Applying PAT in reactive crystallization

The present work focuses on in-line monitoring of reactive crystallization of an organic compound, l-glutamic acid. The used spectroscopic methods were ATR FTIR and Raman spectroscopy. The immersion probes of ATR FTIR and Raman were immersed in a 1-l mixing reactor used as a crystallizer. The studied process variables were mixing conditions, reactant concentrations and batch times. The analysis methods allowed simultaneous monitoring of reactant concentrations (sulfate ion, glutamate ion) and product crystals (composition of alfa and beta polymorph mixtures) during the semi-batch process. Multivariate models were developed for the spectral treatment. The results showed that the used methods allow quantification of different species in the model compound system during the semi-batch precipitation process.