阅读说明：本技术 改进气相聚合中生产的方法 (Process for improving production in gas phase polymerization ) 是由 B·J·萨瓦特斯凯 B·R·格林哈尔希 J·A·穆巴斯 A·C·麦克金尼斯 R·W·艾默尔曼 于 2020-03-04 设计创作，主要内容包括：本发明的公开内容涉及在气相反应器中使用一种或多种冷凝剂(CAs)从烯烃单体生产聚烯烃的方法,和特别地涉及在用于聚合烯烃单体的气相反应器中控制冷凝相冷却。该方法包括在比值下向反应器中引入第一和第二冷凝剂,该比值通过下述步骤确定：确认第一冷凝剂的粘附极限,计算涉及第一冷凝剂和第二冷凝剂的当量因子,确认总体可允许冷凝剂组合物,和计算被移除且被第二冷凝剂替代的第一冷凝剂的用量。该方法可进一步包括计算气相组合物的露点极限,该气相组合物包含烯烃单体以及第一和第二冷凝剂；和确定引入包含烯烃单体和冷凝剂组合物的混合物是否会超过计算的露点极限。(The present disclosure relates to a process for producing polyolefins from olefin monomers using one or more Condensing Agents (CAs) in a gas phase reactor, and in particular to controlling condensed phase cooling in a gas phase reactor used to polymerize olefin monomers. The method includes introducing first and second condensing agents into the reactor at a ratio determined by: the method includes identifying an adhesion limit of a first condensing agent, calculating an equivalence factor related to the first condensing agent and a second condensing agent, identifying an overall allowable condensing agent composition, and calculating an amount of the first condensing agent to be removed and replaced with the second condensing agent. The method can further include calculating a dew point limit for a gas phase composition, the gas phase composition comprising an olefin monomer and first and second condensing agents; and determining whether introduction of the mixture comprising olefin monomer and condensing agent composition would exceed the calculated dew point limit.)

1. A process for polymerizing olefins in a gas phase reactor with controlled cooling of the condensed phase, the process comprising:

introducing one or more polymerization catalysts and one or more olefin monomers into a gas phase polymerization reactor;

introducing a refrigerant composition comprising a first refrigerant and a second refrigerant at a ratio of the first refrigerant to the second refrigerant, wherein the ratio of the first refrigerant to the second refrigerant is calculated by:

the sticking limit of the first condensing agent is confirmed,

calculating an equivalence factor related to the first condensing agent and the second condensing agent,

confirming total allowable condensing agent, and

calculating a first amount of the first condensing agent that is removed and replaced with a second amount of the second condensing agent;

calculating a dew point limit for a gas phase composition comprising one or more olefin monomers, a first condensing agent, and a second condensing agent, thereby producing a calculated dew point limit;

determining whether introduction of a mixture comprising one or more olefin monomer and a condensing agent composition will fall below the calculated dew point limit;

leading out a polyolefin product;

withdrawing a gas phase composition comprising at least a portion of the first condensing agent and the second condensing agent;

condensing a portion of the vapor phase composition to thereby obtain a condensed stream; and

recycling at least a portion of the condensate stream to the gas phase reactor.

2. The method of claim 1, wherein the calculating of the first amount of the first condensing agent removed and replaced with the second amount of the second condensing agent is accomplished using equation (E-14):

wherein X is a first amount of the first refrigerant removed and replaced with a second amount of the second refrigerant, wherein the second amount is X multiplied by α CA2, Z is an overall allowable refrigerant, SL_CA1Is the sticking limit of the first refrigerant, and α CA2 is an equivalence factor related to the first refrigerant and the second refrigerant.

3. The method of any of claims 1-2, wherein if the introducing the mixture comprising one or more olefin monomer and condensing agent compositions exceeds the calculated dew point limit, then incrementally decreasing the equivalence factor until the introducing the mixture comprising one or more olefin monomer and condensing agent compositions does not exceed the calculated dew point.

4. The method of any of claims 1-2, wherein if the introducing the mixture comprising the one or more olefin monomer and condensing agent compositions exceeds the calculated dew point limit, then incrementally decreasing the adhesion limit of the first condensing agent until the introducing the mixture comprising the one or more olefin monomer and condensing agent compositions does not exceed the calculated dew point.

5. The method of any of claims 1-4, wherein the total allowable condensing agent composition is increased by increasing reactor pressure.

6. The method of any of claims 1-4, wherein the total allowable condensing agent composition is increased by decreasing the partial pressure of nitrogen within the reactor.

7. The method of any of claims 1-6, wherein the first condensing agent and the second condensing agent are independently selected from the group consisting of C3-C6 hydrocarbons.

8. The method of any one of claims 1-7, wherein the one or more olefin monomers comprise ethylene.

9. The process of any of claims 1-8, wherein the one or more olefin monomers comprise ethylene and a comonomer selected from propylene, 1-butene, 1-hexene, or 1-octene.

10. The method of any of claims 1-9, wherein the polyolefin product has a density of about 0.890g/cm³To about 0.930g/cm³And g'_visGreater than or equal to about 0.97.

11. The method of any of claims 1-10, wherein the first condensing agent is isopentane and the second condensing agent is isobutane.

12. The method of any of claims 1-11, wherein the first condensing agent is isobutane and the second condensing agent is n-butane.

13. The method of any of claims 1-11, wherein the first condensing agent is n-hexane and the second condensing agent is isopentane.

14. The process of any of claims 1-11, wherein the first condensing agent is isobutane and the second condensing agent is propane.

15. The method of any of claims 1-11, wherein the first condensing agent is isopentane and the second condensing agent is neopentane.

16. The process of any of claims 1-11, wherein the first condensing agent is neopentane and the second condensing agent is isobutane.

17. The method of any one of claims 1-16, wherein the determination of the sticking limit is performed using thermodynamic estimates of hydrocarbon solubility.

18. The method of any one of claims 1-17, wherein the determination of the adhesion limit is performed by a laboratory tack temperature test.

19. The method of any of claims 1-18, wherein the determination involving the equivalents of the first condensing agent and the second condensing agent is made using thermodynamic estimations as a function of pressure, temperature, melt index, gas composition, and density.

20. The method of any of claims 1-18, wherein the determination involving the equivalents of the first condensing agent and the second condensing agent is made by calculating a ratio of the viscosity temperature to a slope of partial pressures of the first condensing agent and the second condensing agent.

21. The method of any of claims 1-18, wherein the determination involving the equivalents of the first condensing agent and the second condensing agent is made by inputting data into an equation that relates an equivalence factor to reactor conditions.

22. The method of any of claims 1-21, further comprising adjusting a ratio of the first condensing agent and the second condensing agent as reactor conditions vary with the control system.

23. The method of claim 22, wherein the control system comprises a DCS control.

24. The method of any of claims 1-23, wherein the condensing agent composition is substantially free of C3-C6 hydrocarbons other than the first condensing agent and the second condensing agent.

25. The method of any of claims 1-24, wherein the gas phase composition is substantially free of C3-C6 aliphatic hydrocarbons other than the first condensing agent, the second condensing agent.

26. The method of any of claims 1-25, wherein recycling at least a portion of the condensate stream to the gas phase reactor further comprises adding one or more of a first condensing agent or a second condensing agent to the condensate stream.

Technical Field

The present disclosure relates to systems and methods for operating a polyolefin polymerization reactor within dew point constraints while improving production rates.

Background

The polyolefin may be produced using a gas phase polymerization process. If the process is a gas fluidised bed polymerisation process then the process may comprise a gas stream comprising the monomer or monomers continuously passed through a fluidised bed of catalyst and growing polymer particles. As polymerization occurs, a portion of the monomer is consumed and the gas stream is heated within the reactor by the heat of polymerization. A portion of the gas stream leaves the reactor and may be recycled back into the reactor along with additional monomers and additives. The recycle stream may be cooled to maintain the temperature of the resin and gas phase composition inside the reactor below the stickiness temperature. The viscosity temperature is the temperature at which the reaction mixture containing the polymer particles begins to adhere together to form aggregates. Particle agglomeration can result in the formation of polymer agglomerates or sheets that are not likely to be withdrawn from the reactor as product and can fall onto the reactor distributor plate, thereby impairing fluidization of the bed or causing reactor failure. In addition, since the polymerization reaction is exothermic, the amount of polymer produced in a fluidized bed polymerization process may be related to the amount of heat that can be withdrawn from the reaction zone.

It may be advantageous to cool the recycle stream below its dew point, resulting in condensation of a portion of the gaseous recycle stream outside the reactor. The dew point of the recycle stream is the temperature at which liquid condensate initially begins to form within the gaseous recycle stream. The dew point can be calculated with known gas composition and defined by thermodynamics using an equation of state. The process of purposefully condensing a portion of the recycle stream is referred to in the industry as "condensing mode" operation. Increased production of polymer may be possible when operating in the condensing mode to lower the temperature of the recycle stream to a temperature below its dew point.

Cooling the recycle stream to a temperature below the dew point temperature produces a two-phase gas/liquid mixture that may have entrained solids contained within both phases. The liquid phase of the two-phase gas/liquid mixture is typically entrained within the gas phase of the mixture in condensed mode operation. Vaporization of the liquid occurs when heat is added or pressure is reduced. Generally, vaporization occurs when the two-phase mixture enters the fluidized bed, and the heat of polymerization provides the heat of vaporization. Vaporization thus provides an additional means of extracting the heat of reaction from the fluidized bed.

The cooling capacity of the recycle gas can be further increased at a given reaction temperature and a given temperature of the cooling heat transfer medium at the same time by adding to the reactor a non-polymerizing, non-reactive substance condensable at the temperatures encountered in the process heat exchanger (cooler). Non-reactive condensable species are collectively referred to as Condensing Agents (CA), sometimes referred to as induced condensing agents, because they induce additional cooling. Increasing the concentration of CA in the reactor causes a corresponding increase in the dew point temperature of the reactor gas, which will promote higher levels of condensation, higher heat transfer (better cooling) and improved production rates from the reactor. However, the use of CA is governed by its solubility in the polymer, where CA acts to suppress the melting point of the polymer. Attempts to operate a polymerization reactor with excessive CA concentrations resulted in the suspended polymer particles within the fluid bed becoming soft and cohesive or "sticky" and, in some cases, resulted in fluidized bed solidification in the form of larger agglomerates or sheets. Although the use of CA can improve polymer production, challenges remain in balancing increased cooling capacity with polymer softening and stickiness.

Due to the increased complexity of viscosity control while using CAs, the addition of CAs to the gas stream entering the reactor affects the dew point of the gas phase composition in the reactor. In many processes the reactor conditions are not close to those which can cause problems with the dew point of the vapor phase composition in the reactor. Moreover, without the addition of CAs, the reactor conditions similarly did not approach the dew point of the gas phase composition. However, the desire to increase production has led to the addition of more CAs and the use of reactors operating at increased pressures, which in turn have brought the reactor conditions and dew point of the gas phase composition closer together.

At temperatures above, but near, the dew point, a portion of the vapor phase composition may undergo capillary condensation. Capillary condensation can occur in porous (or semi-porous) media (which, for example, form a polymer resin), where a closed space can increase the number of vapor interactions and cause condensation to begin at temperatures above the dew point of the vapor phase composition. Since reactor shutdowns can be expensive, and can be caused by capillary condensation, the lower limit of the reactor temperature is set at some number of degrees above the true dew point, which is referred to as the Dew Point Limit (DPL). If the reactor is operated at a temperature below DPL, a portion of the gas may condense and the resulting liquid may create a second viscous condition in which the fluidized bed is compromised, which may lead to reactor failure. The temperature at or below the dew point limit is the lower viscosity temperature at which the reaction mixture containing the polymer particles begins to adhere together to form aggregates. Thus, the benefit of increased cooling capacity should be balanced with the possibility of generating a gas phase composition, a portion of which condenses in the reactor and causes stickiness of the polymer. Typical action content when the reaction conditions approach the dew point limit is to reduce the amount of CAS or to vent the reactor gas thereby causing a drop in reactor pressure.

Furthermore, different polymer products vary widely in their ability to tolerate a particular CA, some with a relatively high tolerance (expressed in the partial pressure of CA within the reactor), such as 50psia, while other polymers may tolerate as little as 5 psia. In polymers with lower tolerances, the production rate at which heat transfer is limited under similar conditions is significantly lower. Polymers with a more uniform comonomer composition distribution have a higher tolerance for the partial pressure of CA in the reactor. Typical metallocene catalysts are good examples of catalysts that can produce polymers with a more uniform comonomer composition. However, at some point even these metallocene-produced polymers reach a limiting CA concentration that induces stickiness.

At higher temperatures, the concentration of CA that causes the polymer particles to become adherent is referred to as the adhesion limit (SL) for that particular CA. The higher temperature that causes the polymer resin to become tacky at a given CA concentration is the upper tack temperature. Similarly, the lower temperature that causes the polymer resin to tack is the lower tack temperature. The DPL is a limit set to avoid lower stickiness temperatures, which may be caused by condensation of a portion of the gas phase composition in the reactor. This temperature determines whether an increased concentration of the CA composition will cause condensation of liquid from the gas phase composition (to the lower tack temperature), or softening of the polymer resin (to the upper tack temperature) caused by the heat and increased solubility of the gas phase composition. The upper stickiness temperature, SL, lower stickiness temperature, and DPL depend on several factors in addition to polymer type, including reactor temperature, pressure, comonomer type, and comonomer concentration. Further, under the influence of temperature, CA content and comonomer content (all of which affect the onset of tack), it can be challenging to determine the moment at which sticking begins to occur. Thus, the CA concentration is maintained below its SL and the temperature is below the upper viscous temperature and above the DPL, allowing the reactor to maintain a non-viscous condition below the upper viscous temperature and above the DPL.

Combinations of CAs (CA compositions) may be used to increase the condensed phase cooling (and hence production rate) while avoiding viscous temperatures within the reactor. In order to produce polyolefins using CA compositions, it is necessary to balance the ratios of the various CAs to provide the maximum production rate while also avoiding stickiness inside the reactor. A process that does not use an equilibrium CA ratio can cause the reactor to run at less than the optimum production rate-which is a disadvantageous economic operating condition. Poor process loss in balancing CA compositions can lead to reactor downtime resulting from inadvertent operation under conditions that produce stickiness. The upper and lower viscous temperatures, and by combining the DPL, can vary with reactor conditions, including the pressure and composition of the gas stream entering the reactor. Since reactor conditions change in real time, the method of balancing the CA ratio should also operate in real time.

Real-time control of gas-phase polymerization reactors is complicated even within the constraints of safe operation. The complexity of reactor control further increases the difficulty and uncertainty of the experiment if one wishes to vary the operating conditions to achieve higher production rates. Large-scale gas phase apparatuses are expensive and have high productivity. The risks associated with experimentation in such devices are high due to costly downtime (e.g., due to exceeding the sticking limit). It is difficult to experimentally explore design and operational boundaries in view of cost and risk.

There remains a need for a method of determining stable operating conditions for gas fluidized bed polymerizations employing a condensing agent in order to facilitate plant design and to determine suitable process conditions for a suitable or maximum production rate in a given plant design. Furthermore, as reactor conditions change over time, there is a need for a process for producing polyolefins in a gas phase reactor that allows for real-time calculation of the CA ratio for condensed phase cooling.

Summary of The Invention

The present disclosure provides a method for controlling condensed phase cooling in a gas phase reactor used to polymerize polyolefins. In at least one embodiment, the process comprises introducing one or more polymerization catalysts and one or more olefin monomers into a gas phase polymerization reactor. The method includes introducing the first condensing agent and the second condensing agent in a ratio of the first condensing agent to the second condensing agent. The method includes calculating an equivalence factor (equivalence factor) related to the first condensate and the second condensate by identifying (idling) an adhesion limit of the first condensate, identifying an overall allowable condensate, and calculating a first amount of the first condensate removed and replaced with a second amount of the second condensate to calculate a ratio of the first condensate to the second condensate. The method includes calculating a dew point limit for a gas phase composition comprising one or more olefin monomers, a first condensing agent, and a second condensing agent, thereby producing a calculated dew point limit; and determining whether introduction of a mixture comprising one or more olefin monomer and a condensing agent composition would exceed the calculated dew point limit. The method includes withdrawing a gas phase composition comprising at least a portion of a first condensing agent and a second condensing agent from a gas phase polymerization reactor. The process comprises condensing a portion of the gas phase composition to obtain a condensed stream. The process includes recycling at least a portion of the condensate stream to the gas phase reactor.

Brief Description of Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are set forth in the appended claims. It is to be noted, however, that the appended claims illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

FIG. 1 is a schematic illustration of a gas phase polymerization system, according to one embodiment.

FIG. 2 is a diagram of a control system for controlling a gas phase polymerization process, according to one embodiment.

FIG. 3 is a comparison of gas phase polymerization in dry mode, enhanced dry mode, and condensed mode, according to one embodiment.

FIG. 4 is a graph of an equivalence factor determined by randomly generated experimental conditions, according to one embodiment.

FIG. 5 is a graph of condensing agent partial pressure versus viscosity temperature, according to one embodiment.

Fig. 6 is a graph of mole percent of condensing agent over time in a reactor under conditions in which a CA composition is automatically adjusted and without automatically adjusting the CA composition, according to one embodiment.

FIG. 7 is a graph of overall condensate composition versus expected production rate, according to one embodiment.

