Abstract: Provided is a method for monitoring a polymerization reaction in a fluid bed reactor to determine in on-line fashion a current value, and preferably also a limiting value, of a stickiness control temperature, and optionally controlling the reaction in response thereto in an effort to prevent occurrence of a discontinuity event. The stickiness control temperature is a temperature indicative of a characteristic of melting behavior of polymer resin in the reactor, and may be indicative of occurrence of resin sheeting or another discontinuity event. Optionally , a predetermined relation between values of acoustic energy in the reactor and values of a stickiness control temperature in used to provide error checking for determination of the stickiness control temperature, or a current value of the stickiness control temperature is determined from acoustic data and a predetermined relation between values of an acoustic condition in the reactor and values of the stickiness control temperature.

Abstract: In some embodiments, a method of monitoring a resin-producing polymerization reaction in a fluid bed reactor system to generate reaction parameter data in on-line fashion, determining an indicator of at least one of entropy and complexity (for example, Kolmogorov or Shannon entropy) of each of at least two subsets of the reaction parameter data, and optionally also determining from at least one value of the indicator (for example, from a time series of Kolmogorov or Shannon entropy values) an indication of at least one of degree of resin stickiness, an approach to or imminence of resin stickiness, and an approach to or imminence of an unsafe or undesired reactor operating condition (e.g., that can result in sheeting or chunking). Optionally also, the reaction is controlled in response to at least one value of the indicator, for example, in an effort to prevent the occurrence of sheeting or another discontinuity event or to maintain the reactor in a stable, non-sticking condition.

Abstract: Provided is a method for monitoring a polymerization reaction in a fluid bed reactor to determine in on-line fashion a current value, and preferably also a limiting value, of a stickiness control temperature, and optionally controlling the reaction in response thereto in an effort to prevent occurrence of a discontinuity event. The stickiness control temperature is a temperature indicative of a characteristic of melting behavior of polymer resin in the reactor, and may be indicative of occurrence of resin sheeting or another discontinuity event. Optionally, a predetermined relation between values of acoustic energy in the reactor and values of a stickiness control temperature is used to provide error checking for determination of the stickiness control temperature, or a current value of the stickiness control temperature is determined from acoustic data and a predetermined relation between values of an acoustic condition in the reactor and values of the stickiness control temperature.

Abstract: The present invention is directed to various methods and systems for detecting at least one impurity in a bulk fluid. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as a gas-phase reactor system.

Abstract: A method for controlling sheeting in a gas phase reactor that includes producing a polyolefin with at least one metallocene catalyst and at least one static control agent in at least one gas phase reactor, measuring entrainment static using a static probe, and adjusting the concentration of the static control agent in response to changes in the measured entrainment static is disclosed.

Abstract: A method for treating at least one interior surface (for example, a bed wall) of a fluidized bed polymerization reactor system, including by applying a solution catalyst (preferably at least substantially uniformly and in liquid form) to each surface, and optionally (where a catalyst component of the solution catalyst comprises at least one chromium containing compound) oxidizing at least some of the applied chromium containing compound in a controlled manner.

Abstract: A method for selecting a semi-conductive coating to be applied to at least a portion of an inner surface of a polyolefin reaction system wherein the coating has certain electrical properties and a fluidized bed reactor vessel wherein at least a portion of a reactor internal surface is coated with a semi-conductive coating is provided.

Abstract: A method of treating a gas phase fluidized bed reactor and a method of polymerizing olefins in a gas phase fluidized bed reactor in the presence of a catalyst prone to cause sheeting by introducing a chromium-containing compound into the reactor and forming a high molecular weight polymer coating on the walls of the reactor. Furthermore, a device for and method of introducing the chromium-containing compound into the fluidized bed reactor at a plurality of locations in proximity to a lower section of a bed section wall of the fluidized bed reactor, and forming a high molecular weight polymer coating on the bed section wall.

Abstract: In some embodiments, a method or system for assessing fluidization quality of a fluidized bed reactor, including by: (a) generating at least one set of temperature data indicative of temperature at a location within the reactor as a function of time during operation of the reactor; (b) generating transformed data by performing a Fourier transform on each said set of temperature data; (c) generating filtered, transformed data by high-pass filtering the transformed data to remove low frequency components thereof (preferably including the frequency component whose frequency is the natural frequency of the cooling control loop); and (d) determining at least one indication of the fluidization quality from the filtered, transformed data. In some embodiments, the reactor has a cooling control loop having a natural frequency and the frequency components removed during step (c) include a frequency component whose frequency is the natural frequency.

Abstract: Embodiments of the present invention relate to measuring and controlling static in a gas phase reactor polymerization. In particular, embodiments relate to monitoring carryover static in an entrainment zone during gas phase polymerization to determine the onset of reactor discontinuity events such as chunking and sheeting. Embodiments also relate to monitoring carryover static to determine the need for effective additions of continuity additives that minimize reactor static activity and thereby preventing discontinuity events.

Abstract: Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.

