Catalytic fast pyrolysis (CFP) is a promising new technology to convert directly solid biomass to gasoline-range aromatics. During CFP, biomass is converted in a single step to produce gasoline-range aromatics which are compatible with the gasoline of current market. CFP has many advantages over other conversion processes including short residence times (2-10 s) and inexpensive catalysts. The major impediment to the further development of CFP is the lack of fundamental understanding of the underlying chemistry and physics of the process. In our recent efforts a multidisciplinary approach has been employed to study the underlying chemistry and hydrodynamics that occur within the CFP reactor and to develop a multi-scale predictive reactor model. This model can be used to predict optimal reactor design and operating conditions that maximize yield and selectivity to aromatics.