Fig. 8 is a graph illustrating data generated by commercial process engineering simulation software showing the amount of iC5 removed and replaced with the amount of iC4 versus production rate relative to gas phase polymerization using only iC5, according to one embodiment.

Fig. 9 is a graph illustrating data generated by commercial process engineering simulation software showing the amount of iC5 removed and replaced with an amount of nC4 versus production rate relative to gas phase polymerization using only iC5, according to one embodiment.

Fig. 10 is a graph illustrating production rates for two CA compositions containing two CAs and a production rate for a CA composition containing three CAs, according to one embodiment.

Fig. 11 is a graph illustrating the production rate for two different CA compositions each containing two CAs and the production rate for a CA composition containing three CAs, according to one embodiment.

Fig. 12 is a graph illustrating production rates for two different CA compositions each containing two CAs and a production rate for a CA composition containing three CAs, according to one embodiment.

Fig. 13 is a graph illustrating production rates for four different CA compositions each containing two CAs.

Fig. 14 is a graph illustrating production rate in a reactor versus overall mol% CA for five different CA compositions each containing two CAs, according to one embodiment.

Fig. 15 is a graph illustrating production rate in a reactor versus overall mol% CA for eight different CA compositions each containing two CAs, according to one embodiment.

Fig. 16 is a graph illustrating upper tack temperature, lower tack temperature, and adhesion limit versus adhesion temperature based on iC5 partial pressure, according to one embodiment.

Fig. 17 is a graph illustrating production rate versus total allowable CA composition at varying equivalence factors involving iC5 and iC4, according to an embodiment.

Fig. 18 is a graph illustrating vapor phase composition dew point versus total allowable CA composition at varying equivalence factors involving iC5 and iC4, according to an embodiment.

Fig. 19 is a graph illustrating production rate versus total allowable CA composition comparing adhesion limit and dew point limit, according to one embodiment.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

Detailed Description

The present disclosure relates to a process for producing polyolefins in a gas phase reactor using a Condensing Agent (CAs), and calculating the ratio of one type of CA to another CA within a CA composition in real time. The use of condensed phase cooling provides an increased production rate compared to dry mode cooling because the heat of vaporization of the liquid portion in the recycle stream increases the cooling capacity. Using more than a single CA may provide even greater cooling, as individual CAs have different effects on the viscosity temperature of the polymer formed inside the reactor. To avoid reactor shutdowns and operation under sub-optimal conditions, a method of adjusting the ratio of CAs entering the polymerization reactor should be implemented in real time. It has been found that calculating and using an appropriate CAs ratio can improve polymer production rates. In addition to improving polymer production rates, suitable ratios of CAs can help avoid CA composition concentrations that are too high and exceed SL. Furthermore, a suitable ratio of CAs may facilitate greater temperature changes without falling below the DPL. In addition, the concentration of CAs in the CA composition can be varied to adjust both SL (based on the concentration of the CA composition) and DPL (based on temperature). Calculation and use of the appropriate ratio of CAs can be achieved in real time by identifying the SL for the first CA, identifying the equivalent weight of the one or more additional CAs and the first CA, determining the dew point limit of the vapor phase composition, adjusting the equivalent factor or SL, and calculating the ratio of CAs within the CA composition. It has been found that in contrast to typical practice, improved production may be achieved without reducing the amount of CA composition in the reactor or by venting the reactor to reduce pressure, but instead by adjusting the concentration of CAs in the CA composition

The process described by adjusting the ratio of different CAs in the CA composition can maintain or reduce the gas phase composition dew point during the polyolefin polymerization. Additionally, the CA composition may be allowed to reach increased cooling while maintaining or reducing the gas phase composition dew point by increasing the overall allowable CA composition at a ratio of CAs calculated inside the CA composition. Balancing the CA types in the CA composition alone reduces or eliminates the "stickiness" disadvantage of excessive CA composition concentrations. Further, the composition of the CA composition can be changed in real time to achieve higher polyolefin production as the reactor conditions vary according to dew point calculations, equivalent factors involving the first CA and the one or more additional CAs, and the adhesion limit of the first CA.

Definition of

The term "CA" refers to a condensing agent. "CAs" refers to a variety of condensing agents. "CA composition" refers to the total condensing agent within the reactor and encompasses compositions having two or more condensing agents. Suitable CAs suitable for use in the methods of the present disclosure may include C3-C6 hydrocarbons or combinations thereof. For example, suitable CAs can include n-butane, isobutane, n-pentane, isopentane, neopentane, hexane, isohexane, and other hydrocarbon compounds that are similarly unreactive in the polymerization process. A "binary CA composition" is a CA composition comprising two CAs, and a "ternary CA composition" is a CA composition comprising three CAs.

The terms "iC 4" and "isobutane" refer to 2-methylpropane.

The terms "nC 4" and "n-butane" refer to n-butane.

The terms "iC 5" and "isopentane" refer to 2-methylbutane.

The terms "nC 5" and "n-pentane" refer to n-pentane.

The terms "neo-C5" and "neo-pentane" refer to 2, 2-dimethylpropane.

The terms "nC 6" and "n-hexane" refer to n-hexane.

The term "C6 inerts" refers to various hexane isomers that are inert to reaction conditions and may include nC6, 2-methylpentane, 3-methylpentane, 2, 2-dimethylbutane, 2, 3-dimethylbutane, 2-hexene, and/or 3-hexene.

The term "dew point" refers to the temperature at which condensation of components in the recycle gas or gas phase composition first begins. The dew point temperature depends on the pressure. The dew point temperature increases as the pressure in the reactor increases. Likewise, the dew point takes into account the temperature, pressure and physical properties of the other gases in the gas mixture. At temperatures at or below the dew point of the components in the gaseous medium, the components in the liquid phase may not evaporate or vaporize into the gaseous medium. On the other hand, if the temperature of the gaseous medium is above the dew point, the liquid phase components may vaporize or evaporate.

"Linear Low Density polyethylene" (LLDPE) is in the crossover density range, i.e. 0.890 to 0.930g/cm³Typically 0.915 to 0.930g/cm³The polyethylene of (1), which is linear and substantially free of long chain branches. LLDPE can be produced in a gas phase reactor and/or in a slurry reactor and/or in a solution reactor using conventional ziegler-natta catalysts, vanadium catalysts, or using metallocene catalysts. By "linear" it is meant that the polyethylene is substantially free of long chain branching, typically referred to as the branching index (g'_vis) Greater than or equal to 0.97, or greater than or equal to 0.98. The branching index g 'was measured as follows'_vis。

M as used herein_nIs the number average molecular weight, M_wIs the weight average molecular weight, and M_zIs the z average molecular weight, wt% is weight percent, and mol% is mole percent. Molecular weight fractionCloth (MWD), also known as polydispersity index (PDI), is defined as Mw divided by Mn. Unless otherwise indicated, all molecular weights (e.g., Mw, Mn, Mz) are reported in units of g/mol.

The term "real-time" refers to a system of data and adjustments that are processed without intentional delay, taking into account the processing limitations of the system and the time at which the data is accurately measured.

Referring to a product produced by a continuous reaction, the expression "instantaneous" value of a property of the product indicates a property value of the most recent production of the product. The recent production typically undergoes mixing with the previously produced product before the mixture of the recent and previously produced products exits the reactor. In contrast, referring to the product produced by a continuous reaction, the "average" (or "bed average") value of the property (at time "T") represents the value of the property of the product exiting the reactor at time T.

The term "polyethylene" denotes a polymer of ethylene and optionally one or more C3-C18 alpha-olefins, while the term "polyolefin" denotes a polymer of one or more C2-C18 alpha-olefins and optionally one or more comonomers. An "olefin" is a hydrocarbon containing at least one carbon-carbon double bond. Alpha-olefins are hydrocarbons containing at least one carbon-carbon double bond at one end of the carbon chain (e.g., 1-butene, vinyl-cyclohexane). For purposes of this disclosure, ethylene should be considered an alpha-olefin.

The term "melt index" refers to a measure used for the melt flow of thermoplastic polymers. Melt index can be measured according to ASTM D1238-13 at a suitable weight and temperature. Generally, the melt index is measured at 2.16kg and 190 ℃, at 5kg and 190 ℃, or at 21.6kg and 190 ℃.

Polymerization reactor

The described process can be used in pilot plant or commercial size reactors including various designs. For example, the model may be used in a commercial grade reaction, such as a gas phase fluidized bed polymerization reaction, which may be monitored and optionally also controlled. Some of these reactions may occur within a reactor having the geometry of the fluidized bed reactor 101 discussed with reference to fig. 1. In other embodiments, the reactor is monitored and optionally also controlled while operating using any of a variety of different methods (e.g., slurry or gas phase processes) to perform the polymerization.

Generally, in a fluidized gas bed process used for the production of polymers, a gas stream containing one or more monomers is continuously circulated through a fluidized bed in the presence of a catalyst under reactive conditions. A portion of the gas stream is withdrawn from the fluidized bed and recycled back to the reactor as a recycle stream. While withdrawing polymer product from the reactor and adding fresh monomer and catalyst to replace polymerized monomer and used catalyst. (see, e.g., U.S. Pat. Nos. 4,543,399; 4,588,790; 5,028,670; 5,317,036; 5,352,749; 5,405,922; 5,436,304; 5,453,471; 5,462,999; 5,616,661; and 5,668,228; all of which are incorporated by reference).

Fig. 1 is a schematic diagram of a polymerization system 100 that may be monitored and controlled according to the described embodiments. The polymerization system 100 includes a fluidized bed reactor 101. The fluidized bed reactor 101 has a bottom end 103, a straight section 105, a top expansion section 107, and a distributor plate 109 within the straight section 105. A fluidized bed 111 of particulate polymer and catalyst particles (once formed) is contained within the straight section 105 and may optionally extend slightly into the top expansion section 107. The bed is fluidised by a steady flow of a gas stream comprising recycle gas through the distributor plate 109. The gas stream passes through line 113 into the fluidized bed reactor and additional reaction and inert gases (including CAs) may be added in adjustable proportions through line 115. The aluminum alkyl (optional) can be added via line 117. The flow rate of the gas stream is adjusted to maintain the circulation of the fluidized bed 111. In some embodiments, a circulating gas velocity of about 1ft/sec to about 3ft/sec, such as about 2ft/sec to about 3ft/sec, or about 2.4ft/sec to about 2.8ft/sec, is used to maintain the fluidized bed 111 within the reactor 101 while operating the reactor 101 at a total pressure of less than or equal to about 4200kPa, about 700kPa to about 4200kPa, about 1300kPa to about 2800kPa, or about 1700kPa to about 2500 kPa. The mixture of gases in the reactor is a gas phase composition.

The polymerization system 100 has one or more catalyst lines 119 for controlling the addition of polymerization catalyst to the fluidized bed 111, and generally to a reaction zone (not shown) within the straight section 105. Inside the reaction zone, the catalyst particles are reacted with a reaction gas comprising olefin monomer (e.g. ethylene) and optionally comonomer and other reaction gases (e.g. hydrogen) to produce particulate polymer particles. While new polymer particles are being produced, additional polymer particles are continuously withdrawn from the fluidized bed 111 through the product discharge line 121 to the product recovery system 123. By withdrawing a portion of the fluidized bed 111 at a rate equal to the rate of formation of the granular product, the fluidized bed 111 can be maintained at a constant height. The product may be continuously or nearly continuously removed by means of a series of valves (not shown) into a fixed volume chamber (not shown) which is simultaneously vented back into the reactor. The fixed volume chamber and venting back into the reactor provides for highly efficient removal of product while recycling most of the unreacted gases back into the reactor.

Unreacted olefin and CA composition inside the product recovery system can be removed via line 125, compressed within compressor 127, and passed via line 129 to heat exchanger 131 to be cooled before being recycled (e.g., via line 133) into line 113. The particles inside product recovery system 123 can be degassed (or "purged") with a flow of inert gas, such as nitrogen, via line 135 to remove substantially all dissolved hydrocarbon material. In some cases, the polymer particles may be treated with a small humidified nitrogen stream to deactivate trace amounts of residual catalyst. The purge gas may be removed via line 137 to be vented to a flare or recycled for further processing.

The polymerization system 100 also has a cooling loop comprising a first recycle gas line 139 connected to the fluidized bed reactor 101, a compressor 141, a second recycle gas line 143, and a cooling system 145 (e.g., a recycle gas cooler). The cooling system 145 may receive cooling water via line 147 and expel heated water via line 149. Cooling of the recycle gas is a method used to cool the polymerization system 100 to reduce or eliminate problems that may result from exothermic polyolefin production. During operation, cooled recycle gas from cooling system 145 flows into fluidized bed reactor 101 via inlet 151 via line 113, then passes upwardly through fluidized bed 111 and exits fluidized bed reactor 102 via outlet 153.

The top expansion section 107 may also be referred to as a "velocity reduction zone" and is designed to reduce the amount of entrainment of particles in the recycle gas from the fluidized bed. The diameter of top expansion section 107 generally increases with distance from straight section 105. The increased diameter causes a decrease in the velocity of the gas stream, which allows most of the entrained particles to settle back into the interior of fluidized bed 111, thereby minimizing the amount of solid particles that are "carried" from fluidized bed 111 via recycle gas line 139. In some cases, a screen (not shown) may be included upstream of the compressor 141 to remove larger materials.

To maintain the reactor temperature, the temperature of the recycle gas can be continuously adjusted upward or downward to accommodate changes in the rate of heat generation due to polymerization. One or more temperature sensors 155 may be located inside the fluidized bed and used with the control system and cooling loop to control the temperature of the fluidized bed 111 near the process set point. The heated portion of the gas phase composition, which carries thermal energy from the fluidized bed reactor 101, is withdrawn from outlet 153 and pumped by compressor 141 via line 143 to cooling system 145, where the temperature of the heated reactor gas is reduced and at least a portion of the CA composition present is condensed to a liquid. Recycle gas from cooling system 145 containing condensed liquid flows via line 113 to reactor inlet 151 to cool fluidized bed 111. Temperature sensors (not shown) near the inlet and outlet of the cooling system 145 may provide feedback to a control system (not shown) to adjust the amount by which the cooling system 145 reduces the temperature of the gas stream entering the fluidized bed reactor 101.

The fluidized bed reactor 101 may also include a skin temperature sensor 157 mounted at a location along the wall of the straight section 105 of the fluidized bed reactor 101 so as to protrude a small amount (e.g., about 1/8 to 1/4 inches) into the bed from the reactor wall. The skin temperature sensor 157 may be configured and positioned to sense the temperature of the resin near the wall of the fluidized bed reactor 101 during operation.

The temperature sensor 155 within the fluidized bed 111 can comprise a resistive temperature sensor positioned and configured to sense the bed temperature during operation of the reactor at a location inside the fluidized bed reactor 101 remote from the reactor wall. The resistive temperature sensor may be mounted so as to protrude deeper into the bed than skin temperature sensor 157 (e.g., about 8-18 inches away from the reactor wall).

Other sensors and other devices may be used to measure other reaction parameters during the polymerization reaction. The reaction parameters may include instantaneous and bed-averaged resin product properties (e.g., melt index and density of the polymer resin product produced by polymerization system 100 during the polymerization reaction). The resin may be periodically (e.g., about once per hour) sampled as it exits the reactor and appropriate testing performed in a quality control laboratory to measure resin product properties.

Other measured reaction parameters may include reactor gas composition (e.g., concentrations and partial pressures of reactant gases, CA, and other inert gases, such as nitrogen, inert hydrocarbons, and the like). The gas composition inside the reactor can be measured by removing gas from the upper portion 107 via line 159 into a gas chromatography ("GC") system 161. The GC system 161 can also be connected to other portions of the polymerization system 100, such as the recycle gas line 139, the compressor 141, the line 143, or any combination thereof, through lines (not shown) other than the line 159.

Process control variables can be controlled to achieve increased productivity of the polymerization system 100 and specific properties of the resin. For example, parameters for controlling the gas phase composition inside the fluidized bed reactor 101 may include the concentration (partial pressure) and composition of the CA composition and comonomer, the partial pressure of the monomer, the type and properties of the catalyst, and the temperature of the reaction process. In addition, the polymerization reaction during the transition from producing a certain grade of polyolefin to a different grade can be controlled by controlling process control variables to ensure that the product (e.g., the particulate resin) has properties consistent with the starting specification set at the beginning of the transition, the product produced during the transition no longer meets the starting specification set at the first time, and the product has properties consistent with the final specification set at the end of the transition. In the methods described herein, the viscosity of the resin during the reaction can be controlled by a control system that adjusts (or adjusts) the temperature and/or composition and concentration of the CA composition used in the reaction.

Fig. 2 is a block diagram of a control system 200 that may be used to control the aggregation system 100. Control system 200 may be a Distributed Control System (DCS), a Direct Digital Controller (DDC), a Programmable Logic Controller (PLC), or any other suitable system or combination of systems. The control system 200 has a processor 201 that executes machine-readable instructions from a storage system 203. Exemplary processors may include single-core processors, multi-core processors, virtual processors, cloud-implemented virtual processors, Application Specific Integrated Circuits (ASICs), or any combination of these systems. Exemplary storage systems 203 may include Random Access Memory (RAM), Read Only Memory (ROM), hard drives, virtual hard drives, RAM drives, cloud storage systems, optical storage systems, physically encoded instructions (e.g., in an ASIC), or any combination of these systems.

