Borealis Ag

Apostolos Krallis

Vasileios Kanellopoulos

Mohammad Al-Haj Ali

Erno Elovainio

Klaus Nyfors

Kauno Alastalo

Ravindra Tupe

Pascal Castro

Kumudini Jayaratne

Henry Sleijster

Samuli Zitting

Gunter Weickert

Eric-Jan Prinsen

Pablo Ivan Aguayo Arellano

Vuokko Ojanperä

Joana Kettner

A process for the production of polyolefins comprising: feeding a slurry comprising at least one polymerization catalyst, at least one carrier liquid, first olefin monomer(s) and optionally at least one first comonomer into at least one loop reactor; polymerizing the first olefin monomer(s) and optionally the at least one first comonomer yielding a first polyolefin; withdrawing the first polyolefin from the loop reactor; feeding the first polyolefin to a gas-solids olefin polymerization reactor, wherein the gas-solids olefin polymerization reactor comprises: a top zone; a middle zone, which comprises a top end in direct contact with said top zone and which is located below said top zone, the middle zone having a generally cylindrical shape; and a bottom zone, which is in direct contact with a bottom end of the middle zone and which is located below the middle zone; introducing a fluidization gas stream into the bottom zone of the gas-solids olefin polymerization reactor; polymerizing second olefin monomer(s) and optionally at least one second comonomer in the presence of the polymerization catalyst and the first polyolefin to a second polyolefin in a dense phase formed by particles of said second polyolefin suspended in an upwards flowing stream of the fluidization gas in the middle zone; introducing a jet gas stream through one or more jet gas feeding ports in a jet gas feeding area of the middle zone at the dense phase in the middle zone of the gas-solids olefin polymerization reactor; withdrawing the second polyolefin from the gas-solids olefin polymerization reactor.

Process and a multi-stage reactor assembly for the production of polyolefins

The present invention is concerned with a process for polymerizing ethylene or copolymerizing ethylene and at least one alpha-olefin comonomer in the presence of a supported polymerization catalyst in a multi-stage process in which the last polymerization stage is a gas phase reactor, the use of said process for reducing particle carry-over in the last polymerization stage and the use of a supported polymerization catalyst with a certain median particle size to polymerize an ethylene homo- or copolymer in said multi-stage process with a span of its particle size distribution which can be predicted from the median particle size of the catalyst.

Process for polymerizing ethylene in a multi-stage polymerization process

The present invention relates to a process for polymerizing at least one olefin in gas phase in a fluidized bed in a polymerization reactor having a top zone of a generally conical shape as such that the equivalent cross-sectional diameter is monotonically decreasing with respect to the flow direction of the fluidization gas, a middle zone in direct contact with and below said top zone of a generally cylindrical shape and a bottom zone in direct contact and below said middle zone and of a generally conical shape as such that the equivalent cross-sectional diameter is monotonically increasing with respect to the flow direction of the fluidization gas, comprising the steps of: a) introducing a first stream of fluidization gas into the bottom zone; b) polymerizing at least one olefin in the presence of a polymerization catalyst in the fluidized bed formed by particles of a polymer of the at least one olefin suspended in an upwards flowing stream of the fluidization gas in the middle zone; c) withdrawing a second stream comprising the fluidization gas and optionally particles of a polymer of the at least one olefin from the top zone; characterized in that the temperature of the particles of the polymer of the at least one olefin in the fluidized bed (T) does not exceed 120% of the operating temperature set point (T) of the polymerization reactor, wherein Tand Tare both given in ° C., and the use of said process for polymerizing an olefin homo- or copolymer having a narrow particle size distribution.

Process for polymerizing olefin in a gas phase reactor with improved thermal homogeneity

A method and arrangement of producing polymer comprising polymerizing in reactor having a top zone having a generally conical shape, a middle zone in direct contact with and below said top zone having a generally cylindrical shape, a bottom zone having a generally conical shape thereby polymerizing at least one olefin, in the presence of a polymerization catalyst and fluidization gas to obtain (i) a first stream comprising fluidization gas and particles of olefin polymer, (ii) a second stream comprising fluidization gas and agglomerates of olefin polymer, (iii) a third olefin polymer product stream, &#x2014;directing the first stream comprising fluidization gas and olefin polymer particles to a series of at least three cyclones connected to the fluidized bed reactor, &#x2014;separating agglomerates of olefin polymer from the second stream, withdrawing from the fluidized bed polymerization reactor the third olefin polymer product stream.

