Closed-loop spray drying solutions for energy efficient powder production

Drying is an energy intensive operation in processing. To comply with the upcoming regulations that arise from the EU goals for sustainable development, the energy consumption of drying processes should be reduced drastically. Emerging technologies are the key for the next step in energy efficiency improvement. A closed-loop spray drying system for milk powder production is simulated and optimized in this work. The proposed technologies are: monodisperse droplet drying, membrane contactor and a zeolite wheel. By applying air dehumidification and heat integration the latent and sensible heat are recovered from the exhaust air. The energy consumption for milk concentration and spray drying has the potential to be lowered from 8.4 to 4.9 MJ heat per kg milk powder. Although milk powder has been considered, the proposed system is also applicable to other food products, as well as in the (bio)chemical, pharmaceutical and paper industry.