Particle-liquid mass transfer coefficient in two-/three-phase stirred tank reactors

Abstract

Knowledge of particle-liquid mass transfer coefficient (k_SL) is important for a rational design of a solid-liquid/solid-liquid-gas stirred tank reactor (STR). Considerable efforts have been made by different investigators to study and correlate the behavior of k_SL in STRs for a variety of geometric and operating conditions. This review attempts to put together and analyze the information available in the literature on k_SL in STRs systematically. Different approaches used by researchers to correlate k_SL are critically discussed. The effect of system configurations (type of the impeller, D/T, and C/T), operating parameters (impeller speed/power input, particle loading, and gas flow rate), and physical properties (d_P, D_m, μ, and Δp) on k_SL have been discussed elaborately. Some new data for six-bladed impellers have been generated to determine the optimum geometric configuration and operating conditions for particle-liquid mass transfer in three-phase STRs. It is concluded that k_SL in two-/three-phase STRs can be correlated reliably over a wide range of system configurations and operating parameters by a relative particle suspension term, N/N_S(G). Scope and need for further studies have been suggested.