Adjustments to the control settings may be determined based on data output from temperature sensors 155 and 157, GC 161, and laboratory data 205, among other things. After determining the new control settings, the control system 200 may make, or recommend, among other things, adjustments to, for example, the process cooling system 207, the CA addition and recirculation system 209, the flow control system 211, and the termination system 213 in real time.

The reactor and related methods may be an element of a staged reactor using two or more reactors in series, where one reactor may produce, for example, high molecular weight polyolefin and the other reactor may produce low molecular weight polyolefin.

The cooled recycle gas can provide an exemplary, non-limiting embodiment of the cooling of the polymerization system. For example, the ability to cool the polymerization system can be directly related to the heat capacity of the recycle gas, referred to as "dry mode". An inert gas can be added to the recycle gas with a greater heat capacity, which improves cooling, but can maintain a direct correlation with heat capacity to cool the polymerization system in an "enhanced drying mode". Additionally or alternatively, the drying mode may be deviated by cooling the circulating gas past its dew point and condensing a portion of the gas into a liquid. The liquid has a greater capacity to cool the polymerization system due to the heat of vaporization of the liquid compared to the gas. Figure 3 shows an example comparing the difference in cooling, cooling capacity, in different embodiments. Line 301 represents the dew point of the circulating gas inside the polymerization system. Under dry conditions (represented by line 303), the recycle gas provides reactor cooling which is directly related to the temperature to which it cools. In the enhanced drying mode (represented by line 305), the addition of inert gas to the recycle gas provides slightly greater reactor cooling based on the temperature to which it is cooled in the cooling system. Finally, line 307 represents condensed phase cooling, which provides even greater cooling by the addition of a condensing agent or inert gas that is condensed past the dew point and therefore has greater ability to cool the reactor due to their heat of vaporization.

Polyolefin production

Olefin polymerization can be carried out by contacting olefin monomer (optionally with comonomer) with one or more (supported or unsupported) catalysts in the presence of a CA composition and optionally hydrogen in a reactor (e.g., fluidized bed reactor 101 of fig. 1). The individual flow rates of the olefin monomer, optional comonomer, optional hydrogen, and the CA composition (or individual components thereof) may be controlled to maintain a fixed gas composition target. The concentration of all gases can be measured chromatographically. The solid catalyst, catalyst slurry, or liquid solution of catalyst may be injected directly into the reactor using a carrier gas (e.g., purified nitrogen), where the flow rate of the catalyst may be adjusted to change or maintain the catalyst inventory within the reactor.

In some embodiments, the polymerization may be conducted at a reactor pressure of less than or equal to about 4200kPa, about 700kPa to about 4200kPa, about 1300kPa to about 2800kPa, or about 1700kPa to about 2500 kPa.

Generally, the olefin monomer concentration is controlled and monitored by the partial pressure of the olefin monomer. In some embodiments, the olefin partial pressure may be less than or equal to about 4200kPa, such as about 500kPa to about 2000kPa, about 1000kPa to about 1800kPa, about 1200kPa to about 1700kPa, or about 1400kPa to about 1600 kPa.

The comonomer concentration can be controlled and monitored by the molar ratio of comonomer to olefin monomer (or alternatively, the flow rates of comonomer and olefin monomer are maintained at a fixed ratio). When present, the comonomer can be at a relative concentration to the olefin monomer that will achieve the desired weight percent incorporation of the comonomer into the final polyolefin. In some embodiments, the comonomer may be present in the gas phase at a molar ratio to the olefin monomer of from about 0.0001 to about 50 (comonomer to olefin monomer), from about 0.0001 to about 5, from about 0.0005 to about 1.0, or from about 0.001 to about 0.5.

The olefin monomer or comonomer may be, for example, a C2-C18 alpha-olefin. In some embodiments, the olefin monomer is ethylene and the comonomer is a C3-C12 alpha-olefin. In some embodiments, the olefin monomer may be ethylene or propylene, and the comonomer may include C4 to C10 alpha-olefins. For example, the C2-C18 alpha-olefins that may be used as comonomers in the described embodiments may include: ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methylpent-1-ene, 1-decene, 1-dodecene, 1-hexadecene and the like; and combinations thereof. Additionally, according to some embodiments described, a multiolefin may be used as a comonomer. For example, the multiolefin may include 1, 3-hexadiene, 1, 4-hexadiene, cyclopentadiene, dicyclopentadiene, 4-vinylcyclohex-1-ene, methyloctadiene, 1-methyl-1, 6-octadiene, 7-methyl-1, 6-octadiene, 1, 5-cyclooctadiene, norbornadiene, ethylidene norbornene, 5-vinylidene-2-norbornene, 5-vinyl-2-norbornene, and olefins formed in situ in the polymerization medium. The formation of the polyene containing long chain branching can occur when the alkene is formed in situ in the polymerization medium. Additional examples of comonomers can include isoprene, styrene, butadiene, isobutylene, chloroprene, acrylonitrile, and cyclic olefins. Combinations of the foregoing may be used in the methods described.

Examples of polymers that can be produced according to the described process may include the following: homopolymers and copolymers of C2-C18 alpha-olefins; polyvinyl chloride, Ethylene Propylene Rubber (EPR); ethylene-propylene diene rubber (EPDM); a polyisoprene; polystyrene; polybutadiene; a butadiene polymer copolymerized with styrene; a butadiene polymer copolymerized with isoprene; polymers of butadiene and acrylonitrile; an isobutylene polymer copolymerized with isoprene; ethylene butene rubber and ethylene butene diene rubber; polychloroprene; norbornene homopolymers and copolymers of norbornene with one or more C2-C18 alpha-olefins; and one or more terpolymers of C2-C18 alpha-olefins and diolefins. In some embodiments, the polyolefin produced by the described process may include an olefin homopolymer (e.g., a homopolymer of ethylene or propylene). In some cases, the polyolefin produced may be a copolymer, terpolymer, and the like of olefin monomers and comonomers.

In some embodiments, the olefin produced may be polyethylene or polypropylene. Exemplary polyethylenes produced by the described process can be homopolymers of ethylene or copolymers of ethylene (or terpolymers of ethylene) with at least one alpha-olefin (comonomer), wherein the ethylene content can be at least about 50% by weight of all monomers involved. Exemplary polypropylenes produced by the described process can be homopolymers of propylene or interpolymers of propylene and at least one alpha-olefin (comonomer), wherein the propylene content can be at least about 50% by weight of all monomers involved.

Hydrogen is often used in olefin polymerization to control the final properties of the polyolefin. For some types of catalyst systems, increasing the hydrogen concentration (or partial pressure) can change the molecular weight or melt index of the polyolefin produced. The melt index can therefore be influenced by the hydrogen concentration. Generally, the amount of hydrogen in the polymerization is expressed as a molar ratio relative to the total polymerizable monomers (e.g., relative to ethylene or relative to a blend of ethylene and hexene or propylene). The amount of hydrogen used in some polymerization processes is that amount necessary to achieve the desired melt index (or molecular weight) of the final polyolefin resin. In some embodiments, the molar ratio of hydrogen to total polymerizable monomer (H) in the gas phase₂Specific monomer) can be greater than or equal to about 0.00001, greater than or equal to about 0.0005, greater than or equal to about 0.001, less than or equal to about 10, less than or equal to about 5, less than or equal toAbout 3, less than or equal to about 0.10, wherein a range can include a combination of the upper mole ratio and the lower mole ratio described.

Catalyst and process for preparing same

Catalysts suitable for use in the described embodiments may include: ziegler natta catalysts, chromium based catalysts, vanadium based catalysts (e.g., vanadium oxytrichloride and vanadium acetylacetonate), metallocene catalysts and other single site or single site based catalysts, cationic forms of metal halides (e.g., aluminum trihalides), anionic initiators (e.g., butyl lithium), cobalt catalysts and mixtures thereof, nickel catalysts and mixtures thereof, rare earth metal catalysts (i.e., those containing a metal having a number of atoms in the periodic table of 57 to 103), such as compounds of cerium, lanthanum, praseodymium, gadolinium and niobium. A single catalyst may be used, or a mixture of catalysts may be used, as desired. The catalyst may be soluble or insoluble, supported or unsupported. Further, the catalyst may be a spray-dried prepolymer, liquid, or solution, slurry/suspension, or dispersion, with or without filler.

Metallocenes can include "half sandwich" and "full sandwich" compounds having one or more pi-bonded ligands (e.g., cyclopentadienyl and ligands isolobal to cyclopentadienyl) bound to at least one group 3 to group 12 metal atom, including lanthanide and actinide elements, and one or more leaving groups bound to at least one metal atom. The metallocene may be supported on a support material and may be supported with or without another catalyst component.

The pi-bonded ligands may be one or more rings or ring systems, such as cycloalkadienyl ligands and heterocyclic homologs. Pi-bonded ligands differ from leaving groups bound to the catalyst compound in that they are not highly affected by substitution or abstraction reactions. The metallocene catalysts may be the same or different if they have more than one pi-bonded ligand, any one or both of which may contain heteroatoms and any one or both of which may be substituted by at least one R group. Non-limiting examples of substituent R groups include groups selected from hydrogen radicals, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, acyl, aroyl, alkoxy, aryloxy, alkanethiol, dialkylamine, alkylamino, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, alkyl-and dialkyl-carbamoyl, acyloxy, acylamino, aroylamino and combinations thereof. In some embodiments, the pi-bonded ligand (independently at each occurrence) is selected from the group consisting of cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, and substituted derivatives of each. With respect to hydrocarbon substituents, the term "substituted" means that the group following the term possesses at least one moiety in place of one or more hydrogens selected from groups such as halogen groups (e.g., Cl, F, Br), hydroxyl, carbonyl, carboxyl, amine, phosphine, alkoxy, phenyl, naphthyl, C1-C10 alkyl, C2-C10 alkenyl, and combinations thereof. Examples of substituted alkyl and aryl groups may include: acyl, alkylamino, alkoxy, aryloxy, alkylthio, dialkylamino, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, alkyl-and dialkyl-carbamoyl, acyloxy, acylamino, arylamino, and combinations thereof.

In some embodiments, each leaving group may be independently selected from the group consisting of halide, hydride, C1-12 alkyl, C2-12 alkenyl, C6-12 aryl, C7-20 alkylaryl, C1-12 alkoxy, C6-16 aryloxy, C7-18 alkylaryloxy, C1-12 fluoroalkyl, C6-12 fluoroaryl, and C1-12 heteroatom-containing hydrocarbon, and substituted derivatives thereof. The phrase "leaving group" refers to one or more chemical moieties bound to the metal center of the catalyst component that can be abstracted from the catalyst component by an activator, thereby providing a species active for olefin polymerization or oligomerization.

The structure of the metallocene catalyst compound can take many forms, such as those disclosed in, for example, U.S. Pat. Nos.5,026,798, 5,703,187, and 5,747,406, including dimeric or oligomeric structures such as those disclosed in U.S. Pat. Nos.5,026,798 and 6,069,213. Other include those described in U.S. patent application publication Nos. US2005/0124487A1, US2005/0164875A1, and US 2005/0148744. In some embodiments, a hafnium metal atom may be used to form a metallocene (e.g., bis (n-propylcyclopentadienyl) hafnium Xn, bis (n-butylcyclopentadienyl) hafnium Xn, or bis (n-pentylcyclopentadienyl) hafnium Xn, where X is one of chloride or fluoride and n is 2), such as described in U.S. patent nos.6,242,545 and 7,157,531.

In certain embodiments, the metallocene catalyst compounds described above may include their structural or optical or enantiomeric (racemic mixtures), and in some embodiments, may be pure enantiomers.

In some embodiments, the catalyst may be a metallocene catalyst in the absence or substantial absence of a scavenger (e.g., triethylaluminum, trimethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum chloride, dibutylzinc, and the like). The term "substantially free" means that the compound is not intentionally added to the reactor or reactor components and, if present, is present in the reactor at less than about 1 ppm.

In some embodiments, the catalyst may be used with a cocatalyst and a promoter (e.g., an aluminum alkyl halide, an aluminum alkyl hydride, and an aluminoxane).

In some embodiments, one or more catalysts may be combined with up to about 10 wt% of one or more antistatic agents, such as metal-fatty acid compounds (e.g., aluminum stearate), based on the weight of the catalyst system (or components thereof). Other metals that may be suitable include other group 2 and group 5-13 metals. One or more antistatic agents may also be added directly to the reactor system.

In some embodiments, the supported catalyst may be combined with an activator, optionally with up to about 2.5 wt% antistatic agent (based on the weight of the catalyst composition), by tumbling and/or other suitable means. Exemplary antistatic agents may include: ethoxylated or methoxylated amines (e.g., KEMAMINE AS-990 from ICI Specialties) and polysulfone copolymers within the family of OCTASTAT compounds, more specifically OCTASTAT 2000, 3000 and 5000 (from Octel).

In some embodiments, an antistatic agent may be mixed with the catalyst and fed into the reactor. In other embodiments, the antistatic agent may be fed into the reactor separately from the catalyst. One advantage of feeding the antistatic agent into the reactor independently of the catalyst is that it allows the level of additive to be adjusted on-line. The antistatic agent may be in solution, slurry, or as a solid (e.g., as a powder) separately prior to introduction into the reactor.

In various embodiments, the polymerization reaction according to the described process may optionally employ other additives, such as inert particulate particles.

In some embodiments, the polymerization temperature may be from about 30 ℃ to about 120 ℃, from about 60 ℃ to about 115 ℃, from about 70 ℃ to about 110 ℃, or from about 70 ℃ to about 105 ℃.

In at least one embodiment, the present disclosure provides a catalyst system comprising a catalyst compound having a metal atom. The catalyst compound may be a metallocene catalyst compound. The metal may be a group 3 to group 12 metal atom, such as a group 3 to group 10 metal atom, or a lanthanide group atom. The catalyst compound having a group 3 to group 12 metal atom may be monodentate or polydentate, such as bidentate, tridentate or tetradentate, wherein hetero atoms of the catalyst, such as phosphorus, oxygen, nitrogen or sulfur, are chelated to the metal atom of the catalyst. Non-limiting examples include bis (phenolate). In at least one embodiment, the group 3 to group 12 metal atoms are selected from group 5, group 6, group 8 or group 10 metal atoms. In at least one embodiment, the group 3 to group 10 metal atoms are selected from Cr, Sc, Ti, Zr, Hf, V, Nb, Ta, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, and Ni. In at least one embodiment, the metal atom is selected from the group consisting of group 4,5, and 6 metal atoms. In at least one embodiment, the metal atom is a group 4 metal atom selected from Ti, Zr, or Hf. The oxidation state of the metal atom may range from 0 to +7, such as +1, +2, +3, +4 or +5, such as +2, +3 or + 4.

The catalyst compound of the present disclosure may be chromium or a chromium-based catalyst. The chromium-based catalyst comprises chromium oxide (CrO)₃) And a silylchromate catalyst. Chromium catalysts in the field of continuous fluidized bed gas phase polymerization for the production of polyethylene polymersMany developments have been made. Such catalysts and polymerization processes are described, for example, in U.S. patent application publication No.2011/0010938 and U.S. patent nos.7,915,357, 8,129,484, 7,202,313, 6,833,417, 6,841,630, 6,989,344, 7,504,463, 7,563,851, 8,420,754, and 8,101,691.

Metallocene catalyst compounds as used herein include metallocenes comprising a group 3 to group 12 metal complex, such as a group 4 to group 6 metal complex, such as a group 4 metal complex. The metallocene catalyst compound in the catalyst system of the present disclosure may be of the formula Cp^ACp^BM′X′_nNon-bridged metallocene catalyst compounds are shown in which each Cp is^AAnd Cp^BIndependently selected from cyclopentadienyl ligands and ligands isolobal to cyclopentadienyl, Cp^AAnd Cp^BOne or both may contain heteroatoms, and Cp^AAnd Cp^BOne or both may be substituted with one or more R' groups. M' is selected from the group consisting of group 3 to group 12 atoms and lanthanide group atoms. X' is an anionic leaving group. n is 0 or an integer from 1 to 4. R' is selected from the group consisting of alkyl, lower alkyl, substituted alkyl, heteroalkyl, alkenyl, lower alkenyl, substituted alkenyl, heteroalkenyl, alkynyl, lower alkynyl, substituted alkynyl, heteroalkynyl, alkoxy, lower alkoxy, aryloxy, alkylthio, lower alkylthio, arylthio, aryl, substituted aryl, heteroaryl, aralkyl, aralkylene, alkaryl, alkarylene, haloalkyl, haloalkenyl, haloalkynyl, heteroalkyl, heterocycle, heteroaryl, heteroatom-containing group, hydrocarbyl, lower hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, silyl, boranyl, phosphino, phosphine, amino, amine, ether and thioether.

In at least one embodiment, each Cp^AAnd Cp^BIndependently selected from the group consisting of cyclopentadienyl, indenyl, fluorenyl, cyclopentaphenanthreneyl, benzindenyl, fluorenyl, octahydrofluorenyl, cyclooctatetraenyl, cyclopentacyclododecene, phenanthroindenyl, 3, 4-benzofluorenyl, 9-phenylfluorenyl, 8-H-cyclopenta [ a ] a]Acenaphthenyl, 7-H-dibenzofluorenyl, indeno [1,2-9 ] s]The anthracene compound (A) is an anthracene compound,thienoindenyl, thienofluorenyl and hydrogenated forms thereof.

