Patent ID: 7754830

Claim:
A method for monitoring a polymer resin-producing polymerization reaction in a fluid bed reactor, where a dry melt reference temperature is characteristic of melting behavior of a dry version of the polymer resin, said method including the steps of: (a) monitoring the reaction to generate monitoring data indicative of at least one parameter of the reaction, including a concentration of at least one condensable diluent gas in the reactor; (b) determining in on-line fashion a maximum ICA concentration in the reactor, by determining in response to the monitoring data a reduced melt reference temperature, MRT R , characteristic of melting behavior of the polymer resin as it exists in the reactor, where MRT R is at least substantially equal to the dry melt reference temperature minus a melt reference temperature depression value by which the dry melt reference temperature is depressed by presence of the at least one condensable diluent gas with the resin in the reactor, and identifying as the maximum ICA concentration a greatest ICA concentration inconsistent with reactor temperature reaching the reduced melt reference temperature in the presence of the at least one condensable diluent gas, whereby performing the reaction with ICA concentration less than the maximum ICA concentration ensures an acceptably low risk that the polymer resin in the reactor with the at least one condensable diluent gas will reach a condition of limiting stickiness; and (c) in on-line fashion, determining whether the maximum ICA concentration is less than an unconstrained optimal ICA concentration for performing the reaction with a desired production rate but without constraint against reaching the condition of limiting stickiness, identifying the unconstrained ICA concentration as an optimal ICA concentration in the reactor if the unconstrained ICA concentration is less than the maximum ICA concentration, and identifying the maximum ICA concentration as the optimal ICA concentration in the reactor if said unconstrained ICA concentration is not less than said maximum ICA concentration.