JPH05140230A - Operation-supporting apparatus for polymerization for producing polyolefin - Google Patents

Abstract

PURPOSE:To provide an operation-supporting apparatus for stably producing a polyolefin of a desired MFR without fail whereby the change in the MFR of the polyolefin is forecast with a computer according to the measured MFR of the polyolefin, and the operating conditions are changed by comparing the forecast value with the target value. CONSTITUTION:In the polymerization of an olefin in a polymerization zone in the presence of hydrogen and a Ziegler catalyst or a like catalyst, the properties of the obtained polyolefin, especially MFR, are measured, the measured value and the operation data K1 to K10 on the reaction conditions are inputted into a computer 30 and processed to estimate the reaction state, and the change in the MFR of the polyolefin to be formed in the reactor in future is forecast, and the quantity of change in the operating conditions are calculated by comparing the forecast value with the target value, and the operating conditions are changed (S1 to S4) according to the calculated quantity. By using this apparatus, a polyolefin having a specified MFR can be stably produced without fail.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymerization reaction operation support device in the production of polyolefin. Specifically, when polymerizing an olefin in a polymerization zone in the presence of hydrogen using a Ziegler-based catalyst, a Phillips-based catalyst, etc., the physical properties of the polyolefin obtained by the polymerization reaction, particularly the melt flow index MFR value, are measured. The measured values and the operating data of the reaction conditions are loaded into a computer, the reaction state is estimated by arithmetic processing, and the MF of the polyolefin produced in the reactor in the future based on the estimated values.
Operation for predicting the transition of the R value, calculating the amount of change in operating conditions by comparing the predicted value with the target value, and changing the operating conditions based on this calculated amount to produce a polyolefin having a predetermined MFR value Regarding the support device.

[0002]

2. Description of the Related Art Conventionally, polyolefin has been molded by various molding methods and used for various purposes. Depending on these molding methods and uses, polyolefins having various physical properties, particularly melt florate (melt flow index; referred to as “MFR” in this specification) and density are desired. Generally, to control these physical properties,
A method is known in which the type, composition, amount, etc. of the catalyst are changed and the polymerization conditions are changed.

By the way, in order to produce polyolefin on an industrial scale, a predetermined amount of catalyst and cocatalyst, a predetermined amount of olefin, and a predetermined amount of hydrogen, and further a solvent are placed in a polymerization zone kept at a predetermined temperature. As supplied, the operation is carried out under conditions such that a polyolefin having a specified standard, that is, a specified MFR and density, is continuously produced.

However, it is difficult to keep the state in the polymerization zone constant even if the continuous polymerization is carried out under the condition that the respective supply amounts are constant as described above. For this reason, it is almost impossible to manufacture a polyolefin having a predetermined physical property standard with a constant production amount. That is, the olefin concentration in the polymerization zone changes due to minute changes in the catalyst due to uncertain disturbances, changes in activity, and the like. For example, when the activity of the catalyst is reduced, the olefin concentration in the zone is increased, the ratio of the concentration of hydrogen, which is a molecular weight regulator, to the olefin is reduced, and the MFR of the produced polyolefin is reduced. .. Such fine disturbances for which the reason is not clear frequently occur, which changes the olefin concentration in the polymerization zone, resulting in physical properties of the produced polyolefin, especially MFR.
And density will change.

Conventionally, various methods for improving such problems have been proposed, for example, the following methods (1) to (3) are available. A method of actually measuring the olefin concentration and the hydrogen gas concentration in the liquid phase portion of the polymerization reactor (USP 3,835,106).
issue). A method of monitoring the polymerization reaction system and measuring the pressure to homogenize the composition of the final ethylene copolymer (U
SP 3,691,142). A method of monitoring the ethylene and hydrogen concentrations in the gas phase or liquid phase of a polymerization reactor and incorporating them into a computerized control system to control the ethylene and / or hydrogen supply (USP 4,469,853, JP 62-25
No. 0010).

[0006]

Of the above-mentioned conventional methods,
The method (1) has a problem that the polymerization reaction proceeds until the sample is taken from the reactor and the state in the reaction system cannot be accurately grasped.

