The Pore Structure Variation of Coal Char during Pyrolysis and Its Relationship with Char Combustion Reactivity

Abstract

We investigated the pore-structure variation of coal char during the devolatilization process of Baganuur coal (BC) and Shievee Ovoo coal (SOC) from Mongolia, and reported the relationship between the char pore structure and its combustion reactivity. SOC char showed much higher combustion reactivity than BC char at real-power-plant temperatures (1100–1400 °C) as well as at the low temperature range below 900 °C. Meanwhile, the surface area of the SOC char was much higher than that of the BC char, and it was confirmed that their surface areas were dominantly derived from their ash pore structure. In addition, the ash phase dispersion of the SOC char was better than that of the BC char. Thus, it was concluded that the higher surface area and better dispersion of ash phase leads to a higher combustion reactivity of the SOC char.