公开(公告)号：CA2551017A1

公开(公告)日：2005-03-03

申请号：CA2551017

申请日：2004-07-19

Applicant: BASELL POLIOLEFINE SPA

Inventor： MEI GABRIELE ,  BAITA PIETRO ,  MEIER GERBEN ,  COVEZZI MASSIMO

IPC: C08F10/02 ,  B01J8/00 ,  B01J8/18 ,  B01J8/24 ,  B01J19/24 ,  C08F2/00 ,  C08F2/34 ,  C08F210/16 ,  C08L23/04 ,  C08L23/06 ,  C08L23/08

Abstract: Process for preparing a broad molecular weight polyethylene by polymerizing ethylene in the presence of a polymerization catalyst, the process comprisin g the following steps, in any mutual order: a) polymerizing ethylene, optional ly together with one or more a-olefinic comono~mers having from 3 to 12 carbon atoms, in a gas-phase reactor in the presence of hydrogen, b) copolymerizing ethylene with one or more a-olefinic comonomers having from 3 to 12 carbon atoms in another gas-phase reactor in the presence of an amount of hydrogen less than step a), where in at least one of said gas-phase reactors the growing polymer particles flow upward through a first polymerization zone under fast fluidization or transport conditions, leave said first polymerization zone and enter a second polymerization zone through which the y flow downward under the action of gravity.

公开(公告)号：AU2003271648A1

公开(公告)日：2004-05-04

申请号：AU2003271648

申请日：2003-09-25

Applicant: BASELL POLIOLEFINE SPA

Inventor： COVEZZI MASSIMO ,  MEIER GERBEN ,  MEI GABRIELE

IPC: B01J8/18 ,  B01J8/24 ,  B01J8/26 ,  B01J8/38 ,  B01J19/24 ,  C08F2/00 ,  C08F2/34 ,  C08F10/00 ,  C08F110/02 ,  C08F110/06 ,  C08F210/06 ,  C08F210/16 ,  C08F210/18

Abstract: Process for the gas-phase catalytic polymerization of olefins carried out in a plurality of interconnected polymerization zones, the process comprising feeding one or more monomers to said polymerization zones in the presence of a catalyst under reaction conditions and collecting the polymer product from said polymerization zones, in which process the polymer particles grow within a first polymerization zone where a fluidized bed is formed, at least a part of said polymer particles leave said first polymerization zone to enter a second polymerization zone through which they flow downward, leave said second polymerization zone and enter a third polymerization zone through which they flow upward under fast fluidization or transport conditions, leave said third polymerization zone and are reintroduced into the first polymerization zone, thus establishing a circulation of polymer between the different polymerization zones.