Research progress on elemental mercury (Hg0) removal in flue gas using non-thermal plasma technology

Elemental mercury (Hg0) 0 ) removal is a crucial target for mercury pollution control in flue gas. This article focuses on Hg0 0 removal in flue gas using corona discharge (CD) and dielectric barrier discharge (DBD) technologies, and provides a mechanistic perspective on the development and influencing factors of non-thermal plasma (NTP) technology for Hg0 0 removal. The influence factors include reactor configurations, power supplies, energy density, residence time, oxidation methods, gas composition, and the synergy between NTP and catalysis/adsorption, etc. This study reveals that the use of a pulsating electrical power supply significantly increases electron densities in both CD and DBD systems, thereby ensuring high energy efficiency and economic viability. Cl2 2 proves to be more effective than HCl as a chlorine source for Hg0 0 removal. NO significantly reduces Hg0 0 oxidation efficiency, while the effects of SO2 2 and H2O 2 O remain unclear. Energy density distribution is closely related to plasma devices, power supplies, and overall reactor configurations. Direct oxidation proves to be more effective than indirect oxidation for Hg0 0 removal. The combination of NTP with adsorption/catalysis technologies shows significantly better Hg0 0 removal efficiency compared to using NTP alone. This study can provide theoretical support for enhancing Hg0 0 removal mechanisms and optimizing process control parameters in industrial applications of NTP technology.