The relationship between HCL and mercury speciation in flue gas from municipal solid waste incinerators

The relationship between mercury speciation and HCl concentration was investigated by measuring mercury in the flue gas of MSW incinerators. The proportion of HgCl2 (HgCl2/total Hg) increased with increasing HCl concentration. The HgCl2 proportion distribution showed different characteristics below and above the HCl concentration borderline of about 1000ppm. This distribution characteristic could be explained by the thermodynamic equilibrium analysis based on the two reactions in which Hg0 reacts with HCl and O2 to generate HgCl2 and HgO. The change in mercury speciation upon passing through a dust collector was also investigated. The part of Hg0 changed into HgCl2 when the mercury contained in the flue gas passed through a fabric filter.