Development of PP Melt Index Inferential Model

The melt index (MI) is an important quality specification in polypropylene (PP) production industries. Accurate online measurement of MI becomes vital in PP quality control. A new MI inferential model is proposed by using macro heat of reaction (MHR) as a key factor in MI correlation. MHR is calculated from a dynamic propylene polymerization model. The proposed MI model is validated by plant data and the prediction error is less than 5%. Simulations are performed by three different MI inferential models. The results show that the proposed model has least errors in various operation conditions. The MI model could be used as online soft sensor model or MI control