Patent Document ID: 9273155
Application ID: 14614102
Patent Flag: 1

Claim One:
1. A method of transitioning a gas-phase polyolefin reactor system, comprising the steps of: a) providing a gas-phase polyolefin reactor system comprising: i) a control valve, wherein a first stream is connected to an input end of the control valve and to an input end of a high-flow valve and a second stream is connected to an output end of the 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 the gas-phase polyolefin reactor; b) selecting an ending reactant component concentration; c) obtaining a starting reactant concentration; d) predicting a required amount of reactant component with an empirical model based upon the starting reactant component concentration and the selected ending reactant component concentration; e) measuring a flow rate of the first stream near the input end of the high-flow valve to obtain a measured flow rate of the first stream; and f) estimating a transition endpoint using the empirical model and a totalizer based upon the required amount of reactant component and the measured flow rate of the first stream.