Basell Poliolefine Italia S.r.l.

Basell Polyolefine Gmbh

Maurizio Dorini

Giuseppe Penzo

Riccardo Rinaldi

Enrico Balestra

Antonio Mazzucco

Silvia Soffritti

Gabriele Mei

Tiziana Caputo

Giulia Mei

Gerhardus Meier

Massimo Covezzi

Pietro Baita

Pier Luigi Di Federico

Luciano Michielin

Gian Luca Bonaccorsi

Ricardo Rinaldi

Sergio Sabbioni

Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

Apparatus and process for the gas-phase polymerization

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 gas-phase polymerization reactor for the gas-phase polymerization of olefins including a polymerization zone having a recycle line for (a) withdrawing reaction gas from the reactor, (b) leading the reaction gas through a heat-exchanger for cooling, and (c) feeding the reaction gas back to the reactor, wherein the recycle line has the heat-exchanger, a centrifugal compressor having variable guide vanes, and a butterfly valve, and a related process for preparing an olefin polymer in the gas-phase polymerization reactor.

Process for polymerizing olefins in the gas-phase

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 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 gas-phase polymerization reactor having interconnected polymerization zones comprising:&#x2014;a riser through which the polymer particles flow upwards under fast fluidization conditions or transport conditions;&#x2014;a downcomer through which the polymer particles flow downward in a densified form under the action of gravity, the bottom of said downcomer being connected to the lower region of said riser by means of a transport section, said transport section being designed as a bend descending from the downcomer to the riser.

Process and apparatus for the gas-phase polymerization of olefins

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.

A method of discharging polymer from a continuously operated polymerization reactor, wherein at least a monomer is polymerized to form polymer particles, the method comprising adjusting the discharge rate of the polymer particles by means of a piston valve having a piston element connected to an actuator, said actuator being able to modulate the piston stroke inside said piston valve.

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Ferrara, Italy

Maurizio Dorini