Patent ID: 7786254

Claim:
A process for finishing polyolefins produced by gas-phase catalytic polymerization of at least one α-olefin in presence of a polymerization diluent selected from a C 3 -C 5 alkane, wherein polyolefin granules discharged from a gas-phase reactor are subjected to: (1) a first degassing step in which said polyolefin is counter-currently contacted with a gaseous stream comprising at least 85% by mol of a stripping agent selected from a C 3 -C 5 alkane, said gaseous stream being continuously derived from a monomer recovery section of a polymerization plant; (2) a second degassing step in which said polyolefin is counter-currently contacted with steam, the amount of steam being from 10 to 200 Kg per 1000 kg of polyolefin.