Abstract: From the perspective of CFD modeling of particle flows, the thermochemical conversion of biomass is analyzed. First, it presented the evolving equations for both particle and fluid phases within the Eulerian-Lagrangian framework. Then, it summarized the recent research progress available in the literature as well as in our group for biomass conversion (such as pyrolysis, gasification, etc.) in common entrained-flow and fluidized-bed reactors. Finally, it reviewed the modeling of large biomass particles, along with our recent development of one-dimensional and multi-dimensional thermally thick models.