Further, the method (1) has the desired physical properties, especially MF.
It is not a suitable technique for producing polyethylene having R and / or density.

In the method (1), the reaction state changes when there is a minute disturbance in the polymerization zone. Therefore, it is necessary to control the ethylene and hydrogen concentrations in the gas phase or the liquid phase to predetermined amounts. It is difficult to obtain a polyolefin having the above physical properties (for example, MFR).

An object of the present invention is to solve the above-mentioned conventional problems and to provide a polymerization reaction operation support device for producing a polyolefin capable of stably and reliably obtaining a polyolefin having a predetermined MFR value. ..

[0010]

A polymerization reaction operation support apparatus for producing a polyolefin of the present invention comprises a step of polymerizing an olefin in a polymerization zone in the presence of a catalyst and hydrogen to obtain a predetermined M.
A polymerization reaction operation support device for producing a polyolefin having FR, comprising a process state detecting means for detecting a process state quantity representing a process state in a polymerization zone, and M of a polyolefin product flowing out from the polymerization zone.
MFR measuring means for measuring FR, process state quantity and MF from the process state detecting means and MFR measuring means
A data storage means for taking in the R measurement value and accumulating the data in time series, and a process state quantity and an MFR from the data storage means at a designated sampling cycle with respect to the past from a designated time in response to a start instruction. The measured values are extracted, and using the time series data, the following equations (1) and (6)
A β value calculation calculation means for dynamically estimating the MFR of the polyolefin instantaneously generated in the polymerization zone by the calculation processing according to the formula, and calculating the β value in the formula (6) from the estimated value.
Using the β value calculated by the β value calculation calculation means and the current process state amount or process state change amount, the following (1)
M in the future by the arithmetic processing by the formula and the formula (6)
MFR prediction calculation means for predicting transition of FR value, and the MF
The process state target value calculating unit includes a process state target value calculating unit that calculates a target value of the process state amount in the overlapping zone by comparing the transition of the MFR value predicted by the R prediction calculating unit with the target value of the MFR. It is characterized in that the set value of the process state quantity is changed based on the calculated process state target value.

[0011]

[Equation 2]

Reference symbol: G _L : Reactor liquid phase capacity C _P : Reactor polymer concentration F _P : Instantaneous reaction amount F _Ol : Olefin supply amount F _S : Solvent supply amount S _Ol : Solvent olefin dissolution amount MFR ₁ : Instantaneous generation MFR MFR ₂ : Reactor outlet MFR Y: Power number log MFR ₁ = α ₁ log (H ₂ / Ol) _G + α ₂ log (Co / Ol) _G + α ₃ log (P _Ol ) + α ₄ log (CE / P _Ol ) + α ₅ log (T) + α ₆ log (OMC / P _Ol ) + β (6) Code: (H ₂ / Ol) _G : (hydrogen / olefin) molar ratio in gas phase (Co / Ol) ) _G : (comonomer / olefin) molar ratio in gas phase (P _Ol ): olefin partial pressure in gas phase (CE / P _Ol ): catalyst activity / olefin partial pressure CE = polymerization amount / catalyst feed amount T: polymerization temperature OMC: cocatalyst feed amount α ₁ ~α _6, β: coefficient determined empirically by the reaction conditions, ie, the present inventors have the prior art Solving the problems, the production of a polyolefin that can quickly change the reaction state even when the reaction state changes due to disturbance, etc., and change the reaction condition to obtain a polyolefin with predetermined physical properties according to the state quantity As a result of repeated studies to provide a method, the operating data in the polymerization zone and the measured value of the MFR of the polyolefin obtained in the polymerization zone are loaded into a computer and arithmetically processed to obtain a polyolefin which is instantaneously produced in the polymerization zone. Dynamically estimating MFR sequentially, predicting future MFR transition based on the estimated value, and calculating the target value of the reaction condition by comparing the predicted value with the target value,
The inventors have found that the above problems can be solved by changing the reaction conditions in the polymerization zone based on the calculated target value, and have completed the present invention.

