Abstract: An apparatus for polymerizing olefins including a polymerization reactor and a vessel system for pre-activating a solid catalyst component, wherein the vessel system is arranged upstream of the polymerization reactor. The vessel system includes a contacting vessel which includes a main portion, a base portion, a head portion, an inlet, an outlet, and a stirrer positioned within the contacting vessel, wherein the ratio (H/D) of the height (H) of the main portion to the diameter (D) of the main portion is 1.8 or greater. The stirrer is located at a position between the inlet and the outlet.

Abstract: A process (and a related system) for collecting samples of a polymerization catalyst or of a catalyst-containing polymer from an operation unit, having an upper end and a lower end, of a polymerization plant, including the steps of: a) extracting a prefixed amount of product from the lower end of the operation unit through a discharge valve; b) directing the product towards a filtering unit through an inlet valve; c) flushing an inert gas through the filtering unit; d) outgassing the filtering unit, through the outlet valve; and e) displacing the filtering unit, for collecting the sample.

Abstract: A process for the continuous solution polymerization including the step of polymerizing a first olefin monomer of formula CH2?CHR1, wherein R1 is hydrogen or a hydrocarbon radical having from 1 to 8 carbon atoms with a second olefin monomer of formula CH2?CHR2, wherein R2 is a hydrocarbon radical having from 3 to 8 carbon atoms, in the presence of a polymerization catalyst and in the absence of an inert solvent, at a polymerization temperature (Tp) satisfying the following relationship: Tp?Tm+20° C. wherein Tm is the melting temperature of the obtained polymer.

Abstract: A process for preparation of an ethylene polymer in a gas-phase polymerization unit comprising a gas-phase polymerization reactor by homopolymerizing ethylene or copolymerizing ethylene and one or more C4-C12-1-alkenes in a reaction gas made from or containing propane as polymerization diluent in the presence of a pre-activated polymerization catalyst, wherein a purified propane feed stream made from or containing at least 99 mol % propane and from 0.1 to 100 ppm mol propylene is fed to the gas-phase polymerization unit.

Abstract: A gas-phase polymerization reactor for the gas-phase polymerization of olefins including a polymerization zone having a recycle line for (a) withdrawing reaction gas from the reactor, (b) leading the reaction gas through a heat-exchanger for cooling, and (c) feeding the reaction gas back to the reactor, wherein the recycle line has the heat-exchanger, a centrifugal compressor having variable guide vanes, and a butterfly valve, and a related process for preparing an olefin polymer in the gas-phase polymerization reactor.

Abstract: A gas-phase polymerization reactor for the gas-phase polymerization of olefins including a polymerization zone having a recycle line for (a) withdrawing reaction gas from the reactor, (b) leading the reaction gas through a heat-exchanger for cooling, and (c) feeding the reaction gas back to the reactor, wherein the recycle line has the heat-exchanger, a centrifugal compressor having variable guide vanes, and a butterfly valve, and a related process for preparing an olefin polymer in the gas-phase polymerization reactor.

Abstract: A process for preparing an ethylene polymer including the step of homopolymerizing ethylene or copolymerizing ethylene with one or more comonomers in a gas-phase polymerization reactor including a riser unit wherein growing polymer particles flow upwards under fluidization, fast fluidization or transport conditions and a downcomer wherein growing polymer particles flow downward in a densified form, wherein the hold-up of polymer particles in the downcomer is from 55 wt. % to 80 wt. % of the total hold-up of polymer particles in the gas-phase polymerization reactor.

Abstract: The present disclosure generally relates to ethylene alpha-olefin copolymers and methods of making ethylene alpha-olefin copolymers. The ethylene alpha-olefin copolymers may have a density of about 0.915 g/mL to about 0.918 g/mL, a rheological polydispersity index greater than 0.8, a melt index of about 0.4 dg/10 min to about 2.0 dg/10 min, and/or a CEF T50 of 84° C. or less. The ethylene alpha-olefin copolymers may be made by combining an ethylene monomer and one or more alpha-olefin monomers in the presence of a catalyst, such as a Ziegler-Natta catalyst.

Abstract: A solid catalyst component (i) made from or containing a titanium compound, a magnesium compound and an ether, is activated by using two different aluminum alkyl compounds (ii) and (iii) in sequence and under specific molar ratios relative to each other and to the ether of the solid catalyst component (i).

Abstract: A gas-phase process for the homopolymerization or copolymerization of olefins carried out in the presence of a catalyst system formed by a contacting, in a liquid hydrocarbon and in the presence of hydrogen, (a) a solid catalyst component comprising Ti, Mg, and Cl, and optionally an internal electron donor compound, (b) an aluminum alkyl compound and optionally (c) an external donor compound.

