Abstract: Methods for producing a polymer include contacting at least one monomer under polymerization conditions with a fluidized bed of a polymerization catalyst on a particulate support; measuring a plurality of pressures of the fluidized bed at a plurality of locations corresponding to increasing heights from a bottom of the fluidized bed; calculating a plurality of pressure drops between the plurality of locations based on the measured pressures; performing a regression analysis on the calculated plurality of pressure drops; correlating the plurality of pressure drops to corresponding heights from the bottom of the fluidized bed based on the regression analysis; determining a height of the fluidized bed based on the correlating; and controlling polymerization conditions based on the determined height of the fluidized bed. The method can also be used to detect malfunctioning pressure transducers based on deviation between measured and expected values.

Abstract: A polymeric composition that is suitable for use as a film or a coating. The polymeric composition comprises: (a) a first component comprising copolymer derived from ethylene and one or more C3 to C20 ?-olefin comonomers. The first component has a density of about 0.911 to about 0.918 g/cm3, a compositional distribution breadth index (CDBI) of about 60% to about 85%, a melt index (MI) of about 16.0 to about 30.0 g/10 min, a molecular weight distribution (MWD) of about 1.5 to about 4.0, and a melt index ratio (MIR) of less than about 25; and (b) a second component comprising a low density polyethylene (LDPE). The second component has a g? of about 0.8 to about 0.15 and a MI that is lower than the MI of the first component.

Abstract: Methods for shutting down and restarting polymerization in a gas phase polymerization reactor are provided. The method can include introducing a polymerization neutralizer to the reactor in an amount sufficient to stop polymerization therein. The method can also include stopping recovery of a polymer product from the reactor and stopping introduction of a catalyst feed and a reactor feed to the reactor. The method can also include adjusting a pressure within the reactor from an operating pressure to an idling pressure. The method can also include adjusting a superficial velocity of a cycle fluid through the reactor from an operating superficial velocity to an idling superficial velocity. The method can also include maintaining the reactor in an idled state for a period of time.

Abstract: Methods for shutting down and restarting polymerization in a gas phase polymerization reactor are provided. The method can include introducing a polymerization neutralizer to the reactor in an amount sufficient to stop polymerization therein. The method can also include stopping recovery of a polymer product from the reactor and stopping introduction of a catalyst feed and a reactor feed to the reactor. The method can also include adjusting a pressure within the reactor from an operating pressure to an idling pressure. The method can also include adjusting a superficial velocity of a cycle fluid through the reactor from an operating superficial velocity to an idling superficial velocity. The method can also include maintaining the reactor in an idled state for a period of time.

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: A polymeric composition that is suitable for use as a film or a coating. The polymeric composition comprises: (a) a first component comprising copolymer derived from ethylene and one or more C3 to C20 ?-olefin comonomers. The first component has a density of about 0.911 to about 0.918 g/cm3, a compositional distribution breadth index (CDBI) of about 60% to about 85%, a melt index (MI) of about 16.0 to about 30.0 g/10 min, a molecular weight distribution (MWD) of about 1.5 to about 4.0, and a melt index ratio (MIR) of less than about 25; and (b) a second component comprising a low density polyethylene (LDPE). The second component has a g? of about 0.8 to about 0.15 and a MI that is lower than the MI of the first component.

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 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 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: 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 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: 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 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.