The present invention will be described in detail below.

Examples of the catalyst used for producing the polyolefin according to the present invention include Ziegler type catalysts and Phillips type catalysts. An organoaluminum compound is used as the cocatalyst. If desired, a third component such as an electron donating compound may be used.

As the solvent, there may be used an aliphatic hydrocarbon such as hexane and heptane, an aromatic hydrocarbon such as benzene, toluene and xylene, and an inert hydrocarbon solvent such as an alicyclic hydrocarbon such as cyclohexane and methylcyclohexane.

Examples of olefins include α-olefins such as ethylene, propylene, butene-1, hexene-1, 4-methylpentene-1. These olefins may be used alone or as a mixture of two or more olefins. For example, ethylene is used alone or as a mixture of ethylene and another olefin of 30 mol% or less with respect to ethylene.

The olefin polymerization reaction is carried out by adding olefin, hydrogen, a catalyst and a cocatalyst, optionally a solvent and a third
Predetermined amount of ingredients and comonomers, usually 50-150
It is carried out under reaction conditions of a temperature of C, a pressure of 0.1 to 100 kg / cm ² G and a hydrogen / olefin molar ratio in the gas phase of 0.01 to 1000. Of course, the reaction conditions are appropriately selected within the above range depending on the desired physical properties of the polyolefin.

Embodiments of the driving support system of the present invention will be described in more detail below with reference to the drawings. FIG. 1 is a block diagram of a polyolefin manufacturing process to which the driving support device of the present invention is applied.

In FIG. 1, a hydrogen supply line 2, an olefin supply line 3, a solvent supply line 4, a catalyst supply line 5, a co-catalyst and a third component supply line 5'are connected to the polymerization reactor 1, and hydrogen is supplied. , Olefin, solvent, catalyst, co-catalyst, third component and the like are continuously supplied in a predetermined amount according to the MFR of the polyolefin to be produced.

Inside the polymerization reactor 1, a liquid phase portion 1a and a gas phase portion 1b are formed by the above-mentioned feed, and the olefin is polymerized while being stirred by the stirrer 1c.

The produced polyolefin is continuously extracted from the polyolefin extraction line 6 and supplied to the degassing tank or the gas separator 12 to separate the unreacted gas from the pipe 12A and then to the feed line 6A. The solvent is supplied to the solvent separator 13 and the solvent is separated from the pipe 13A. Next, it is supplied to the dryer (dryer) 14 through the feeding line 6B to be a dried polyolefin solid. This is supplied to the extruder 15 by a feeding line 6C to be pelletized,
Extract from the polyolefin pellet extraction line 16.

In the present invention, the polyolefin extracted from the polymerization reactor 1, preferably the polyolefin pellets extracted from the extraction line 16 is sampled from the sampling line 16A at predetermined time intervals and guided to the MFR measuring device 17 to be manufactured. Measure the MFR of the polyolefin. A signal based on this measured value (actual measured value) is input to the data storage unit 31 of the computer 30 (signal K ₁ ).

Further, the above-mentioned hydrogen supply line 2, olefin supply line 3 and solvent supply line 4 are provided with supply valves 2a, 3a, 4a for adjusting the respective supply amounts, and flow rate detectors 2b, for detecting the respective supply amounts. 3b and 4b are provided respectively, and the detection signals (K ₂ , K ₃ and K ₄ ) correlated with the flow rate from the flow rate detectors 2b, 3b and 4b are input to the data storage section 31 of the computer 30. On the other hand, a control signal S from a control unit 36 of the computer 30, which will be described later,
_{1 to} S ₄ , the stroke of the catalyst supply pump 5a, the co-catalyst supply pump 5'to change the olefin concentration and the hydrogen concentration so as to produce a polyolefin having a predetermined MFR.
The stroke of a, the opening degree of the olefin supply valve 3a and the hydrogen supply valve 2a are controlled.