Method, an arrangement and use of an arrangement of preparing polymer

An olefin polymerisation method and arrangement comprising polymerising at least one olefin 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 wherein (i) fluidisation gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor; (ii) the fluidisation gas is withdrawn from the top zone of the reactor; (iii) a fluidised bed is formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream; and wherein the polymerisation reactor has an operating temperature set point and which reactor comprises at least one temperature measurement sensor, wherein a temperature difference (DT) between the temperature measurement sensor (Tm), and the operating temperature set point (Ts) of the reactor is equal to or less than 10&#xb0; C.

Method, an arrangement and use of an arrangement for olefin polymerisation

The present invention is directed to a process for separating an olefin copolymer from volatile gases using a flash separator. The flash separator can be used with a solution or high pressure process. The mass transport of volatile gases from the viscous polymer melt is increased.

Method for separating hydrocarbons from polymer

A process for polymerising alpha-olefin monomers in a loop reactor comprising the steps of introducing a main feed stream () comprising at least one alpha-olefin monomer into the loop reactor (); introducing a polymerisation catalyst into the loop reactor (); polymerising the at least one alpha-olefin monomer in the presence of the polymerisation catalyst in the loop reactor () to produce a slurry comprising polyolefin particles; withdrawing an outlet stream () comprising at least a portion of the slurry from the loop reactor (); adding a first feed stream () comprising the at least one alpha-olefin monomer and/or hydrogen to the outlet stream () to form a concentrator inlet stream (); introducing the concentrator inlet stream () into a concentrator (); withdrawing from the concentrator () an overflow stream () comprising the polyolefin particles, wherein the concentration of the polyolefin particles in the overflow stream () is smaller than in the concentrator inlet stream (); withdrawing from the concentrator () a bottom outlet stream () comprising the polyolefin particles, wherein the concentration of the polyolefin particles in the bottom outlet stream () is greater than in the concentrator inlet stream (); returning the overflow stream () into the loop reactor () in an area different from that from which the outlet stream () is withdrawn.

Process for polymerising alpha-olefin monomers

The present invention is directed to a process for separating hydrocarbons from a solution comprising a polymer. The process comprises the steps of: (A) withdrawing a solution stream comprising the polymer from a first vessel; (B) passing the solution stream into a flash vessel; (C) spraying the solution stream into droplets in the first flash vessel thereby establishing a stream of droplets within the flash vessel. The solution forms a downwards falling film within the flash vessel.

Process for separating hydrocarbons from polymer

An olefin polymerization process comprising polymerizing olefins in gas phase in a fluidized bed in the presence of an olefin polymerization catalyst in a polymerization reactor having a vertical body; a generally conical downwards tapering bottom zone; a generally cylindrical middle zone having a height to diameter ratio L/D of at least 4, above and connected to said bottom zone; and a generally conical upwards tapering top zone above and connected to said middle zone wherein (i) fluidization gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor; (ii) the fluidization gas is withdrawn from the top zone of the reactor, filtered, compressed, cooled and returned into the bottom zone of the reactor; (iii) a fluidized bed is formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream; and (iv) there is no fluidization grid in the reactor; characterized in that the gas velocity is maintained in the reactor such that Nis within the range of from 2.5 to 7.

Gas phase polymerization process

The present invention is directed to a process for polymerizing olefins in gas phase in a fluidized bed reactor having a vertical body, a generally conical downwards tapering bottom zone, a generally cylindrical middle zone above the bottom zone, and a generally conical upwards tapering top zone above the middle zone. The fluidization gas is withdrawn from the top zone of the reactor, compressed and cooled so that a part of the fluidization gas condenses and then introduced to the bottom zone of the reactor. The bed is thus cooled upon evaporation of the liquid. There is no fluidization grid in the reactor.

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Espoo, Finland

Apostolos Krallis