A METHOD FOR RETURNING POLYMER TO A FLUIDISED BED REACTOR

    公开(公告)号:US20180369775A1

    公开(公告)日:2018-12-27

    申请号:US15776848

    申请日:2016-12-21

    Applicant: Borealis AG

    Abstract: The present invention deals with a process of polymerising at least one olefin in a fluidised bed in a fluidised bed polymerisation reactor comprising a top zone, a middle zone in direct contact and below, a bottom zone in direct contact with and below the middle zone and wherein the reactor does not comprise a fluidisation grid. The process comprises passing a stream comprising the fluidisation gas and polymer particles into a separation step and withdrawing a stream comprising the polymer particles from the separation step and returning it to the polymerisation reactor. The process comprises adding a support gas stream to the stream comprising the polymer particles downstream of the separation step.

    PROCESS AND APPARATUS FOR REMOVING POLYMER MATERIAL FROM A GAS-SOLIDS OLEFIN POLYMERIZATION REACTOR

    公开(公告)号:US20210094008A1

    公开(公告)日:2021-04-01

    申请号:US16499361

    申请日:2018-05-30

    Applicant: Borealis AG

    Abstract: The present invention relates to a process for removing polymer material from a gas-solids olefm polymerization reactor wherein the gas-solids olefm polymerization reactor is connected to the top part of an outlet vessel via a feed pipe wherein the powder surface of discharged polymer material and the barrier gas injection point are situated in the outlet vessel as such to fulfill the following criteria: R′=X/Y≤2.0; and R″=X/D≥1.0; wherein X=Distance between the powder surface and the barrier gas injection point; Y=Distance between the barrier gas injection point and the vessel outlet; and D=Equivalent outlet vessel diameter, an apparatus for continuously removing polymer material comprising a gas-solids olefm polymerization reactor, an outlet vessel and a feed pipe connecting the gas-solids olefm polymerization reactor with the top part of the outlet vessel and the use of said apparatus for polymerizing alpha-olefm homo- or copolymers having alpha-olefin monomer units of from 2 to 12 carbon atoms and for increasing the barrier gas efficiency of the gas-solids olefin reactor to at least 75%.

    Method and apparatus for polymerising olefins in gas phase

    公开(公告)号:US10450391B2

    公开(公告)日:2019-10-22

    申请号:US15569954

    申请日:2016-06-10

    Applicant: Borealis AG

    Abstract: The present invention deals with an olefin polymerisation process. At least one olefin is polymerised in gas phase in a fluidised bed in the presence of an olefin polymerisation catalyst in a polymerisation reactor having a vertical body; a generally conical downwards tapering bottom zone; a generally cylindrical middle zone above and connected to said bottom zone; and a generally conical upwards tapering top zone above and connected to said middle zone. Fluidisation gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor, and withdrawn from the top zone of the reactor. The gas is then compressed, cooled and returned into the bottom zone of the reactor. A fluidised bed is thus formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream wherein the superficial velocity of the fluidisation gas is less than the transport velocity of the particles. There is no fluidisation grid in the reactor. The fluidisation gas is passed from an inlet chamber into the bottom zone and the gas flows from the upper part of the inlet chamber to the lower part thereof and the gas flows from the lower part of the inlet chamber to the bottom zone.

    Process and apparatus for removing polymer material from a gas-solids olefin polymerization reactor

    公开(公告)号:US11179690B2

    公开(公告)日:2021-11-23

    申请号:US16499361

    申请日:2018-05-30

    Applicant: Borealis AG

    Abstract: The present invention relates to a process for removing polymer material from a gas-solids olefin polymerization reactor wherein the gas-solids olefin polymerization reactor is connected to the top part of an outlet vessel via a feed pipe wherein the powder surface of discharged polymer material and the barrier gas injection point are situated in the outlet vessel as such to fulfill the following criteria: R′=X/Y≤2.0; and R″=X/D≥1.0; wherein X=Distance between the powder surface and the barrier gas injection point; Y=Distance between the barrier gas injection point and the vessel outlet; and D=Equivalent outlet vessel diameter, an apparatus for continuously removing polymer material comprising a gas-solids olefin polymerization reactor, an outlet vessel and a feed pipe connecting the gas-solids olefin polymerization reactor with the top part of the outlet vessel and the use of said apparatus for polymerizing alpha-olefin homo- or copolymers having alpha-olefin monomer units of from 2 to 12 carbon atoms and for increasing the barrier gas efficiency of the gas-solids olefin reactor to at least 75%.

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