PROCESS FOR START-UP OF A POLYMERISATION REACTION FLUIDISED BED

摘要

The present invention relates to a process for polymerisation, and, in particular, to a process for start-up of a gas phase fluidised bed polymerisation reaction, said reaction comprising polymerisation of one or more monomers using a catalyst in a reactor, and said process comprising:a) providing a start-up bed of particles in the reactor in the presence of the one or more monomers but in the absence of the catalyst, b) introducing catalyst to the reactor to initiate reaction and start-up polymer production, said introduction being designated as time T0, c) at a time Ti, Ti being between 1 and 6 hours after T0, the value of Xi is less than a threshold value, wherein: X1 = Gumulative production in the-time period Tn to T1 (Cumulative catalyst injection the time period T0 to Ti * PiC2=), PiC2= being the ethylene partial pressure in the reactor at the time Ti, d) subsequently stopping the injection of catalyst, e) talcing a corrective action to address the low value of Xi.