Abstract:
The present invention discloses a method for controlling the onset and development of swelling in a slurry loop reactor by progressively diluting the reactor, the amount of dilution being driven by the amplitude of the fluctuations measured on some plant measurement.
Abstract:
The present invention discloses a slurry loop reactor comprising one or more loops, capable of improving the properties of the product by enhanced homogeneity of the circulating slurry.
Abstract:
A method for the copolymerization of ethylene and a C3+ olefin in a loop reactor and polymers formed therefrom are described herein. The method generally includes introducing an ethylene monomer, a C3+ olefin and a diluent carrier liquid into a loop reactor. A catalyst system can be supplied to said loop reactor. The diluent liquid, ethylene monomer, and C3+ olefin can be circulated through said loop reactor, while copolymerizing said ethylene and C3+ olefin in the presence of said catalyst system to produce a slurry. The slurry can be diverted into a settling leg, and sequentially discharged therefrom and withdrawn from said loop reactor. An ethylene monomer co-feed can be introduced into said loop reactor at spaced locations downstream of the ethylene and diluent. The ethylene co-feed can be introduced in an amount effective to reduce the variation in the ratio of ethylene and C3+ olefin.
Abstract:
The present invention discloses a slurry loop reactor comprising at least two loop reactors connected in series and wherein the line connecting the two loops is subject to a dynamic pressure difference.
Abstract:
The present invention relates to the use of a catalyst preparation system for the preparation of a diluted catalyst slurry. In particular, the invention relates to a catalyst preparation system comprising a mixing vessel for mixing a particulate catalyst and a liquid hydrocarbon diluent. According to the invention, diluted catalyst slurry is prepared in a mixing vessel comprising a rotatable axial impeller system comprising at least two double-bladed hubs. The invention also relates to a process for preparing diluted catalyst slurry for use in the preparation of a particulate polyethylene product in a loop reactor with the catalyst preparation system as described herein.
Abstract:
An apparatus defined as a set of loop reactors suitable for the polymerization process of a monomer, preferably ethylene and optionally an olefin co-monomer, comprising for each of said reactors: a plurality of interconnected pipes P defining a flow path for a polymer slurry, said slurry consisting essentially of ethylene, optionally a co-monomer, a polymerization catalyst, liquid diluent and solid olefin polymer particles, means for feeding monomer, optionally a co-monomer, diluent and optionally hydrogen in the reactor, means for feeding a polymerization catalyst in the reactor, a pump suitable for maintaining the polymer slurry in circulation in such reactor, one or more settling legs connected to the pipes P of such reactor for settling of polymer slurry, one or more control valves connected to the outlet of such settling legs, and one or more flash lines for discharging settled polymer slurry out of the reactor characterized in that each of said loop reactors comprises a three-or-more-way valve defining three-or-more ends, one end A being positioned at the outlet of said one or more control valves.
Abstract:
The present invention relates to a loop reactor suitable for olefin polymerization process comprising: a plurality of interconnected pipes defining a flow path for a polymer slurry, said slurry consisting essentially of an olefin reactant, a polymerization catalyst, liquid diluent and solid olefin polymer particles, means for introducing olefin reactant, polymerization catalyst and diluent into said reactor, a pump suitable for maintaining the polymer slurry in circulation in said reactor, and single settling leg connected to said loop reactor through (a) a take off line extending from said reactor to said settling leg and configured to remove said polymer slurry from said reactor, and (b) a return line extending from said settling leg to said reactor, characterized in that said take off line is radially connected to said single settling leg.
Abstract:
An apparatus defined as a set of loop reactors suitable for the polymerization process of a monomer, preferably ethylene and optionally an olefin co-monomer, comprising for each of said reactors:a plurality of interconnected pipes P defining a flow path for a polymer slurry, said slurry consisting essentially of ethylene, optionally a co-monomer, a polymerization catalyst, liquid diluent and solid olefin polymer particles,means for feeding monomer, optionally a co-monomer, diluent and optionally hydrogen in the reactor,means for feeding a polymerization catalyst in the reactor,a pump suitable for maintaining the polymer slurry in circulation in such reactor,one or more settling legs connected to the pipes P of such reactor for settling of polymer slurry,one or more control valves connected to the outlet of such settling legs, andone or more flash lines for discharging settled polymer slurry out of the reactor characterized in that each of said loop reactors comprises a three-or-more-way valve defining three-or-more ends, one end A being positioned at the outlet of said one or more control valves.A method to switch from series to parallel configuration a set of loop reactors.The use of the apparatus to switch polymerization reactors from parallel to series configuration and vice-versa.
Abstract:
Reactor systems suitable for the polymerization of an olefin monomer including first and second loop reactors effective for the polymerization of an olefin monomer and polymers formed therefrom are described herein. Each of said reactors generally include at least one settling leg connected to said reactor for receiving polymer slurry from said reactor and sequentially discharging settled polymer from said at least one settling leg to withdraw said polymer slurry from said reactor; a transfer line extending from the outlet at least one first reactor settling leg to an inlet for said second loop reactor; a flash line extending from said transfer line at a valve location intermediate said first reactor settling leg and said inlet for said second reactor; and a multiway valve located in said transfer line at said valve location intermediate said first reactor settling leg and the inlet to said second reactor and having one position in which said multiway valve provides for the flow of polymer slurry through said transfer line to said second reactor and another position in which said first reactor settling leg is connected to said flash line for the discharge of polymer slurry from said first reactor settling leg to said flash line and removal of said polymer from said polymer system.
Abstract:
Methods for supplying a catalyst to an ethylene slurry loop polymerization reactor and polymers formed therefrom are described herein. The method generally includes preparing a catalyst slurry in a preparation vessel wherein the slurry includes a hydrocarbon diluent liquid which contains a Ziegler-Natta catalyst; supplying the catalyst slurry from the preparation vessel to a buffer vessel; withdrawing the catalyst slurry from the buffer vessel and supplying the catalyst slurry to a slurry loop polymerization reactor in which ethylene is polymerized; mixing a co-catalyst with the Ziegler Natta catalyst in the slurry prior to the supplying of the catalyst slurry to the slurry loop polymerization reactor; and controlling the transfer of catalyst slurry from the preparation vessel to the buffer vessel and the withdrawal of catalyst slurry from the buffer vessel to maintain the level of catalyst slurry in the buffer vessel substantially constant relative to the level of catalyst slurry in the preparation vessel.