摘要:
This invention relates to processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, the invention relates to processes for transitioning among olefin polymerization reactions utilizing Ziegler-Natta catalyst systems, metallocene catalyst systems and chromium-based catalyst systems.
摘要:
Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.
摘要:
Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.
摘要:
A continuous gas phase circulating bed reactor, including: a riser for contacting a catalyst and a first gas composition comprising an olefin to form a polyolefin under fast-fluidization regime or a dilute-phase pneumatic conveying regime conditions; a downer for contacting the catalyst and a second gas composition comprising an olefin to form additional polyolefin under fast fluidization regime or a dilute-phase pneumatic conveying regime conditions; and a transport section for conveying at least a portion of the catalyst, polyolefin, and additional polyolefin from the downer to the riser. Also disclosed is a polymerization process using such a circulating bed reactor.
摘要:
A continuous gas phase circulating bed reactor, including: a riser for contacting a catalyst and a first gas composition comprising an olefin to form a polyolefin under fast-fluidization regime or a dilute-phase pneumatic conveying regime conditions; a downer for contacting the catalyst and a second gas composition comprising an olefin to form additional polyolefin under fast fluidization regime or a dilute-phase pneumatic conveying regime conditions; and a transport section for conveying at least a portion of the catalyst, polyolefin, and additional polyolefin from the downer to the riser. Also disclosed is a polymerization process using such a circulating bed reactor.
摘要:
Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.
摘要:
Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.
摘要:
Catalyst systems and methods for making and using the same. The catalyst system can include a single site catalyst compound, a support comprising fluorinated alumina, and an aluminoxane. The aluminoxane can be present in an amount of about 10 mmol or less per gram of the support.
摘要:
A process for the polymerization of olefins is disclosed. The process may include: feeding a catalyst, a liquid diluent, and an olefin to a polymerization vessel having, from a polymerization vessel bottom to a polymerization vessel top, a vapor introduction zone, a three-phase reaction zone and a vapor disengagement zone; contacting the catalyst and olefin under conditions of temperature and pressure in the presence of the liquid diluent as a continuous phase in the three-phase reaction zone to form a solid phase polyolefin; withdrawing a gas phase composition from an outlet in fluid communication with the vapor disengagement zone; circulating the gas phase composition through a gas circulation loop to an inlet in fluid communication with the vapor distribution zone at a rate sufficient to agitate the solid and liquid phases within the three-phase reaction zone; and withdrawing a reaction mixture comprising polyolefin and diluents from the three-phase reaction zone.
摘要:
A continuity additive according to one general approach includes a substance having an ability to reduce, prevent, or mitigate at least one of fouling, sheeting, and static level of a material present in a polymerization reactor system when added to the reactor system in an effective amount, with the proviso that the substance is not a polysulfone polymer, a polymeric polyamine, or an oil-soluble sulfonic acid; and a scavenger contacted with the substance, optionally, the scavenger neutralizing water coming in contact therewith. Additional continuity additives, methods of making continuity additives, and use of continuity additives are also presented.