A modeling and control framework for extraction processes

Many continuously operated pharmaceutical process routes have been presented recently. Most of these cover the synthesis of the active pharmaceutical ingredient (API) or solid dosage processing. However, the API purification is also gaining attraction. One widespread and waste-intensive unit operation for purification is the liquid–liquid-extraction (LLE). In continuous manufacturing active process control is required, especially for fast processes. Control concepts must be able to react on product quality deviations caused by disturbances or inadequate process settings in real-time. In this study different control concepts for LLE were developed for an extraction column and a multistage extraction. A universally applicable process model was derived and parametrized. The impact of several control concepts including different real-time measurements was evaluated in simulation for both LLE process routes. The results show that simulation tools based on proper process models can support the selection of the most efficient process route and of suitable control concepts.