Abstract: A method for polymerizing olefins in a fluidized-bed reactor is provided. The method involves introducing a fluid into the fluidized-bed reactor at an angle and amount sufficient to induce one or more swirls in the fluidized bed in the reactor.

Abstract: A process for producing a polyolefin comprising a combination of liquid phase polymerization of ?-olefin conducted in one or more liquid phase polymerization reactors and gas phase polymerization of ?-olefin conducted in one or more gas phase polymerization reactors after the liquid phase polymerization in a material flow.

Abstract: Process for the gas-phase catalytic polymerization of olefins carried out in a plurality of interconnected polymerization zones, the process comprising feeding one or more monomers to said polymerization zones in the presence of a catalyst under reaction conditions and collecting the polymer product from said polymerization zones, in which process the polymer particles grow within a first polymerization zone where a fluidized bed is formed, at least a part of said polymer particles leave said first polymerization zone to enter a second polymerization zone through which they flow downward, leave said second polymerization zone and enter a third polymerization zone through which they flow upward under fast fluidization or transport conditions, leave said third polymerization zone and are reintroduced into the first polymerization zone, thus establishing a circulation of polymer between the different polymerization zones.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: In some embodiments, a method for determining initial conditions for a transition from an initial reaction to a target reaction to minimize (or substantially minimize) the amount of off-grade material produced during the transition, and optionally also process control variables for implementing the transition. Some embodiments also include the steps of setting the reaction conditions to determined initial conditions and then implementing the transition.

Abstract: The present invention relates to a process for improving the start up of polymerization or copolymerization of ethylene in a gas phase reactor, preferably a fluidized bed gas phase reactor.

Abstract: Properties of a polymer produced in gas phase or slurry phase using a dual catalyst such as polydispersity and comonomer incorporation, may be controlled by controlling reaction parameters such as temperature, (co)monomer pressure, hydrogen partial pressure and the presence of non-polymerizable hydrocarbon. This provides an easy method to control the bimodality of a polymer as well as comonomer incorporation.

Abstract: A process and apparatus for gas phase polymerization of olefins in a fluidized bed reactor are disclosed. The process and apparatus employ a vertically oriented fines ejector in order to reduce fouling and reactor downtime.

Abstract: Properties of a polymer produced using a dual catalyst on the same support, such as polydispersity and comonomer incorporation, may be controlled by controlling reaction parameters such as temperature, monomer pressure, hydrogen partial pressure and the presence of non-polymerizable hydrocarbon. This provides an easy method to control the bimodality of a polymer as well as comonomer incorporation.

Abstract: A process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of a catalyst system which comprises a bridged indenoindolyl transition metal complex on a support material, an alkylalumoxane, a titanium tetralkoxide, and a branched alkyl aluminum compound. The process provides polyethylenes with low density from ethylene alone.

Abstract: The use of high activity “Single Site” polymerization catalysts often causes the fouling of polymerization reactors. The problem is particularly acute with gas phase polymerizations. While not wishing to be bound by theory it is believed that the fouling is initiated by the buildup of static charges in the reactor. The use of anti-static agents mitigates this problem, but typical antistatic agents contain polar species, which can deactivate the polymerization catalyst. We have now discovered that the use of a porous metal oxide support allows large levels of a selected antistatic agent to be used in a manner that reduces static/fouling problems in highly active polymerization catalysts.

Abstract: The instant invention is a high-density polyethylene composition, and method of making the same. The high-density polyethylene composition of the instant invention includes an ethylene alpha-olefin copolymer having a density in the range of 0.935 to 0.952 g/cm3, a melt index (I2) in the range of 30 to 75 g/10 minutes, an I21/I2 ratio in the range of 13-35, a Mw/Mn ratio in the range of 3.5-8. The high-density polyethylene composition has a brittleness temperature of at least less than ?20° C. The process for producing a high-density polyethylene composition according to instant invention includes the following steps: (1) introducing ethylene, and an alpha-olefin comonomer into a reactor; (2) copolymerizing the ethylene with the alpha-olefin comonomer in the reactor; and (3) thereby producing the high-density polyethylene composition, wherein the high-density polyethylene composition having a density in the range of 0.935 to 0.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: The present invention relates to a continuous gas phase process comprising polymerizing one or more hydrocarbon monomer(s) in a fluidized bed reactor in the presence of catalyst system or polymerization catalyst and a condensable fluid for a period of at least 12 hours where the bed temperature is less than the Critical Temperature and the dew point temperature of the gas composition in the reactor is within 25° C. of the bed temperature.

