Abstract:
The invention is directed to a process for the treatment of plastic material comprising a) providing a liquid; b) contacting the plastic material with the liquid; c) keeping the plastic material in the liquid at Tb−25° C. to Tb of the liquid, wherein Tb is the boiling point of the liquid at the applied pressure; and d) removing the plastic material from the liquid. Furthermore, the invention is directed to the use of a liquid for the treatment of plastic material and to a plant for treating plastic material with a liquid.
Abstract:
A method and an apparatus of discharging polymer from a continuously operated gas phase reactor, wherein at least one monomer is polymerized in a bed containing active catalyst formed by catalyst and polymer particles suspended in a fluid, the bed defining a fluidized bed level in said reactor. The invention comprises continuously withdrawing polymer powder from the reactor; and adjusting the discharge rate of the polymer powder so as to maintain a constant bed level during polymerization. By means of the invention the discharge of the polymer can be made truly continuous without any disturbance of the polymerization. The rate of withdrawn polymer can be flexibly adjusted depending on the progress of the polymerization and it can also easily be scaled up if the capacity of the reactor is increased.
Abstract:
Process and apparatus for recovering polymer from a gas phase reactor having a distribution plate via an outlet vessel comprising at least one apparatus for the breakup of polymeric agglomerates, the apparatus further comprising a feed pipe connecting the gas phase reactor and the outlet vessel a return gas line connecting the gas phase reactor and the outlet vessel, means for varying the flow rate through the return gas line from the outlet vessel to the gas phase reactor, and means for varying the outlet rate of polymer product from the outlet vessel.
Abstract:
Process and apparatus for recovering polymer from a a gas phase reactor having a distribution plate via an outlet vessel comprising at least one apparatus for the breakup of polymeric agglomerates, the apparatus further comprising a feed pipe connecting the gas phase reactor and the outlet vessel a return gas line connecting the gas phase reactor and the outlet vessel, means for varying the flow rate through the return gas line from the outlet vessel to the gas phase reactor, and means for varying the outlet rate of polymer product from the outlet vessel.
Abstract:
The present invention provides a process for recovering transition metal tetrahalides from a waste stream coming from a catalyst manufacturing process by (a) establishing a mixed stream comprising transition metal tetrahalide and transition metal alkoxyhalides; (b) forming a falling liquid film from the mixed stream of step (a) at a temperature of from 25 to 85° C. and an absolute pressure of from 0.05 to 0.6 bar; and (c) establishing from the film of step (b) a first vapour stream containing from 90 to 100% of recoverable components and a second liquid stream containing about 10 to 80% of titanium haloalkoxides.
Abstract:
The present invention relates to a process for the preparation of multimodal ethylene homo- or copolymers in at least two stages, the process comprising preparation of a first ethylene homo- or copolymer fraction in a loop reactor in slurry phase, preparation of a second ethylene homo- or copolymer fraction in a gas phase reactor, by using a catalyst not containing an inorganic oxide support, and operating the gas phase reactor in such conditions that at least part of the gas is recycled, and that at least a part of the recycled gas is condensed and the (partially) condensed gas is re-introduced into the gas phase reactor.
Abstract:
The present invention provides a process for recovering transition metal tetrahalides from a waste stream coming from a catalyst manufacturing process by (a) establishing a mixed stream comprising transition metal tetrahalide and transition metal alkoxyhalides; (b) forming a falling liquid film from the mixed stream of step (a) at a temperature of from 25 to 85° C. and an absolute pressure of from 0.05 to 0.6 bar; and (c) establishing from the film of step (b) a first vapor stream containing from 90 to 100% of recoverable components and a second liquid stream containing about 10 to 80% of titanium haloalkoxides.
Abstract:
The invention relates to a reactor assembly for the production of polymers including a fluidized bed reactor (1) comprising a bottom zone (5), a middle zone (6) and an upper zone (7), an inlet (8) for the fluidization gas located in the bottom zone (5), an outlet (9) for the fluidization gas located in the upper zone (7); the outlet (9) for the fluidization gas being coupled with the fluidized bed reactor (1) via inlet (8); the equivalent cross-sectional diameter of the bottom zone (5) being monotonically increasing with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the middle zone (6) having an essentially constant equivalent cross-sectional diameter with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the equivalent cross-sectional diameter of the upper zone (7) being monotonically decreasing with respect to the flow direction of the fluidization gas through the fluidized bed reactor; wherein that the ratio of the height of the fluidized bed reactor to the equivalent cross-sectional diameter of the middle zone of the fluidized bed reactor is from 2 to 10; and wherein there is an unobstructed passageway in the direction of flow of the fluidization gas through the fluidized bed reactor from the bottom zone (5) to the upper zone (7).
Abstract:
Reactor assembly for the production of polymers including a fluidized bed reactor (1) comprising a bottom zone (5), a middle zone (6) and an upper zone (7), an inlet (8) for the fluidization gas located in the bottom zone (5), an outlet (9) for the fluidization gas located in the upper zone (7); the outlet (9) for the fluidization gas being coupled with the fluidized bed reactor (1) via inlet (8) via a gas circulation line; means for separation of solids from gas (2) being connected to said gas circulation line; the equivalent cross-sectional diameter of the upper zone (7) being monotonically decreasing with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the middle zone (6) having an essentially constant equivalent cross-sectional diameter with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the equivalent cross-sectional diameter of the bottom zone (5) being monotonically increasing with respect to the flow direction of the fluidization gas through the fluidized bed reactor; characterized in that the ratio of the height of the fluidized bed reactor to the equivalent cross-sectional diameter of the middle zone of the fluidized bed reactor is from 2 to 10; and whereby said upper zone (7) is directly connected to said middle zone (6).
Abstract:
A method and an apparatus of discharging polymer from a continuously operated gas phase reactor, wherein at least one monomer is polymerized in a bed containing active catalyst formed by catalyst and polymer particles suspended in a fluid, the bed defining a fluidized bed level in said reactor. The invention includes continuously withdrawing polymer powder from the reactor; and adjusting the discharge rate of the polymer powder so as to maintain a constant bed level during polymerization. By means of the invention the discharge of the polymer can be made truly continuous without any disturbance of the polymerization. The rate of withdrawn polymer can be flexibly adjusted depending on the progress of the polymerization and it can also easily be scaled up if the capacity of the reactor is increased.