To produce polypropylene (PP) homopolymer, random copolymers and impact copolymers, including Metallocene PP in the Novolen process.
In the Novolen process, polymerization is conducted in one or two gas-phase reactors, (1) and (2). The reactors contain a bed of polypropylene powder, which is agitated below the fluidization point by a helical agitator to keep the bed in motion and prevent powder agglomeration. A wide range of products can be produced with, at most, two reactors connected in series, including super-highimpact copolymers. The second reactor is used either to incorporate rubber into the homopolymer matrix produced in the first reactor, or the reactors are configured in parallel while producing homopolymers or random copolymers at capacities up to 600,000 metric tpy. It is also possible to switch between parallel and cascade mode in one line—Versatile Reactor Concept (VRC)—providing great flexibility with respect to capacities and product production capability.
Polymerization heat is removed from the reactors by external cooling circuits. Polymer powder is continually withdrawn from the reactors. The powder transfer from the first to the second reactor and from the second reactor to the gas/solids separation unit (3) is pressure driven. In this gas/solids separation unit polymer powder is separated from unreacted monomer and directly fed to the extruder (4) for pelletizing. The unreacted monomer is recovered and recycled. Removal of catalyst residues or amorphous polymer is not required.
Products: The process can produce a wide variety of homopolymers, random copolymers including terpolymers and pentene copolymers, and impact copolymers with up to 50% rubber content. Product range also includes metallocene PP based on a simple drop-in technology.
Licensor: Lummus Novolen Technology GmbH