Method for feeding a liquid catalyst to a fluidized bed polymerization reactor

A process for producing a polymer in a gas fluidized bed reaction vessel having a polymerization zone containing a bed of growing polymer particles under polymerization conditions which comprises:

• (i) continuously or intermittently introducing one or more monomers, optionally at least one diene, optionally at least one inert particulate material, and optionally one or more inert gases into the polymerization zone;
• (ii) continuously or intermittently introducing into the reaction vessel an unsupported polymerization catalyst in liquid form without immediately contacting the bed of growing polymer particles so as to provide a particle lean zone;
• (iii) continuously or intermittently withdrawing polymeric product from the reaction vessel;
• and
• (iv) continuously withdrawing unreacted monomers and gases from said polymerization and optionally compressing and cooling said gases while maintaining the temperature within the polymerization zone below the dew point of at least one monomer present in the polymerization zone.