摘要:
The present invention relates to an apparatus and process for polymerizing olefins. One embodiment comprises polymerizing at least one monomer in a first loop reactor in the presence of a catalyst to produce a first polyolefin fraction. A portion of the first polyolefin fraction is transferred to a second loop reactor, connected in series with the first loop reactor. The process further comprises polymerizing in the second loop reactor at least one monomer in the presence of a catalyst to produce a second polyolefin fraction in addition to the first polyolefin fraction. The combination of the first and second polyolefin fractions can produce a polymer resin fluff having bimodal molecular weight distribution.
摘要:
A method for controlling the injection of catalyst slurry in a polymerization reactor is described herein. The method includes the preparation of polyethylene with a solid catalyst and a hydrocarbon diluents. The method includes providing solid catalyst and a hydrocarbon diluent in one or more storage vessels such that a catalyst slurry is obtained in said vessel, transferring said catalyst slurry from said storage vessel to a mixing vessel wherein said catalyst slurry is diluted for obtaining a suitable concentration for use in a polymerization reaction, pumping said diluted catalyst slurry at a controlled flow rate from said mixing vessel to said polymerization reactor through one or more conduits, by means of a membrane pump provided in each of said conduits, and the membrane pump is controllable as a function of reactant concentration within the polymerization reactor.
摘要:
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 The slurry can be diverted into a settling leg, and sequentially discharged therefrom and withdrawn from said loop reactor.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.
摘要:
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.
摘要:
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.
摘要:
A Polymerisation process and a loop reactor comprising polymerising olefins in a liquid diluent to produce a liquid slurry containing particles of normally solid polymer within the loop reactor, allowing the polymer to settle in a settling leg, periodically opening a 180° rotating product take-off valve located at the end of the settling leg to allow a charge of particles to flow out of the settling leg, the product take-off valve being operated by a pneumatically driven double-acting actuator, the pneumatic system being regulated by a system comprising pneumatic control valves, the improvement which consists in using automatic control valves, which are automatic v-ball valves.
摘要:
A Polymerisation process and a loop reactor comprising polymerising olefins in a liquid diluent to produce a liquid slurry containing particles of normally solid polymer within the loop reactor, allowing the polymer to settle in a settling leg, periodically opening a 180° rotating product take-off valve located at the end of the settling leg to allow a charge of particles to flow out of the settling leg, the product take-off valve being operated by a pneumatically driven double-acting actuator, the pneumatic system being regulated by a system comprising pneumatic control valves, the improvement which consists in using automatic control valves, which are automatic v-ball valves.