Release characteristics of elemental mercury during low calorific value coal combustion.

The dynamic release characteristics of Hg during low calorific value coal combustion were investigated in a combining laboratory-scale furnace coupled with atomic fluorescence spectroscopy. The results show that the sulfur has an inhibitory effect on the homogeneous oxidation of Hg in flue gas. The instant intensity of Hg release increases with increasing temperature while the amount of Hg release gradually decreases with increasing temperature. Compared with that under air, the instant intensity of Hg release under O/CO atmosphere increases to some extent with a lower decreasing rate of Hg release peak. The release ratio of elemental mercury (Hg) from Yuwu (YW) and Qinxin (QX) coal increases while that from Yonghao (YH) coal decreases under O/CO atmosphere. In the range of 800-1100°C, the release rate of Hg reaches more than 96% under the residence time of 50 s.