A process comprises polymerizing an olefin monomer in a loop reactor in the presence of a catalyst and a diluent, and producing a slurry comprising solid particulate olefin polymer and diluent. The Biot number is maintained at or below about 3.0 within the loop reactor during the polymerizing process. The slurry in the loop reactor forms a slurry film having a film coefficient along an inner surface of the reactor wall, and the film coefficient is less than about 500 BTU.Math.hr.sup.−1.Math.ft.sup.−2.Math.° F..sup.−1.

A process comprises polymerizing an olefin monomer in a loop reactor in the presence of a catalyst and a diluent, and producing a slurry comprising solid particulate olefin polymer and diluent. The Biot number is maintained at or below about 3.0 within the loop reactor during the polymerizing process. The slurry in the loop reactor forms a slurry film having a film coefficient along an inner surface of the reactor wall, and the film coefficient is less than about 500 BTU.Math.hr.sup.−1.Math.ft.sup.−2.Math.° F..sup.−1.

The present invention relates to a method for olefin oligomerization and comprising i) injecting an olefin monomer and a solvent into a continuous stirred tank reactor (CSTR); ii) injecting an oligomerization catalyst system comprising a ligand compound, a transition metal compound, and a co-catalyst into the continuous stirred tank reactor; and iii) performing a multimerization reaction of the olefin monomer, wherein a ratio of the flowing rates of the olefin monomer and the solvent is from 1:1 to 2:1. In the method for olefin oligomerization according to the present invention, high linear alpha-olefin selectivity may be attained even with a small amount of a solvent used by controlling reaction conditions during the multimerization reaction of olefin by a continuous reaction using a continuous stirred tank reactor.

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. The valve piston of the at least one withdrawal valve comprises a valve plate at an end directed to the at least one loop reactor and/or at an end directed to the at least one transfer line, the valve plate being shaped according to an inner wall of the at least one loop reactor and/or according to an inner wall of the at least one transfer line such that the valve piston is flush with the inner wall of the at least one loop reactor and/or with the inner wall of the at least one transfer line in a closed position of the withdrawal valve. By using such a withdrawal valve, a limitation of the effective withdrawal area can be avoided or at least be reduced such that the liquid slurry can efficiently be withdrawn and the risk of plugging is reduced. Further disclosed is a method for producing an olefin polymer in the inventive polymerization reactor system.

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. The valve piston of the at least one withdrawal valve comprises a valve plate at an end directed to the at least one loop reactor and/or at an end directed to the at least one transfer line, the valve plate being shaped according to an inner wall of the at least one loop reactor and/or according to an inner wall of the at least one transfer line such that the valve piston is flush with the inner wall of the at least one loop reactor and/or with the inner wall of the at least one transfer line in a closed position of the withdrawal valve. By using such a withdrawal valve, a limitation of the effective withdrawal area can be avoided or at least be reduced such that the liquid slurry can efficiently be withdrawn and the risk of plugging is reduced. Further disclosed is a method for producing an olefin polymer in the inventive polymerization reactor system.

Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

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.