Basell Poliolefine Italia S.r.l.

Basell Polyolefine Gmbh

Enrico Balestra

Antonio Mazzucco

Gabriele Mei

Tiziana Caputo

Riccardo Rinaldi

Maurizio Dorini

Giuseppe Penzo

Davide Tartari

Silvia Soffritti

Massimo Covezzi

Roberto Pantaleoni

Gerhardus Meier

Paola Massari

Pietro Baita

Ulf Schueller

Mara Destro

Maria Di Diego

Lorella Marturano

Gilberto Moscardi

Gian Luca Bonaccorsi

Ricardo Rinaldi

Propylene ethylene random copolymer

Process for the preparation of heterophasic propylene copolymer compositions (RAHECO) made from or containing a random propylene copolymer (RACO) and an elastomeric propylene copolymer (BIPO), the process being carried out in a reactor having two interconnected polymerization zones, a riser and a downcomer, wherein growing polymer particles:

Process for gas-phase polymerization of olefins

A process for the polymerization of olefins in gas phase carried out in a reactor having two interconnected polymerization zones, a first zone (riser) and a second zone (downcomer), wherein growing polymer particles:

A manhole for a polymerization unit having a through-hole formed with a shoulder matching a corresponding shoulder of a plug of a closure member operatively inserted in the through-hole. The through-hole can be closed with a minimum clearance, such that polymer particles do not deposit in the gap between the wall of the unit and the plug of the closure member.

Polymerization unit with improved manhole

A fluid is fed into a polymer bed of a fluidized bed gas phase polymerization reactor by introducing the fluid into the polymer bed through a distributor protruding into the fluidized bed zone of the reactor and terminating with a discharge end positioned so that the following equation is fulfilled:&#x3e;0.002wherein d is the distance of the distributor's discharge end from the wall of the reactor, and D is the diameter of the reactor in the fluidized bed zone.

Method for feeding a fluid to a gas phase polymerization reactor

A process for the preparation of polyolefins carried out in the presence of an antistatic composition made from or containing: a) a compound of formula R&#x2014;OH wherein R represents hydrogen or a linear or branched, saturated alkyl group having from 1 to 15 carbon atoms; and b) an oligomeric or polymeric organic compound having one or more terminal hydroxyl groups and a viscosity at 40&#xb0; C. of at least about 20 mm/sec (DIN 51562).

Olefin polymerization process in the presence of antistatic composition

A process for starting a multizone circulating reactor containing no polyolefin particles, comprising the steps of conveying gas through the reactor and the gas recycle line, feeding a particulate material comprising a polymerization catalyst and optionally polyolefin into the reactor, controlling the gas flow in a vertical reactor zone equipped with a throttling valve at the bottom so that the upwards gas velocity in the bottom part of this reaction zone is lower than the terminal free-fall velocity of the particulate material fed into the reactor, and, after the weight of the particulate polyolefin in this reactor zone is higher than the drag force of the upward moving gas, controlling the circulation rate of the polymer particles within the multizone circulating reactor by adjusting the opening of the throttling valve and adjusting the flow rate of a dosing gas.

Process for start-up of a multizone circulating reactor

A process and apparatus for producing olefin polymers are disclosed, comprising: a. polymerizing one or more olefins in the gas phase, in the presence of an olefin polymerization catalyst, whereby growing polymer particles flow along a cylindrically-shaped downward path in densified form under the action of gravity so as to form a densified bed of downward-flowing polymer particlesb. allowing said polymer particles to flow through a restriction of the densified bed, such restriction being positioned in a restriction zone extending from the bed upward to a distance of 15% of the total height of the densified bed; andc. metering an antistatic agent through a feed line connected to the densified bed at a feed point being located in a feed zone extending from the top of the restriction upward, to a distance five times the diameter of the section of the densified bed above the restriction.

Process for the gas-phase polymerization of olefins

A process for the gas-phase copolymerization of: (a) propylene, (b) at least one C-C&#x3b1;-olefin, and (c) optionally ethylene, the process being carried out in a reactor having two 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, thus establishing a circulation of polymer between the riser and the downcomer, the gas mixture present in the riser being at least partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid barrier having a composition different from the gaseous mixture present in the riser and comprising at least one C-C&#x3b1;-olefin in a total amount of from 0.1% to 35% by mol.

A process for the gas-phase polymerization of &#x3b1;-olefins carried out in two 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, the process being characterized in that: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid stream LB having a composition different from the gaseous mixture present in the riser; (b) the ratio R between the flow rate Fof polymer circulated between said downcomer and said riser and the flow rate LB of said liquid being adjusted in a range from 10 to 50.

A process for the polymerization of olefins carried out in a gas-phase reactor having interconnected polymerization zones, where the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity, leave said downcomer and are reintroduced into the riser, a gas recycle stream being withdrawn from said first polymerization zone, subjected to cooling below its dew point and then returned to said first polymerization zone, the process being characterized in that said gas recycle stream is cooled at a temperature Tc ranging from 0.05&#xb0; C. to 3&#xb0; C. below its dew point.

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Ferrara, Italy

Enrico Balestra