CFD modelling of a novel stirred reactor for the bio-production of hydrogen

In this work the Computational Fluid Dynamics simulation of a stirred bioreactor purposely designed for the production of hydrogen from organic wastes fermentation is presented. The bio-reactor is a vortex-ingesting, dual impeller, mechanically-agitated vessel equipped with a central draft tube. Due to the geometrical and physical complexity, the selected reactor offers a very challenging benchmark for the multiphase flow model capability and poses additional numerical and modelling issues with respect to previously investigated gas-liquid stirred tanks. The fluid dynamics experimental data, available for the same geometrical and operating features of the reactor, allow to strictly evaluate the model capability and to highlight the possible critical issues of the simulation. The applicability of the CFD simulation method proposed in this work for the optimization and the scale up of the bioreactor for the H2 production is discussed through a critical analysis of the prediction results.