The metallocene catalyst compound may be of the formula Cp^A(A)Cp^BM′X′_nThe bridged metallocene catalyst compound shown, wherein each Cp^AAnd Cp^BIndependently selected from cyclopentadienyl ligands and ligands isolobal to cyclopentadienyl. Cp^AAnd Cp^BOne or both may contain heteroatoms, and Cp^AAnd Cp^BOne or both may be substituted with one or more R' groups. M' is selected from the group consisting of group 3 to group 12 atoms and lanthanide group atoms. X' is an anionic leaving group. n is 0 or an integer from 1 to 4. (A) Selected from the group consisting of divalent alkyl, divalent lower alkyl, divalent substituted alkyl, divalent heteroalkyl, divalent alkenyl, divalent lower alkenyl, divalent substituted alkenyl, divalent heteroalkenyl, divalent alkynyl, divalent lower alkynyl, divalent substituted alkynyl, divalent heteroalkynyl, divalent alkoxy, divalent lower alkoxy, divalent aryloxy, divalent alkylthio, divalent lower alkylthio, divalent arylthio, divalent aryl, divalent substituted aryl, divalent heteroaryl, divalent aralkyl, divalent aralkylene, divalent alkylaryl, divalent alkarylene, divalent haloalkyl, divalent haloalkenyl, divalent haloalkynyl, divalent heteroalkyl, divalent heterocycle, divalent heteroaryl, divalent heteroatom-containing group, divalent hydrocarbyl, divalent lower hydrocarbyl, divalent substituted hydrocarbyl, divalent heterohydrocarbyl, divalent silyl, divalent boranyl, divalent phosphine groups, divalent phosphines, divalent amino groups, divalent amines, divalent ethers, divalent thioethers. R' is selected from the group consisting of alkyl, lower alkyl, substituted alkyl, heteroalkyl, alkenyl, lower alkenyl, substituted alkenyl, heteroalkenyl, alkynyl, lower alkynyl, substituted alkynyl, heteroalkynyl, alkoxy, lower alkoxy, aryloxy, alkylthio, lower alkylthio, arylthio, aryl, substituted aryl, heteroaryl, aralkyl, aralkylene, alkaryl, alkarylene, haloalkyl, haloalkenyl, haloalkynyl, heteroalkyl, heterocycle, heteroaryl, heteroatom-containing group, hydrocarbyl, lower hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, silyl, boranyl, phosphino, phosphine, amino, amine, germanium, amino, and the likeEthers and thioethers.

In at least one embodiment, Cp^AAnd Cp^BEach of which is independently selected from the group consisting of cyclopentadienyl, n-propylcyclopentadienyl, indenyl, pentamethylcyclopentadienyl, tetramethylcyclopentadienyl, and n-butylcyclopentadienyl. (A) Can be O, S, NR 'or SiR'₂Wherein each R' is independently hydrogen or C₁-C₂₀A hydrocarbyl group.

In another embodiment, the metallocene catalyst compound is represented by the formula:

T_yCp_mMG_nX_q

wherein Cp is independently a substituted or unsubstituted cyclopentadienyl ligand or a substituted or unsubstituted ligand isolobal to cyclopentadienyl group such as indenyl, fluorenyl and indacenyl. M is a group 4 transition metal. G is of formula JR_zThe heteroatom radicals shown, wherein J is N, P, O or S, and R is linear, branched or cyclic C₁-C₂₀A hydrocarbyl group. z is 1 or 2. T is a bridging group. y is 0 or 1. X is a leaving group. m is 1, n is 1,2 or 3, q is 0, 1,2 or 3, and the sum of m + n + q is equal to the oxidation state of the transition metal.

In at least one embodiment, J is N, and R is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclooctyl, cyclododecyl, decyl, undecyl, dodecyl, adamantyl or isomers thereof.

The metallocene catalyst compound may be selected from:

bis (1-methyl, 3-n-butylcyclopentadienyl) zirconium dichloride;

dimethylsilylbis (tetrahydroindenyl) zirconium dichloride;

bis (n-propylcyclopentadienyl) hafnium dimethyl;

dimethylsilyl (tetramethylcyclopentadienyl) (cyclododecylamino) titanium dimethyl;

dimethylsilyl (tetramethylcyclopentadienyl) (cyclododecylamino) titanium dichloride;

dimethylsilyl (tetramethylcyclopentadienyl) (tert-butylamino) titanium dimethyl;

dimethylsilyl (tetramethylcyclopentadienyl) (tert-butylamino) titanium dichloride;

μ-(CH₃)₂si (cyclopentadienyl) (l-adamantylamino) M (R)₂；

μ-(CH₃)₂Si (3-tert-butylcyclopentadienyl) (1-adamantylamino) M (R)₂；

μ-(CH₃)₂(Tetramethylcyclopentadienyl) (1-adamantylamino) M (R)₂；

μ-(CH₃)₂Si (tetramethylcyclopentadienyl) (1-adamantylamino) M (R)₂；

μ-(CH₃)₂C (tetramethylcyclopentadienyl) (1-adamantylamino) M (R)₂；

μ-(CH₃)₂Si (tetramethylcyclopentadienyl) (1-tert-butylamino) M (R)₂；

μ-(CH₃)₂Si (fluorenyl) (1-tert-butylamino) M (R)₂；

μ-(CH₃)₂Si (tetramethylcyclopentadienyl) (1-cyclododecylamino) M (R)₂；

μ-(C₆H₅)₂C (tetramethylcyclopentadienyl) (1-cyclododecylamino) M (R)₂；

μ-(CH₃)₂Si(η⁵-2,6, 6-trimethyl-1, 5,6, 7-tetrahydro-s-indacen-1-yl) (tert-butylamino) M (R)₂；

Wherein M is selected from Ti, Zr and Hf; and R is selected from halogen or C₁-C₅An alkyl group.

In at least one embodiment, the catalyst compound is a bis (phenoxide) catalyst compound represented by formula (I):

m is group 4A metal. X¹And X²Independently is monovalent C₁-C₂₀Hydrocarbyl radical, C₁-C₂₀Substituted hydrocarbyl, heteroatom or heteroatom-containing group, or X¹And X²Joined together to form C₄-C₆₂Cyclic or polycyclic ring structures. R¹，R²，R³，R⁴，R⁵，R⁶，R⁷，R⁸，R⁹And R¹⁰Independently of one another is hydrogen, C₁-C₄₀Hydrocarbyl radical, C₁-C₄₀Substituted hydrocarbyl, heteroatom or heteroatom-containing group, or R¹，R²，R³，R⁴，R⁵，R⁶，R⁷，R⁸，R⁹Or R¹⁰Are joined together to form C₄-C₆₂Cyclic or polycyclic ring structures, or combinations thereof. Q is a neutral donor group. J is heterocycle, substituted or unsubstituted C₇-C₆₀Fused polycyclic groups wherein at least one ring is aromatic and wherein at least one ring (which may or may not be aromatic) has at least 5 ring atoms. G is as defined for J or may be hydrogen, C₂-C₆₀Hydrocarbyl radical, C₁-C₆₀Substituted hydrocarbyl, or may be independently substituted with R⁶，R⁷Or R⁸Or combinations thereof to form C₄-C₆₀Cyclic or polycyclic ring structures. Y is divalent C₁-C₂₀Hydrocarbyl or divalent C₁-C₂₀The substituted hydrocarbyl groups or (-Q-Y-) together form a heterocyclic ring. The heterocyclic ring may be aromatic and/or may have multiple fused rings.

In at least one embodiment, the catalyst compound of formula (I) is:

m is Hf, Zr or Ti. X¹，X²，R¹，R²，R³，R⁴，R⁵，R⁶，R⁷，R⁸，R⁹，R¹⁰And Y is as defined for formula (I). R¹¹，R¹²，R¹³，R¹⁴，R¹⁵，R¹⁶，R¹⁷，R¹⁸，R¹⁹，R²⁰，R²¹，R²²，R²³，R²⁴，R²⁵，R²⁶，R²⁷And R²⁸Independently of one another is hydrogen, C₁-C₄₀Hydrocarbyl radical, C₁-C₄₀Substituted hydrocarbyl radicals, functional groups containing elements of groups 13-17, or R¹，R²，R³，R⁴，R⁵，R⁶，R⁷，R⁸，R⁹，R¹⁰，R¹¹，R¹²，R¹³，R¹⁴，R¹⁵，R¹⁶，R¹⁷，R¹⁸，R¹⁹，R²⁰，R²¹，R²²，R²³，R²⁴，R²⁵，R²⁶，R²⁷And R²⁸May be independently joined together to form C₄-C₆₂Cyclic or polycyclic ring structures, or combinations thereof. R¹¹And R¹²May be joined together to form a 5-to 8-membered heterocyclic ring. Q is a group 15 or 16 atom. z is 0 or 1. J is CR ' or N, and G is CR ' or N, wherein R ' is C₁-C₂₀Hydrocarbyl or carbonyl-containing C₁-C₂₀A hydrocarbyl group. Z is 0 if Q is a group 16 atom and z is 1 if Q is a group 15 atom.

In at least one embodiment, the catalyst is an iron complex represented by formula (IV):

wherein:

a is chlorine, bromine, iodine, -CF₃OR-OR¹¹，

R¹And R²Each independently of the other being hydrogen, C₁-C₂₂-an alkyl group,C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, arylalkyl, wherein the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, or a 5-, 6-or 7-membered heterocyclic group containing at least one atom selected from N, P, O and S;

wherein R is¹And R²Optionally with halogen, -NR¹¹ ₂，-OR¹¹or-SiR¹² ₃Substitution;

wherein R is¹Optionally with R³Is bonded with R²Optionally with R⁵A bond, in each case independently, forming a 5-, 6-or 7-membered ring;

R⁷is C₁-C₂₀An alkyl group;

R³，R⁴，R⁵，R⁸，R⁹，R¹⁰，R¹⁵，R¹⁶and R¹⁷Each of (A) is independently hydrogen, C₁-C₂₂-alkyl radical, C₂-C₂₂-alkenyl, C₆-C₂₂Aryl, arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, -NR¹¹ ₂，-OR¹¹Halogen, -SiR¹² ₃Or a 5-, 6-or 7-membered heterocyclic group containing at least one atom selected from N, P, O and S;

wherein R is³，R⁴，R⁵，R⁷，R⁸，R⁹，R¹⁰，R¹⁵，R¹⁶And R¹⁷Optionally with halogen, -NR¹¹ ₂，-OR¹¹or-SiR¹² ₃Substitution;

wherein R is³Optionally with R⁴Bonding of R⁴Optionally with R⁵Bonding of R⁷Optionally with R¹⁰Bonding of R¹⁰Optionally with R⁹Bonding of R⁹Optionally with R⁸Bonding of R¹⁷Optionally with R¹⁶Is bonded with R¹⁶Optionally with R¹⁵Bonded, in each case independently, to form a 5-, 6-or 7-membered carbocyclic or heterocyclic ringThe heterocyclic ring contains at least one atom selected from the group consisting of N, P, O and S;

R¹³is C bonded to the aryl ring via a primary or secondary carbon atom₁-C₂₀-an alkyl group,

R¹⁴is chlorine, bromine, iodine, -CF₃OR-OR¹¹Or C bonded to an aryl ring₁-C₂₀-an alkyl group;

each R¹¹Independently of one another is hydrogen, C₁-C₂₂-alkyl radical, C₂-C₂₂-alkenyl, C₆-C₂₂Aryl, arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, or-SiR¹² ₃Wherein R is¹¹Optionally substituted with halogen, or two R¹¹The groups are optionally bonded to form a 5-or 6-membered ring;

each R¹²Independently of one another is hydrogen, C₁-C₂₂-alkyl radical, C₂-C₂₂-alkenyl, C₆-C₂₂Aryl, arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, or two R¹²The groups are optionally bonded to form a 5-or 6-membered ring,

E¹，E²and E³Each of which is independently carbon, nitrogen or phosphorus;

if E is¹，E²And E³Is nitrogen or phosphorus each u is independently 0, and if E¹，E²And E³Is carbon and each u is independently 1,

each X is independently fluorine, chlorine, bromine, iodine, hydrogen, C₁-C₂₀-alkyl radical, C₂-C₁₀-alkenyl, C₆-C₂₀Aryl, arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, -NR¹⁸ ₂，-OR¹⁸，-SR¹⁸，-SO₃R¹⁸，-OC(O)R¹⁸-CN, -SCN, β -diketone (β -diketonate), -CO, -BF₄ ^-，-PF₆ ^-Or a bulky non-coordinating anion, and the groups X may be bonded to each other;

each R¹⁸Independently of one another is hydrogen, C₁-C₂₀-alkyl radical, C₂-C₂₀-alkenyl, C₆-C₂₀Aryl, arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, or-SiR¹⁹ ₃Wherein R is¹⁸May be substituted by halogen or nitrogen-or oxygen-containing groups, and two R¹⁸The groups are optionally bonded to form a 5-or 6-membered ring;

each R¹⁹Independently of one another is hydrogen, C₁-C₂₀-alkyl radical, C₂-C₂₀-alkenyl, C₆-C₂₀Aryl or arylalkyl, where the alkyl has 1 to 10 carbon atoms and the aryl has 6 to 20 carbon atoms, where R¹⁹May be substituted by halogen or nitrogen-or oxygen-containing groups, or two R¹⁹The groups are optionally bonded to form a 5-or 6-membered ring;

s is a number of atoms of 1,2 or 3,

d is a neutral donor, and

t is 0 to 2.

In at least one embodiment, the catalyst is a quinolinyldiamido transition metal complex represented by formulas (V) and (VI):

wherein:

m is a group 3-12 metal;

j is a three-atom length bridge between the quinoline and the amino nitrogen;

e is selected from carbon, silicon or germanium;

x is an anionic leaving group;

l is a neutral Lewis base;

R¹and R¹³Independently selected from hydrocarbyl, substituted hydrocarbyl and silyl;

R²-R¹²independently selected from the group consisting of hydrogen, hydrocarbyl, alkoxy, silyl, amino, aryloxy, substituted hydrocarbyl, halogen, and phosphino;

n is 1 or 2;

m is 0, 1 or 2

n + m is not more than 4; and

any two adjacent R groups (e.g. R)¹And R²，R²And R³Etc.) rings that may be joined to form a substituted or unsubstituted hydrocarbyl or heterocyclic ring, wherein the ring has 5,6,7, or 8 ring atoms and wherein substituents on the ring may join to form additional rings;

any two X groups may be joined together to form a dianionic group;

any two L groups may be joined together to form a bidentate lewis base;

the X group may be joined to the L group to form a monoanionic bidentate group;

m is a group 4 metal, zirconium or hafnium in at least one embodiment;

in at least one embodiment J is an arylmethyl, dihydro-1H-indenyl, or tetralin group;

in at least one embodiment E is carbon;

x is alkyl, aryl, hydride, alkylsilane, fluoro, chloro, bromo, iodo, triflate, carboxylate or alkylsulfonate in at least one embodiment;

in at least one embodiment L is an ether, amine or thioether;

in at least one embodiment, R⁷And R⁸Joined to form a 6-membered aromatic ring and joined R⁷R⁸The radical is-CH ═ CHCH ═ CH —;

in at least one embodiment R¹⁰And R¹¹Joined to form a 5-membered ring and joined R¹⁰And R¹¹The radical being-CH₂CH₂-；

In at least one embodiment, R¹⁰And R¹¹Joined to form a 6-membered ring and joined R¹⁰And R¹¹The radical being-CH₂CH₂CH₂-；

In at least one embodiment, R¹And R¹³May be independently selected from phenyl variously substituted with 0 to 5 substituents including: f, Cl, Br, I, CF₃，NO₂Alkoxy, dialkylamino, aryl, and alkyl groups having 1 to 10 carbons such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and isomers thereof.

In some embodiments, the catalyst is a phenoxyimine compound represented by formula (VII):

wherein M represents a transition metal atom selected from the group consisting of metals of groups 3 to 11 of the periodic Table; k is an integer from 1 to 6; m is an integer of 1 to 6; r^a-R^fMay be the same as or different from each other and each represents a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, in which 2 or more groups may be bonded to each other to form a ring; when k is 2 or more, R^aGroup, R^bGroup, R^cGroup, R^dGroup, R^eGroup or R^fThe radicals may be identical to or different from each other, R being contained in one ligand^a-R^fOne group of (A) and R contained in the other ligand^a-R^fOne of the groups of (a) may form a linking group or a single bond, and R^a-R^fThe heteroatom contained in (a) may be coordinated to or bound to M; m is a number satisfying the valence of M; q represents a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group or a tin-containing group; when m is 2 or more, plural groups represented by Q may be the same as or different from each other, and plural groups represented by Q may be bonded to each other to form a ring.

In another embodiment, the catalyst is a bis (imino) pyridyl group of formula (VIII):

wherein:

m is Co or Fe; each X is an anion; n is 1,2 or 3, such that the total number of negative charges on the one or more anions is equal to the oxidation state of the Fe or Co atoms present in (VIII);

R¹，R²and R³Each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;

R⁴and R⁵Each independently is hydrogen, hydrocarbyl, an inert functional group or substituted hydrocarbyl;

R⁶is of formula (IX):

and R⁷Is of formula (X):

R⁸and R¹³Each independently is a hydrocarbyl, substituted hydrocarbyl or inert functional group;

R⁹，R¹⁰，R¹¹，R¹⁴，R¹⁵and R¹⁶Each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;

R¹²and R¹⁷Each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;

and with the proviso that R⁸，R⁹，R¹⁰，R¹¹，R¹²，R¹³，R¹⁴，R¹⁵，R¹⁶And R¹⁷Any two adjacent to each other may together form a ring.

