Abstract: Catalyst activator, in particular, a catalyst activator for heat conditioning a catalyst. The activator includes a vessel for containing a catalyst charge having an internal diameter of at least 1.2 meters and/or an internal volume of at least 5 m3; a fluidisation grid plate disposed in the vessel, the fluidisation grid plate having an upper major surface and a lower major surface; an array of generally conical depressions in the upper major surface that overlap by less than 17%; and an array of holes perforating the fluidisation grid plate, the holes extending from at least some of the generally conical depressions through the lower surface.

Abstract: The present invention relates to the treatment and recycle of effluent streams from a polymerisation process, and in particular provides a polymerisation process comprising the steps of: 1) Polymerising a monomer and a comonomer in a polymerisation reaction, 2) Withdrawing an effluent stream comprising solid polymer and a mixture comprising unreacted monomer and unreacted comonomer, and passing the effluent to a high pressure recovery system comprising a. a high pressure separation step for separating a vapour comprising unreacted monomer and unreacted comonomer from said solids, and b. a high pressure recycle system for recycling a portion of the vapour to the polymerisation reaction, 3) Passing the solids from the high pressure recovery system to a low pressure recovery system comprising a. a low pressure separation step for separating further unreacted monomer and unreacted comonomer from said solids, and b.

Abstract: The present invention relates to a process for the introduction of liquid feeds to a polymerisation process, and in particular provides a process for the introduction of a fresh feed selected from fresh comonomer and fresh inert hydrocarbon to a polymerisation reactor, which process comprises passing said fresh feed and a process stream comprising a first component selected from hydrogen, nitrogen and methane and a second component which is a monomer to a separator at a pressure of 0.4 MPa (4 bar) or less to produce a first stream comprising the majority of the first component and a second stream comprising the majority of the fresh feed and the majority of the second component, and passing the second stream to the polymerisation reactor.

Abstract: The present invention relates to a polymerisation process, in particular to the polymerisation of olefins in a reactor system comprising two reactors in series, and most particularly provides a process for the polymerisation of monomer in at least first and second reactors operated in series, which process comprises contacting a first stream comprising vapour derived from the effluent withdrawn from the second reactor with a feed stream to the second reactor, said feed stream comprising effluent derived from the first reactor.

Abstract: Process for polymerizing in a loop reactor an olefin monomer optionally together with an olefin comonomer in the presence of a polymerization catalyst in a diluent to produce a slurry including solid particulate olefin polymer and the diluent. The Froude number is in the range 3 to 10, the internal diameter of the loop reactor is over 600 millimeters, the solids concentration of the slurry in the loop reactor is above 20% by volume and, when the polymer produced is polyethylene and the diluent is an alkane, the solids concentration is above 40 wt % based on the total weight of the slurry.

Abstract: The present invention relates to slurry polymerisation, and in particular, to a slurry heater apparatus comprising at least two heating sections connected in fluid communication in series to form an initial slurry heater, wherein the slurry heater apparatus is adapted such that it can be reconfigured to form a subsequent slurry heater also comprising at least two heating sections connected in fluid communication in series, wherein the subsequent slurry heater has a different total length and/or a different average internal diameter than the initial slurry heater.

Abstract: A process comprising polymerising in a loop reactor an olefin monomer optionally together with an olefin commoner in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number is maintained at or below 20 is disclosed.

Abstract: A process comprising polymerizing in a loop reactor an olefin monomer optionally together with an olefin commoner in the presence of a polymerization catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number is maintained at or below 20 is disclosed.

Abstract: The invention relates generally to a catalyst activator, and in particular to a catalyst activator for heat conditioning a catalyst, comprising: a) a vessel for containing a catalyst charge having an internal diameter of at least 1.2 metres and/or an internal volume of at least 5 m3; b) a fluidisation grid plate disposed in said vessel, said fluidisation grid plate and having an upper major surface and a lower major surface; c) an array of generally conical depressions in said upper major surface that overlap by less than 17%; and d) an array of holes perforating said fluidisation grid plate, said holes extending from at least some of said generally conical depressions through said lower surface.

