Applications of nonlinear observers and control: Improving productivity and control of free radical solution copolymerization

A nonlinear state observer that uses the rate of heat generation due to che mical reaction for the real-time evaluation of key parameters during free r adical solution copolymerization is presented. These parameters include the cumulative and instantaneous copolymer compositions, the overall and indiv idual monomer conversions, and the overall termination rate constant associ ated with the reaction. The information thus obtained is used to control th e cumulative copolymer composition and to maintain the productivity of a se mibatch reactor for the solution copolymerization of butyl acrylate (BuA) a nd vinyl acetate (VAc) in ethyl acetate (EAc) at its highest possible level . Both the state and parameter estimation of this observer were then used f or the nonlinear control of copolymer composition and optimal reactor produ ctivity.