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: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

Abstract: A continuity additive according to one general approach includes a substance having an ability to reduce, prevent, or mitigate at least one of fouling, sheeting, and static level of a material present in a polymerization reactor system when added to the reactor system in an effective amount, with the proviso that the substance is not a polysulfone polymer, a polymeric polyamine, or an oil-soluble sulfonic acid; and a scavenger contacted with the substance, optionally, the scavenger neutralizing water coming in contact therewith. Additional continuity additives, methods of making continuity additives, and use of continuity additives are also presented.

Abstract: A method of synthesizing an alkyl cyclopentadiene compound is disclosed. The method includes contacting at least one cyclopentadienyl anion source and at least one alkyl group source to form at least one alkyl cyclopentadiene compound. The method further includes extracting the alkyl cyclopentadiene compound with a hydrocarbon solvent. The alkyl cyclopentadiene compound may be converted to a metallocene catalyst compound.

Abstract: Catalyst compositions for the polymerization of olefins having improved flowability properties are provided.

Abstract: Metallocene catalyzed polyethylenes are found to have improved physical properties, improved processability and improved balance of properties. Surprisingly, there is a direct relationship between MD shrinkage, and MD tear. Additionally, MD tear is greater than TD tear, and MD tear is also greater than intrinsic tear. MD tear to TD tear ratios are above 0.9, and dart drop impact is above 500 g/mil. The polyethylenes have a relatively broad composition distribution and relatively broad molecular weight distribution.

Abstract: Systems and methods for monitoring a polymerization reactor are provided. The method can include estimating an acoustic condition of a polymer produced in a reactor. The method can also include estimating a stickiness control parameter of the polymer produced in the reactor. The method can further include pairing the acoustic condition with the stickiness control parameter to provide a paired acoustic condition and stickiness control parameter.

Abstract: Bimodal polyethylene compositions and methods for making the same are provided. In at least one specific embodiment, the bimodal polyethylene composition can include a high molecular weight component having a weight average molecular weight (Mw) of from about 400,000 to about 950,000. The bimodal polyethylene composition can also include a low molecular weight component having a weight average molecular weight (Mw) of from about 3,000 to about 100,000. The high molecular weight component can be present in an amount ranging from about 25 wt % to about 40 wt % of the bimodal polyethylene composition. The bimodal polyethylene composition can also have a percent die swell of less than about 80%.

Abstract: A process for the production of an ethylene alpha-olefin copolymer is disclosed. The process includes polymerizing ethylene and at least one alpha-olefin by contacting the ethylene and the at least one alpha-olefin with a metallocene catalyst in at least one gas phase reactor at a reactor pressure of from 0.7 to 70 bar and a reactor temperature of from 20° C. to 150° C. to form an ethylene alpha-olefin copolymer. The resulting ethylene alpha-olefin copolymer may have a density of 0.927 g/cc or greater and environmental stress crack resistance (ESCR) of 500 hr or more when measured according to ASTM 1693/B in 10% Igepal.

Abstract: Provided are various compositions, including but not limited to a bimodal polyethylene composition having a density of 0.940 g/cc or more, the composition comprising a high molecular weight polyethylene component and a low molecular weight polyethylene component, wherein the composition qualifies as a PE 100 material such that in accordance with ISO 1167 a pipe formed from the composition that is subjected to internal pipe resistance has an extrapolated stress of 10 MPa or more when the internal pipe resistance curve is extrapolated to 50 or 100 years in accordance with ISO 9080:2003(E), and wherein the melt strength is greater than 18 cN.

Abstract: A method for cleaning a distributor plate in a fluidized bed polymerization reactor system according to one embodiment includes, in a first mode, operating with about a normal, baseline value of superficial gas velocity in a fluidized bed polymerization reactor system having a reactor vessel, a recycle line, and a distributor plate in the reactor vessel near an inlet of the reactor vessel. In a second mode, the superficial gas velocity is increased above the baseline value of the first mode to a level sufficient to raise the temperature of the cycle gas at the inlet above an average temperature of the cycle gas at the inlet in the first mode, and to a level sufficient to dislodge foulant from holes in the distributor plate.

Abstract: Polyethylene compositions having improved properties are provided. In one aspect, a polyethylene composition having a long chain branching index (g?avg) of 0.5 to 0.9; a Melt Flow Rate (MFR) of greater than (49.011×MI(?0.4304)), where MI is Melt Index; and a weight average molecular weight to number average molecular weight (Mw/Mn) of less than or equal to 4.6 is provided.

Abstract: A method of performing a polymerization reaction in a gas phase polymerization reactor to produce a bimodal polymer while controlling activity of a bimodal polymerization catalyst composition in the reactor by controlling concentration of at least one induced condensing agent (‘ICA’) in the reactor is provided. In some embodiments, the ICA is isopentane (or another hydrocarbon compound) and the bimodal catalyst composition includes a Group 15 and metal containing catalyst compound (or other HMW catalyst for catalyzing polymerization of a high molecular weight fraction of the product), and a metallocene catalyst compound (or other LMW catalyst for catalyzing polymerization of a low molecular weight fraction of the product).

Abstract: A method and apparatus are disclosed for controlling product discharge from a fluidized bed reactor and for minimizing the loss of the unreacted monomer in the fluidizing gas upon removing the solid polymer product from the reactor. The method and apparatus utilize at least one detector in the product tank or its vent line and a control system in communication with the detector and the product tank fill valve, along with certain algorithms, to adjust by an iterative process, the product discharge time, thereby maximizing resin fill in the product tank and minimizing the lost reactor gas volume.

Abstract: A system for feeding a slurry catalyst composition including: a primary slurry feed system comprising a primary slurry flow meter and a primary catalyst injection device, wherein the primary slurry flow meter measures a primary slurry catalyst composition flow rate to the primary catalyst injection device; and a secondary slurry feed system comprising a secondary slurry flow meter, a secondary carrier liquid, a secondary carrier liquid control device, and a secondary catalyst injection device, wherein the secondary slurry flow meter measures a secondary slurry catalyst composition flow rate to the secondary catalyst injection device, wherein the secondary carrier liquid control device controls a process parameter of the secondary slurry feed system based a ratio of the primary slurry catalyst composition flow rate to the secondary slurry catalyst composition flow rate.

Abstract: Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze.

Abstract: In some embodiments, a method including the steps of monitoring a polymerization reaction which produces a polymer resin in a fluid bed reactor, where a dry melt reference temperature is characteristic of melting behavior of a dry version of the resin, and in response to data indicative of at least one monitored parameter of the reaction, determining in on-line fashion a reduced melt reference temperature that is at least substantially equal to the difference between the dry melt reference temperature and a temperature by which the dry melt reference temperature is depressed by the presence of condensable diluent gas with the resin in the reactor. Optionally, the method also includes the step of controlling the reaction in response to the reduced melt reference temperature or a stickiness parameter determined from the reduced melt reference temperature.

Abstract: Catalyst compositions for the polymerization of olefins having improved flowability properties are provided.

Abstract: The invention generally provides for methods for controlling polymer properties. In particular, invention provides for methods for controlling the comonomer composition distribution of polyolefins such as ethylene alpha-olefin copolymers by altering at least one or more of the following parameters: the molar ratio of hydrogen to ethylene, the molar ratio of comonomer to ethylene, the partial pressure of ethylene, and the reactor temperature without substantially changing the density and/or the melt index of the copolymer.

Abstract: The invention provides for ethylene copolymers having a polymodal CD, wherein under temperature rising elution fractionation (TREF) analysis the ethylene copolymers evidence at least two peaks.