Abstract: Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80 wt % of a first polymer is made in suspension in a first reactor and 80-20 wt % of a second polymer is made in suspension in a second reactor in the presence of the first polymer, and a stream or slurry containing the resulting polymer is withdrawn from the second reactor and transferred to a flash tank operating at a pressure and temperature such that at least 50 mol % of the liquid component of the slurry, or the non-polymer component of the stream entering the flash tank, is withdrawn from the flash tank as a vapour, wherein the concentration in the stream or slurry entering the flash tank of components having a molecular weight below 50 g/mol, Clights (mol %), satisfies the equation Clights<7+0.07(40?Tc)+4.4(Pc?0.8)?7(CH2/CEt) where Tc and Pc are respectively the temperature (in ° C.

Abstract: Process for producing a multimodal polyethylene in at least two loop reactors connected in series. In the process 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order. The ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and the volumes of the two reactors differ by less than 10%.

Abstract: Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor in the presence of the HMW polymer, wherein the solids concentration in the second LMW reactor, defined as the mass of polymer divided by the total mass of slurry, is at least 35 wt %, most preferably between 45 wt % and 60 wt %, and/or the ratio of solids concentration in the first reactor to that in the second reactor is maintained at less than 1.0, preferably between 0.6 and 0.8, and further wherein the volume of the second reactor is at least 10%, preferably at least 30% and more preferably at least 50% greater than the volume of the first reactor.

Abstract: Polymerisation process in which polyethylene is produced in slurry in a polymerisation reactor in the presence of a Ziegler Natta catalyst and an activator, and a stream or slurry containing the polymer is withdrawn from the reactor and transferred to a flash tank operating at a pressure and temperature such that at least 50 mol % of the liquid or non-polymer component of the stream entering the flash tank or slurry is withdrawn from the flash tank as a vapour and at least 98 mol % of the vapour withdrawn from the flash tank is capable of being condensed at a temperature of between 15 and 50° C., without compression. A by-product suppressor, which reduces the amount of by-product formed per unit of polyethylene produced by at least 10%, compared with an identical polymerisation process where the by-product suppressor is not present, is used in the reactor. The molar ratio of the by-product suppressor added to the reactor to titanium added to the reactor is between 0.2 and 1.

Abstract: Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor. The ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr). The volume of the second reactor is at least 10% greater than the volume of the first reactor, and the ratio of length to diameter of the first reactor, L/D(1), is greater than that of the second reactor, L/D(2).

Abstract: Process for transferring a slurry stream containing polymer through a transfer line from a polymerisation reactor to a downstream vessel by, prior to entry into the downstream vessel, separating the slurry stream into two flows, the first flow being recycled upstream of the flow separation and the second flow being passed into the downstream vessel. The flow separation is located more than halfway along the transfer line between the reactor and the downstream vessel.

Abstract: A process comprising polymerising in a loop reactor of continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the internal diameter of at least 50% of the total length of the reactor is at least 700 millimeters and the solids concentration in the reactor is at least 20 volume % is disclosed.

Abstract: A process for transferring a slurry stream containing polymer through a transfer line from a first polymerisation reactor to a second polymerisation reactor is disclosed, wherein prior to entry from the transfer line into the second polymerisation reactor, the slurry stream is separated into two flows and the first flow is returned to the first reactor whilst the second flow passes into the second reactor, the length of the transfer line between the first reactor and the location of the flow separation being more than that between the second reactor and the location of the flow separation.

Abstract: Olefin polymerisation process in which a slurry of olefin polymer is produced within a polymerisation zone, followed by withdrawing a polymer slurry stream from the polymerisation zone, and passing the polymer slurry stream through a transfer line to a centrifugal concentrating device which separates the polymer slurry stream into a solids-lean stream or streams each having a solids concentration less than that of the polymer slurry stream entering the concentrating device and a solids-rich stream or streams each having a solids concentration greater than that of the polymer slurry stream entering the concentrating device. At least part of the solids-rich stream or streams is recycled back into the polymer slurry stream upstream of the concentrating device and downstream of the polymerisation zone, and 2-60 vol % of the solids-rich slurry stream is recycled back into the polymer slurry stream upstream of the concentrating device.

Abstract: Process comprising polymerizing in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerization catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent, wherein the average internal diameter of at least 50% of the total length of the continuous tubular loop reactor is at least 700 mm wherein the HMW polymer is produced in a reactor upstream of the LMW polymer reactor and the ratio of the average internal diameter of the HMW reactor to the average internal diameter of the LMW reactor is between 0.8 and 1.4.

Abstract: A process comprising polymerising in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the average internal diameter of at least 50% of the total length of the reactor is at least 650 millimeters, the solids concentration in the reactor is at least 15 volume % and having a particle size distribution such that (D90?D10)/D50 is less than 2.