Simultaneous control of metals and organics using a fluidized bed adsorber

Abstract

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.

The effect of ash and filter media characteristics on particle filtration efficiency in fluidized bed

“…Due to its high heating value, high mass transfer and the ability of continuous operating and capturing harmful material, the fluidized bed reactor has been gradually applied on incineration process. In previous study, fluidized bed could control the pollutants such as acid gases [1], organic compounds [2,3], heavy metals [2] and particulates [3,4] during incineration.…”

Filtration of nano-particles by a gas–solid fluidized bed

“…The nanoparticles are very small and the diffusion mechanism dominates, so the fluidized bed can capture nanoparticles. In the authors' earlier works, the fluidized bed was used to remove acid gas, organic compounds and heavy metals [12][13][14]. A series studies also focused on the filtration of the fly ash of a coalfired power plant and a municipal solid waste incinerator by fluidized beds [15][16][17].…”

The prospect and development of incinerators for municipal solid waste treatment and characteristics of their pollutants in Taiwan

“…According to these studies, solid sorbents are used to capture heavy metals through two mechanisms: chemical adsorption and physical deposition during incineration processes. On the other hand, fluidized bed adsorber also provides good performance for heavy metals control [27,28].…”

“…Scrubbing technology, such as wet scrubbing, semi-dry scrubbing and dry scrubbing, is used to reduce acid gases in incineration systems [34]. Previous studies have demonstrated the effective control of acid gases like SO 2 and HCl by using fluidized bed adsorber, spray dryer and fabric filter in series [22,27,28,34,35]. Applying catalyst to oxidize or reduce the acid gases is in practice due to its high removal efficiency (above 90%) [31,[36][37][38][39][40].…”