Chapter 12: Computational Fluid Dynamics Modeling of Biomass Gasification

Biomass thermochemical conversion holds great promise for producing biofuels and will play a determining role in displacing petroleum-based fuel consumption toward renewable sources. Empirical approaches have shown severe limitations in their capability to understand and control the conversion processes. However, without the ability to accurately predict and optimize thermochemical conversion performance, large-scale commercialization of these systems is severely compromised. In this context, Computational Fluid Dynamics (CFD) appears as an essential tool to better comprehend the complex physical and chemical processes involved, paving the way toward efficient control and design strategies. After a brief description of the numerical models needed to simulate biomass gasification and pyrolysis, the contributions of CFD to process design and optimization are detailed. Finally, the state of the art in terms of numerical models for the dense, reactive particulate flows typically found in conversion processes are reviewed. Shortcomings of existing CFD simulations, especially in terms of validation and predictability, are examined; and directions for future research based on the progress of CFD in other fields are suggested.