Observer Design for Estimation of Particle Size Distribution in Emulsion Polymerization of Styrene

Particle size distribution measurement tools are generally offline, expensive and slow. So, it is very important to design an observer with the ability to estimate particle size distribution in emulsion polymerization. In this paper, a non-isothermal model based on population balance equations (Zero-one model) including nucleation, particle growth, and coagulation is chosen for estimation of particles size distribution. Then a reduced observer is presented for estimation of particle size distribution with the assumption of having free active surface material density. It is shown that in case of presence of immeasurable turbulence and modeling error, the observer’s performance is better than wide open circuit observer. In addition, by measuring conversion percentage made possible by use of density measurement, the observer performance will be enhanced. As it is hard to measure concentration of free active surface material directly, it will be measured using an electrical conduction method. The results show that in case of presence of immeasurable turbulence, performance of observer by use of electrical conduction measurement is better than wide open circuit observer, but in case of presence of modeling error, no considerable enhancement were observed compared with wide open circuit observer