A one-step non-isothermal method for the determination of effective moisture diffusivity in powdered biomass

The effective moisture diffusivity (Deff) is an important drying parameter. Deff is usually calculated using a traditional two-step isothermal method. The current study presents a one-step non-isothermal method as a promising alternative for determining Deff of biomass particles. Non-isothermal drying experiments were performed at various heating rates (2, 4, 6, 8, and 10 °C min−1) from room temperature to 100 °C. Isothermal drying experiments were also performed to obtain Deff at five temperatures (50, 60, 70, 80, and 90 °C) for comparison. All experiments were conducted using a thermogravimetric analyzer (TGA) due to its precise temperature control capability and accurate recording of mass loss. Thermal lag was significantly reduced under non-isothermal conditions, and the values obtained by the one-step non-isothermal method were in agreement with those obtained by isothermal procedures. ► The one-step method is suitable for determining diffusivity of powdered biomass. ► Thermal lag is significantly reduced under non-isothermal conditions by TGA. ► Thermal lag in isothermal condition limits the application of the two-step method. ► The results obtained by one-step method are similar to those in previous studies.