Models and Mechanisms to Explore the Global Oxidation Kinetics of Blends of feed corn stover and Illinois No. 6 Coal

Abstract

Biomass-coal co-firing has the potential to reduce SOx and net CO2 emissions from coal-fired power plants.Given the heterogeneity of biomass and coal feed stocks, the oxidation kinetic behavior of such blends is not wellunderstood. In this investigation, we probe the applicability of a variety of kinetic models to describe the fast oxidationof feed corn stover, Illinois No. 6 coal, and their blends using thermogravimetric analyzer. We find that a first order reaction assumption (often referred to as the Arrhenius Equation), as well as three-dimensional diffusion reaction models offer the best fit to the data as measured through correlation coefficients, and return reasonably similar activation energies. Derivative thermogravimetric curves show that peak mass loss rates occur within ~30K of each other for each fuel and blend, though the peak mass loss rate is dependent on the specific fuel and blend. Evidenceof reaction synergism between the fuels in the blends, in the form of a non-additive activation energy predictionscheme, suggests that the biomass promotes decomposition of the coal at lower temperatures.