was 9.1 wt%.

Table 2 small fluidized bed large fluidized bed reactor: Fluidized bed diameter (mm) 100 350 Height of fluidized section (mm) 1300 1000 Height of expansion section(mm) 100 900 Angle of expansion section (°) 11 11 Height of settlement section (mm) - 100 Settlement section diameter (mm) - 700 Large/small fluidized bed position relationship The small fluidized bed is located inside the large fluidized bed Internals with stirring - Polymerization Conditions: Reactor temperature (°C) 66 70 Reactor pressure (MPa) 2.31 2.30 Stirring speed (rpm) 15 - Reactor superficial gas velocity (m/s) 0.08 0.59 Amount of liquid in gas stream (wt%) 85 15 Fluidized bulk density (kg/m ³ ) 375 310 Productivity (kg/hr) 2.0 8.5 Gas composition in the reactor: Ethylene (mol%) 0.1 10.3 Propylene (mol%) 86.6 71.4 Propane (mol%) 10.0 10.7 Hydrogen (mol%) 0.53 4.4 Nitrogen (mol%) 2.77 3.2 Polymerization product characteristics: Melt index (g/10min) 1.65 Ethylene content (wt%) 9.1 Average particle size (mm) 0.816 Bulk density(kg/m ³ ) 430.5

The preparation of embodiment 3 bimodal polyethylene

Using the polymerization device shown in Figure 5 and the polymerization process flow shown in Figure 6, other polymerization conditions and the obtained polymer results are shown in Table 3.

The catalyst is the BCG catalyst developed by the Beijing Research Institute of Chemical Industry of China Petrochemical Corporation and produced by the Beijing Aoda Petrochemical New Technology Development Center. The batch number of the catalyst used in this example is BCG-04-01. The catalyst is added as a dry powder. Others are the same as in Example 1, and the reaction conditions and polymer characteristics are shown in Table 3.

The material ratio of the small fluidized bed (the first reaction zone): the molar ratio of hydrogen/ethylene/butene is 0.89/100/30.9, the gas superficial velocity is controlled at 0.10m/s, the polymerization temperature is controlled at 80°C, and the polymerization pressure is 2.35MPa.

The material ratio of the large fluidized bed (the second reaction zone): the molar ratio of hydrogen/ethylene/butene is 19/100/29.4, the gas superficial velocity is controlled at 0.65m/s, the polymerization temperature is controlled at 85°C, and the polymerization pressure is 2.34MPa.

By controlling the residence time ratio of the two reaction zones, the polymer obtained in the small fluidized bed (the first reaction zone) accounts for about 17% of the total yield, and the polymer obtained in the large fluidized bed (the second reaction zone) The polymer accounted for 83% of the total yield, and the molecular weight distribution of the obtained polyethylene was Mw/Mn=15.4.

table 3 small fluidized bed large fluidized bed reactor: Fluidized bed diameter (mm) 100 350 Height of fluidized section (mm) 1300 1000 Height of expansion section(mm) 100 900 Angle of expansion section (°) 11 11 Height of settlement section (mm) - 100 Settlement section diameter (mm) - 700 Large/small fluidized bed position relationship The small fluidized bed is located outside the large fluidized bed Internals with stirring - Polymerization Conditions: Reactor temperature (°C) 80 85 Reactor pressure (MPa) 2.35 2.34 Stirring speed (rpm) 15 - Reactor superficial gas velocity (m/s) 0.10 0.65 Amount of liquid in gas stream (wt%) 28.4 6.3 Fluidized bulk density (kg/m ³ ) 350.0 304.5 Productivity (kg/hr) 0.9 4.5 Gas composition in the reactor: Ethylene (mol%) 47.0 31.0 Butene-1(mol%) 14.5 9.1 Hydrogen (mol%) 0.42 5.9 Nitrogen (mol%) 19.0 42.9 Propane (mol%) 18.9 10.9 Ethane (mol%) 0.2 0.2 Methane (mol%) - - Polymerization product characteristics: Melt index (g/10min) 2.10 Resin density (kg/m ³ ) 917.5 Average particle size (mm) 1.06 Bulk density(kg/m ³ ) 412.5

The preparation of embodiment 4 impact polypropylene

Same as Example 3, using the polymerization device shown in Figure 5 and the polymerization process flow shown in Figure 6, other polymerization conditions and the results of the obtained polymer are shown in Table 4.

The catalyst is the DQ catalyst developed by Beijing Research Institute of Chemical Industry of China Petroleum & Chemical Corporation and produced by Beijing Aoda Petrochemical New Technology Development Center. The batch number of the catalyst used in this example is DQ-03-85. The production method of the catalyst can be found in patent CN1330086A. Catalyst preparation and injection method are the same as in Example 2, and the reaction conditions and polymer characteristics are shown in Table 4.

The material ratio of the small fluidized bed (the first reaction zone): the molar ratio of hydrogen/ethylene/propylene is 0.59/0.12/100, the gas superficial velocity is controlled at 0.09m/s, the polymerization temperature is controlled at 67°C, and the polymerization pressure is 2.31 MPa.

The material ratio of the large fluidized bed (the second reaction zone): the molar ratio of hydrogen/ethylene/propylene is 6.5/16.3/100, the gas superficial velocity is controlled at 0.62m/s, the polymerization temperature is controlled at 70°C, and the polymerization pressure is 2.30 MPa.