Further, a sampling line 7 is provided in the gas phase portion 1b of the polymerization reactor 1, and the gas in the gas phase portion 1b is introduced into an analyzer 8, for example, gas chromatography, through an on-off valve 7a. The analyzer 8 measures the hydrogen concentration and the olefin concentration in the gas. The signal (K ₅ ) based on the hydrogen concentration and olefin concentration measured by the analyzer 8 is also input to the data storage unit 31 of the computer 30.

Numerals 9 and 10 denote detectors for the pressure in the gas phase and the temperature in the liquid phase of the polymerization reactor 1, and detection signals (K) that correlate with the pressure and the temperature from the pressure detector 9 and the temperature detector 10. ₆ , K ₇ ) is also a data storage unit 31 of the computer 30.
Entered in.

Reference numeral 11 is a supply line for supplying cooling water to the polymerization reactor 1, which is provided with a supply valve 11a for adjusting the supply amount and a flow rate detector 11b for detecting the supply amount. The detection signal (K ₈ ) correlated with the flow rate from 11b is input to the data storage unit 31 of the computer 30. The cooling water supply valve 11a also generates a polyolefin having a predetermined MFR according to a control signal S ₅ from a control unit 36 of the computer 30, which will be described later.
The opening is controlled to change the polymerization temperature.

Further, a solvent supply line 18 is connected to the degassing tank 12 for adjusting the slurry concentration, and a supply valve 18a for adjusting the supply amount and a flow rate detector 18b for detecting the supply amount are provided. The detection signal (K ₉ ) correlated with the flow rate from the flow rate detector 18b is sent to the computer 3
0 is input to the data storage unit 31.

A solvent supply line 20 is also connected to the solvent separator 13 for adjusting the slurry concentration,
A supply valve 20a for adjusting the supply amount and a flow rate detector 20b for detecting the supply amount are provided, and the flow rate detector 20b is provided.
The detection signal (K ₁₀ ) that is correlated with the flow rate from is input to the data storage unit 31 of the computer 30.

The pipe 19A is a line for returning the hot water to the cooling tower, and the pipe 19B is a line for circulating the hot water.

As described above, in this embodiment, the process state quantity representing the process state in the polymerization reactor 1, that is, the supply amounts of olefin, hydrogen, solvent, catalyst and cocatalyst, the concentration of olefin and hydrogen in the gas phase, the reaction pressure, MFR of reaction temperature and liquid level, etc. signal K ₂ ~K ₈ and polyolefin products withdrawn from the polymerization reactor 1 to the operating data of the reaction conditions detected in each process state detection means of the liquid phase portion
Measured value (in the present invention, as shown in FIG. 1, polyolefin pellets obtained through the degassing tank 12, the solvent separator 13, the dryer 14 and the extruder 15 are used as MFR measuring devices 17
It is desirable to adopt the actual measured value of MFR measured in. Signal K ₁ of ₁ ) is taken into the computer 30, and the data is stored in the data storage unit 31 as time series data.

The computer 30 includes a data storage unit 31,
A β value calculation calculation unit 32, an MFR prediction calculation unit 33, a process state target value calculation unit 34, and a display 3
5, a printer 37, and a reaction condition setting value changing unit 38.

As described above, the driving support system of this embodiment is
Process state detecting means for transmitting the detection signals K _{2 to} K ₁₀ ,
MFR measuring means (MFR measuring device 17) for transmitting the detection signal K ₁ , data storage means (data storage section 31), β value calculation calculation means (β value calculation calculation section 32), MFR prediction calculation means (MFR prediction calculation section) 33) and process state target value calculation means (process state target value calculation unit 34). The operation of the driving support device will be described. By inputting a start instruction from the outside (for example, by inputting on the display 35), a sampling cycle designated from the designated time to the past, for example, data of the past 24 hours. 1
Data of the process state quantity and the MFR measurement value (detection signals K _{1 to} K ₁₀ ) are extracted as time series data from the data storage unit 31 for each time period, and the β value calculation operation unit 32 uses the data to extract the The MFR of the polyolefin instantaneously generated in the polymerization zone is dynamically estimated by the arithmetic processing by the equations (1) and (6), and β in the equation (6) is calculated from the estimated value.
Calculate the value.

