The effect of atmosphere on elemental mercury release during thermal treatment of two bituminous coals

Abstract

The dynamic release behavior of elemental Hg (Hg0) during thermal treatment of two bituminous coals was studied under N2, CO2 and air atmospheres. The results show that the profiles of Hg0 released present several peaks during thermal treatment of two bituminous coals. The Hg peak profiles for the same coal are different with the different atmosphere used. The amount of Hg0 released from the coals is about 92-94, 73-74 and 31-33% under N2, CO2 and air atmosphere, respectively. This indicates that the Hg0 is the dominant form during thermal treatment of the coals under N2 atmosphere whereas part of Hg0 is converted into the oxidized Hg during thermal treatment of the coals under CO2 and air atmosphere. The total Hg released is promoted by the volatile matter release to some extent while the Hg0 released is mainly affected by the atmospheres used.