Biomass fast pyrolysis is emerging as a front-running approach for the generation of renewable chemical and fuel resources. The pyrolysis temperature, solid- and gas-phase residence times, and biomass particle size and type have a substantial impact on char, oil, and gas yields. A laboratory-scale fast pyrolysis technique was demonstrated using manufactured biomass microspheres. A unique single-particle (similar to 10 mu g) microreactor technology coupled to a millisecond response flame ionization detector was used to investigate the effects of relevant particle and process parameters and to capture the dynamics of real-time microscale single-particle pyrolysis for the first time. The manufactured biomass microspheres were produced by spray-drying finely milled microcrystalline cellulose, switchgrass (Panicum virgatum), and tall fescue straw (Festuca arundinacea) flour.