Abstract: A method for controlling sheeting in a gas phase reactor that includes producing a polyolefin with at least one metallocene catalyst and at least one static control agent in at least one gas phase reactor, measuring entrainment static using a static probe, and adjusting the concentration of the static control agent in response to changes in the measured entrainment static is disclosed.

Abstract: The present invention describes a method for determining reactor continuity of a polymerization reactor by non-linear dynamics. Specifically, the invention relates to a method of analyzing system variables to indicate gas phase reactor continuity in real-time and controlling the reactor continuity to maintain operability.

Abstract: Reactor wall coatings for polymerization reactors and processes for forming such coatings are disclosed. The reactor wall coatings can have a thickness of at least 100 ?m and a molecular weight distribution including a major peak having one or more of an Mw/Mn ratio of less than 10; an Mz/Mw ratio of less than 7; and a maximum value of d(wt %)/d(log MW) at less than 25,000 daltons in a plot of d(wt %)/d(log MW), where MW is the molecular weight in daltons. The reactor wall coatings can be formed in-situ during polymerization, on reactor walls initially free of a reactor wall coating, or having a pre-existing reactor wall coating.

Abstract: Reactor wall coatings for polymerization reactors and processes for forming such coatings are disclosed. The reactor wall coatings can have a thickness of at least 100 &mgr;m and a molecular weight distribution including a major peak having one or more of an Mw/Mn ratio of less than 10; an Mz/Mw ratio of less than 7; and a maximum value of d(wt %)/d(log MW) at less than 25,000 daltons in a plot of d(wt %)/d(log MW), where MW is the molecular weight in daltons. The reactor wall coatings can be formed in-situ during polymerization, on reactor walls initially free of a reactor wall coating, or having a pre-existing reactor wall coating.

Abstract: The present invention describes a method for determining reactor continuity of a polymerization reactor by non-linear dynamics. Specifically, the invention relates to a method of analyzing system variables to indicate gas phase reactor continuity in real-time and controlling the reactor continuity to maintain operability.

Abstract: A polymer of ethylene and at least one alpha olefin having at least 5, carbon atoms obtainable by a continuous gas phase polymerization using supported catalyst of an activated molecularly discrete catalyst such as a metallocene in the substantial absence of an aluminum alkyl based scavenger which polymer has a Melt Index (MI) as herein defined of from 0.1 to 15; a Compositional Distribution Breadth Index (CDBI) as defined herein of at least 70%, a density of from 0.910 to 0.930 g/ml; a Haze value as herein defined of less than 20%; a Melt Index ratio (MIR) as herein defined of from 35 to 80; an averaged Modulus (M) as herein defined of from 20 000 to 60 000 psi (pounds per square inch) and a relation between M and the Dart Impact Strength in g/mil (DIS) complying with the formula: DIS≧0.8×[100+e(11.71-0.000268×M+2.183×10−9×M2)].

Abstract: A polymer of ethylene and at least one alpha olefin having at least 5, carbon atoms obtainable by a continuous gas phase polymerization using supported catalyst of an activated molecularly discrete catalyst such as a metallocene in the substantial absence of an aluminum alkyl based scavenger which polymer has a Melt Index (MI) as herein defined of from 0.1 to 15; a Compositional Distribution Breadth Index (CDBI) as defined herein of at least 70%, a density of from 0.910 to 0.930 g/ml; a Haze value as herein defined of less than 20%; a Melt Index ratio (MIR) as herein defined of from 35 to 80; an averaged Modulus (M) as herein defined of from 20 000 to 60 000 psi (pounds per square inch) and a relation between M and the Dart Impact Strength in g/mil (DIS) complying with the formula: DIS≧0.8×[100+e(11.71−0.000268×M+2.183×10−9×M2)].

Abstract: The disclosed invention relates to a polymerization process comprising contacting ethylene, and optionally, one or more olefinically unsaturated comonomers, with an active supported Group 3, 4, 5, or 6 metallocene catalyst system having an unsubstituted or substituted fused-ring cyclopentadienyl ligand, preferably indenyl or fluorenyl, and a substituted or unsubstituted cyclopentadienyl ligand under gas-phase or slurry polymerization conditions. The process is suitable for the production of high-density polyethylene homopolymers and copolymers. The benefits to industrial practice are both the ease of preparation and low-cost of the precursor metallocene compound and the commercially feasible polymerization activity levels in stable, low fouling level reactor conditions surprisingly associated with it. Additionally, the polymers made under the invention process conditions have narrow molecular weight distributions, low MI, and low values for MIR.

Abstract: This invention relates generally to supported metallocene catalyst systems and to methods for their production which comprising combining inorganic porous support material having an average particle size of from about 30.mu. to about 40.mu., metallocene, and alumoxane wherein the amount of metallocene is in the range of 0.005 to 0.06 mmoles transition metal/g support material and the ratio of aluminum to transition metal is in the range of 10:1 to 300:1. Specifically, this invention relates to supported metallocene catalyst systems having improved metallocene loading and optionally reduced support particle size. These catalyst systems are particularly useful for the polymerization of ethylene polymers.