Abstract:
The present invention concerns a process for the gas phase polymerization of at least one alpha-olefin comprising: polymerizing at least one alpha-olefin in a fluidized bed reactor with a polyolefin purging unit and a vent gas recovery system, wherein the fluidized bed reactor operates in a condensed mode or super condensed mode with a recycle stream comprising one or more alkane(s) having 3 to 5 C atoms, wherein further at least one additional alkane with 6 to 12 C atoms is added to the recycle stream in an amount so that it represents between 0.0095 mol. % and 7,0000 mol. % of the recycle stream composition introduced into the 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 present invention relates to a pipe comprising an ethylene-based polymer, wherein the ethylene-based polymer: ⋅ comprises ≥0.10 mol % of units derived from 1-hexene, with regard to the total molar quantity of polymeric units of the ethylene-based polymer; ⋅ has an Mw/Mn as determined in accordance with ASTM D6474 (2012) of ≥2.5 and ≤4.0, preferably of ≥2.5 and ≤3.4; ⋅ has a density as determined in accordance with ASTM D792 (2008) of ≥925 and ≤945 kg/m3; and ⋅ in the molecular weight range of log(Mw) between 4.0 and 5.5, has a comonomer branch content of between 2 and 15 comonomer-derived branches per 1000 carbon atoms in the polymer, as determined via 13C NMR. Such pipe provides a desirably high long-term strength, as demonstrated by its high strain hardening modulus, as well as desirably high impact strength, as demonstrated by its high Charpy impact strength. Further, such pipe may be compliant with the PE-RT requirements of ISO 22391-1 (2009). For example, such pipe may be used for containing water at temperatures in the range of 40° C. to 80°.
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) withdrawing fluids from a reactor (b) cooling fluids comprising the withdrawn fluids with a cooling unit (c) 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 (d) introducing the gas/liquid phase below to the reactor below a distribution plate (e) introducing the liquid phase to a settling tank to separate liquid from fines that settle down in the settling tank (f) introducing liquid from the settling tank up stream of the cooling unit.
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.
Abstract:
Process for producing a supported metallocene catalyst system includes: (i) preparing mixture (a) by mixing a metallocene with a cocatalyst; (ii) preparing mixture (b) by reacting an aluminium (II) with an amine (III)t;
wherein each R6 and R10 is hydrogen or a C1-30 hydrocarbon; R7, R8, and R11 are C1-30 hydrocarbon; R9 is hydrogen or a functional moiety comprising at least one active hydrogen; (iii) providing a support material, into a reaction vessel; (iv) providing a solvent into the reaction vessel; (v) supplying mixture (a) and mixture (b) to the reaction vessel; (vi) subjecting the contents of the reaction vessel to a temperature of >60° C. for a period of >3 hrs to obtain a supported catalyst system; and (vii) removing the solvent from the supported catalyst system. Such process allows for the production of a supported metallocene catalyst system having reduced fouling in olefin polymerisation.
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 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 polymer composition comprising a linear low-density polyethylene produced in the presence of a single-site catalyst system and 0.01-2.00% by weight of a nucleating agent, the linear low-density polyethylene having a density as determined according to ISO 1183-1 (2012), method A of >900 kg/m3and ≤940 kg/m3, wherein films produced using the polymer composition have a total defected area of ≤50 ppm of surface, the total defected area being the fraction of surface area of the film accounted for by gels having an equivalent diameter of >50 μm. Such polymer compositions are suitable for the production of films having a low oxygen transmission rate and a low water vapour transmission rate.
Abstract:
The invention relates to a process for transitioning from a first continuous polymerization reaction in a gas phase reactor conducted in the presence of a first catalyst to a second polymerization reaction conducted in the presence of a second catalyst in the gas phase reactor wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst into the gas phase reactor; (b) introducing an effective amount of cyclohexylamine into the reactor to at least partially deactivate the first catalyst; (c) introducing an organometallic compound into the reactor and reacting the organometallic compound with cyclohexylamine; (d) introducing a gas composition into the reactor for the second polymerization reaction and (e) introducing the second catalyst into the reactor.