Oxy-fuel combustion effects on trace metals behaviour by equilibrium calculations

► Trace elements fate in oxyfiring was evaluated through equilibrium calculations. ► Hg and Cd vaporization increased in oxyfiring in comparison to air combustion. ► Cl speciation changed during biomass oxyfiring, affecting trace metals behaviour. ► CO2 interacts with ash forming compounds changing trace metals volatilization. ► Results were strongly influenced by the fuel composition.