Abstract: A method of preventing or inhibiting fouling in an olefin polymerization fluidized-bed reactor is provided. The method involves varying the fluidization velocity inside the reactor over time about a set point.

Abstract: A method for polymerizing olefins in a fluidized-bed reactor is provided. The method involves introducing a fluid into the fluidized-bed reactor at an angle and amount sufficient to induce one or more swirls in the fluidized bed in the reactor.

Abstract: Copolymers and methods of forming copolymers are described herein. The methods generally include providing a transition metal compound represented by the formula [L]mM[A]n, wherein L is a bulky ligand including bis-indenyl, A is a leaving group, M is a transition metal and m and n are such that the total ligand valency corresponds to the transition metal valency and providing a support material having a bonding sequence selected from Si—O—Al—F, F—Si—O—Al, F—Si—O—Al—F and combinations thereof. The methods further include contacting the transition metal compound with the support material to form an active supported catalyst system, wherein the contact of the transition metal compound with the support material occurs in proximity to contact with monomer and contacting the active supported catalyst system with a plurality of monomers to form an olefin copolymer.

Abstract: The present invention relates to a process for improving the start up of polymerization or copolymerization of ethylene in a gas phase reactor, preferably a fluidised bed gas phase reactor.

Abstract: A method for preventing or inhibiting fouling in a gas-phase polyolefin polymerization process. The method includes maintaining the inside surface temperature of the process equipment below the dew point temperature of the gas mixture passing through the equipment.

Abstract: The present invention relates to a method for preparing polymers by gas-phase deposition polymerization, initiated by a zero valent metal and an initiator.

Abstract: A method for the treatment of catalysts or catalyst carriers by: a) introducing and distributing a gas in the lower section of a reactor containing a catalyst or catalyst carrier bulk material; b) forming a fluidized bed in the reactor; c) treating the particles in the fluidized bed while removing the fine particles an/or retaining the course particles by means of a separating organ and d) discharging the reactor. To this end, a reactor bottom which tapers downwards is used.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: A compound useful as a cocatalyst or cocatalyst component, especially for use as an addition polymerization catalyst compound, corresponding to the formula: (A*+a)b(Z*J*j)?cd, wherein: A* is a proton or a cation of from 1 to 80 atoms, preferably 1 to 60 atoms, not counting hydrogen atoms, said A* having a charge +a; Z* is an anion group of from 1 to 50 atoms, preferably 1 to 30 atoms, not counting hydrogen atoms, further containing two or more Lewis base sites, said Z* being the conjugate base of an inorganic Bronsted acid or a carbonyl- or non-cyclic, imino-group containing organic Bronsted acid; J* independently each occurrence is a Lewis acid of from 1 to 80 atoms, preferably 1 to 60 atoms, not counting hydrogen atoms, coordinated to at least one Lewis base site of Z*, and optionally two or more such J* groups may be joined together in a moiety having multiple Lewis acidic functionality; j is a number from 1 to 12; and a, b, c, and d are integers from 1 to 3, with the proviso that a×b is equal to c×d.

Abstract: Methods for controlling a melt viscosity of a polyolefin, controlling comonomer distribution of a polyolefin, achieving a targeted melt viscosity of a polyolefin, and films made from such polyolefins are provided. The methods include contacting an olefin monomer and at least one comonomer with a catalyst system in the presence of a condensable fluid comprising a saturated hydrocarbon having from 2 to 8 carbon atoms. The catalyst system in one embodiment includes a hafnium metallocene catalyst component.

Abstract: A catalyst composition for the polymerization of olefins and process for the use thereof, comprising the combination of one or more Ziegler-Natta catalysts, comprising one or more transition metal compounds, one or more aluminum containing cocatalyts, and a mixture of different selectivity control agents, including in said mixture of selectivity control agents at least one normally dominating selectivity control agent and one normally dominated selectivity control agent, characterized in that the individual selectivity control agents are present in the mixture in relative amounts to each other and relative to the one or more transition metal compounds, such that the effect of the selectivity control agents on the resulting polymer properties is not determined solely or substantially solely by the normally dominating selectivity control agent.

Abstract: Disclosed are catalyst systems and methods of making the catalyst systems/supports for the polymerization of an olefin containing a solid titanium catalyst component having a substantially spherical shape and containing an internal electron donor, a support made from a magnesium compound, an alcohol, an ether, a surfactant, and an alkyl silicate. The catalyst system may further contain an organoaluminum compound and an organosilicon compound. Also disclosed are methods of making an impact copolymer involving polymerizing an olefin to provide a polyolefin matrix and polymerizing a polyolefin rubber using a catalyst component containing a support made from a magnesium compound, an alcohol, an ether, a surfactant, and an alkyl silicate.

