Abstract: Embodiments of the present disclosure are directed towards metal complexes that can be utilized to form polymers. As an example, the present disclosure provides a metal complex of Formula (I) wherein M is Zr, Hf, or Ti; each Het is independently a heterocyclic; each L is independently a bridging group; each X is independently Cl, Br, I, or alkyl; each R1 is independently selected from the group including hydrogen, alkyls, alkenyls, alkynyls, cycloalkyls, aryls, acyls, aroyls, alkoxys, aryloxys, alkylthiols, dialkylamines, alkylamidos, alkoxycarbonyls, aryloxycarbonyls, carbomoyls, alkyl- and dialkyl-carbamoyls, acyloxys, acylaminos, aroylaminos, aromatic rings, fused aromatic rings, and combinations thereof; and each n is independently an integer having a value of one to five.

Abstract: Disclosed are insert assemblies with stacked gas flow gaps to add and/or remove gases from a solid/gas mixture travelling through a barrier. An example system may comprise a barrier and an insert assembly in the barrier defining an annulus between the insert assembly and the barrier, wherein the insert assembly comprises stacked flow gaps configured for addition and/or removal of gas from a solid/gas mixture flowing in the annulus.

Abstract: Catalyst systems and methods for making and using the same are provided. The catalyst system can include a catalyst support, wherein the catalyst support has an average particle size of about 2 microns to about 200 microns. Nanoparticles are adhered to the catalyst support, wherein the nanoparticles have an average particle size of about 2 to about 200 nanometers. A catalyst is supported on the catalyst support.

Abstract: Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.

Abstract: Catalyst systems and methods for making and using the same are disclosed. In an example, a method of synthesizing a monocyclopentadienyl compound is provided. The method includes melting a di-cyclopentadienyl compound including the following structure: (A). As used herein, M is hafnium or zirconium. Each R is independently an H, a hydrocarbyl group, a substituted hydrocarbyl group, a heteroatom group. Each X is a leaving group selected from a halogen or a heteroatom group. A reaction melt is formed by adding a metal salt including the following structure: (B). A monocyclopentadienyl compound is deposited from a vapor formed over the reaction melt, wherein the monocyclopentadienyl compound includes the following structure: (C).

Abstract: Modified chromium-based catalyst compositions for olefin polymerization are disclosed. The modifiers prevent or reduce catalyst particle aggregation providing improved catalyst particle dispersion and consistent flow index response of the compositions in olefin polymerization.

Abstract: Disclosed are novel bridged bi-aromatic phenol ligands and transition metal catalyst compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds, and polymerization processes utilizing the transition metal compounds for the production of olefin polymers.

Abstract: Catalyst systems and methods for making and using the same are described herein. A catalyst system can include at least three catalysts. The three catalysts include a metallocene catalyst, a first non-metallocene including a ligand complexed to a metal through two or more nitrogen atoms, and a second non-metallocene including a ligand complexed to a metal through one or more nitrogen atoms and an oxygen atom.

Abstract: Disclosed are novel bridged bi-aromatic phenol ligands and transition metal compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds.

Abstract: A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

Abstract: Methods for producing polyolefin polymers may use a predictive melt index regression to estimate the melt index of the polyolefin during production based on the composition of the gas phase and, optionally, the concentration of catalyst in the reactor or reactor operating conditions. Such predictive melt index regression may include multiple terms to account for concentration of ICA in the reactor, optionally concentration of hydrogen in the reactor, optionally concentration of comonomer in the reactor, optionally the catalyst composition, and optionally reactor operating conditions. One or more terms may independently be represented by a smoothing function that incorporates a time constant.

