Energy-Efficient Vacuum Sublimation Drying of Camel Milk: Numerical Simulation and Parametric Analysis

This study uses both experimental and numerical investigations into the heat and mass transfer processes governing the vacuum freeze-drying of camel milk, with a specific focus on improving energy efficiency. A three-dimensional model was developed and solved using the finite element method to simulate temperature evolution and sublimation interface progression during drying. The numerical model was validated against experimental data, achieving strong agreement with an R2 value of 0.94. A detailed parametric analysis examined the effects of shelf temperature, sample thickness, and chamber pressure on drying kinetics and energy input. Results indicate that optimising these parameters can significantly reduce energy consumption and processing time while maintaining product quality. Notably, reducing sample thickness to 4 mm shortened drying time by up to 40% and reduced specific energy consumption (SEC) from 358 to 149 kWh/kg. These findings offer valuable insights for designing more energy-efficient freeze-drying systems, with implications for sustainable milk powder production and industrial-scale process optimisation.