(70a) Flow Pattern Simulation in a High Solids Cellulose-to-Ethanol Bioreactor Using Computational Fluid Dynamics

The agitation system plays an important role in bioethanol production from the Simultaneous Saccharification Fermentation (SSF) and Saccharification Following Fermentation (SFF) processes. To understand and improve mixing and mass transfer in the viscous non-Newtonian systems, flow behavior was simulated in a bench scale bioreactor (BioFlo 3000). This study focused on designing an agitation system for a high solids system using FLUENT. The solids particle size distribution ranged from was approximately 57.8 to70.0 μm, and 44.0 to57.5 μm for the SSF and SFF process at 10, 15, and 20 percent initial solids (w/v), respectively. The simulation results indicated a slow or stagnant flow region which could result in poor mass and heat transfer in the reactor between the impellers and bottom of the tank.