Using the β value and the current process state amount or its change amount, the MFR prediction calculation unit 33 performs the calculation process according to the equations (1) and (6) to calculate the future (future) MFR value. The transition is predicted, and the transition of the MFR value is displayed on a printout or a CRT screen by using the predicted value as a table or a graph.

The transition of the MFR value and the target value of the MFR are used to compare the two in the process state target value calculation unit 34, and the process state quantity is changed until the transition of the predicted MFR value matches the target value. Then, the prediction of the transition of the MFR value is repeated by a trial-and-error method by the arithmetic processing according to the following equations (1) and (6) to calculate the target value of the process state quantity.

Based on the process state target value calculated by the process state target value calculating section 34, for example, the hydrogen / olefin molar ratio in the gas phase, the polymerization temperature, and the promoter concentration in the liquid phase, the process of the polymerization reactor 1 is performed. The control signals S _{1 to} S ₅ are output to change the state amount, for example, the supply amount of olefin, hydrogen, the catalyst or the co-catalyst, or the set value of the polymerization temperature,
A polyolefin having a predetermined MFR value is produced.

The MFR of the polyolefin instantaneously produced in the polymerization reactor is calculated by the calculation process based on the prediction model using the measured MFR value of the polyolefin produced in the polymerization reactor 1 and the operation data of the polymerization reaction conditions. The estimation method will be described in detail.

The symbols indicate the following. G _L1 : Liquid phase capacity of polymerization reactor 1 G _L2 : Liquid phase capacity of degassing tank 12 G _L3 : Liquid phase capacity of solvent separator 13 C _P1 : Polymer concentration of polymerization reactor 1 C _P2 : Degassing tank 12 Polymer concentration C _P3 : Polymer concentration in the solvent separator 13 F _P1 : Instantaneous reaction amount in the polymerization reactor 1 F _Ol1 : Olefin supply amount in the polymerization reactor 1 F _S1 : Solvent supply amount in the polymerization reactor 1 F _S2 : Desorption Solvent supply amount in gas tank 12 F _S3 : Solvent supply amount in solvent separator 13 S _Ol1 : Solvent olefin dissolution amount in polymerization reactor ₁ MFR ₁ : Instantaneous formation of polymerization reactor 1 MFR MFR ₂ : Polymerization reactor MFR MFR _{3 at} 1 outlet: MFR MFR _{4 at} outlet of degassing tank 12: MFR MFR _{5 at} outlet of solvent separator 13: MFR MFR _{6 at} outlet of dryer 14: MFR Y at extruder 15 Y: Exponent L: delay time k: Powder drop-off staff Number k = f (type and concentration of additive, specific energy of extruder, etc.) First, the polymerization reactor 1, the degassing tank 12, the solvent separator 13,
M of polyolefin in the dryer 14 and the extruder 15
The material balance of the dynamic characteristics of FR is represented by the following prediction model formula.

(1) Polymerization reactor 1 During unsteady operation (when the polymerization reaction is started or stopped, when disturbance is generated, or when the polymerization reaction conditions are changed)

[0039]

[Equation 3]

During steady operation (C _L1 , C _P1 , F _P1 , S
_(Ol1 is constant)

[0041]

[Equation 4]

(2) Degassing tank 12 during unsteady operation

[0043]

[Equation 5]

During steady operation (G _L2 and C _P2 are constant)

[0045]

[Equation 6]

(3) Solvent Separator 13 During unsteady operation

[0047]

[Equation 7]

During steady operation

[0049]

[Equation 8]

