Simultaneous control of metals and organics using a fluidized bed adsorber

A previous study has examined the performance of a fluidized activated carbon adsorber for removal of organics and particulate emissions from an incinerator under various fluidized operating conditions. The results show that it is an effective control device to treat the organics and coarse particles. However toxic heavy metal compounds cannot be completely destroyed during the incineration process and will volatilize at high temperature and then condense to form metallic particulates during the cooling of the flue gas. Therefore, continuing the previous study, the removal of metals generated from incineration by a fluidized bed adsorber at relatively low temperature was performed in the current study. Activated carbons with different additives (limestone, aluminum oxide and silica sand) were added in the adsorber to remove single metal (Pb, Cr and Cd) or mixed metals in the flue gas. Furthermore, an impulse bag house integrated after the adsorber and serving as an air pollution control device to control the metals and organics simultaneously was also identified. The results indicate that different additives can increase the removal efficiency of metals from 4% to 24% when the feedstock contains single metal. The integration of the fluidized bed adsorber and a bag house was effective to remove the heavy metals, organics and particulates in the flue gas.