Abstract:
Methods for supplying a catalyst to an ethylene slurry loop polymerization reactor and polymers formed therefrom are described herein. The method includes preparing a catalyst slurry in a preparation vessel. The slurry includes a hydrocarbon diluent liquid that contains a Ziegler-Natta catalyst. The catalyst slurry is supplied to a buffer vessel, withdrawn therefrom and supplied to a slurry loop polymerization reactor in which ethylene is polymerized. A co-catalyst is mixed with the Ziegler Natta catalyst in the slurry prior to supplying the catalyst slurry to the slurry loop polymerization reactor. The transfer of the catalyst slurry from the preparation vessel to the buffer vessel and the withdrawal of catalyst slurry from the buffer vessel are controlled to maintain the level of catalyst slurry in the buffer vessel substantially constant relative to the level of catalyst slurry in the preparation vessel.
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 a process of preparing a polyolefin in a loop reactor by introducing anti-fouling agent in by-pass pipes. Also, the invention relates to the use of anti-fouling agent to prevent blockage by feeding the anti-fouling agent into the by-pass pipes of the loop reactor.
Abstract:
The present invention relates to a method of continuously feeding catalyst slurry into an olefin polymerization reactor comprising the steps of: a) continuously feeding catalyst slurry into the reactor through a catalyst feeding line and then through a valve connected to the wall of the reactor, wherein said valve comprises a piston device comprising an actuator and a hollow casing, wherein said piston is connected to the actuator and wherein said piston is arranged in the hollow casing; and b) closing said valve by moving the piston through at least part of said valve towards the reactor and at least until the wall of the reactor, upon at least partial blockage of said valve.
Abstract:
The present invention relates to a method for monitoring the level of an ethylene polymerization catalyst slurry in a mud pot (2), whereby said catalyst slurry is prepared by introducing a solid catalyst and a liquid diluent in said mud pot (2), and whereby through sedimentation an interface (35) is formed between said diluent and the obtained catalyst slurry, characterized in that said interface (35) is monitored with Time Domain Reflectometry.
Abstract:
A method for the copolymerization of ethylene and a C3+ olefin copolymer in a loop reactor system and polymers formed therefrom are described herein. The method generally includes introducing an ethylene monomer, a C3+ alpha olefin comonomer and a diluent carrier liquid into a reactor system comprising at least one loop reactor; supplying at least one polymerization catalyst system to said reactor system; circulating said diluent liquid, ethylene monomer, and alpha olefin copolymer through said loop reactor while copolymerizing said ethylene and said alpha olefin monomer in the presence of said catalyst system to produce a slurry of polymer fluff particles in said diluent carrier liquid; diverting the flow of said slurry through said loop reactor into at least one settling leg connected to the loop reactor and sequentially discharging the settled polymer slurry from said at least one settling leg to withdraw said polymer slurry from said reactor system; and introducing an ethylene monomer co-feed into said loop reactor at least two spaced locations downstream of the point of introduction of ethylene comonomer and diluent in subparagraph a), said ethylene co-feed being introduced in an amount effective to reduce the variation in the ratio of ethylene monomer and comonomer within said loop reactor.
Abstract:
The present invention discloses multiple loop reactor wherein one of the settling legs transferring polymer product from one loop to a further loop can be taken out of service or re-opened without interfering with the operation of said multiple loop reactor.
Abstract:
The present invention discloses a method for transforming a single reactor line into a double reactor line wherein the existing single reactor line is equipped with a flash tank for separating the solid polymer product from the flash vapour and wherein the vapour is sent to a system of at least two separating columns allowing the separation of its constituents into monomer, diluent and comonomer.
Abstract:
The present invention discloses a transfer system between the first and second reactors in a double loop reactor that is equipped to reduce clogging in the transfer lines by providing a regulation mechanism arranged to insure equivalent flushing in each transfer line.
Abstract:
The present invention discloses multiple loop reactor wherein one of the settling legs transferring polymer product from one loop to a further loop can be taken out of service or re-opened without interfering with the operation of said multiple loop reactor.