Abstract: The present invention relates to a continuous gas phase process comprising polymerizing one or more hydrocarbon monomer(s) in a fluidized bed reactor in the presence of catalyst system or polymerization catalyst and a condensable fluid for a period of at least 12 hours where the bed temperature is less than the Critical Temperature and the dew point temperature of the gas composition in the reactor is within 25° C. of the bed temperature.

Abstract: A process for polymerizing an alpha-olefin is disclosed. The polymerization is performed in the presence of a catalyst system comprising a three-membered titanacycle. A wide variety of titanacycles can be readily prepared, making this a versatile and inexpensive olefin polymerization process.

Abstract: The invention encompasses late transition metal catalyst systems immobilized on solid supports and their use in heterogenous polymerization processes, particularly in gas phase polymerization of olefin monomers. Preferred embodiments include a late transition metal catalyst system comprising a Group 9, 10, or 11 metal complex stabilized by a bidentate ligand structure immobilized on a solid porous metal or metalloid oxide particle support, particularly those comprising silica. The gas phase polymerization process for olefin monomers comprises contacting one or more olefins with these catalyst systems under gas phase polymerization conditions.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: The present invention relates to a process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a chromium oxide catalyst characterized in that the polymerization is performed in the presence of a polymer structure modifier.

Abstract: The tendency of copolymer fluff grains of propylene and ethylene to agglomerate is reduced by injecting at least one olefin comonomer, such as ethylene monomer, into more than one point along the length of the reactor, rather than injecting all of the ethylene at one point. This process reduces the tendency of copolymer fluff grains to agglomerate and cause processing problems as compared with injecting the comonomer at only one point. Copolymer made by this process is expected to have lower substantially amorphous polypropylene content and better organoleptics than copolymer made where the ethylene is injected at only one point. In one non-limiting embodiment the copolymerization reactor is a loop-type reactor.

Abstract: A process to support a homogeneous catalyst on a porous solid support is performed in two separate zones. In the first zone the solid is contacted, under stirring, with an amount of a catalyst solution lower than the total pore volume of the solid. In the second zone the solid is dried from the solvent while flowing under pneumatic conveying. A loop circulation of solid is established between the two zones, so that the solid is subject to more contacting steps. The process is particularly suitable to support a metallocene-alumoxane polymerization catalyst on a porous prepolymer. The process can be advantageously performed in continuous, thus fitting the needs of an industrial scale production process.

Abstract: Provided herein is an oligomerization product formed from alpha-olefins having at least three carbon atoms comprising dimers, at least about 80 weight percent of which are linear. In an embodiment, an oligomerization product formed from alpha-olefins having at least three carbon atoms comprises trimers, at least about 20 weight percent of which are linear. In another embodiment, an oligomerization product formed from alpha-olefins having at least three carbon atoms comprises tetramers, at least about 5 weight percent of which are linear. In yet another embodiment, an oligomerization product formed from alpha-olefins having at least three carbon atoms comprises pentamers, at least about 5 weight percent of which are linear.

Abstract: Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.

Abstract: A process for polymerizing ethylene is disclosed. The ethylene is polymerized with a catalyst system which comprises an activator and an indeno[2,1-b]indolyl Group 4-6 transition metal complex having open architecture. The process gives polyethylene having a broad molecular weight distribution for improved processability.

Abstract: Films and methods of forming films comprising first combining in a reactor olefins, a catalyst composition and an activator; wherein the activator is present from less than 50 wt % in a diluent by weight of the activator and diluent; followed by isolating a polyolefin having a density of from 0.940 to 0.980 g/cm3; and finally, extruding the polyolefin into a film having a gel count of less than 200 gels/m2.

Abstract: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

Abstract: The present invention relates to a process for polymerizing monomer and comonomer(s) utilizing a bulky ligand transition metal metallocene-type catalyst or catalyst system, where the process is operated in the absence of or with a low amount of any of the isomers of the comonomer(s). The level of these isomers in the process of the invention are eliminated or maintained below a threshold level. It has been discovered that removal of certain isomers of the comonomer used in a polymerization process using metallocene-type catalysts results in an improved process.

Abstract: Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.

Abstract: The present invention relates to a process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor wherein fouling is prevented and/or flowability of polymer is improved thanks to the use of a process aid additive.

