Abstract: The present invention relates to a multi-stage process for producing a C2 to C8 olefin polymer composition in a process comprising at least two reactors, wherein a pre-polymerized solid Ziegler-Natta catalyst is prepared by carrying out an off-line pre-polymerization of a solid Ziegler-Natta catalyst component with a C2 to C4 olefin monomer before feeding to the polymerization process.

Abstract: The present invention relates to a process and apparatus for producing alpha-olefin polymers in the presence of a polymerization catalyst in a continuously operated multistage polymerisation sequence, the process comprising the steps of (a) polymerizing an alpha-olefin monomer and optionally one or more alpha-olefin co-monomers in a slurry reactor in the presence of a hydrocarbon diluent or liquid monomer in a slurry phase to obtain an alpha-olefin polymer, the slurry phase having a first concentration of solids, (b) continuously withdrawing from the slurry reactor a polymer slurry containing polymer and a fluid phase, (c) concentrating at least a part of the polymer slurry by removing a part of the fluid phase to provide a 1st product stream comprising a concentrated slurry having a second solids concentration, which is higher than the first solids concentration, and a 2nd product stream mainly comprising the fluid phase, (d) polymerizing said 1st product stream in the presence of alpha-olefin monomers and o

Abstract: The present invention relates to a process for feeding a polymerization catalyst into a polymerization reactor, said process comprising the steps of: (i) forming a catalyst slurry comprising oil and a solid catalyst component in a first catalyst preparation vessel; (ii) transferring the catalyst slurry from the first catalyst preparation vessel to a first catalyst feed vessel; (iii) maintaining the catalyst slurry in the first catalyst feed vessel in a homogeneous state; (iv) withdrawing a portion of the catalyst slurry from the first catalyst feed vessel, preferably continuously withdrawing the catalyst slurry from the first catalyst feed vessel, and introducing the withdrawn portion of the catalyst slurry into a polymerization reactor; wherein the oil has a dynamic viscosity of from 25 to 1500 mPa*s at the conditions within the first catalyst preparation vessel and the first catalyst feed vessel, wherein the catalyst slurry is transferred along a substantially vertical path downwards from the first catalyst

Abstract: Described herein is a polymerization reactor system comprising at least one loop reactor and/or at least one transfer line, and further comprising at least one withdrawal valve, wherein the at least one withdrawal valve is mounted to a wall of a lower horizontal segment of the loop reactor and/or to a wall of the transfer line, at an angle a of more than 0° and equal to or less than 85°, determined from perpendicular to a tangent of the wall at the mounting position in flow direction of a slurry in the loop reactor and/or in the transfer line.

Abstract: The present invention relates to a process for producing alpha-olefin polymers in a multistage polymerization process which includes at least two gas phase polymerization reactors, wherein unreacted gas withdrawn from the second gas phase polymerization reactor is compressed in a compressor and said compressed gas is fed via a conveying gas line into an outlet between a first outlet vessel downstream of the first gas phase polymerization reactor and said second gas phase polymerisation reactor. Such a process can alleviate problems of malfunction, disturbances or plugging of the transfer lines and enables higher productivity and considerable saving of energy and equipment cost. Moreover, the production of alpha-olefin polymers with varying and tailored properties is possible.

Abstract: The present invention relates to a method for improving the cooling capacity of a gas solids olefin polymerization reactor by splitting the fluidization gas and returning part of the fluidization gas to the reactor into the bottom zone of the reactor and another part of the fluidization gas directly into the dense phase 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 of the reactor.

Abstract: The invention relates to a system for producing polyolefin. The system comprises a gas phase reactor (1) for polymerizing an olefin to obtain polymerization product. The gas phase reactor (1) comprises a gas distribution plate (11) arranged inside the gas phase reactor (1); a first outlet (12) for continuously withdrawing polymerization product from the gas phase reactor (1) as a first product stream, the first outlet (12) being arranged above the gas distribution plate (11); and a second outlet (13) for continuously withdrawing polymerization product from the gas phase reactor (1) as a second product stream, the second outlet (13) being arranged above the gas distribution plate (11).

Abstract: The present invention relates to a process for polymerizing olefin monomer(s) in a gas solids olefin polymerization reactor wherein the fluidization gas is split and returned to the reactor into the bottom zone of the reactor and directly into the dense phase formed by particles of a polymer of the olefin monomer(s) suspended in an upwards flowing stream of the fluidization gas in the middle zone of the reactor.

Abstract: 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)

Abstract: A process for polymerizing olefin monomer(s) in a gas-solids olefin polymerization reactor comprising 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; comprising the following steps: introducing a fluidization gas stream into the bottom zone; polymerizing olefin monomer(s) in the presence of a polymerization catalyst in a dense phase formed by particles of a polymer of the olefin monomer(s) 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; wherein the kinetic energy (EJG) input in the reactor by the jet stream is betwe

Abstract: 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, —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, —separating agglomerates of olefin polymer from the second stream, withdrawing from the fluidized bed polymerization reactor the third olefin polymer product stream.

Abstract: The present invention relates to a method for improving the cooling capacity of a gas solids olefin polymerization reactor by splitting the fluidization gas and returning part of the fluidization gas to the reactor into the bottom zone of the reactor and another part of the fluidization gas directly into the dense phase 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 of the reactor.

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.

Abstract: The present invention relates to a multi-stage process for producing a C2 to C8 olefin polymer composition in a process comprising at least two reactors, wherein a pre-polymerized solid Ziegler-Natta catalyst is prepared by carrying out an off-line pre-polymerization of a solid Ziegler-Natta catalyst component with a C2 to C4 olefin monomer before feeding to the polymerization process.

Abstract: 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

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.

Abstract: The present invention is directed to a process for feeding a polymerisation catalyst into a polymerisation reactor (7), comprising the steps of: (i) maintaining a catalyst slurry comprising a diluent and a solid catalyst component in a catalyst feed vessel (4); (ii) continuously withdrawing a stream of the catalyst slurry from the catalyst feed vessel (4); and (iii) introducing the withdrawn portion of the catalyst slurry into the polymerisation reactor (7), wherein the catalyst slurry is transferred by using a valveless piston pump (5) from the catalyst feed vessel (4) into the polymerisation reactor (7); the diluent has a dynamic viscosity of from 0.01 to 20 mPas at the conditions within the catalyst feed vessel (4), and wherein the catalyst slurry is transferred along a substantially vertical path downwards from the catalyst feed vessel (4) to the reactor (7).

Abstract: The present invention relates to a process for polymerizing olefin monomer(s) in a gas solids olefin polymerization reactor wherein the fluidization gas is split and returned to the reactor into the bottom zone of the reactor and directly into the dense phase formed by particles of a polymer of the olefin monomer(s) suspended in an upwards flowing stream of the fluidization gas in the middle zone of the reactor.

Abstract: Described herein is a polymerization reactor system comprising at least one loop reactor and/or at least one transfer line, and further comprising at least one withdrawal valve, wherein the at least one withdrawal valve is mounted to a wall of a lower horizontal segment of the loop reactor and/or to a wall of the transfer line, at an angle ? of more than 0° and equal to or less than 85°, determined from perpendicular to a tangent of the wall at the mounting position in flow direction of a slurry in the loop reactor and/or in the transfer line.

Abstract: 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—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—separating agglomerates of olefin polymer from the second stream, withdrawing from the fluidized bed polymerization reactor the third olefin polymer product stream.