In at least one embodiment, the catalyst compound is represented by formula (XI):

M¹selected from titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten. In at least one embodiment, M¹Is zirconium.

Q¹，Q²，Q³And Q⁴Each of which is independently oxygen or sulfur. In at least one embodiment, Q¹，Q²，Q³And Q⁴Is oxygen, alternatively all Q¹，Q²，Q³And Q⁴Is oxygen.

R¹And R²Independently hydrogen, halogen, hydroxy, hydrocarbyl, or substituted hydrocarbyl (e.g. C)₁-C₁₀Alkyl radical, C₁-C₁₀Alkoxy radical, C₆-C₂₀Aryl radical, C₆-C₁₀Aryloxy radical, C₂-C₁₀Alkenyl radical, C₂-C₄₀Alkenyl radical, C₇-C₄₀Arylalkyl radical, C₇-C₄₀Alkylaryl group, C₈-C₄₀An arylalkenyl group, or a conjugated diene, optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl, or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 non-hydrogen atoms). R¹And R²May be a halogen selected from fluorine, chlorine, bromine or iodine. In at least one embodiment, R¹And R²Is chlorine.

Alternatively, R¹And R²May also be joined together to form alkanediyl or conjugated C₄-C₄₀Diene ligands coordinated to M¹The above. R¹And R²Also conjugated dienes which may be identical or different, optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 atoms (not counting hydrogen) and/or being conjugated with M¹A pi-complex is formed.

Is suitable for R¹Andor R²Exemplary groups of (a) may include 1, 4-diphenyl, 1, 3-butadiene, 1, 3-pentadiene, 2-methyl-1, 3-pentadiene, 2, 4-hexadiene, 1-phenyl, 1, 3-pentadiene, 1, 4-dibenzyl, 1, 3-butadiene, 1, 4-di (tolyl) -1, 3-butadiene, 1, 4-bis (trimethylsilyl) -1, 3-butadiene, and 1, 4-dinaphthyl-1, 3-butadiene. R¹And R²May be the same and is C₁-C₃Alkyl or alkoxy radicals, C₆-C₁₀Aryl or aryloxy radical, C₂-C₄Alkenyl radical, C₇-C₁₀Arylalkyl radical, C₇-C₁₂Alkylaryl or halogen.

R⁴，R⁵，R⁶，R⁷，R⁸，R⁹，R¹⁰，R¹¹，R¹²，R¹³，R¹⁴，R¹⁵，R¹⁶，R¹⁷，R¹⁸And R¹⁹Each of which is independently hydrogen, halogen, C₁-C₄₀Hydrocarbyl or C₁-C₄₀Substituted hydrocarbon radicals (e.g. C)₁-C₁₀Alkyl radical, C₁-C₁₀Alkoxy radical, C₆-C₂₀Aryl radical, C₆-C₁₀Aryloxy radical, C₂-C₁₀Alkenyl radical, C₂-C₄₀Alkenyl radical, C₇-C₄₀Arylalkyl radical, C₇-C₄₀Alkylaryl group, C₈-C₄₀Arylalkenyl, or a conjugated diene, optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 non-hydrogen atoms), -NR'₂，-SR′，-OR，-OSiR′₃，-PR′₂Wherein each R' is hydrogen, halogen, C₁-C₁₀Alkyl or C₆-C₁₀Aryl, or R⁴And R⁵，R⁵And R⁶，R⁶And R⁷，R⁸And R⁹，R⁹And R¹⁰，R¹⁰And R¹¹，R¹²And R¹³，R¹³And R¹⁴，R¹⁴And R¹⁵，R¹⁶And R¹⁷，R¹⁷And R¹⁸And R¹⁸And R¹⁹One or more of which join to form a saturated ring, an unsaturated ring, a substituted saturated ring, or a substituted unsaturated ring. In at least one embodiment, C₁-C₄₀The hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, isooctyl, sec-octyl, n-nonyl, isononyl, sec-nonyl, n-decyl, isodecyl, and sec-decyl.

In at least one embodiment, R¹¹And R¹²Is C₆-C₁₀Aryl, e.g. phenyl or naphthyl, optionally with C₁-C₄₀Hydrocarbyl radicals such as C₁-C₁₀Hydrocarbyl substitution. In at least one embodiment, R⁶And R¹⁷Is C_1-40Alkyl radicals, e.g. C₁-C₁₀An alkyl group.

In at least one embodiment, R⁴，R⁵，R⁶，R⁷，R⁸，R⁹，R¹⁰，R¹³，R¹⁴，R¹⁵，R¹⁶，R¹⁷，R¹⁸And R¹⁹Each of which is independently hydrogen or C₁-C₄₀A hydrocarbyl group. In at least one embodiment, C₁-C₄₀The hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, isooctyl, sec-octyl, n-nonyl, isononyl, sec-nonyl, n-decyl, isodecyl, and sec-decyl. In at least one embodiment, R⁶And R¹⁷Each of (A) is C₁-C₄₀Hydrocarbyl and R⁴，R⁵，R⁷，R⁸，R⁹，R¹⁰，R¹³，R¹⁴，R¹⁵，R¹⁶，R¹⁸And R¹⁹Is hydrogen. In at least one embodiment, C₁-C₄₀The hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, isooctyl, sec-octyl, n-nonyl, isononyl, sec-nonyl, n-decyl, isodecyl, and sec-decyl.

R³Is C₁-C₄₀Unsaturated alkyl or substituted C₁-C₄₀Unsaturated alkyl (e.g. C)₁-C₁₀Alkyl radical, C₁-C₁₀Alkoxy radical, C₆-C₂₀Aryl radical, C₆-C₁₀Aryloxy radical, C₂-C₁₀Alkenyl radical, C₂-C₄₀Alkenyl radical, C₇-C₄₀Arylalkyl radical, C₇-C₄₀Alkylaryl group, C₈-C₄₀An arylalkenyl group, or a conjugated diene, optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl, or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 non-hydrogen atoms).

In at least one embodiment, R³Is a hydrocarbon group containing a vinyl moiety. As used herein, "vinyl" and "vinyl moiety" are used interchangeably and include terminal olefins, such as the structureAs shown. R³The hydrocarbon group (e.g. C) may be further substituted₁-C₁₀Alkyl radical, C₁-C₁₀Alkoxy radical, C₆-C₂₀Aryl radical, C₆-C₁₀Aryloxy radical, C₂-C₁₀Alkenyl radical, C₂-C₄₀Alkenyl radical, C₇-C₄₀Arylalkyl radical, C₇-C₄₀Alkylaryl group, C₈-C₄₀Arylalkenyl, or conjugated dienes optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 non-hydrogen atoms). In at least one embodiment, R³Is C₁-C₄₀Unsaturated alkyl (which is vinyl) or substituted C₁-C₄₀Unsaturated alkyl (which is vinyl). R³May be substituted by the structure-R' CH ═ CH₂Wherein R' is C₁-C₄₀Hydrocarbyl or C₁-C₄₀Substituted hydrocarbon radicals (e.g. C)₁-C₁₀Alkyl radical, C₁-C₁₀Alkoxy radical, C₆-C₂₀Aryl radical, C₆-C₁₀Aryloxy radical, C₂-C₁₀Alkenyl radical, C₂-C₄₀Alkenyl radical, C₇-C₄₀Arylalkyl radical, C₇-C₄₀Alkylaryl group, C₈-C₄₀An arylalkenyl group, or a conjugated diene, optionally substituted with one or more hydrocarbyl, tri (hydrocarbyl) silyl or tri (hydrocarbyl) silylhydrocarbyl groups, the diene having up to 30 non-hydrogen atoms). In at least one embodiment, C₁-C₄₀The hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, isooctyl, sec-octyl, n-nonyl, isononyl, sec-nonyl, n-decyl, isodecyl, and sec-decyl.

In at least one embodiment, R³Is 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl, 1-nonenyl or 1-decenyl.

In at least one embodiment, the catalyst is a group 15 containing metal compound represented by formula (XII) or (XIII):

wherein M is a group 3-12 transition metal or a group 13 or group 14 main group metal, a group 4,5 or 6 metal. In some embodiments, M is a group 4 metal, such as zirconium, titanium or hafnium. Each X is independently a leaving group, e.g., an anionic leaving group. Should leaveThe substituent may include hydrogen, hydrocarbyl, heteroatom, halogen or alkyl; y is 0 or 1 (the group L' is absent when y is 0). The term 'n' is the oxidation state of M. In various embodiments, n is +3, +4, or + 5. In some embodiments, n is + 4. The term'm ' represents the formal charge of the YZL or YZL ' ligand and is 0, -1, -2, or-3 in various embodiments. In some embodiments, m is-2. L is a group 15 or 16 element, such as nitrogen or oxygen; l' is a group containing a group 15 or 16 element or a group 14 element, such as carbon, silicon or germanium. Y is a group 15 element, such as nitrogen or phosphorus. In some embodiments, Y is nitrogen. Z is a group 15 element, such as nitrogen or phosphorus. In some embodiments, Z is nitrogen. R¹And R²Independently is C₁-C₂₀A hydrocarbyl group, a heteroatom-containing group having up to 20 carbon atoms, silicon, germanium, tin, lead, or phosphorus. In some embodiments, R¹And R²Is C₂-C₂₀Alkyl, aryl or aralkyl radicals, e.g. C₂-C₂₀Linear, branched or cyclic alkyl, or C₂-C₂₀A hydrocarbyl group. R¹And R²And may also be interconnected with each other. R³May be absent or may be hydrocarbyl, hydrogen, halogen, heteroatom containing groups. In some embodiments, R³Is absent, for example, if L is oxygen, or hydrogen, or a linear, cyclic or branched alkyl group having 1 to 20 carbon atoms. R⁴And R⁵Independently an alkyl group, an aryl group, a substituted aryl group, a cyclic alkyl group, a substituted cyclic alkyl group, a cyclic aralkyl group, a substituted cyclic aralkyl group, or a polycyclic ring system, often having up to 20 carbon atoms. In some embodiments, R⁴And R⁵Having 3 to 10 carbon atoms, or is C₁-C₂₀Hydrocarbyl radical, C₁-C₂₀Aryl or C₁-C₂₀Aralkyl, or a heteroatom containing group. R⁴And R⁵May be interconnected with each other. R⁶And R⁷Independently absent, hydrogen, alkyl, halogen, heteroatom or hydrocarbyl, for example linear, cyclic or branched alkyl having 1 to 20 carbon atoms. In some embodiments, R⁶And R⁷Is absent. R may be absent, or may be hydrogen, a group 14 atom-containing group, a halogen or a heteroatom-containing group.

"formal charge of a YZL or YZL' ligand" means the charge of the entire ligand in the absence of metal and leaving group X. "R¹And R²Or interconnected "means R¹And R²May be bonded directly to each other or may be bonded to each other through other groups. "R⁴And R⁵Or interconnected "means R⁴And R⁵May be bonded directly to each other or may be bonded to each other through other groups. The alkyl group can be a linear, branched alkyl, alkenyl, alkynyl, cycloalkyl, aryl, acyl, aroyl, alkoxy, aryloxy, alkylthio, dialkylamino, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, alkyl-or dialkyl-carbamoyl, acyloxy, acylamino, aroylamino, a linear, branched, or cyclic alkylene group, or a combination thereof. Aralkyl is defined as a substituted aryl group.

In one or more embodiments, R⁴And R⁵Independently, a group represented by the following structure (XIV):

bond to Z or Y (XIV)

Wherein R is⁸-R¹²Each is independently hydrogen, C₁-C₄₀Alkyl, halo, heteroatom containing groups containing up to 40 carbon atoms. In some embodiments, R⁸-R¹²Is C₁-C₂₀Linear or branched alkyl, for example methyl, ethyl, propyl or butyl. Any two of the R groups may form a cyclic group and/or a heterocyclic group. The cyclic group may be aromatic. In one embodiment, R⁹，R¹⁰And R¹²Independently methyl, ethyl, propyl or butyl (including all isomers). In another embodiment, R⁹，R¹⁰And R¹²Is methyl, and R⁸And R¹¹Is hydrogen.

In one or more embodiments, R⁴And R⁵Are all groups represented by the following structure (XV):

bond to Z or Y (XV)

Wherein M is a group 4 metal, such as zirconium, titanium or hafnium. In some embodiments, M is zirconium. Each of L, Y and Z may be nitrogen. R¹And R²May be-CH₂-CH₂-。R³May be hydrogen, and R⁶And R⁷May not be present.

In some embodiments, the maximum amount of aluminoxane is up to 5000 times the molar excess of Al/M relative to the catalyst compound (per metal catalytic center). The ratio of minimum aluminoxane to catalyst compound is 1:1 molar. Alternative ranges include 1:1 to 500:1, alternatively 1:1 to 200:1, alternatively 1:1 to 100:1, or alternatively 1:1 to 50: 1.

Other catalysts used in the process of the present disclosure include "non-metallocene complexes," which are defined as transition metal complexes that are not characterized by cyclopentadienyl anions or substituted cyclopentadienyl anion donors (e.g., cyclopentadienyl, fluorenyl, indenyl, methylcyclopentadienyl). Examples of potentially suitable families of non-metallocene complexes may include late transition metal pyridyldiimines (e.g., U.S.7,087,686), pyridyldiamines of group 4 elements (e.g., U.S.7,973,116), quinolinyldiamines (e.g., U.S. publication No.2018/0002352 a1), pyridylamines (e.g., U.S.7,087,690), phenoxyimines (e.g., Accounts of Chemical Research 2009,42,1532-.

CA compositions

The methods of the present disclosure provide increased reactor production rates (e.g., by altering CAs within a CA composition) as compared to adding a previously used CAs or CA composition, while avoiding conditions within the reactor that may lead to excessive sticking or liquid formation within the reactor. These methods use variable processes and may be implemented at a factory site or online, in a process control system, or offline (e.g., using spreadsheet programs, databases, or application specific programs).

An increase in the productivity of the polymerization process may be achieved by controlling the relative concentrations of the two or more CAs within the reactor (i.e., the molar percentage of CA relative to the total reactor gas, which may be derived from the respective partial pressures relative to the total pressure within the reactor). The SL of the first condensing agent (within the gas composition having a single CA) may be based on the relationship of the total allowable CA composition_CA1) The equivalence factor and dew point limit of the gas phase composition involving the first CA with additional CA(s) changes the concentration of the two or more CAs.

Dew point and dew point limit

The dew point depends on the concentration of the various gas components in the gas phase composition, and the reactor pressure. Since the concentration of the gas in the reactor and the reactor pressure will change as the reaction proceeds, the change in dew point is calculated and monitored. The addition of the CA composition to the gas stream entering the reactor affects the dew point of the gas phase composition within the reactor.

The estimation of the dew point may include identifying the concentration of various gases within the gas composition, which may be determined in real time by gas chromatography. Further, the estimation of the dew point may include identifying the pressure within the reactor, which may be defined as the reactor pressure just upstream of the distributor plate (e.g., 109 in FIG. 1). The pressure upstream of the distributor plate may include (i) the reactor pressure at the top of the reactor, (ii) the head pressure from the polymer bed inside the reactor, and (iii) the pressure drop across the distributor plate. Defining the reactor pressure in this manner facilitates a conservative estimate of the dew point, since the combination of pressures results in a higher pressure result than if the pressure were measured at another location in the reactor. Alternatively, other pressure measurement locations may be used, for example, the pressure of the gas exiting the top of the reactor. If the pressure is measured at other locations, the dew point limit may be shifted further from the predicted dew point to account for the pressure differential across the reactor.

The dew point of the gas phase composition may be predicted using thermodynamic state equations, such as the Soave/Redlich/Kwong (SRK) equation or the Benedict/Webb/Rubin (BWR) equation. For hydrocarbon mixtures at temperature and pressure within the gas phase reactor, the SRK equation can be used to predict the dew point. Dew point prediction of a multi-component mixture can be accomplished by setting the fugacity of each component in the gas phase equal to its fugacity in the liquid phase. The fugacity is defined for each phase by means of thermodynamic equations of state that predict the activity coefficient of each component in the liquid phase and the fugacity coefficient in the same gas phase.

Due to the presence of several components in the gas phase composition, several simultaneous equations also exist. The equation can be simplified since the concentration and pressure of the gas within the gas phase composition are measured, and the remaining unknown is the dew point temperature. The equation can be solved for dew point temperature by an iterative method, where any temperature is used to find the desired mole fraction of liquid phase. The temperature was varied until the sum of the liquid mole fractions was equal to 1. If the sum of the liquid mole fractions is not equal to 1, the calculation is repeated using different temperatures. Such calculations may be performed in an iterative manner on a control system (e.g., control system 200, from fig. 2). Dew point can be predicted once results are obtained from online GC, or at specified time periods, e.g., every 5 minutes, 10 minutes, 15 minutes, or longer.

