The retention capacity for trace elements by the flue gas desulphurisation system under operational conditions of a co-combustion power plant

► The retention capacity of the FGD was studied in a co-combustion power plant. ► Water re-circulation increases the emission of particles in the gas OUT-FGD. ► Co-combustion enhances the formation of HgCl2 (g) and condensed species OUT-FGD. ► High gaseous retention (>83%) is attained for S, Cl, F, As, and B by the plant. ► Gaseous Hg and particulate As, Zn, and Ni are the proportion emitted.