(91b) Simulation and Optimization of Internal-Loop Airlift Slurry Reactor Design Using Computational Fluid Dynamics

Internal-loop airlift reactors (ILAR) are widely used in biotechnology and chemical industry, because they are suitable for processes with good mixing and close contact between the phases. However, the fundamental hydrodynamic behaviors in ILAR, which are essential for reactor scale-up and design, are still not fully understood. In the paper, the three-dimensional computational fluid dynamics (CFD) modeling is used to study the performance of three-phase ILAR with multi-layer ring gas distributor. The global flow characteristics, such as gas holdup, liquid velocity and solid particles distribution, are simulated, and the results agree well with the experimental data. Then, the effect of the sparger structure of gas distributor, including the number of layers, orifice size and angle, porosity, on hydrodynamic behaviors in ILAR is investigated based on CFD model. The optimal configuration of the multi-layer ring distributor is obtained and verified by cold model experiment, which results in even gas distribution and promotes the gas-liquid-solid mixing in ILASR, thus improves its yield and productivity.