Abstract: In processes and systems having a loop slurry polymerization reactor, a sample separator can be operated at low pressure conditions that provide better separation of liquids from a sample of the reactor effluent, so that measurement of the composition of the vapor phase recovered from the sample separator can more accurately reflect the composition of the liquid in the loop slurry polymerization reactor compared to the composition of the vapor phase recovered from the product separator.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Catalysts and catalytic processes for the synthesis of acrylic acid and other ?,?-unsaturated carboxylic acids and their salts, which are carried out in a diluent or in the absence of a diluent. In an aspect, ethylene and CO2 can be contacted with a Group 8-11 transition metal precursor compound or a Group 8-11 transition metal metalalactone compound in the presence of a metal-treated chemically-modified solid oxide (MT-CMSO) or a metal-treated solid oxide (MT-SO), to form a metal acrylate. As the catalytic activity wanes in either the presence or absence of a diluent, pressure cycling—that is, pressurizing the reaction system with CO2 and an olefin such as ethylene for a time period, releasing the pressure, then re-pressurizing with CO2 and ethylene—can rejuvenate the catalyst and restore its declining catalytic activity.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Silica composites and supported chromium catalysts having a bulk density of 0.08 to 0.4 g/mL, a total pore volume of 0.4 to 2.5 mL/g, a BET surface area of 175 to 375 m2/g, and a peak pore diameter of 10 to 80 nm are disclosed herein. These silica composites and supported chromium catalysts can be formed by combining two silica components. The first silica component can be irregularly shaped, such as fumed silica, and the second silica component can be a colloidal silica or a silicon-containing compound, and the second silica component can act as a glue to bind the silica composite together.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Silica composites and supported chromium catalysts having a bulk density of 0.08 to 0.4 g/mL, a total pore volume of 0.4 to 2.5 mL/g, a BET surface area of 175 to 375 m2/g, and a peak pore diameter of 10 to 80 nm are disclosed herein. These silica composites and supported chromium catalysts can be formed by combining two silica components. The first silica component can be irregularly shaped, such as fumed silica, and the second silica component can be a colloidal silica or a silicon-containing compound, and the second silica component can act as a glue to bind the silica composite together.

Abstract: Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

Abstract: Silica composites and supported chromium catalysts having a bulk density of 0.08 to 0.4 g/mL, a total pore volume of 0.4 to 2.5 mL/g, a BET surface area of 175 to 375 m2/g, and a peak pore diameter of 10 to 80 nm are disclosed herein. These silica composites and supported chromium catalysts can be formed by combining two silica components. The first silica component can be irregularly shaped, such as fumed silica, and the second silica component can be a colloidal silica or a silicon-containing compound, and the second silica component can act as a glue to bind the silica composite together.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Disclosed are metallocene compounds, catalyst compositions comprising a metallocene compound, processes for polymerizing olefins, methods for making catalyst compositions, olefin polymers and articles made from olefin polymers. In an aspect, a metallocene compounds contain a fluorenyl ligand and a cyclopentadienyl ligand which are bridged by a linking group, in which the metallocene is characterized by [1] the cyclopentadienyl ligand being substituted with a C2-C18 heterohydrocarbyl group having an oxygen atom positioned 5 atoms distance or less from the cyclopentadienyl ligand and [2] the linking group having a pendant C3-C12 alkenyl group having a terminal C?C double bond. It has been discovered that a catalyst composition comprising a metallocene compound having these features can produce polyethylene having a low melt index in the absence of a second metallocene.