A Review on Biofuel Production Using Oscillatory Baffled Reactors: Effects ofBaffle Geometry

Biofuels are known as sustainable alternatives for fossil fuels and new technologies forintensification of their production are being developed. Oscillatory baffled reactors (OBRs) area novel approach to process intensification of biofuel production. The diverse geometry ofbaffles inside this type of reactor has a substantial impact on the mass and heat transfer and itdetermines the application of the OBRs. Baffles serve the purpose of facilitating improvedmixing within the reactor by directing the fluid flow. In this study, the effects of different bafflegeometries on the mixing performance parameters, namely pressure drop, energy dissipation,and the characteristics of flow and shear strain rate fields were reviewed. The five geometriesexamined include the single orifice baffle, the disc-and-donut baffle, as well as three newvariations of helical blades (as the most well-known shapes). Moreover, the baffle spacingfactor and its influence on the dispersion and residence time were analyzed. The results of theprevious research showed that the type of baffle design influences the fluid behavior in thereactor. However, this study shows that each geometry and size can be beneficial for a specificapplication of processes within the reactor and one model cannot be used as the most optimalmodel for all processes, and choosing the best type of baffle to optimize the mixing andconstruction of oscillatory reactors on scales larger than laboratory scales can be challenging.