(4) Dryer 14 MFR ₅ (t + L) = MFR ₄ (t) (4) (5) Extruder 15 MFR ₆ = k · MFR ₅ (5) Here, for example, the extruder The polyolefin pellets (granular particles) extracted from 15 are sampled every predetermined time, the MFR of the polyolefin is measured by the MFR measuring device 17, and the measured value MFR ₆ is used to calculate the formula (5) → the formula (4) → The MFR of the polyolefin instantaneously generated in the polymerization reactor 1 can be estimated by sequentially performing the arithmetic processing based on the formula (3) → the formula (2) → the formula (1). This M
The β value is calculated from the FR estimated value MFR ₁ and the following equation (6). (Each symbol in the formula (6) is as described above.) Log MFR ₁ = α ₁ log (H ₂ / Ol) _G + α ₂ log (Co / Ol) _G + α ₃ log (P _Ol ) + α ₄ log (CE / P _Ol ) + α ₅ log (T) + α ₆ log (OMC / P _Ol ) + β (6) Next, this β value and the process state quantity of the polymerization reactor 1, that is,
MFR of polyolefin to be produced in the polymerization reactor 1 in the future by using the operation data of the reaction conditions or the changed amount thereof and the calculation process of the formula (6) → the formula (1).
Predict changes in value.

The predicted value of the transition of the MFR is compared with the target value of the MFR, and the process state quantity in the formula (6) is changed until the predicted value matches the target value, and the formula (6) and the formula (6) are changed. The prediction of the transition of the MFR value is repeated by a trial and error method by the calculation processing according to 1), and the target value of the process state quantity in the formula (6), especially the hydrogen / olefin molar ratio in the gas phase part, the polymerization temperature, the liquid phase Calculate the target value for the promoter concentration.

Based on this target value, the reaction condition set value changing unit 38 and the control unit 36 output control signals S _{1 to} S ₄ to supply the olefin, hydrogen, catalyst or co-catalyst in the polymerization reactor 1. Alternatively, a polyolefin having a predetermined MFR value can be produced by changing the set value of the polymerization temperature.

[0053]

As described above, in the driving support system of the present invention, the above signals input to the computer are processed in accordance with a preset program in the computer, and the hydrogen content in the gas phase portion (1b in FIG. 1) is calculated. Calculated values such as pressure, olefin partial pressure, hydrogen / olefin molar ratio, polymerization amount of polyolefin in the polymerization reactor, polymer concentration, co-catalyst concentration, catalytic activity, etc. To obtain the deviation by comparison and calculation processing with respective target values set in advance, and operate the hydrogen supply valve (2a in FIG. 1), for example, by the control signal based on the deviation. The hydrogen concentration in the phase part (1b) is adjusted, or the stroke of the olefin supply valve (3a) or the catalyst supply pump (5a) is operated to By adjusting the olefin concentration in the phase part (1b) and adjusting the hydrogen / olefin molar ratio in the gas phase part to a predetermined value, the hydrogen concentration and the olefin concentration are adjusted so as to produce a polyolefin having a predetermined MFR. To control.

The predetermined MFR can also be obtained by operating the stroke of the co-catalyst supply pump (5'a) as necessary to adjust the co-catalyst concentration, or by changing the setting of the polymerization temperature. A polyolefin having can be produced.

The method of changing the reaction conditions depends on the type of brand of the polyolefin product, but it is effective as an MFR control means for generally carrying out the above hydrogen / olefin molar ratio control.

[0056]

The present invention will be described in more detail with reference to specific control examples.

Example 1 Using the apparatus shown in FIG. 1, a polyolefin was produced according to the control method described above.

FIG. 2 shows a future MFR which is calculated by the driving assist system of the present invention shown in FIG.
5 is a graph showing the prediction result of the transition of FIG.

FIG. 3 shows the change of the process state quantity (particularly in this case, the H ₂ / ethylene molar ratio in the gas phase part) for producing a polyolefin having a predetermined MFR based on the prediction result of the transition of MFR shown in FIG. Amount and MFR based on this change amount
5 is a graph showing the prediction result of the transition of FIG.

FIG. 4 is a graph showing changes in the actual measurement value and estimated value of the MFR when the process state quantity is adjusted based on these results.

As is clear from FIG. 4, the estimated value of the MFR and the actually measured value are in good agreement, and the operation assisting device of the present invention can favorably adjust the process state quantity.

[0062]

As described in detail above, according to the polymerization reaction operation support device for producing the polyolefin of the present invention,
An olefin can be polymerized in the polymerization zone in the presence of a catalyst and hydrogen to reliably, stably and efficiently produce a polyolefin having a predetermined MFR.

