Further study on biomass ash characteristics at elevated ashing temperatures: The evolution of K, Cl, S and the ash fusion characteristics

► Inorganic S is released in the form of SO2 by the silicate of K2SO4 above 1000 °C. ► K is mainly reduced by the evaporation of KCl and K2SO4 aerosols. ► Cl disappears at 815 °C in the form of HCl due to the aluminosilicate of sylvite. ► Biomass AFC is mainly dependent on the high-temperature molten material. ► High-temperature molten material is built up by SiO2, K3FeO2 and silicates.