Ash partitioning during the oxy-fuel combustion of lignite and its dependence on the recirculation of flue gas impurities (H2O, HCl and SO2)

► Recirculation of HCl during oxy-firing ha the potential to promote the vaporization of organically bound metals. ► Recirculation of SO2 during oxy-firing affects the partitioning of Na through the preferential formation of sulfate. ► Co-existence of steam with HCl and SO2 is favorable for the conversion of chlorides into molten alumino-silicates.