(446e) Real-Time Mass Spectroscopy in Fast Pyrolysis Process

Biomass pyrolysis is inherently dynamic. Each individual particle entering an otherwise steady-state reactor must be heated to reaction conditions. Upon heating, regardless of the rate, the biomass particle will begin to pyrolyze under conditions of changing temperature. Thus, there are no true stead-state pyrolysis experiments from which kinetics can be extracted. In an effort to provide true real-time kinetic information from which reliable kinetic information can be extracted, a novel micro-reactor micro-particle technology was develop and coupled to a fast mass spectrometer. The newly developed micro-sphere micro-reactor (MSMR) was coupled with a fast mass spectrometer capable of sampling pyrolysis vapors at a rate of 100 Hz over a total reaction time of 100 to 10000 ms. A Q Exactive (QE) mass spectrometer at the Pacific Northwester National Laboratory (PNNL) Environmental Molecular Science Laboratory (EMSL) was used. In this study two types of biomass (tall fescue and switchgrass) and microcrystalline cellulose were formed into microspheres of different sizes and pyrolyzed at different temperatures to study the effect of particle size and process conditions on kinetics and chemistry of reaction. The results show clear dynamics even for fast pyrolysis conditions in which particles are complete pyrolyzed in less than 100 ms.