Elemental mercury removal from simulated coal-fired flue gas by modified tonstein in coal seam

Tonstein in coal seam (TCS) is a kind of mining solid waste, which was developed to a novel adsorbent (CuBr2-TCS) by using copper bromide modification. In this paper, CuBr2-TCS was subjected to elemental mercury (Hg-0) removal experiment in simulated coal-fired flue gas (SFG). Several characterization methods were used to determine the mineralogical characteristics of TCS and reaction mechanisms. In-depth, the Hg-0 removal performances of CuBr2-TCS under different flue gas components were explored. The results revealed that CuBr2-TCS exhibited 92.1% and 78.3% Hg-0 removal efficiency in dry and wet SFG, respectively. HCl and O-2 facilitated Hg-0 removal performance of CuBr2-TCS by supplementing oxygen atoms and halogens, respectively, accompanying some intermediate transition products such as Cu2OBr2. SO2 played a serious suppressive role. SO2 acting alone or NO and SO2 acting simultaneously caused irreversible changes in the surface functional groups that formed active sites with NO. However, the thermal stability of the adsorbed mercury on the adsorbent which was spent in N-2 + SO2 + O-2 atmosphere became better. In addition, the spent adsorbent that first went through the Hg-0 removal process in N-2 + NO atmosphere, exhibited higher Hg-0 removal efficiency in N-2 + SO2 + NO atmosphere than that first reacted in N-2 + SO2 atmosphere. CuBr2-TCS is a cost-effective adsorbent for the Hg-0 abatement from the coal-fired flue gas (CFG).

Automated summary

The study investigated the efficacy of CuBr2-TCS as an adsorbent for removing Hg-0 in simulated coal-fired flue gas, demonstrating high removal efficiency. The in-depth exploration of Hg-0 removal performance under different flue gas components proved that CuBr2-TCS has a good removal effect on Hg-0.