Abstract: Catalyst systems and methods for making and using the same are described. A method includes selecting a catalyst blend using a blend polydispersity index (bPDI) map. The polydispersity map is generated by generating a number of polymers for at least two catalysts. Each polymer is generated at a different hydrogen to ethylene ratio. At least one catalyst generates a higher molecular weight polymer and another catalyst generates a lower molecular weight polymer. A molecular weight for each polymer is measured. The relationship between the molecular weight of the polymers generated by each of the catalysts and the ratio of hydrogen to ethylene is determined. A family of bPDI curves for polymers that would be made using a number of ratios of a blend of the at least two catalysts for each of a number of ratios of hydrogen to ethylene.

Abstract: New methods of preparing bridged bi-aromatic ligands are disclosed. The methods employ direct di-ortho-lithiation of aromatic rings of bridged protected bi-aromatic diphenols. The ligands may be used to prepare transition metal compounds useful as catalysts in olefin polymerization.

Abstract: Catalyst systems and methods for making and using the same. A method for making a catalyst support includes forming a mixture of a support material and a fluoride donor. The mixture is added to a fluidized bed reactor. The mixture is fluidized to form a fluidized bed while maintaining a flow rate of a fluidizing gas of about 0.1 ft./sec at less than about 370° C. and greater than about 0.35 ft./sec at temperatures greater than about 370° C. The mixture is calcined to decompose the fluoride donor, forming a fluorinated support.

Abstract: Disclosed herein are methods of controlling polymer properties in polymerization processes that use a chromium-based catalyst. An embodiment discloses a method of producing a polyolefin comprising: contacting a reaction mixture and a reduced chromium oxide catalyst in a gas-phase reactor to produce the polyolefin, wherein the reaction mixture comprises a monomer and a co-monomer; and changing a reaction temperature in the gas-phase reactor by about 1° C. or more whereby a gas molar ratio of the co-monomer to the monomer is changed by about 2% or more and a co-monomer content of the polyolefin at substantially constant density is changed by about 2% or more. Additional methods and compositions are also provided.

Abstract: A method for transitioning a gas phase polymerization reactor between metallocene catalysts is provided. The method comprises first reducing the superficial gas velocity and increasing the height of the fluidized bed within the reactor prior to stopping a feed comprising a first metallocene catalyst. The method further comprises introducing a first polymerization neutralizer to the reactor, wherein the first polymerization reactor does not comprise water, and then introducing a second polymerization neutralizer to the reactor, wherein the second polymerization neutralizer is different from the first polymerization neutralizer. After this, the method comprises purging the reactor with an inert gas and then introducing a feed comprising a second metallocene catalyst to the reactor.

Abstract: A catalyst system for polymerizing olefin-based polymers and interpolymers is disclosed. The catalyst system may include a supported chromium catalyst and a Ziegler-Natta catalyst comprising a bulking agent, Mg, and Ti. The Ziegler-Natta catalysts in catalyst systems disclosed herein run exceptionally well without addition of excessive amounts of co-catalyst, thus allowing for use of chromium based supported catalysts that would otherwise be overwhelmed by aluminum alkyl. Further, embodiments disclosed herein may be run without an internal electron donor, and the lack of an internal electron donor in the system also prevents poisoning of the chromium catalysts by the internal electron donor. By including or co-feeding a chromium based catalyst with these Ziegler-Natta catalysts, it has been found that the molecular architecture of the resulting polyolefins, such as polyethylenes, may provide for resins with excellent processing properties.

Abstract: A system and method for feeding a chromium-based catalyst to a polymerization reactor; adding a reducing agent to the chromium-based catalyst, and polymerizing an olefin into a polyolefin in the polymerization reactor in the presence of the chromium-based catalyst.

Abstract: Catalyst systems and methods for making and using the same. A method for making a catalyst support includes forming a mixture of a support material and a fluoride donor. The mixture is added to a fluidized bed reactor. The mixture is fluidized to form a fluidized bed while maintaining a ratio of a pressure drop across a distributor plate to a pressure drop across the fluidized bed of greater than about 7%. The mixture is calcined to decompose the fluoride donor, forming a fluorinated support.

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.