[Brief description of drawings]

FIG. 1 is a block diagram of a polyolefin manufacturing process using a driving support device according to an embodiment of the present invention.

FIG. 2 is a graph showing a prediction result of a future transition of MFR, which is performed by the driving support apparatus shown in FIG. 1 by a calculation process using a process state amount and an actual MFR value.

3 is based on the prediction result of the transition of MFR shown in FIG.
It is a graph which shows the process state quantity for manufacturing the polyolefin of predetermined MFR, the amount of change, and the prediction result of the transition of MFR based on this amount of change.

FIG. 4 is a graph showing changes in the actual measurement value and estimated value of MFR when the process state quantity is adjusted based on the results of FIGS.

[Explanation of symbols]

 1 Polymerization Reactor 2 Hydrogen Supply Line 3 Olefin Supply Line 4 Solvent Supply Line 5 Catalyst Supply Line 6 Polyolefin Extraction Line 7 Sampling Line 8 Analyzer 12 Degassing Tank 13 Solvent Separator 14 Dryer 15 Extruder 17 MFR Meter 30 Computer 31 Data storage unit 32 β value calculation calculation unit 33 MFR prediction calculation unit 34 Process state target value calculation unit 36 Control unit 38 Reaction condition set value change unit

Claims (1)

[Claims] 1. An olefin is polymerized in a polymerization zone in the presence of a catalyst and hydrogen to obtain a predetermined melt flow index (hereinafter referred to as "MFR").
Called. And a process state detecting means for detecting a process state quantity representing a process state in a polymerization zone, and a MFR of a polyolefin product flowing out from the polymerization zone. MFR measuring means, data storage means for taking in the process state quantity and MFR measurement value from the process state detecting means and MFR measuring means, and accumulating the data in time series, and from the time designated by receiving the start instruction to the past. On the other hand, the process state quantity and the MFR measurement value are extracted from the data storage means at a designated sampling cycle, and the time series data is used to perform the arithmetic processing according to the following equations (1) and (6) in the overlap band. Instantaneous polyolefin M
FR is dynamically estimated, and β in the following equation (6) is estimated from the estimated value.
The following (1) is used by using a β value calculation calculation unit that calculates a value and the β value calculated by the β value calculation calculation unit and the current process state amount or process state change amount.
M in the future by the arithmetic processing by the formula and the formula (6)
MFR prediction calculation means for predicting transition of FR value, transition of MFR value predicted by the MFR prediction calculation means, and MF
Process state target value calculating means for calculating a target value of the process state quantity in the polymerization zone by comparison with the target value of R, and based on the process state target value calculated by the process state target value calculating means, the process state A polymerization reaction operation support device for producing a polyolefin, characterized in that the set value of the amount is changed. [Equation 1] Code: G _L : Reactor liquid phase capacity C _P : Reactor polymer concentration F _P : Instantaneous reaction amount F _Ol : Olefin supply amount F _S : Solvent supply amount S _Ol : Solvent olefin dissolution amount MFR ₁ : Instant production MFR MFR ₂ : Reactor outlet MFR Y: Power number log MFR ₁ = α ₁ log (H ₂ / Ol) _G + α ₂ log (Co / Ol) _G + α ₃ log (P _Ol ) + α ₄ log (CE / P _Ol ) + Α ₅ log (T) + α ₆ log (OMC / P _Ol ) + β (6) Code: (H ₂ / Ol) _G : (hydrogen / olefin) molar ratio in gas phase (Co / Ol) _G : (Comonomer / Olefin) Molar Ratio in _{Gas Phase} (P _Ol ): Olefin _Partial Pressure in _{Gas Phase} (CE / P _Ol ): Catalyst Activity / Olefin _Partial Pressure CE = Polymerization Amount / Catalyst Feed Amount T: Polymerization Temperature OMC: Co-catalyst feed amount α _{1 to} α ₆ , β: empirically determined coefficient under each reaction condition