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). The system further comprises a first outlet tank (2) in fluid communication with the first outlet (12) via a first passage (22), wherein the first passage (22) comprises a first valve means (221) for controlling the flow of the first product stream in the first passage (22) and wherein the first outlet tank (2) is arranged to receive the first product stream and to concentrate the first product stream; a product receiver tank (3) in fluid communication with the second outlet (13) via a second passage (31), wherein the second passage (31) comprises a second valve means (311) for controlling the flow of the second product stream in the second passage (31), and wherein the product receiver tank (3) is arranged to receive the second product stream; and a control means in communication with the first valve means (221) and the second valve means (311) and arranged to control the operation of the first valve means (221) and the second valve means (311) so that flow in only one of the first passage (22) and the second passage (31) is allowed at a time.

The invention relates also to a process for recovering polymerization product from a gas phase reactor (1). The gas phase reactor (1) is suitable for polymerizing an olefin to obtain polymerization product and 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), 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), the second outlet (13) being arranged above the gas distribut

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). The system further comprises a first outlet tank (2) in fluid communication with the first outlet (12) via a first passage (22), wherein the first passage (22) comprises a first valve means (221) for controlling the flow of the first product stream in the first passage (22) and wherein the first outlet tank (2) is arranged to receive the first product stream and to concentrate the first product stream; a product receiver tank (3) in fluid communication with the second outlet (13) via a second passage (31), wherein the second passage (31) comprises a second valve means (311) for controlling the flow of the second product stream in the second passage (31), and wherein the product receiver tank (3) is arranged to receive the second product stream; and a control means in communication with the first valve means (221) and the second valve means (311) and arranged to control the operation of the first valve means (221) and the second valve means (311) so that flow in only one of the first passage (22) and the second passage (31) is allowed at a time.

The invention relates also to a process for recovering polymerization product from a gas phase reactor (1). The gas phase reactor (1) is suitable for polymerizing an olefin to obtain polymerization product and 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), 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), the second outlet (13) being arranged above the gas distribut

Methods for producing a polymer include contacting at least one monomer under polymerization conditions with a fluidized bed of a polymerization catalyst on a particulate support; measuring a plurality of pressures of the fluidized bed at a plurality of locations corresponding to increasing heights from a bottom of the fluidized bed; calculating a plurality of pressure drops between the plurality of locations based on the measured pressures; performing a regression analysis on the calculated plurality of pressure drops; correlating the plurality of pressure drops to corresponding heights from the bottom of the fluidized bed based on the regression analysis; determining a height of the fluidized bed based on the correlating; and controlling polymerization conditions based on the determined height of the fluidized bed. The method can also be used to detect malfunctioning pressure transducers based on deviation between measured and expected values.

Methods for producing a polymer include contacting at least one monomer under polymerization conditions with a fluidized bed of a polymerization catalyst on a particulate support; measuring a plurality of pressures of the fluidized bed at a plurality of locations corresponding to increasing heights from a bottom of the fluidized bed; calculating a plurality of pressure drops between the plurality of locations based on the measured pressures; performing a regression analysis on the calculated plurality of pressure drops; correlating the plurality of pressure drops to corresponding heights from the bottom of the fluidized bed based on the regression analysis; determining a height of the fluidized bed based on the correlating; and controlling polymerization conditions based on the determined height of the fluidized bed. The method can also be used to detect malfunctioning pressure transducers based on deviation between measured and expected values.

Provided are an apparatus and a method for manufacturing high-pressure method low-density polyethylene, the apparatus and the method having excellent characteristics that a chain transfer agent can be supplied by a simpler apparatus, a deviation (variation) of the concentration of the chain transfer agent supplied to a reactor can be reduced, and compression energy of the chain transfer agent can be reduced. An apparatus for manufacturing high-pressure method polyethylene includes a chain transfer agent supply line that is a line connected to a low pressure recycle ethylene supply line for supplying a chain transfer agent.

Provided are an apparatus and a method for manufacturing high-pressure method low-density polyethylene, the apparatus and the method having excellent characteristics that a chain transfer agent can be supplied by a simpler apparatus, a deviation (variation) of the concentration of the chain transfer agent supplied to a reactor can be reduced, and compression energy of the chain transfer agent can be reduced. An apparatus for manufacturing high-pressure method polyethylene includes a chain transfer agent supply line that is a line connected to a low pressure recycle ethylene supply line for supplying a chain transfer agent.

The present invention relates to a new multimodal ethylene copolymer (P), to the use of the copolymer in film applications and to a film comprising the copolymer of the invention.

The present invention relates to a new multimodal ethylene copolymer (P), to the use of the copolymer in film applications and to a film comprising the copolymer of the invention.

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.

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.