Optimization of efficiency of lactose drying process in an industrial continuous fluidized bed dryer using dynamic flowsheet simulation

The fluidized bed drying of wet lactose plays a crucial role in the industrial production of lactose powder for pharmaceutical purposes. Currently, such a process is often controlled using empirical operating parameters, which may result in variability in product properties and suboptimal consumption of resources and energy. Hence, the work presented in our paper aims to address this issue by proposing a new dynamic fluidized bed dryer model for wet lactose drying in the flowsheet simulation framework Dyssol. This model was implemented based on fundamental equations for heat and mass balance, thermodynamics, and powder drying kinetics. It enables a fast and accurate prediction of the product moisture content and the exhaust air temperature for a wide range of wet lactose flow rates, fluidization air flow rates, and fluidization air temperatures. Optimization was conducted based on the proposed model, offering a pathway to reduce energy consumption and stabilize product properties. Furthermore, this model contributes to establishing a digital twin, which provides real-time simulation and optimization of the entire lactose production process beyond conventional flowsheet modelling. Incorporating further process units for the upstream and downstream treatments will allow for faster and more efficient control of existing processes and facilitate the implementation of more advanced optimization techniques.