(783e) A Novel Single Microsphere-Microreactor Approach Modeling and Experimental for Study of Biomass Fast Pyrolysis

Many technologies are being investigated and developed for chemicals and fuel production from renewable resources. Biomass fast pyrolysis is emerging as a promising approach. Practical question still remain, however, regarding the kinetics of fast pyrolysis; mainly due to the very fast, three-phase reactions that occur. It appears that the pyrolysis heating rate, solid/gas phase residence time at temperature and biomass particle size have an important impact on char, condensable and gas yields and selectivity. In an effort to elucidate reaction kinetics, a novel micro-particle micro-reactor system has been developed allowing reaction and quantification of rates for single manufactured spherical particles of nominally 10 microgram. The very fast rate of reaction for pyrolysis makes all pyrolysis experiments dynamic at some level. This new approach, wherein a single 10 microgram particle is injected into a hot furnace, achieves heating rates as high as 5000 ^oC/s. Experimental data is captures in the time-domain wherein time and gas-phase response (using fast flame ionization) are trapped at rates as high as 10,000 Hz. Translation of this time-domain data to temperature-domain can only be done by a model-based approach. This presentation focuses on modeling the reactor dynamics and correlation of time-temperature-reaction rate datasets. Prior studies show that for fast pyrolysis of single microspheres, the amount of hydrocarbon and char production increases linearly as the biomass particle size increases, however the reaction rate decreases. Furthermore, the amount of volatilized hydrocarbon appears to increase linearly as the temperature increases. Finally, the rate of reaction decreases as the size of biomass particle increases and increases as the temperature increases.