Effect of operating conditions and particle properties on performance of vertical air-lift

► Maximum solids mass flow rate was obtained when the solids bed became fluidized. ► Solids mass flow rate at first increased with air velocity but then leveled off. ► Pressure drop was higher in pneumatic transport of larger and heavier particles. ► Pressure drop was often non-linearly related to the solids mass flow rate. ► Analysis of pressure drop fluctuations indicated transition of flow regimes.