Abstract: A system in one embodiment includes a barrier; an inverted cone in the barrier; and a member under the inverted cone and having dimensions that cause solids passing therealong between the member and the barrier to have about a constant velocity profile thereacross. A method for purging a gas from a solid/gas mixture according to one embodiment includes adding solids to a barrier having an inverted cone therein and a member under the inverted cone, wherein the solids passing along the member have about a constant vertical velocity profile thereacross; and injecting a purge gas into the solids from at least one point adjacent the member.

Abstract: A film of an ethylene polymer.

Abstract: Provided are processes and systems for recovering hydrocarbons in a vent stream from a polymerization process. The methods and systems may include the recovery of an olefin monomer from a polymerization vent gas using ethylene refrigeration to condense and recover the olefin monomers from the vent gas. In some embodiments, the methods and systems may also include compression and condensation of polymerization vent gas, recompression of ethylene refrigerant, and use of an expander compressor turbine device for ethylene refrigeration.

Abstract: Disclosed is a method for using at least one static probe during polymerization in a fluid bed polymerization reactor system to monitor a coating on a surface of the reactor system and a distal portion of each static probe, wherein the coating is exposed to flowing fluid within the reactor system during the reaction. The surface may be a reactor bed wall (exposed to the reactor's fluid bed) and the coating is exposed to flowing, bubbling fluid within the fluid bed during the reaction. The method may include steps of: during the polymerization reaction, operating the static probe to generate a sequence of data values (“high speed data”) indicative of fluid flow variation (e.g., bubbling or turbulence), and determining from the high speed data at least one electrical property of the coating (e.g., of a portion of the coating on the distal portion of the static probe).

Abstract: Systems and methods for monitoring a particle/fluid mixture are provided. The method can include flowing a mixture comprising charged particles and a fluid past a particle accumulation probe. The method can also include measuring electrical signals detected by the probe as some charged particles pass the probe without contacting the probe while other charged particles contact the probe. The measured electrical signals can be manipulated to provide an output. The method can also include determining from the output if the charged particles contacting the probe have, on average, a different charge than the charged particles that pass the probe without contacting the probe.

Abstract: Described herein are methods for monitoring and restoring electrical properties of polymerization reactor wall films. The method may comprise using a reactor wall monitor to monitor and determine an electrical property, such as the bed voltage or breakdown voltage, of the wall film The method may further comprise adding continuity additive to the reactor and/or adjusting the feed rate of continuity additive being added to the reactor in response to the measured electrical property.

Abstract: A polymerization catalyst system and polymerization processes using the catalyst systems are disclosed. The polymerization catalyst systems may include a) a first catalyst compound, and b) a second catalyst compound, wherein the first catalyst compound includes an oxadiazole-containing compound. In some embodiments, the oxadiazole-containing compound has essentially no hydrogen response, thus allowing better and/or tailored control of product properties when producing polymers using the catalyst system.

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 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: 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 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: Polymer blends and films made therefrom are provided. The polymer blend can include a first polyethylene having a density of less than about 0.940 g/cm3, a melt index (I2) greater than 0.75 g/10 min, and a melt index ratio (I21/I2) of less than 30. The polymer blend can also include a second polyethylene having a density of less than about 0.940 g/cm, a melt index (I2) of less than 1 g/10 min, a melt index ratio (I21/I2) greater than 30, and a molecular weight distribution (Mw/Mn) of less than 4.5.

Abstract: Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.

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: 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: 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: 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 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: 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.