(39d) Kinetic Modeling of the Thermal Decomposition of Pine Sawdust with the Dynamic Optimization Method

Biomass is a renewable and carbon-neutral energy source. The applications of biomass including pyrolysis and combustion have no change on the carbon storage in ecosystems. During pyrolysis, valuable bio-products including char, tars and gases are generated. Char is a good solid fuel and tars can be processed into valuable polymers and biofuels. The gases from pyrolysis, such as H₂, CO and CH₄, are widely used in industry. However, utilizing this technology is challenging in the current state. The reaction kinetics of biomass pyrolysis is complicated and can be affected by numerous factors. These limitations lead this research to focus on the kinetic modeling of biomass pyrolysis. Sawdust is a common waste product from lumber industries and it can be used to generate valuable bio-products through pyrolysis. In this work, the reaction kinetics of biomass pyrolysis was investigated in the global reaction mechanism. A transient kinetic model was developed to simulate pyrolysis process of pine sawdust with the global reaction mechanism. The pyrolysis process was predicted and validated with the thermogravimetric analysis data. A dynamic optimization model was applied and integrated with the kinetic model to achieve better model fitting. The kinetic model was applied to predict thermal decomposition at different heating rates (5, 10, and 15 ºC/min). Additionally, the production of biogases and bio-char was predicted by this model.