Abstract: Continuous gas-phase polymerization process for preparing ethylene and propene homopolymers and copolymers, in which ethylene, propene or mixtures comprising ethylene or propene and C3-C8-?-monoolefins are polymerized in the polymerization zone of a gas-phase polymerization reactor at from 30 to 125° C. and pressures of from 1 to 100 bar in the gas phase in a bed comprising finely divided polymer in the presence of a catalyst. To remove the heat of polymerization, the reactor gas is circulated and firstly passes through a cyclone after leaving the reactor. To prevent polymer deposits in the circulating gas system, a catalyst poison having a boiling point above the maximum temperature within the circulating gas system is fed into this circulating gas system at a position between the reactor and the cyclone.

Abstract: A process for preparing polyethylene from “feed ethylene” comprises: a) a hydrogenation stage in which “feed ethylene” containing impurities or secondary components such as acetylene and ethane is reacted with hydrogen to remove the acetylene by catalytic hydrogenation to form ethylene and part of the ethylene is converted into ethane, and b) a polymerization stage in which the ethylene leaving stage a) is reacted in the gas phase in a fluidized-bed reactor to form polyethylene, where the fluidizing gas used comprises, on entering the reactor, ethene and from 20 to 70% by volume of ethane, based on the total volume of the fluidizing gas, possibly together with further components, where, in a), ethylene is converted in a targeted manner into ethane in addition to the ethane already present in the “feed ethylene” so that the concentration specified in b) results. An apparatus for carrying out the process is also provided.

Abstract: The invention relates to a process for the preparation of an olefin polymer comprising at least two polymerization stage in the presence of an olefin polymerization catalyst material, an olefin polymer produced by such process, and the use of such polymers for the production of fibres, pipes, films, moulded products and products for wire and cable applications.

Abstract: The object of the present invention is to provide a polyolefin polymerization method which prevents fine particles of polymer from scattering from a fluidized bed in a gas phase polymerization reactor. This object is achieved by a process for polymerization of ?-olefin in multi-stage polymerization process and in at least two serially arranged polymerization reactors including a gas phase polymerization reactor, the process comprising; drawing out polyolefin particles from a polymerization reactor, and transferring the polyolefin particles into the interior of fluidized bed of a gas phase polymerization reactor of the next stage.

Abstract: The invention provides a catalyst system and a method of making polyethylene using the catalyst system, the method comprising combining ethylene; an activator; and a metallocene catalyst compound; wherein in one embodiment the metallocene catalyst compound is selected from: wherein M is a Group 4 atom; X is a leaving group; n is an integer from 0 to 3; and R1 to R12 are independently selected from hydrides, halogens, hydroxy, C1 to C6 alkoxys, C1 to C6 alkenyls, and C1 to C10 alkyls; characterized in that when the comonomer is 1-hexene, and the mole ratio of 1-hexene to ethylene combined is varied between 0.015 to 0.05, the density of the resultant polyethylene changes by less than 5% and the I21/I2 varies from 10 to 150.

Abstract: Processes for the production of alpha-olefins, including dimerization and isomerization of olefins using a cobalt catalyst complex are provided herein. The olefins so produced are useful as monomers in further polymerization reactions and are useful as chemical intermediates.

Abstract: A process for the continuous gas-phase (co)polymerization of one or more olefins for which a rising stream of a gas mixture, comprising at least one olefin to be (co)polymerized, maintains polymer particles in the course of formation in the fluidized state in a polymerization reactor, the said stream entraining fine particles above the fluidized bed outside the reactor, the said fine particles being substantially separated from the gas mixture using a separator, thus dividing the said stream into (i) one or more gas streams (A) substantially devoid of solid particles which is cooled and reintroduced below and/or into the bottom part of the fluidized bed, and (ii) one or more gas streams (B) comprising at least a portion of the said particles which is introduced into or above the fluidized bed, which process is characterized in that at least one of the gas streams (B) comprising the solid particles is introduced directly into the fluidized bed by a dilute-phase transport in a simple pipe, that is to say prefer

Abstract: A method for the analysis by on-line gas phase chromatography of a gaseous phase produced by an olefin polymerization process which includes carrying out a chromatographic analysis of a gaseous phase produced by an olefin polymerization process with carrier gases containing mainly hydrogen and/or nitrogen, wherein the content of oxygen and of water of the hydrogen and the nitrogen in the carrier gases is less than 5 ppm by weight.

Abstract: Ethylenically unsaturated monomers are polymerized in a gas-phase fluidized-bed reactor comprising a reactor space (1) in the form of a vertical tube, a calming zone (2) adjoining the upper part of the reactor space, a circulated gas line (3), a circulated gas compressor (4), a cooling apparatus (5), a gas distributor plate (6) which forms the lower boundary of the reactor space and, if desired, a flow divider (7), wherein the gas distributor plate (6) has a plurality of gas flow orifices (8) whose outlet sides are widened conically.