摘要:
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.
摘要:
Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer is formed by a trimmed catalyst system including a supported catalyst including bis(n-propylcyclopentadienyl) hafnium (R1)(R2) and a trim catalyst comprising meso-O(SiMe2Ind)2Zr(R1)(R2), wherein R1 and R2 are each, independently, methyl, chloro, fluoro, or a hydrocarbyl group.
摘要:
A method of polymerizing olefins is disclosed. The method comprises contacting ethylene and at least one comonomer with a catalyst system to produce a polyolefin polymer that is multimodal. The catalyst system comprises a first catalyst that promotes polymerization of the ethylene into a low molecular weight (LMW) portion of the polyolefin polymer and a second catalyst that promotes polymerization of the ethylene into a high molecular weight (HMW) portion of the polyolefin polymer. The first catalyst and at least a portion of the second catalyst are co-supported to form a commonly-supported catalyst system and at least a portion of the second catalyst is added as a catalyst trim feed to the catalyst system.
摘要:
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.
摘要:
The use of induced condensing agent (ICA) in fluidized bed gas phase reactor systems enables higher production rates but can affect the resulting polyolefins melt index. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, by altering the concentration of olefin monomer within the reactor system.
摘要:
The catalyst productivity of a polyolefin catalyst in the methods disclosed herein may be increased by increasing the concentration of an induced condensing agent (ICA) in the reactor system. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, in various ways.
摘要:
The use of induced condensing agent (ICA) in fluidized bed gas phase reactor systems enables higher production rates but can affect the resulting polyolefins melt index. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, by altering the concentration of olefin monomer within the reactor system.
摘要:
Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer has a melt index ratio (MIR) greater than about 40. The polymer also has a value for Mw1/Mw2 of at least about 2.0, wherein Mw1/Mw2 is a ratio of a weight average molecular weight (Mw) for a first half of a temperature rising elution (TREF) curve from a cross-fractionation (CFC) analysis to an Mw for a second half of the TREF curve. The polymer also has a value for Tw1−Tw2 of less than about −15° C., wherein Tw1−Tw2 is a difference of a weight average elution temperature (Tw) for the first half of the TREF curve to a Tw for the second half of the TREF curve.
摘要:
The number of small gels that form in polyolefin thin films may be reduced by altering certain production parameters of the polyolefin. In some instances, the number of small gels may be influenced by the melt index of the polyolefin. However, in many instances, melt index is a critical part of the polyolefin product specification and, therefore, is not manipulated. Two parameters that may be manipulated to mitigate small gel count while maintaining the melt index are polyolefin residence time in the reactor and ICA concentration in the reactor.
摘要:
Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer has a melt index ratio (MIR) greater than about 40. The polymer also has a value for Mw1/Mw2 of at least about 2.0, wherein Mw1/Mw2 is a ratio of a weight average molecular weight (Mw) for a first half of a temperature rising elution (TREF) curve from a cross-fractionation (CFC) analysis to an Mw for a second half of the TREF curve. The polymer also has a value for Tw1−Tw2 of less than about −15° C., wherein Tw1−Tw2 is a difference of a weight average elution temperature (Tw) for the first half of the TREF curve to a Tw for the second half of the TREF curve.