Co-firing biomass in existing utility boilers can substantially increase the use of renewable energy sources and reduce CO2 emissions. Compared to pulverized coal particles, biomass particles prepared for suspension-firing are often large and highly non-spherical, which results in very different particle motion and thus different conversion. This paper presents a closed model for non-spherical particle motion, with the aim to improve biomass suspension-firing simulation and then advance biomass combustion technology. Different from the conventional model for tracking tiny, spherical and heavy particles, the closed model numerically solves the coupled equations of translational and rotational motion of non-spherical particles and fully addresses the effects of their shape and orientation. To validate the model, an experimental study is performed to characterize the motion of cylindrical polyvinylchloride (PVC) particles in a water tank. The model prediction shows a good agreement with the experimental results in both particle translation and rotation. The model has been successfully used in simulation of a biomass suspension-fired furnace. The model has also been successfully applied by other groups for different purposes. To further improve the accuracy of the model, accommodate the latest achievements in force and torque coefficient correlations for non spherical particles, and make the model applicable to the latest biomass suspension-firing, the model will be properly extended and pneumatic transport of biomass particles in a lab-scale set-up will be experimentally characterized.