this disclosure relates to a process for polymerization , and in particular to minimizing undesired polymerization reactions downstream of a polymerization reaction zone , for instance by use of a quenching agent that enables fast reaction rates with active polymerization catalyst in the polymerization effluent , so as to quench the catalyst quickly , thereby preventing uncontrolled polymerization reactions . a preferred quenching agent is methanol . also provided are means for treating polymer recycle streams containing oxygenates , which may result from the use of such quench agents , particularly in polymerization processes including polyene monomers .