Gray-Box Modeling of the Molecular Weight Distribution in a Batch Polymerization Reactor

We introduce a gray-box approach for modeling the molecular weight distribution in step-growth polymerization reactions using the aggregation population balance equation. The approach is based on extracting a data-based kernel function from in-process measurements of the molecular weight distribution. The method is applied to historical data from an industrial batch polymerization reactor. The resulting model is used for decision support in production by predicting the reaction endpoint corresponding to a target molecular weight. The accuracy of the predictions proved to be sufficient for the deployment of the method.