Patent ID: 8986618
Filing Date: 2015-03-24
Classification: B01J,C08F

Abstract:
1. A gas-phase polyolefin reactor system, comprising: a) a steady-state control valve, wherein a first stream is connected to an input end of the steady-state control valve and to an input end of a high-flow valve and a second stream is connected to an output end of the steady-state control valve and the high-flow valve, wherein the second stream is connected to a third stream, wherein the third stream is connected to an input of a gas-phase polyolefin reactor; b) wherein the first, second and third streams comprise a reaction component, wherein an on-line analyzer measures an initial concentration of the reaction component in the third stream upstream from the gas-phase polyolefin reactor, wherein an empirical model predicts a required amount of a reaction component based upon the measured initial concentration and a selected ending concentration, wherein a flow meter measures a flow rate of the first stream near the input end of the high-flow valve and outputs the measured flow rate to a totalizer, wherein the totalizer determines a totalized amount when the flow rate of the first stream reaches the required amount of reaction component based upon the measured flow rate and outputs the totalized amount to the empirical model, and wherein the empirical model compares the required amount of reactant component to the totalized amount to determine a transition endpoint.