Abstract:
The invention relates to a process for transitioning from a first continuous polymerization in a gas phase reactor conducted in the presence of a metallocene catalyst to a second polymerization conducted in the presence of a Ziegler-Natta catalyst in the gas phase reactor wherein the metallocene catalyst and the Ziegler-Natta catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the metallocene catalyst into the gas phase reactor; (b) introducing an effective amount of cyclohexylamine into the reactor to at least partially deactivate the metallocene catalyst; (c) introducing an organometallic compound into the reactor and reacting the organometallic compound with cyclohexylamine; (d) degas the gas composition of the reactor and build up a new composition inside the reactor for the second polymerization with the Ziegler-Natta catalyst (e) introducing the Ziegler-Natta catalyst into the reactor.
Abstract:
The invention relates to a multi-zone reactor for the continuous fluidized bed polymerization of one or more α-olefin monomers of which at least one is ethylene or propylene, which multi-zone reactor is operable in condensed mode, which multi-zone reactor comprises a first zone, a second zone, a third zone, a fourth zone and a distribution plate, wherein the second zone contains an inner wall, wherein the third zone contains an inner wall, wherein at least part of the inner wall of the third zone is either in the form of a gradually increasing inner diameter or a continuously opening cone, wherein the diameter or the opening increases in the vertical direction towards the top of the multi-zone reactor, wherein the largest diameter of the inner wall of the third zone is larger than the largest diameter of the inner wall of the second zone.
Abstract:
The invention relates to a process and system for the continuous polymerization of one or more α-olefin monomers comprising the steps of: a) introducing catalyst and/or polymer from at least one loop reactor to at least one second reactor b) withdrawing fluids from the at least one second reactor c) cooling fluids comprising the withdrawn fluids with a cooling unit d) introducing the cooled fluids to a separator to separate at least part of the liquid from these fluids to form a liquid phase and a gas/liquid phase e) introducing the gas/liquid phase below to the reactor below a distribution plate f) introducing the liquid phase to a settling tank to separate liquid from fines that settle down in the settling tank g) introducing liquid from the settling tank upstream of the cooling unit, h) introducing the slurry comprising solid polymer particles from the settling tank to the at least one loop reactor.
Abstract:
The invention relates to a system for the continuous polymerization of α-olefin monomers comprising a reactor, a compressor, a cooling unit and an external pipe, wherein the reactor comprises a first outlet for a top recycle stream, wherein the system comprises apparatus, wherein the reactor comprises a first inlet for receiving a bottom recycle stream, wherein the reactor comprises an integral separator, wherein the first inlet of the integral separator is connected to a first outlet, wherein the first outlet for the liquid phase is connected to the second outlet of the reactor for the liquid phase, wherein the external pipe comprises a second inlet for receiving a solid polymerization catalyst, wherein the first outlet of the external pipe is connected to a second inlet of the reactor, wherein the reactor comprises a third outlet, wherein the system comprises a first inlet for receiving a feed.
Abstract:
The invention relates to a process and system for the continuous polymerization of one or more ±-olefin monomers comprising the steps of: a) introducing catalyst and/or polymer from at least one loop reactor to at least one second reactor b) withdrawing fluids from the at least one second reactor c) cooling fluids comprising the withdrawn fluids with a cooling unit d) introducing the cooled fluids to a separator to separate at least part of the liquid from these fluids to form a liquid phase and a gas/liquid phase e) introducing the gas/liquid phase below to the reactor below a distribution plate f) introducing the liquid phase to a settling tank to separate liquid from fines that settle down in the settling tank g) introducing liquid from the settling tank upstream of the cooling unit, h) introducing the slurry comprising solid polymer particles from the settling tank to the at least one loop reactor.
Abstract:
The present invention relates to a process for the continuous preparation of a polyolefin in a reactor from one or more α-olefin monomers of which at least one is ethylene or propylene, wherein the reactor comprises a fluidized bed, an expanded section located at or near the top of the reactor, a distribution plate located at the lower part of the reactor and an inlet for a recycle stream located under the distribution plate wherein the process comprises—feeding a polymerization catalyst to the fluidized bed in the area above the distribution plate—feeding the one or more α-olefin monomers to the reactor—withdrawing the polyolefin from the reactor—circulating fluids from the top of the reactor to the bottom of the reactor, wherein the circulating fluids are compressed using a compressor and subsequently cooled using a heat exchanger to form a cooled recycle stream comprising liquid, and wherein the cooled recycle stream is introduced into the reactor using the inlet for the recycle stream wherein a part of the cooled recycle stream is drawn to form a liquid comprising stream, wherein the liquid comprising stream is introduced into the expanded section during at least part of the polymerization process, and wherein the liquid comprising stream is brought into contact with at least part of the interior surface of the expanded section.
Abstract:
The present invention relates to a process for the continuous preparation of polypropylene in a reactor from propylene and optionally ethylene and/or at least one other oolefin monomer, wherein the reactor comprises a fluidized bed, an expanded section located at or near the top of the reactor, a distribution plate located at the lower part of the reactor and an inlet for a recycle stream located under the distribution plate, wherein the process comprises—feeding a polymerization catalyst to the fluidized bed in the area above the distribution plate—feeding the propylene and the optional at least one other oolefin monomer to the reactor—withdrawing the polypropylene from the reactor—circulating fluids from the top of the reactor to the bottom of the reactor, wherein the circulating fluids are compressed using a compressor and cooled using a heat exchanger, resulting in a cooled recycle stream comprising liquid, and wherein the cooled recycle stream is introduced into the reactor using the inlet for the recycle stream wherein an alkane chosen from the group of iso-butane, n-butane, cyclopropane and mixtures thereof is added to the reactor and wherein the molar composition of the components in the recycle stream is chosen such that the dew temperature of the recycle stream at the reactor pressure is at least 0.10° C. below the temperature of the reactor
Abstract:
The invention relates to a process for the continuous polymerization of one or more a-olefin monomers of which at least one is ethylene or propylene comprising the steps of: (1) feeding the one or more a-olefins to a vertically extended reactor suitable for the continuous fluidized bed polymerization of one or more a-olefin monomers of which at least one is ethylene or propylene, which reactor is operable in condensed mode, wherein the reactor comprises a distribution plate and an integral gas/liquid separator located below the distribution plate, (2) withdrawing the polyolefin from the reactor (3) withdrawing fluids from the top of the reactor, (4) cooling the fluids to below their dew point, resulting in a bottom recycle stream, (5) introducing the bottom recycle stream under the distribution plate, (6) separating at least part of the liquid from the bottom recycle stream using the integral separator to form a liquid phase and a gas/liquid phase, (7) feeding the liquid phase to an external pipe, (8) adding a solid polymerization catalyst to the liquid phase in the external pipe resulting in the formation of a slurry stream comprising prepolymer and/or polymer and (9) feeding the slurry stream comprising the prepolymer and/or polymer into the reactor above the distribution plate, wherein the prepolymer and/or polymer are present in the slurry stream in an amount of from 0.01 to 99 wt % based on the total slurry stream upon introduction of the slurry stream into the reactor.