Combustion performance and kinetic modeling of lignite blended with torrefied biomass of different origin

Abstract

ABSTRACT Biomass materials of different origin were upgraded by torrefaction and blended with lignite. Combustion characteristics, reactivity, and synergistic effects were determined through thermal analysis tests. An independent parallel reactions model was developed to describe combustion kinetics. According to the results, torrefaction delayed ignition and reduced the reactivity of biomass fuels. Blending of lignite with either raw or torrefied materials exhibited some synergy and improved the reactivity of lignite up to two times/fold. The model applied fitted the experimental results accurately. The kinetic parameters of lignite/torrefied biomass blends were closer to the values corresponding to lignite (ΔΕl = 74–235 kJ/mol, ΔΕl/t biomass = 80–223 kJ/mol), pointing to a higher similarity in mechanism of combustion and thermal behavior.