By controlling the residence time ratio of the two reaction zones, the polymer obtained in the small fluidized bed (the first reaction zone) accounts for about 26% of the total yield, and the polymer obtained in the large fluidized bed (the second reaction zone) The polymer accounted for 74% of the total yield, and the ethylene content in the obtained polymer was 10.5 wt%.

Table 4 small fluidized bed large fluidized bed reactor: Fluidized bed diameter (mm) 100 350 Height of fluidized section (mm) 1300 1000 Height of expansion section(mm) 100 900 Angle of expansion section (°) 11 11 Height of settlement section (mm) - 100 Settlement section diameter (mm) - 700 Large/small fluidized bed position relationship The small fluidized bed is located outside the large fluidized bed Internals with stirring - Polymerization Conditions: Reactor temperature (°C) 67 70 Reactor pressure (MPa) 2.31 2.30 Stirring speed (rpm) 15 - Reactor superficial gas velocity (m/s) 0.09 0.62 Amount of liquid in gas stream (wt%) 84 16.5 Fluidized bulk density (kg/m ³ ) 374 309 Productivity (kg/hr) 2.5 7.0 Gas composition in the reactor: Ethylene (mol%) 0.1 11.5 Propylene (mol%) 86.5 70.5 Propane (mol%) 9.5 10.5 Hydrogen (mol%) 0.51 4.6 Nitrogen (mol%) 3.39 2.9 Polymerization product characteristics: Melt index (g/10min) 1.8 Ethylene content (wt%) 10.5 Average particle size (mm) 1.96 Bulk density(kg/m ³ ) 435.0

Although the invention has been described and illustrated by specific embodiments of the invention, it will be apparent to those skilled in the art that the invention is applicable to various modifications not described herein, for example, the use of catalysts with increased activity to increase Production rates, or lowering the temperature of the recycle stream by means of refrigeration, etc., are within the scope of this invention. In order to determine the scope of the invention, therefore, reference must be made to the appended claims.

Claims (13)

1, alkene CH ₂The polymerization process of=CHR, R is hydrogen or alkyl, cycloalkyl or the aryl that contains 1-12 carbon atom in the formula, this method is included under catalyzer existence and the polymeric reaction condition, comprises in the placed in-line gas fluidised bed polymerisation reaction zone one and carries out CH ₂The polyreaction of=CHR, it is characterized in that, described placed in-line gas fluidised bed polymerisation reaction zone comprises a fluidized reaction zone and comprise a quick fluidized reaction zone at least at a slow speed at least, polymkeric substance that fluidized reaction zone generated or mixture are delivered to continuous quick fluidized reaction zone continuously or off and at a slow speed, and fast fluidized reaction zone is 2～50 with the ratio of the fluidizing velocity of fluidized reaction zone at a slow speed.

2, polymerization process according to claim 1, wherein fast fluidized reaction zone is 3～20 with the ratio of the fluidizing velocity of fluidized reaction zone at a slow speed.

3, polymerization process according to claim 1, wherein fluidized reaction zone gas empty tower gas velocity scope is 0.01～0.3m/s at a slow speed.

4, polymerization process according to claim 1, at least 75% introduces fluidized reaction zone at a slow speed in the catalyzer total amount.

5, polymerization process according to claim 1 is in fluidized reaction zone at a slow speed, by means of gas distributor, introduce polymerization single polymerization monomer from the below of polymkeric substance bed, polymkeric substance that is generated or mixture are drawn from the top of polymerization zone or polymkeric substance bed, enter quick fluidized reaction zone.

6, polymerization process according to claim 1, in fluidized reaction zone at a slow speed, partially polymerized at least reaction heat is removed by polymerization single polymerization monomer that is frozen state or the volatilization of other inert substances.

7, polymerization process according to claim 1, unreacted monomer and other inert liq volatile matters flow into quick fluidized reaction zone continuously or off and on polymkeric substance in fluidized reaction zone at a slow speed.

8, polymerization process according to claim 1 in quick fluidized reaction zone, is introduced fresh polymerization single polymerization monomer in arbitrary position, unreacted gas the top of reaction zone and solids constituent from and flow out, the polymkeric substance that is generated discharges continuously or off and on.

9, polymerization process according to claim 1, wherein be cooled to below the temperature of dew point from quick fluidized reaction zone effluent air mixture, wherein phlegma returns fluidized reaction zone and/or fluidized reaction zone at a slow speed fast, and non-condensable gas all turns back to quick fluidized reaction zone bottom.

10, polymerization process according to claim 1, wherein the operating pressure of gas fluidised bed polymerisation reaction zone is 0.5～10MPa.

11, polymerization process according to claim 1, wherein there is at least a rare gas element in the gas fluidised bed polymerisation reaction zone, and its dividing potential drop sum is 5～80% of a gas stagnation pressure.

12. polymerization process according to claim 11, wherein said rare gas element are nitrogen or the paraffinic hydrocarbons that contains 2～6 carbon atoms.

13, polymerization process according to claim 1, wherein said catalyzer comprises the reaction product of an aluminum alkyls and a titanium-containing catalyst component.

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