Abstract: A process for starting a multizone circulating reactor containing no polyolefin particles, comprising the steps of conveying gas through the reactor and the gas recycle line, feeding a particulate material comprising a polymerization catalyst and optionally polyolefin into the reactor, controlling the gas flow in a vertical reactor zone equipped with a throttling valve at the bottom so that the upwards gas velocity in the bottom part of this reaction zone is lower than the terminal free-fall velocity of the particulate material fed into the reactor, and, after the weight of the particulate polyolefin in this reactor zone is higher than the drag force of the upward moving gas, controlling the circulation rate of the polymer particles within the multizone circulating reactor by adjusting the opening of the throttling valve and adjusting the flow rate of a dosing gas.

Abstract: A process for preparing an ethylene polymer including the step of homopolymerizing ethylene or copolymerizing ethylene with one or more comonomers in a gas-phase polymerization reactor including a riser unit wherein growing polymer particles flow upwards under fluidization, fast fluidization or transport conditions and a downcomer wherein growing polymer particles flow downward in a densified form, wherein the hold-up of polymer particles in the downcomer is from 55 wt. % to 80 wt. % of the total hold-up of polymer particles in the gas-phase polymerization reactor.

Abstract: A gas-phase process for the homopolymerization or copolymerization of olefins carried out in the presence of a catalyst system formed by a contacting, in a liquid hydrocarbon and in the presence of hydrogen, (a) a solid catalyst component comprising Ti, Mg, and Cl, and optionally an internal electron donor compound, (b) an aluminum alkyl compound and optionally (c) an external donor compound.

Abstract: A method for feeding an antistatic compound to a polymerization reactor comprising the steps of: a) dispersing, under mixing conditions, a catalyst powder and an antistatic compound in an oil, so as to form a suspension of catalyst powder and antistatic compound in said oil; b) successively adding, under mixing conditions, a molten thickening agent to said suspension from step a), while maintaining said suspension at a temperature such that said thickening agent solidifies on contact with said suspension; c) transferring the product obtained from b) to a polymerization reactor.

Abstract: The present technology relates to a method of introducing a supported antistatic compound that does not comprise a transition-metal-based catalyst component for use in an olefin polymerization reactor. In some embodiments, the methods disclosed herein avoid the formation of polymer agglomerates in the reactor and minimize potentially negative effects on catalyst yield.

Abstract: Process for preparing a polyolefin polymer comprising the steps of a) forming a particulate polyolefin polymer by polymerizing one or more olefins in the presence of a polymerization catalyst system in a polymerization reactor; b) discharging the formed polyolefin particles from the polymerization reactor; c) degassing the polyolefin particles by a process comprising at least a final step of contacting the polyolefin particles with a nitrogen stream in a degassing vessel; and d) transferring the polyolefin particles from the vessel, in which the contacting of the polyolefin particles with the nitrogen stream is carried out, to a melt mixing device, in which the polyolefin particles are melted, mixed and thereafter pelletized, without passing the particles through a buffering device, wherein the degassing vessel is only partly filled with polyolefin particles and the empty volume within the degassing vessel is sufficient to take up additional polyolefin particles for at least 3 hours if the transfer of pol

Abstract: The present disclosure generally relates to ethylene alpha-olefin copolymers and methods of making ethylene alpha-olefin copolymers. The ethylene alpha-olefin copolymers may have a density of about 0.915 g/mL to about 0.918 g/mL, a rheological polydispersity index greater than 0.8, a melt index of about 0.4 dg/10 min to about 2.0 dg/10 min, and/or a CEF T50 of 84° C. or less. The ethylene alpha-olefin copolymers may be made by combining an ethylene monomer and one or more alpha-olefin monomers in the presence of a catalyst, such as a Ziegler-Natta catalyst.

Abstract: The present disclosure provides a gas-phase polymerization process for preparing polyethylene, wherein halogenated alcohols in combination with a Ti based catalyst component and aluminum alkyls as co-catalyst suppress ethane formation or increase polymerization activity.

Abstract: The present disclosure provides a catalyst system made from or containing: (A) a solid catalyst component made from or containing (i) a titanium compound supported on a magnesium dichloride; (B) an aluminum alkyl compound; and (C) a halogenated organic ester of formula A-COOR, wherein R is a C1-C10 hydrocarbon group and A is a C1-C15 saturated or unsaturated hydrocarbon group in which at least one of the hydrogen atoms is replaced by a chlorine atom. The present disclosure also provides a process for preparing an olefinic polymer, including a polymerization step of polymerizing an olefin in the presence of the catalyst system. The present disclosure also provides an olefinic polymer made therefrom.

Abstract: A process for starting a multizone circulating reactor containing no polyolefin particles, comprising the steps of conveying gas through the reactor and the gas recycle line, feeding a particulate material comprising a polymerization catalyst and optionally polyolefin into the reactor, controlling the gas flow in a vertical reactor zone equipped with a throttling valve at the bottom so that the upwards gas velocity in the bottom part of this reaction zone is lower than the terminal free-fall velocity of the particulate material fed into the reactor, and, after the weight of the particulate polyolefin in this reactor zone is higher than the drag force of the upward moving gas, controlling the circulation rate of the polymer particles within the multizone circulating reactor by adjusting the opening of the throttling valve and adjusting the flow rate of a dosing gas.