An expert system for a semi-batch pilot scale emulsion copolymerisation facility

A knowledge-based system (KBS) has been developed for a semi-batch pilot scale emulsion copolymerisation reactor facility. A simulation model was developed for the feed of styrene and MMA monomers as well as surfactant and initiator to control the particle size distribution (PSD) and molecular weight distribution (MWD) over the entire monomer conversion. The expert system architecture provides continuous support and rectification of product off-specs, monitoring and maintaining safety functionality, as well as retaining process continuity. Process events such as the particle growth and secondary nucleation could be picked up by the rule-based expert system. The knowledge-based system is built under multiple layers of a proposed supervisory architecture. This expert system was built using G2 (Gensym Corp). The expert system provides diagnostic and decision support to the operator. The diagnostic module triggers alarm and send message queues whenever a process upset occurs. The decision support system (DSS) incorporates several features such as intelligent polymer recipe input interface to pre-select optimal pump controls. The expert system was put to test on the actual facility and has been aiding the operator running the facility.