Combustion kinetic behavior of different ash contents coals co-firing with biomass and the interaction analysis

Abstract

Coal co-firing with biomass is considered as a prospective energy production method in the world. The different coals and biomass co-firing is studied for the combustion behavior and the interactions by thermogravimetric analysis. The effects of coal ash content, biomass mixing ratio and oxygen concentration on coal/biomass interactions are discussed. The interaction is found significantly in the blends of biomass and low ash content coal under small biomass mixing ratio. Biomass mixing makes blends burning sensitive to oxygen. SN is utilized to evaluate the blends combustibility. Biomass mixing improves low ash content coal combustibility, but weakens SN of high ash content coal to some extent. Kinetic analysis is conducted through Coats–Redfern method with selecting appropriate mechanism function. Blends of coal and biomass burning activity energy variation are impacted by the coal ash contents. Biomass mixing can help high ash content coal burning easily, but not guarantee low ash content coal burning process with low activity energy. The apparent E of blend affected by oxygen varies significantly.