Basell Poliolefine Italia S.r.l.

Basell Poliolefine Italia, S.p.a.

Gerben Meier

Gabriele Mei

Massimo Covezzi

Pietro Baita

Joachim T M Pater

Stefano Bertolini

Stefan Ziegler

Guiseppe Penzo

Christian Ulrich Schmidt

TM Joachim Pater

Method for monitoring the velocity of growing polymer particles flowing in a two-phase stream during a polymerization process, said method comprising measuring the degree of attenuation in the propagation of light in said two-phase stream by means of a photometric instrument, said photometric instrument comprising: one or more transmitting optical waveguides connecting one or more light sources to said two-phase stream, one or more receiving optical waveguides connecting said two-phase stream to a light detector.

Monitoring velocities in a polymerization process

A process for the gas-phase polymerization of &#x3b1;-olef&#xca;ns CH&#x2550;CHR, where R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, carried out in a first and a second interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, in which process: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer, and (b) the gaseous composition inside a portion of the downcomer is maintained substantially similar to the gaseous composition reacting in the riser.

Process for the gas-phase polymerization of olefins

Process for preparing a broad molecular weight polyethylene by polymerizing ethylene in the presence of a polymerization catalyst, the process comprising the following steps, in any mutual order:

Process for the polymerization of ethylene

A continuous process for the olefin polymerization in a fluidized bed reactor, said process comprising continuously passing a gaseous stream comprising one or more &#x3b1;-olefin monomers through the fluidized bed in the presence of a polymerization catalyst under reactive conditions, withdrawing polymeric product and unreacted fluids from the reactor, cooling part of said unreacted fluids below the dew point to form a two-phase mixture of gas and condensed liquid and reintroducing said two-phase mixture into the reactor, the process being characterized in that said two-phase mixture is reintroduced under the distribution plate of the reactor so that a part of condensed liquid is separated from the gas and is successively fed above the fluidized bed through an external pipe connecting the bottom of the reactor to a point situated above the upper limit of the fluidized bed of polymer particles.

Gas-phase olefin polymerization process

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.

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Frankfurt-am-Main, Germany

Gerben Meier