Reaching the dew point in the gas phase reactor can lead to reactor downtime. The dew point limit is set at a temperature above the predicted dew point of the gas phase composition for safe and continuous reactor operation. For example, the dew point limit can be from about 0.5 ℃ higher to about 20 ℃ higher, from about 1 ℃ higher to about 15 ℃ higher, from about 5 ℃ higher to about 10 ℃ higher, or from about 1 ℃ higher to about 5 ℃ higher than the dew point of the gas phase composition. Automation of reactor conditions including adjustment of the CA composition can facilitate a dew point limit that is closer to the calculated dew point of the gas phase composition, for example, the dew point limit can be from about 0.5 ℃ higher to about 10 ℃, from about 1 ℃ higher to about 8 ℃, or from about 4 ℃ higher or to about 8 ℃ higher than the calculated dew point of the gas phase composition. The dew point limit can be a fixed temperature from the calculated dew point of the gas phase composition, for example, 15 ℃ above, 14 ℃ above, 13 ℃ above, 12 ℃ above, 11 ℃ above, 10 ℃ above, 9 ℃ above, 8 ℃ above, 7 ℃ above, 6 ℃ above, 5 ℃ above, 4 ℃ above, 3 ℃ above, 2 ℃ above, 1 ℃ above, or 0.5 ℃ above the calculated dew point of the gas phase composition. Alternatively, the limit may vary in relation to the specific reactor conditions, for example, the dew point limit may increase in difference to the calculated dew point of the gas phase composition as the reactor pressure increases.

If the pressure is constant, the dew point limit may appear as a line in the graph comparing the temperature and concentration of the first CA. The dew point may similarly be presented as a line at a lower temperature, for example 10 ℃ below the dew point limit.

Total permissible refrigerant composition

A fluidized bed process is conducted wherein the velocity of the gas recycle stream is sufficient to maintain the reaction zone in a fluidized state. In a fluidized bed polymerization process, the amount of fluid circulated to remove the heat of polymerization can be greater than the amount of fluid required to support the fluidized bed and to adequately mix the solids within the fluidized bed. Excessive velocity provides additional gas flow to (and throughout) the fluid bed for additional cooling capacity and more intense mixing of the reactor bed. However, to prevent excessive entrainment of solids within the gas stream withdrawn from the fluidized bed, the velocity of the gas stream may be adjusted.

The fluidized bed in the gas phase reactor may include reactive components, other agents (anti-slip agents, antistatic agents), and inert components including inert gases and CAs. The combination of all of these components may account for 100% (e.g., volume or mass balance) of the gas flow within and throughout the gas phase reactor. The total allowable CA composition (Z) is the combined amount of CAs that undergoes concentration of the other components in the fluidized bed.

Thus, to increase Z, a portion of another component in the gas stream may be reduced. An increase in Z can provide greater cooling of the reactor and thus increased production rates, but is limited by reactor volume and venting. Substantially all (e.g., 100%) of the components entering the reactor exit the reactor either in the product stream or in the recycle stream. Z is increased by decreasing the other component. For example, an increase in Z can be achieved by lower amounts of other inert components including nitrogen. Alternatively, Z may be increased by using monomers and comonomers with less inert impurities, higher purity feedstocks may provide increased addition of CA compositions.

The ratio of inert components may be varied but may be limited by reactor venting. To maintain mass balance for a given inert gas concentration, the inert gas flow into the reactor must be equal to the inert gas vented from the reactor. Reducing the concentration of inert gas in the reactor can result in more overall purge flow. Increased blowdown may result in greater material loss and is also limited by reactor design. For a given reactor producing a particular grade of polyolefin, the minimum amount of inert gas can be identified based on a cost analysis that balances the reactor design, including limitations on vent flow and raw material loss associated with increased production rates (which involve improved cooling from a larger CA composition).

The reactive and other components that assist in product formation may remain constant as they may be specific to one embodiment of the desired product. Alternatively, Z may be increased by decreasing the concentration of monomer or comonomer. Without being bound by theory, reducing the pressure of monomer and comonomer can reduce catalyst activity, but the costs that may be associated with reduced catalyst activity are overcome by improved production rates accompanied by increased cooling from the additional Z.

In addition, Z can be increased by increasing the overall reactor pressure. For example, if the individual components are at a particular partial pressure, increasing the total pressure within the reactor will therefore increase the pressure available to the CA composition. The increase in pressure within the reactor may be limited by reactor design, feed pressure and compression costs, solubility variations and product to reactant viscosities.

Thus, the overall allowable CA composition may be an analysis of the cost benefits of the separate option of increasing Z, including but not limited to removing a portion of the other components or reactor pressurization. Cost analysis may take into account a number of factors including catalyst activity, feedstock purity and availability, reactor design (pressure, volume and blowdown), product grade, and flow rate sufficient for fluidized bed. The cost of any of these factors can be balanced by the increased production rate resulting from improved cooling due to the additional volume (or pressure) allocated to the CA composition.

If the reactor conditions are near the dew point limit of the gas phase composition, the response is typically to reduce the total allowable CA composition or to reduce the reactor pressure by venting. Reducing the overall allowable CA composition lowers the dew point of the gas phase composition by allowing less of the less volatile gas in the reactor. Similarly, venting the reactor reduces the partial pressure of CAs, and the total pressure within the same reactor. Reactor venting is a rapid process that can be used to avoid dew point limits. While reducing the overall allowable CA composition and lowering the reactor pressure both have a detrimental effect on production rates, either can be used to avoid reactor shutdowns, and subsequent time consuming cleaning and restarting. Reducing the overall allowable CA composition or venting the reactor compared to reaching the dew point limit and causing condensation and resin stickiness may therefore be less expensive.

Limit of adhesion

There may be a limit to the concentration of condensable gases (whether CAs, comonomer or a combination thereof) that can be tolerated in the reaction system. Above a certain threshold concentration, condensable gases may not cause sudden fluidization losses in the reactor due to condensation near the dew point. Fluidization loss, not due to condensation near the dew point, is an indication of Sticking Limit (SL). SL is the CA limit in a CA composition with a single CA under certain conditions in a gas phase reactor. SL for a particular CA may be confirmed by laboratory methods or by computational methods.

Suitable laboratory methods for determining SL are described in U.S. Pat. No.10,029,226, which is incorporated by reference. The method estimates SL by measuring the rotational speed of the stirrer per minute in the autoclave as the temperature increases. When the mixture becomes excessively adherent, the stirrer is stopped at a certain temperature. The experiments were conducted at varying amounts of condensing agent and viscosity temperature related to SL as a linear function. Thus, the adhesion limit for a particular grade of polyolefin is calculated as a linear function of various laboratory experiments to determine the tack temperature.

Another suitable laboratory method for determining tack and SL is described in U.S. patent No.8273834, which is incorporated by reference. The method describes the use of differential scanning calorimetry and prediction of the solubility of the reaction mixture in polyethylene, using melting point suppression to determine stickiness. SL can be calculated by determining the reaction temperature and the melt initiation temperature difference, also referred to as the change in melt initiation temperature (Δ MIT), of the polyolefin reaction mixture. Δ MIT is an indication of how far the reaction temperature entered the DSC melting curve under the reactor conditions.

Suitable calculation methods are based on model phase behavior (modeling phase behavior) within the polymer mixture. Model phase behavior within a polymer mixture can have a number of complexities. The complexity of the model phase behavior may result from the distribution of molecular weight and composition of industrially produced polymers, the tendency of some polymer chains to crystallize at low temperatures in a high density state (while others remain amorphous), and the inaccessibility of the crystalline region within the absorbing solute. Equilibrium thermodynamic models calculate solubility in the amorphous phase because they are based on the equilibrium between species in solution with the polymer (e.g., in the amorphous phase, rather than the crystalline phase, as described above) and those same species in the coexisting phases. Thus, the comparison between experimental and theoretical values involves an overallAnd amorphous formA clear distinction between solubility, and possibly the appearance of crystallinity (C) itself. These are related to equation (E-1):

wherein x_wiIs the mass fraction of species i; what is needed isThe ratio of the mass of adsorbed species i to the sum of the mass of species i and the mass of polymer. The superscript a indicates the case where only the amorphous mass in the polymer is considered, while the superscript T indicates the case where the total polymer mass is considered.Is the mass fraction of polymer on an amorphous basis, and C is the crystallinity in mass fraction; the ratio of the mass of crystalline polymer to the total mass of polymer.

Simply considering this solubility benchmark is not sufficient, since the presence of crystalline polymers (or more specifically of the linker chains linking them) may affect the amount of solvent that may be adsorbed into the amorphous phase of the polymer. One way to consider this is to consider the effect of this adapter strand, as in equation (E-2), using the activity coefficient:

wherein 'V' represents vapor and 'A' represents a mixture of amorphous polymer and adsorbed species, y_iAnd x_iIs the mole fraction composition of these respective phases.Is the fugacity coefficient of species i in the vapor phase, andare the fugacity coefficients of species within the amorphous phase without elastic constraints.Consider the effect of elastic constraints on the fugacity coefficient and hence solubility of species within the amorphous phase.

The Sako-Wu-Praussnitz equation of state (SWP-EOS) can be used because it is a simple cubic EOS that can be applied to both small molecules (volatile molecules) and polymers, as shown in equation (E-3):

where P is the pressure, T is the absolute temperature, v is the molar volume, R is the universal gas constant, and a, b and c are the attraction, repulsion and freedom parameters of the mixture under consideration.

As in equation (E-4), the expression for the SWP-EOS fugacity coefficient is calculated:

wherein the symbol 'x' in the equation (E-4) represents a mole fraction.

For accurate solubility calculations, there is an elastic relationship where Serna et al, j.appl.polym.sci.2008,107,138 and Banaszak et al, Macromolecules 2004,37,9139 discuss the activity coefficient and are expressed by equation (E-5):

wherein:

k ═ or 'i' or 'poly'

T is absolute temperature

T_mAbsolute atmospheric boiling point of ═ polymer

φ_kVolume fraction of species k in amorphous phase

χ_kThe Flory interaction parameter for species k in the amorphous phase is given by equation (E-6):

wherein delta_kThe solubility parameter, for volatile species, is given by equation (E-7):

and for polyethylene, delta_{Multiple purpose}Approximately 16.7MPa 0.5, and f ═ the fraction of elastic affected chains.

The solubility can be determined by calculating the composition of the amorphous phase (x) taking into account the fixed temperature, pressure and vapor phase of composition (y). The set of equations to be solved may consist of the representation of equilibrium and material tare. These can be expressed by equations (E-8) and (E-9):

as shown, the unknown in the model is the number of moles of material dissolved in the polymer phase. The unknown is the "number of moles" to be considered, which will yield the corresponding "mole fraction". These are met by the species conservation equations requiring the sum of units of dissolved moles. The problem can be described as an unconstrained optimization, as shown in equation (E-10):

by setting n_{Multiple purpose}0.05, and n_j～(1-n_{Multiple purpose})y_{j ≠ multiple}A starting estimate may be generated which may then be redefined by Newton iterations, equations (E-11) and (E-12)：

Δn_j＝-H_ij ^-1F_i (E-11)

Wherein:

the mole fraction can be converted to a mass fraction by using the number average molecular weight (Mn) of the polymer.

Although a given model contains a large number of parameters, most can be estimated from literature or characterization data. Furthermore, two model parameters (f and T) may be fitted_m) Accurate solubility predictions were made by experimental data. Our parameterization method is:

I. isopentane solubility isotherms measured at low and high temperatures (typically 50 ℃ and 85 ℃ respectively) were used to fit both f and T for a given polymer_m。

For each of these polymers, a low pressure isopentane solubility isotherm was simulated at a pressure of about 0.01 bar to about 0.8 bar and at a temperature of 50 ℃ to 90 ℃.

For each of these polymers, the Henry constant for isopentane was derived under the temperature equation (E-13):

Fy_iP＝w_iH_i (E-13)

for each of these polymers, the derived Henry constant provides a determination of the slope of ln (H) versus 1/T.

For a range of polyethylenes, the median and standard deviation of the Henry constant slope identified using the above procedure of Roman numerals I to III, for each polymer, relative to f and T_mThe following objective function is minimized.

In other words, the described method identifies a target value for the slope of the isopentane Henry constant, and then adjusts f and T_mTo match this target and an isopentane isotherm (85 ℃ or highest available) simultaneously for that particular polymer. And using two isotherms for each polymerIn contrast, the target value for the Henry constant slope may be applied to a given type of polymer (e.g., C4 and C6 Linear Low Density Polyethylenes (LLDPEs) produced in GPPE reactors) and involve only a single isotherm (unique for each polymer).

CA equivalent factor

The term "equivalence factor" refers to the mole-to-mole relationship of a first CA to a second CA, wherein 1 mole of the first CA may be replaced with α moles of the second CA. To compare the two CAs, the second CA was more volatile than the first CA. For example, in some embodiments, isopentane (less volatile than n-butane) and n-butane can have a CA equivalence factor of about 1.8 to about 2.5, meaning that 1 mole of isopentane can be replaced with about 1.8 to about 2.5 moles of n-butane while maintaining the same stickiness temperature during polyolefin production. Replacing a portion of the isopentane with an equivalent amount of n-butane can increase cooling capacity without causing stickiness and thus provide increased production rates.

Simulations of the process at various reactor conditions can be used to achieve a CAs ratio that will provide high production rates. For example, business model software may be used, such as that manufactured by SimSci^TMPRO/II produced or Aspen Plus produced by Aspentech achieved appropriate process simulation. Each individual set of conditions in the simulation takes time to prepare and model. Thus, using simulations to determine the ratio of CAs is not only expensive and labor intensive, but also cannot be achieved in real time without significant programming effort when the reactor is running.

In some cases, the equivalence factor may relate to the solubility of a first CA in a polyolefin as compared to the solubility of a second CA within the same polyolefin. Without being bound by theory, the stickiness of the polyolefin mixed with the CA composition in the gas phase reactor may be related to the solubility of the CA composition in the polyolefin. The solubility of a single CA in a polymer is affected not only by many reaction conditions (e.g., pressure, temperature, product density), but also by the presence of other CAs, additives and reaction components. Since the stickiness of the polyolefin may limit the production rate (because of the correlation between production and temperature), the CA composition is a balance between the ability to cool the reaction mixture and the solubility of the CA composition in the polyolefin produced.

The equivalent factor is calculated from the solubility of the CAs alone in the polyolefin at the reactor conditions. Since the reactor conditions differ for different polyolefins and for different grades of a single polyolefin, and since the reactive conditions change over time, the solubility and thus the equivalence factor of the two CAs also changes. Variation in the equivalence factor means that laboratory experiments and/or computational studies need to be conducted or extensive in order to determine the equivalence factor associated with reasonable reactor conditions for each polymer.

The equivalence factors for the first and second CA at specific reactor conditions can be calculated by linear regression of the partial pressure versus viscosity temperature for each individual CA and dividing by the slope of the line. The calculations can be repeated for various reactor conditions including variations in temperature, pressure, reactant concentrations and the proportion of comonomer included. Once sufficient data is collected (either empirically or by calculation), various equivalence factors can be fitted to a line to provide a formula that can be used to quickly calculate an equivalence factor involving both condensing agents for a given polyolefin under a set of reactor conditions. Linear regression enables the equivalence factor to be calculated in real time as reactor conditions change during the course of a polymerization process.

Linear regression of the equivalence factor may provide an equation relating reactor conditions and recycle gas composition, facilitating the calculation of the equivalence factor as reactor conditions and gas composition change. Also before a change in gas composition occurs, this linear regression facilitates calculation of the change in the equivalence factor associated with the change in gas composition, but at the current reactor conditions. The linear regression of the equivalence factor may include reactor conditions such as reactor temperature, reactor pressure, resin melt index, and resin density. The linear regression may also include factors related to the gas composition or recycle gas composition, including the mole fraction of olefin monomer, comonomer, inert gas, and CAs or CA composition.

FIG. 4 is a chart illustrating the equivalence factor calculations for various C6-hydrocarbons associated with iC 5. For a random set of conditions, thermodynamic approximations of the solubilities used to calculate viscosity can be used to determine the equivalence factor.

Table 1 provides exemplary, non-limiting equivalent factors for various CA components.

The CA concentration in the reactor (i.e., the mole percent of CA in the reactor or the sum of the mole percent of each CA component as a function of the total reactor gas) can be varied as the CA composition is varied. For example, using a CA equivalence factor of 2 for n-butane isopentane, the partial pressure of CA in the reactor can be increased when substituting n-butane for isopentane to achieve a larger dew point approach temperature and higher polyolefin production rate. Using the same CA equivalence factor, in some cases the reactor may have a maximum polyolefin production rate, which if exceeded, may be reduced by replacing n-butane with isopentane, which would reduce the CA partial pressure within the reactor. Alternatively, the CA concentration within the reactor may not change when the CA composition changes.

In some embodiments, the CA partial pressure within the reactor may be up to about 1400kPa, such as from about 30kPa to about 1000kPa, or from about 100kPa to about 700 kPa.

In some embodiments, the mole percentage of the individual CA components may be up to about 50 mol%, such as from about 1 mol% to about 40 mol%, from about 5 mol% to about 30 mol%, or from about 10 mol% to about 20 mol%, relative to the overall reactor gas.

Calculating CA compositions

Once each factor relevant to calculating the condensing agent ratio is identified, the SL (SL) of the first CA is subtracted from the total allowable CA (Z)_CA1) And divides the result by the equivalence factor (α CA2) associated with the second CA and the first CA minus 1. According to equation (E-14):

wherein X is a first amount of the first refrigerant removed and replaced with a second amount of the second refrigerant, wherein the second amount is X multiplied by α CA2, Z is an overall allowable refrigerant, SL_CA1Is the sticking limit of the first refrigerant, and α CA2 is an equivalence factor related to the first refrigerant and the second refrigerant. For example, if the overall allowable CA composition is 25 mol%, the adhesion limit of the first condensing agent is 17 mol%, and the equivalence factor relating to the second condensing agent and the first condensing agent is 3, then X (the first amount of the first condensing agent removed) is 4 mol% and the second amount is 12 mol%.

