Abstract:
Halogenated alcohols used in gas phase polymerization of ethylene in combination with a Ti based catalyst component and aluminum alkyls as co-catalyst allows to efficiently suppress ethane formation and to simultaneously increase the polymerization activity.
Abstract:
A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C 3 -C 12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C 3 -C 12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from -20 °C to 60 °C; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.
Abstract:
A process and a system for collecting samples of a polymerization catalyst or of a catalyst-containing polymer from an operation unit of a polymerization plant, the operation unit comprising an upper end and a lower end, the process comprising: a) extracting a prefixed amount of product from the lower end of the operation unit through a discharge valve; b) directing said 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; e) displacing the filtering unit in order to collect the polymerization catalyst or the catalyst-containing polymer sample.
Abstract:
A catalyst system for the (co)polymerization of olefins, comprising (A) a solid catalyst component comprising a titanium compound supported on magnesium dichloride (B) an aluminum alkyl compound and (C) an halogenated organic ester of formula A-COOR in which R is a C 1 C 10 hydrocarbon group and A is a C 1 C 5 saturated or unsaturated hydrocarbon group in which at least one of the hydrogen atoms is replaced by chlorine. Said catalyst systems has improved polymerization activity and reduced ethane generation.
Abstract:
Feeding a supported antistatic compound that does not comprise a transition- metal-based catalyst component to an olefin polymerization reactor allows avoiding the formation of polymer agglomerates in the reactor while at the same time minimizing negative effects on catalyst yield.
Abstract:
A process for the gas-phase polymerization of α-olefÊns CH 2 =CHR, where R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, carried out in a first and a second interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, in which process: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer, and (b) the gaseous composition inside a portion of the downcomer is maintained substantially similar to the gaseous composition reacting in the riser.
Abstract translation:其中R是氢或具有1-12个碳原子的烃基的α-烯烃CH 2 R 2 = CHR的气相聚合方法是在第一和第二互连聚合区 ,其中生长的聚合物颗粒在快速流化条件下流过第一个所述聚合区(提升管),离开所述提升管并进入其中以致密化形式向下流动的所述聚合区(降液管)中的第二个,离开所述降液管和 重新引入所述提升管中,在该过程中:(a)存在于提升管中的气体混合物完全或部分地被阻止进入降液管,并且(b)降液管的一部分内的气态组合物保持基本上类似于气体 组合物在提升管中反应。
Abstract:
There is described a process for the continuous solution polymerization comprising polymerizing olefins of formula CH2=CHR, wherein R is hydrogen or a hydrocarbon radical having from 1 to 8 carbon atoms, and wherein one of the olefins has at least five 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:
The present disclosure generally relates to a catalyst (i) which comprises a titanium compound, a magnesium compound and an ether, where the catalyst is activated by using two different 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). In some embodiments, the activated catalyst has an increased polymerization activity.
Abstract:
A gas-phase process for the homo 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 a Ti, Mg and C1, and optionally an internal electron donor compound, (b) an aluminum alkyl compound and optionally (c) an external donor compound.
Abstract:
Catalyst component comprising Mg, Ti, and halogen atoms, and is characterized in that (a) the Ti atoms are present in an amount higher than 4% based on the total weight of the said catalyst component, (b) the amount of Mg and Ti atoms is such that the Mg/Ti molar ratio is higher than 2 and (c) by a X-ray diffraction spectrum, in which, in the range of 2θ diffraction angles between 47° and 52°, at least two diffraction lines are present at diffraction angles 2θ of 48.3 ± 0.2°, and 50.0 ± 0.2°, the most intense diffraction lines being the one at 2θ of 50.0 ± 0.2°, the intensity of the other diffraction line being equal to or lower than the intensity of the most intense diffraction line.