Abstract: In a process for making a copolymer, a first product stream comprising a semi-crystalline polymer and a chain terminating agent is produced in a first reactor system. The first product is provided to a second reactor system wherein a low crystallinity polymer is produced in the presence of the semi-crystalline polymer. At least a portion of the chain terminating agent is removed from the second reactor system by an in-situ process.

Abstract: A method is provided for polymerizing an olefin monomer in a reactor with a highly active polyolefin polymerization catalyst system. The method includes introducing a catalyst system comprising a catalyst and a catalyst activator into the reactor containing the olefin monomer with less than 10 seconds or no pre-contacting time of the catalyst and the catalyst activator prior to introducing the catalyst and the catalyst activator into the reactor. The catalyst system may have a standard adjusted catalyst activity of greater than 10 gPgcat?1hr?1.

Abstract: In a process for making a copolymer, a first product stream comprising a semi-crystalline polymer and a chain terminating agent is produced in a first reactor system. The first product is provided to a second reactor system wherein a low crystallinity polymer is produced in the presence of the semi-crystalline polymer. At least a portion of the chain terminating agent is removed from the second reactor system by an in-situ process.

Abstract: Disclosed herein are methods for controlling bubble formation in a polymerization reactor. The method includes: (a) determining a concentration of at least one component at a location in the reactor using a mathematical model; (b) determining a vapor pressure of the composition based at least in part upon the concentration of the component; (c) determining an operating pressure of the reactor at the location; (d) determining a pressure difference as ?P =PX-PV, wherein PX is the operating pressure and PV is the vapor pressure; (e) comparing the ?P to a threshold value; and (f) implementing an effect when the ?P is less than the threshold value.

Abstract: Bubble formation is monitored in a reactor such as a loop polymerization reactor which effectively operates at pressures above or near the vapor pressure of a circulating slurry liquid. The method measures a property of the reactor composition at a first location within the reactor, and then at a second location within the reactor. The process is repeated, followed by determining if the difference in measured property varies from a reference difference, derived under bubble-free conditions. When the difference in measured physical property has changed relative to the reference difference, an effect may be implemented, e.g., increase of reactor pressure, decrease of composition vapor pressure, and decrease of reactor temperature, to an extent sufficient to reduce or eliminate bubbling.

Abstract: An injection method for feeding a particulate material to a process vessel, including a valve with at least one cavity adapted for receipt of a predetermined volume of particulate and a sweep stream source for providing a sweep stream having flow in a direction generally toward the valve to remove substantially all of the particulate from the cavity of the valve.

Abstract: An injection system and method for feeding a particulate material to a process vessel, including a valve with at least one cavity adapted for receipt of a predetermined volume of particulate and a sweep stream source for providing a sweep stream having flow in a direction generally toward the valve to remove substantially all of the particulate from the cavity of the valve.