Research on Flue Gas Mercury Removal on a Lab-Scale and a Pilot-Scale Reactor

Due to its harm to human health, mercury emission from coal combustion power stations has brought more and more concern. The existed APCDs such as bag filter, electrostatic precipitator and wet FGD may remove the oxidized mercury from the flue gas. However, they have no obvious removal efficiency on the elemental mercury. The main direction in the development of new mercury removal technology is to transform the elemental mercury into oxidized mercury and particulate-bounded mercury, which may be effectively removed. A lab-scale reaction system and a pilot-scale reactor were set up to conduct the experiment on removal of Hg in the sorbent evaluation test-bed in order to research different sorbents for the mercury removal efficiency. The experimental results indicate that the experimental systems can provide accurate information of sorbent evaluation under real flue gas atmosphere. The mercury removal efficiency of different sorbents vary in a wide range, from 28.6% to 91.2%. For a same sorbent, the mercury removal efficiency shows a better performance on lab-scale reactor. Under the same condition, the sorbent would have higher mercury capturing efficiency with higher injection rate and longer residence time.