On-line monitoring of emulsion copolymerisations using hardware sensors and calorimetry

We have used a simplified model of emulsion polymerisation, along with an adaptive calorimetric approach and a set of non-linear state estimators to monitor the individual monomer conversions in a pilot scale polymerisation reactor for the production of methyl methacrylate/butyl acrylate/carboxylic acid polymers. The usefulness of reaction calorimetry for the monitoring of such systems is demonstrated. It is also shown that non-linear, high gain estimators can be used to monitor such systems even if they are based on simplified models that ignore polymerisation of the two principal monomers in the aqueous phase, and of the carboxylic acid. The advantages and disadvantages of several different types of on-line sensors for use in industrial situations are also reviewed.