A semi-detailed kinetic model of char combustion with consideration of thermal annealing

The present paper presents a semi-detailed kinetic model of coal char combustion which embodies consideration of thermal annealing as a mechanism leading to the loss of char combustion reactivity along burn off. The distinctive feature of this model is that deactivation induced by thermal annealing is followed along with combustion. Thermodeactivation is modelled according to the power-law equation proposed by Senneca and Salatino [1]. A semi-detailed combustion mechanism was taken after Hurt and Calo [2] and includes three steps: formation of carbon–oxygen complexes (chemisorption), switch-over of surface oxides and desorption of oxygen complexes to yield combustion products. Computation results allow to discuss the impact of thermal annealing on char combustion under conditions of practical interest.