Hydrodynamics and mass transfer in a slurry external airlift loop reactor integrating mixing and separation

Abstract

A pilot external airlift loop reactor (EALR) integrating mixing and separation was first proposed by combining directional flow in the EALR and liquid-solid separation in two parallel hydrocyclones. In this developed reactor, mixing, mass transfer, and liquid-solid separation can be simultaneously realized without extra energy input. Technical feasibility was firstly verified, and then hydrodynamics and mass transfer were measured. It was found that the minimum diameter of solid particles retained for circulation was 6.82 μm, and the treatment capacity of clean liquid was up to 3.0 m3/h. Additionally, global gas holdup, liquid circulating velocity, and volumetric mass transfer coefficient increased monotonously with increasing the superficial gas velocity while declined with the increase of solid concentration. Axial inhomogeneity of solid particles was decayed with increasing the superficial gas velocity and solid concentration. This new type of slurry EALR is promising to be applied in the gas-liquid-solid catalytic industries.