Since X represents the amount of CA1 that may be removed, X may be no less than 0 or greater than SL_CA1. Since X is limited in this way, if SL_CA1Greater than the total allowable CA composition, no change occurs within the CA composition, and X is 0. Furthermore, the constraint on X means that the equivalence factor may not be less than 1, since X will be negative, and thus the volatility of the first CA must be less than the second CA.

Linear regression of the equivalence factors for a given combination of CAs facilitates real-time calculation of CA compositions that will provide improved polymer production. The equations may be programmed into a control system that provides for adjustment of the reaction conditions when processing information from the reactor.

Without being bound by theory, the combination of two CAs may provide greater polymer production within a binary CA composition as compared to the combination of more than two CAs. It may be beneficial for the polymer production rate to reduce or eliminate inert gases that are not part of the binary CA composition. Moreover, CAs within a binary CA composition that provides improved production may vary with reactor conditions and specifically with overall allowable CA compositions. When the overall allowable CA composition is lower, it may favor a CA composition with less volatile CAs, and when the overall allowable CA composition is increased, the binary CA composition that provides improved production may be a combination of more volatile CAs.

Avoiding dew point limits

Typically, the degree in the past includes continuously increasing the CA composition content without using methods to target specific ratios of CAs within the CA composition. Eventually, the upper viscous temperature (or upper artificial limit) or dew point limit is reached and then the overall allowable CA composition is reduced or the reactor pressure is reduced, either measure causing a reduction in production rate. Furthermore, rapid adjustment of the overall allowable CA composition or reactor pressure may result in polymers produced during the change not having the desired properties. The same situation may occur repeatedly but at different ratios of CAs within the CA composition, but this situation is unlikely to result in improved production rates relative to other methods of lowering the dew point due to the ratio not being directed to CAs.

Furthermore, the calculation of the equivalence factor does not take into account the dew point of the gas phase composition, and therefore, the results of the calculation of the CA composition may suggest that the CA composition will cause the reactor temperature to fall below the dew point limit. Dropping below the DPL may not be a change in the reactor temperature, but an increase in the DPL temperature. However, it has been found that adjusting the concentration of CAs in the CA composition can be used to avoid viscous conditions including those below the dew point limit while also maintaining improved production rates relative to other methods of lowering the dew point. Since the on-line calculation of reactor conditions may be nearly continuous, the CA composition may be adjusted while monitoring the dew point to remain in a non-sticking condition (safe production zone).

It has been found that reducing the equivalence factor or SL of the first CA (SL)_CA1) The reaction conditions may be brought to a non-sticking condition within the dew point limit. This can be done as follows: (i) equivalent factor and SL were calculated for certain reactor conditions_CA1(ii) calculating the concentration of CAs within the CA composition, (iii) calculating the dew point limit of a gas phase composition produced from the CA composition, and (iv) determining whether the reactor temperature is below the dew point limit. If the temperature is not below the dew point limit, it is done with the CA composition as calculated. (v) if the temperature falls below the dew point limit, (v) incrementally increasing the equivalence factor or SL_CA1(vi) recalculating the CA composition from those reductions determined in (i), and (iv) recalculating the dew point limit for the gas phase composition produced from the recalculated CA composition from (vi), and (vii) determiningIt is determined whether the reactor temperature is below the dew point limit. (vii) if the reactor temperature falls below the dew point limit, repeating the process of steps (v) to (vii) until the equivalent factor or SL_CA1Low enough that the new dew point limit is below the reactor temperature.

Since these calculations may be performed on a computer processor, the initial calculated equivalent factor or SL_CA1The incremental decrease of (c) may be performed in smaller increments, such as 0.1, 0.05, 0.01, 0.005, or 0.0001 or smaller increments. Equivalent factor or SL_CA1The reduction in (b) may also reduce the production rate. Thus, the equivalent factor and SL_CA1May provide improved production rates due to higher equivalent factors or higher SLs for a particular binary CA composition_CA1The production rate is improved. Alternatively, to save computation time, relative to dew point and equivalence factor or SL_CA1The calculation of (A) may be by decreasing and increasing the equivalent factor or SL_CA1Both are performed in descending increments. For example, the initial incremental decrease may be larger, followed by a smaller increase until the dew point limit is passed, and then followed by a smaller incremental decrease until the non-stick condition is returned, and so on, until the calculation has been scaled to the equivalent factor or SL in the non-stick condition_CA1A predetermined number of small bits.

It has been found that reducing the equivalent factor or SL in this manner compared to reducing the overall allowable CA composition (Z) or reducing the reactor pressure by venting_CA1Greater polyolefin production rates are obtained. Typically, when reactor conditions approach the dew point of a particular gas phase composition, the practice is to reduce the overall allowable CA composition or vent the reactor to reduce the pressure until the reactor conditions are within the dew point limit. This is effective but causes a significant reduction in production compared to adjusting the amount of individual CAs in the CA composition. Calculated equivalent factor or SL_CA1A small decrease in cooling capacity and hence production rate may cause a slight decrease in cooling capacity, while a decrease in overall allowable CA composition and/or reactor blowdown greatly decreases cooling capacity and hence production rate.

Polyolefin products

The present disclosure also relates to compositions of matter produced by the described methods.

In some embodiments, the described methods produce M_w/M_nAn ethylene homopolymer or an ethylene copolymer of from greater than 1 to 4, or from greater than 1 to 3, such as an ethylene-alpha-olefin (e.g., C3 to C20) copolymer (e.g., an ethylene-butene copolymer, an ethylene-hexene copolymer, and/or an ethylene-octene copolymer).

Also, the process of the present disclosure produces ethylene copolymers. In some embodiments, the polyolefin copolymer produced has from about 0 mol% to about 25 mol%, from about 0.5 mol% to about 20 mol%, from about 1 mol% to about 15 mol%, or from about 3 mol% to about 10 mol% of one or more C₃-C₂₀An olefin comonomer. One or more C₃-C₂₀The olefin comonomer may comprise C₃-C₁₂Alpha-olefins, for example propene, butene, hexene, octene, decene or dodecene.

In some embodiments, the monomer is ethylene and the comonomer is hexene, for example from about 1 mol% to about 15 mol% hexene, for example from about 1 mol% to about 10 mol%.

In at least one embodiment, a catalyst having i) at least 50 mol% ethylene; ii) a density greater than or equal to 0.89g/cc, such as greater than or equal to 0.918g/cc, or greater than or equal to 0.935 g/cc; and an ethylene polymer composition having a g' vis of greater than or equal to about 0.97.

In some embodiments, M of the polymer produced_wIs from 5,000g/mol to 1,000,000g/mol, such as from 25,000g/mol to 750,000g/mol, or from 50,000 to 500,000g/mol, and/or M_w/M_nIs greater than 1 to about 40, such as about 1.2 to about 20, about 1.3 to about 10, about 1.4 to about 5, about 1.5 to about 4, or about 1.5 to about 3.

In at least one embodiment, the polymer produced has a monomodal or multimodal molecular weight distribution as determined by Gel Permeation Chromatography (GPC). "unimodal" means that the GPC curve has one peak or inflection point. "multimodal" means that the GPC curve has at least two peaks or inflection points. An inflection point is a point where the second derivative of the curve changes from negative to positive or vice versa.

In at least one embodiment, the polymer produced has a bimodal molecular weight distribution as determined by Gel Permeation Chromatography (GPC). "bimodal" means that the GPC curve has two peaks or inflection points.

Unless otherwise stated, morphology, M, was determined by using a high temperature size exclusion chromatograph (obtained from Waters Corporation or Polymer Laboratories)_w，M_n，M_zMWD, g value and g'_visThe chromatograph may be equipped with a differential refractive index Detector (DRI), a Light Scattering (LS) detector, and a viscometer. Experimental details including detector calibration are described in t.sun, p.branch, r.r.chance and w.w.graceful, Macromolecules, volume 34, stage 19, 6812-6820, (2001). The various transfer lines, columns and differential refractometer (DRI detector) were housed in an oven maintained at 145 ℃. The solvents used for the experiments were prepared by dissolving 6 grams of butylated hydroxytoluene as antioxidant in 4 liters of Aldrich reagent grade 1,2, 4-Trichlorobenzene (TCB). The TCB mixture was then filtered through a 0.7 μm glass prefilter and then through a 0.1 μm Teflon filter. The TCB was then degassed with an in-line degasser prior to entering the size exclusion chromatograph. The polymer solution was prepared by placing the dried polymer in a glass container, adding the required amount of TCB, and then heating the mixture at 160 ℃ for about 2 hours with continuous stirring. All amounts were determined gravimetrically. The TCB density used, expressed as mass/volume units of polymer concentration, was 1.463g/ml at room temperature and 1.324g/ml at 145 ℃. The injection concentration is 0.75-2.0mg/ml, with lower concentrations being used for higher molecular weight samples. The DRI detector and syringe were flushed prior to running each sample. The flow rate in the apparatus was then increased to 0.5ml/min and the DRI was allowed to stabilize for 8-9 hours before injecting the first sample. The LS laser was turned on for 1 to 1.5 hours before running the sample. Using the following equation (E-15), the baseline-subtracted DRI signal I_DRIThe concentration c at each point of the chromatogram was calculated:

c＝K_DRII_DRI/(dn/dc) (E-15)

wherein K_DRIIs a constant determined by calibrating the DRI, and (dn/dc) is the refractive index increment of the system. For TCB and λ 690nm at 145 ℃, the refractive index n is 1.500. For the purposes of this disclosure, 0.104 for propylene polymers (dn/dc), 0.098 for butene polymers and 0.1 in other cases. The units of the parameters in the entire description of the SEC method are such that the concentration is in g/cm³Expressed as molecular weight in g/mole and intrinsic viscosity in dL/g.

The LS detector is Wyatt Technology High Temperature mini-DAWN. The molecular weight at each point of the chromatogram was determined by analyzing the LS output using the Zimm model for static LIGHT SCATTERING of equation (E-16), M (m.b. huglin, LIGHT SCATTERING FROM POLYMERs, Academic Press, 1971):

where Δ R (θ) is the excess Rayleigh scattering intensity measured at the scattering angle θ, c is the polymer concentration determined from the DRI analysis, A₂Is the second virial coefficient [ for the purposes of this disclosure, for Polypropylene A₂0.0006 for butene polymers 0.0015 and in other cases 0.001]P (θ) is the form factor of a monodisperse random coil, and K is 0.104 for propylene polymers (dn/dc), 0.098 for butene polymers, and 0.1 in other cases_oIs the optical constant of the system in equation (E-17):

wherein N is_AIs the Afugardo constant, and (dn/dc) is the refractive index increment of the system. The refractive index n is 1.500 for TCB at 145 ℃ and λ 690 nm.

A high temperature Viscotek Corporation viscometer (with four arranged in a Wheatstone bridge configuration) was usedCapillary tube and two pressure sensors) to determine the specific viscosity. One sensor measures the total pressure drop across the detector and the other sensor, located between the two sides of the bridge, measures the differential pressure. Calculating from their outputs the specific viscosity η of the solution flowing through the viscometer_s. The intrinsic viscosity [ eta ] at each point in the chromatogram was calculated from the following equation (E-18)]：

η_s＝c[η]+0.3(c[η])² (E-18)

Wherein c is concentration and is determined from the DRI output.

The branching index (g ') was calculated using the method of SEC-DRI-LS-VIS above'_vis) As follows. The average intrinsic viscosity [ eta ] of the sample was calculated by the equation (E-19)]_avg：

Where the sum is taken from all chromatographic sections i between the integration limits. The branching index g' vis is defined using the equation (E-20):

where for the purposes of this disclosure α is 0.695 and k 0.000579 for linear ethylene polymers, 0.705 and k 0.000262 for linear propylene polymers, and 0.695 and k 0.000181 for linear butene polymers. M_vIs the viscosity average molecular weight based on the molecular weight determined by LS analysis.

In at least one embodiment, the polymer produced has a Composition Distribution Breadth Index (CDBI) greater than, or equal to, 50%, such as greater than, or equal to, 60%, or greater than, or equal to, 70%. CDBI is a measure of the composition distribution of monomers within a polymer chain and is measured by PCT publication WO 93/03093, specifically columns 7 and 8, published at 2/18/1993, and the procedures described in Wild et al, j.poly.sci., poly.phys.ed., volume 20, page 441 (1982) and US 5,008,204, whereinIncluding ignoring weight average molecular weight (M) when determining CDBI_w) Fractions below 15,000.

In another embodiment, the polymer produced in the TREF measurement (see below) has two peaks. Two peaks in a TREF measurement as used in the present specification and the appended claims refer to the presence of two different normalized ELS (evaporation mass light scattering) response peaks in a graph of normalized ELS response (vertical or y-axis) versus elution temperature (horizontal or x-axis and left-to-right temperature rise) using the TREF method below. "Peak" in the context of the present invention refers to the case where the general slope of the graph changes from positive to negative as the temperature increases. Between the two peaks is a local minimum where the general slope of the graph changes from negative to positive as the temperature increases. The "general trend" of the graph is intended to exclude a plurality of local minima and maxima which may occur within an interval of less than or equal to 2 ℃. In some embodiments, the two distinct peaks are separated by at least 3 ℃, at least 4 ℃, or at least 5 ℃. In addition, different peaks all appear at temperatures above 20 ℃ and below 120 ℃ of the graph, with elution temperatures running at 0 ℃ or lower. This limitation avoids confusion with the apparent peaks on the graph at low temperatures due to species that remain soluble at the lowest elution temperature. The two peaks on this graph indicate a bimodal Composition Distribution (CD). An alternative TREF measurement method can be used if the following method does not show two peaks, see B.Monrabal, "Crystallization Analysis Fractionation: A New Technique for the Analysis of branched Distribution in polymers," Journal of Applied Polymer Science, Vol.52, 491-499 (1994).

TREF method

Temperature Rising Elution Fractionation (TREF) analysis was performed using a CRYSTAF-TREF 200+ instrument from Polymer Char, S.A., Valencia. In Monrabal, B.; a general description of the principles of the TREF analysis and the specific apparatus used is given in the del hirrro, p.anal.bioanal.chem.2011,399,1557 article. Figure 3 of the article is a general schematic of the particular apparatus used; however, the connection to the 6-port valve may differ from the device used in that the tubing connected to the 11-o 'clock port is connected to the 9-o' clock port and the tubing connected to the 9-o 'clock port is connected to the 11-o' clock port. The details of the analysis method and the associated apparatus features used are as follows.

1, 2-dichlorobenzene (ODCB) solvent stabilized with about 380ppm of 2, 6-bis (1, 1-dimethylethyl) -4-methylphenol (butylated hydroxytoluene) was used for sample solution preparation and for elution. The sample to be analyzed (about 25mg but as low as about 10mg) was dissolved in ODCB (25 ml metered at ambient temperature) by stirring at 150 deg.C for 60 minutes. A small volume (0.5ml) of this solution was introduced into a column (15-cm length by 3/8' outer diameter) packed with an inert support (stainless steel balls) at 150 ℃ and the column temperature was stabilized at 140 ℃ for 45 minutes. The sample volume was then allowed to crystallize in the column by lowering the temperature to 30 ℃ at a cooling rate of 1 ℃/min. The column was held at 30 ℃ for 15 minutes, after which an ODCB stream (1ml/min) was injected into the column over 10 minutes to elute and measure the polymer without crystallization (soluble fraction). The infrared detector used (Polymer Char IR4) generated an absorbance signal proportional to the Polymer concentration in the elution stream. A complete TREF curve was then generated by raising the temperature of the column from 30 to 140 ℃ at a rate of 2 ℃/min while maintaining the ODCB flow at 1ml/min to elute and measure the dissolved polymer.

In at least one embodiment, the polymer produced has an ethylene content of greater than or equal to about 70 wt%, greater than or equal to about 80 wt%, greater than or equal to about 90 wt% and/or a density of greater than or equal to about 0.910g/cc, such as greater than or equal to about 0.93g/cc, greater than or equal to about 0.935g/cc, or greater than or equal to about 0.938 g/cc. In some embodiments, the density of the produced polymer is greater than or equal to 0.910g/cc, alternatively 0.935 to 0.960 g/cc.

Examples

FIG. 5 is a graph illustrating a density at production of 0.918g/cm³And MI_2.16A graph illustrating linear regression used to calculate a single equivalent factor in 2g/10min of polyethylene. The adhesion limits for iC5 and iC4 are plotted on the graph, where the y-axis is the viscosity temperature and the x-axis is the partial pressure of CA. The linear regression of the points for each individual CA provides the ratio of the lines and the slopes of those lines provides for oneEquivalent factor to reactor conditions. By comparing the slope ratios, the data of fig. 5 shows that the equivalence factor of iC4 is 3.1 relative to iC5 at these reactor conditions. The data in fig. 5 were obtained by the laboratory method described in U.S. patent No.10,029,226.

Table 2 (in sections 2.1 and 2.2) shows an exemplary table of equivalent factor linear regression coefficients:

TABLE 2.1

Intercept of a beam

Temperature of

Pressure of

MI

Density of

C2＝

iC4

7.489

-7.55E-03

4.38E-04

2.24E-03

-3.186

-0.404

nC4

6.623

-2.88E-03

9.84E-05

2.39E-03

-4.325

-0.175

C4＝

10.102

-4.13E-03

1.92E-04

4.03E-03

-7.691

-0.218

nC5

1.128

1.86E-04

5.88E-05

2.38E-04

-0.400

0.004

nC6

-0.254

5.90E-04

6.59E-05

-2.45E-04

0.501

0.024

C6＝

0.083

5.79E-04

7.45E-05

-7.67E-05

0.133

0.024

cis-2C 6 ═

-0.122

7.46E-04

5.14E-05

-1.57E-04

0.332

0.021

trans-2C 6 ═

-0.231

8.27E-04

4.15E-05

-2.18E-04

0.459

0.021

TABLE 2.2

	nC4	iC4	C4＝	nC5	iC5	nC6	C6＝
								iC4	-0.729	n/a	0.279	0.268	1.35	4.039	3.283
nC4	n/a	-0.281	0.133	0.119	0.819	1.373	0.882
								C4＝	-0.22	-0.284	n/a	0.551	1.175	2.637	2.21
nC5	0.006	0.019	0.098	n/a	0.278	-0.217	-0.278
								nC6	0.042	0.054	0.095	-0.022	0.127	n/a	-0.267
C6＝	0.069	0.068	0.066	0.066	0.19	-0.031	n/a
								cis-2C 6 ═	0.033	0.046	0.099	-0.039	0.115	-0.257	-0.34
trans-2C 6 ═	0.022	0.039	0.111	-0.068	0.099	-0.328	-0.424

The combination of factors in linear regression results in an equation that allows the equivalent factor that associates iC4 with iC5 to be calculated:

αiC4＝7.489-0.00755T+0.000438P+0.00224MI-3.186ρ-0.404X_C2＝-0.729X_nC4+0.279X_C4＝+0.268X_nC5+1.350X_iC5+4.039X_nC6+3.283X_C6＝。

wherein T ═ reactor temperature (° F); p ═ reactor pressure (psia); MI ═ resin melt index (g/10 min); ρ ═ resin density (g/cc); x_C2＝The mole fraction of ethylene in the reactor recycle gas; xn_C4The mole fraction of n-butane in the reactor recycle gas; x_C4＝The mole fraction of 1-butene in the reactor recycle gas; x_nC5The mole fraction of n-pentane in the reactor recycle gas; x_iC5The mole fraction of isopentane in the reactor recycle gas; x_nC6The mole fraction of n-hexane in the reactor recycle gas; and X_C6＝The mole fraction of 1-hexene in the reactor recycle gas. In this example, the method is obtained by using a method from the above description (see English original text [0135-0145 ]]Segment) to develop a linear regression for the equivalence factor. The various variables in the linear regression are adjusted over a wide range to allow the development of the regression equations described. The regression equation is appropriate over the range of reactor conditions used to develop the model, but further extrapolation may lead to inaccuracies.

FIG. 6 is a graph of the mole percent of condensing agent over time under DCS controlled reactor conditions and under manually controlled reactor conditions. When reactor conditions change, the amount of CAs can be increased, cooling improved, and thus production rate increased, with the appropriate ratio of CAs calculated and automatically adjusted using the control system.

FIG. 7 is a graph of total condensing agent composition versus expected production rate. Overall production when increasing overall CA compositionThe rate increases. Line 701 shows the equivalent factor for iC5 and iC4 of 3.1 with 1.0 mol% C6 inerts (antistatic agent) for total SL_iC5It was 16.5 mol%. Line 703 shows the equivalent factor for iC5 and iC4 of 2.4 with 0.8 mol% of C6 inerts (antistatic agent) for total SL_iC5It was 17 mol%. Line 705 shows an equivalent factor of 2.4 for iC5 and iC4 with 1.0 mol% C6 inerts (antistatic agent) for total SL_iC5It was 16 mol%. Line 707 shows an equivalent factor of 2.4 for iC5 and iC4 with 1.5 mol% C6 inerts (antistatic agent) for total SL_iC5It was 14.5 mol%. Total allowable CA (Z) is the expected production rate on the x-axis and on the y-axis.

FIG. 8 is a graph illustrating data generated by commercial process engineering simulation software showing the density for 0.918g/cc and MI_2.16For LLDPE at 1g/10min, the amount of iC4 to replace iC5 that was removed versus running the gas phase polymerization with iC5 alone versus the production rate. PROII is a software package that provides steady state simulation of process engineering. The polymerization system was simulated and the production rate was calculated for varying CA compositions, as iC4 increased and iC5 decreased with an equivalence factor of 3.1. The simulation data plot gives the maximum production at about 12.4 mol% iC 4. The reaction conditions were set such that the reactor had an overall allowable CA composition of 25.4%, an adhesion limit of iC5 of 17% and an equivalence factor of 3.1. Using equation E-14, it was found that 4 mol% iC5 could be replaced by 4 × 3.1 or 12.4 mol% iC4, where the same maximum was obtained in a simple calculation rather than modeling 7 different iC4 doses. For this simulation, the model from SimSci was used^TMPRO/II software produced.

FIG. 9 is a graph illustrating data generated by commercial process engineering simulation software showing the density for 0.918g/cc and MI_2.16For LLDPE at 1g/10min, the amount of nC4 to replace the iC5 removed versus running the gas phase polymerization with iC5 alone versus the production rate. The polymerization system was simulated and the production rate was calculated for varying CA compositions, as the equivalence factor of 2 was employed, nC4 increased and iC5 decreased. The simulation data plot gives the maximum production at about 16.8 mol% of nC 4. Setting the reaction conditions so that the reaction is carried outThe vessel had an overall allowable CA composition of 25.4%, an adhesion limit of iC5 of 17% and an equivalence factor of 2. Using formula F-1, it was found that 8.4 mol% of iC5 could be replaced by 8.4 × 2 or 12.4 mol% of nC4, achieving the same maximum in a simple calculation rather than simulating 9 different iC4 doses. For this simulation, the model from SimSci was used^TMPRO/II software produced.

FIG. 10 is a graph showing the use of 25 mol% Z and 15 mol% SL_CA1According to an equivalence factor involving the second CA and iC5, a graph comparing production rates when the second CA replaces at least a portion of iC 5. The second CAs is iC4 and nC4, and iC4 provides a greater overall production rate at about 85 tons/hr, with nC4 compositions having a maximum production rate of greater than 83 tons/hr. To determine if the three component mixture provided additional advantages, a ternary CA composition was tested in which nC4 was added to the iC5/iC4 mixture that provided about 85 tons/hour production. The addition of nC4 to this mixture provides no additional benefit. As nC4 increases, the production rate decreases.

The balance of CAs within a CA composition when producing polyolefins in the gas phase provides valuable cost benefits since a binary CA composition can provide the maximum production rate.

FIG. 11 is a graph showing the use of 25 mol% Z and 15 mol% SL_CA1According to an equivalence factor involving the second CA and iC5, a graph illustrating production rates when the second CA replaces at least a portion of iC 5. The second CAs is iC4 and C3, and iC4 provides a greater overall production rate at about 85 tons/hr, with the C3 composition having a maximum production rate of about 77 tons/hr. To determine if the three component mixture provided additional benefits, ternary CA compositions were tested in which iC4 was increased in amount to provide an iC5/C3 mixture produced at greater than 77 tons/hour. Addition of iC4 to this mixture improved the production rate, but did not exceed the production rate of CA compositions containing only iC4 and iC 5.

FIG. 12 is a graph showing the use of 25 mol% Z and 15 mol% SL_CA1According to an equivalence factor involving the second CA and iC5, a graph illustrating production rates when the second CA replaces at least a portion of iC5. The second CAs is iC4 and new C5, and new C5 provides a greater overall production rate at about 87 tons/hour, with iC4 composition having a maximum production rate of about 85 tons/hour. To determine if the three component blend provides additional benefits, ternary CA compositions were tested, with new amounts of C5 added to the iC5/iC4 blend. The ternary CA composition was shown to have a greater production rate than the new C5/iC5 peak due to the sticking limit reached before the overall allowable CA composition was reached in the binary new C5/iC5 mixture. If the adhesion limit is not reached before the total allowable CA composition, the binary CA composition has a greater production consistent with the results shown in FIGS. 10 and 11.

Fig. 13 is a graph illustrating polymer production rates of exemplary binary CA compositions when a second CA replaces at least a portion of iC5, according to an equivalence factor involving the second CA and iC 5. Under the reaction conditions of these experiments, the new C5 provided the greatest production rate improvement, but reached the sticking limit before its inflection point. iC4 provides a sub-optimal production rate improvement. The binary CA compositions tested did not include all possible binary CA compositions, but included many compositions typically used and evaluated.

Fig. 14 is a graph illustrating polymer production rate versus overall CA for an exemplary binary CA composition, with the specific exclusion of new C5 due to its lower availability. FIG. 14 shows a signal at SL_iC5At 10 mol%, certain binary CA compositions provide improved production over certain ranges of overall allowable CA. For example, a CA composition comprising nC6 and iC5 may provide improved production if the total allowable CA is less than or equal to about 10 mol%. CA compositions containing iC5 and iC4 may provide improved production if the total allowable CA is from about 10 mol% to about 30 mol%. Finally, CA compositions containing iC4 and C3 may provide improved production if the total allowable CA is greater than or equal to about 30 mol%. Without being bound by theory, the general trend observed is that the new binary CA compositions provide improved production beyond the adhesion limit of the more volatile component. If the overall allowable CA composition is greater than the adhesion limit of the more volatile component, the more volatile CA component may be used, for exampleImproved rates are achieved, for example, by using the more volatile CA component from the binary composition of the previously tacky region, in combination with the even more volatile component. For example, since the adhesion limit of new C5 within the binary mixture of new C5/iC5 was reached before CA was generally allowable in fig. 12, improved production rates were observed for the binary new C5/iC4 mixture, even greater than the ternary new C5/iC4/iC5 mixture. In this example, new C5 was the more volatile CA component from the previous viscous zone, and iC4 was the more volatile component added. Figures 14 and 15 illustrate certain advantages of exemplary binary CA compositions over other compositions.

FIG. 15 is a graph illustrating polymer production rate versus total CA for a binary CA composition, including New C5. As shown in fig. 15, the additional overall CA composition may provide additional areas in which production is improved by varying the binary CA composition. In addition, at SL_iC5At 10 mol%, certain binary CA compositions provide improved production over certain ranges of overall allowable CA. For example, a CA composition comprising nC6 and iC5 may provide improved production if the total allowable CA is less than or equal to about 10 mol%. CA compositions containing iC5 and new C5 can provide improved production where the overall allowable CA is from about 10 mol% to about 17 mol%. CA compositions containing the novel C5 and iC4 may provide improved production where the overall allowable CA is from about 17 mol% to about 30 mol%. Finally, CA compositions containing iC4 and C3 may provide improved production if the total allowable CA is greater than or equal to about 30 mol%.

Based on the static equivalence factor, the region within which the CA composition provided the greatest production was calculated. In a binary CA composition that provides improved production rates, the boundaries of a particular region can be calculated by multiplying the adhesion limit of a first condensing agent by the equivalence factor of a second condensing agent. When reactor conditions vary, including the production of varying grades of polyolefin, the CA composition that provides for improved production may vary for a particular set of reactor conditions, thereby providing different overall allowable CA. In combinations of CAs with maximum production rates, the maximum production rate can be achieved by SL_CA1Term multiplied by volatilityThe equivalence factor of the large component, the viscous zone boundary was calculated.

Figures 10-15 show that under these conditions, CA compositions containing two CAs are more effective than the corresponding ternary CA compositions. Without being bound by theory, the binary CA compositions with the greatest production rate improvement are negatively impacted by the addition of additional CAs and provide improved production under certain reactor conditions as compared to CA compositions containing three or more CAs.

Fig. 16 is a graph of an operating window to avoid resin build-up. As shown in the graph, the temperature of the reactor and the equivalent partial pressure of the first CA define a two-dimensional space for the operation of the reactor. In this graph, the x-axis represents the equivalent partial pressure of the first CA, iC5 in this example. The y-axis represents the reactor temperature. The expected upper viscosity temperature is plotted as upper dashed line 1602. At a particular temperature, the first CA concentration crossing line 1602 is the adhesion limit, since passing this point can cause stickiness. Since sticking in the reactor can cause reactor downtime, an artificial upper limit can be placed to reduce or eliminate the risk of agglomeration represented by line 1604. This manual upper limit provides false buffering in the measured or calculated upper viscous temperature. This artificial upper limit is shown to be 10 ℃, but does not require such a large buffer, especially if the CA composition is to be controlled automatically. The lower stick temperature (gas phase composition dew point) is plotted as lower dashed line 1606, and, similar to the upper stick temperature, may have an artificial lower limit 1608, which is arranged to buffer against error to avoid potential problems with sticking or aggregation (dew point limit). At a particular CA concentration, the temperature crossing line 1606 is the dew point limit due to condensation and viscosity induced by passing this point. An artificial lower limit may consider capillary condensation, which may be performed at temperatures above the dew point. The lower artificial limit is shown to be 10 ℃, but such a large buffer is not required, especially if the CA composition is controlled automatically and the reactor fluidization is monitored.

The artificial upper limit 1604 and the artificial lower limit 1608 define a non-sticking condition 1610 for the reactor. Other areas defined by these limits are sticking conditions where a combination of gas phase composition temperature or condensation combine to render the resin tacky. In region 1612, the higher temperature increases the solubility of the gas-phase composition in the polymer resin to cause stickiness. In region 1614, the high temperature and high equivalent partial pressure of the first CA combine to create an adhesion condition in which a portion of the gas phase composition condenses to a liquid and the temperature increases the solubility of the gas and liquid in the polymer resin. Sticking regime 1616 is a liquid regime where the vapor phase composition begins to condense and render the resin tacky. The square 1618 represents a set of reactor conditions operating within the non-sticking condition 1610. An operator, or control system, may change the reactor conditions to move the square 1618 toward a point that would meet the limits 1604 and 1608 to increase productivity while staying within the bounds of the non-sticking condition 1610. As the reactor conditions are moved toward the point where limits 1604 and 1608 are met, the flexibility of operation becomes less and the margin for making mistakes is reduced, making process upsets, including temperature, pressure, and concentration deviations, more problematic.

FIG. 17 is a graph showing that for a production density of 0.918g/cm using a reactor pressure of 320psig³And MI_2.16A chart illustrating the production rate for a polyethylene polymer of 1.0g/10 min. Production rates correlated with overall allowable CA compositions at varying equivalence factors associated with iC5 and iC 4. The production rate increases in relation to the overall allowable CA composition in an almost linear manner and correlates with the equivalence factor used. Line 1702 represents iC4/iC5 equivalent factor 3, line 1704 represents iC4/iC5 equivalent factor 2.75, and line 1706 represents iC4/iC5 equivalent factor 2.46.

FIG. 18 is a graph of density 0.918g/cm at 320psig using reactor pressure³And MI_2.16A chart illustrating the dew point of the gas phase composition in a polyethylene polymer of 1.0g/10 min. The vapor phase composition exposures were plotted against the overall allowable CA composition at varying equivalence factors associated with iC5 and iC 4. Line 1802 represents iC4/iC5 equivalent factor 3, and the upward slope of the line indicates an increase in the dew point of the gas phase composition as the overall allowable CA composition is increased. Line 1804 represents iC4/iC5 equivalent factor of 2.75, and the nearly flat slope of line 1804 indicates that a change in equivalent factor can maintain the gas phase composition dew point over a range of overall allowable CA compositions. This is achieved byIn addition, line 1806 represents iC4/iC5 equivalent factor 2.46, and the downward slope of line 1806 indicates a decrease in the dew point of the gas phase composition as the overall allowable CA composition is increased. Taken together, the various lines indicate that changes in the equivalence factor can have a significant effect on the dew point within the reactor. A comparison of fig. 17 and fig. 18 shows that lowering the equivalence factor can have a greater effect on the dew point of the gas phase composition in the reactor while not greatly affecting the production rate.

FIG. 19 is a graph illustrating the adhesion limit and dew point limit as a function of production rate and overall allowable CA composition. Line 1902 represents the sticking limit and line 1904 represents the dew point limit. Point 1906 represents a theoretical failure past the dew point limit, which can be corrected by reducing the overall allowable CA composition or reducing the equivalence factor related to CAs within the CA composition. Point 1908, which is the point where the sticking limit and the dew point limit intersect, and point 1910 represent a change in the equivalence factor of 0.1. It can be confirmed that the decrease in the overall allowable CA composition along the adhesion limit (represented by arrow 1912) causes a greater loss in production rate than the decrease in the equivalence factor until the conditions do not pass the dew point limit (represented by arrow 1914). Increasing the equivalence factor results in an increase in production rate. In addition, the incremental effect on production rate is less for changes in the equivalence factor than for changes made to the overall allowable CA composition.

In summary, it has been found that the ratio of CAs in a CA composition can be calculated using a simplification of many factors affecting viscosity, including the solubility and dew point of the gas phase composition inside the reactor in the production of polyolefins. This calculation facilitates the adjustment of the ratio of CAs within the CA composition in real time and facilitates control of the adjustment by a control system that handles the reactor conditions and adjusts the CA composition accordingly. The calculations and adjustments made to the CA composition may facilitate increasing the production rate of the polyolefin relative to previous methods. For example, with respect to approaching the dew point of the gas phase composition in the reactor, previous methods included reducing the overall allowable CA composition causing a significant loss in production rate.

While the disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the disclosure.