Surface modification of fly ash by non-thermal air plasma for elemental mercury removal from coal-fired flue gas

作者：Mengting Shi, Guangqian Luo, Hailu Zhu, Renjie Zou, Jingyuan Hu, Xu Yang, Hong Yao · 发表于：Environmental Technology · 年份：2019 · DOI：10.1080/09593330.2019.1627423 · 被引用次数：12 · 研究领域：Mercury impact and mitigation studies、Plasma Applications and Diagnostics、Analytical chemistry methods development

The fly ash from a coal-fired power plants was modified with non-thermal plasma in air to improve the elemental mercury (Hg0) removal performance. The Hg0 adsorption experiments were implemented via a bench-scale fixed-bed reactor system. Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), ultimate, X-ray diffraction (XRD) and XRF analysis were employed to characterize the fly ash. The effect of non-thermal plasma voltage and time on Hg0 removal efficiency was investigated. The results showed that fly ash had better Hg0 removal performance when treatment voltage was 3.0 kV and treatment time was 7 min. Furthermore, the results showed that non-thermal plasma treatment had little influence on the specific surface area. However, non-thermal plasma treatment increased the relative content of oxygen. XPS and temperature programmed desorption results indicated that Hg0 removal process included adsorption and oxidation of Hg0. Moreover, ester and carbonyl groups played extremely vital roles in the improvement of Hg0 removal performance, and their temperature programmed desorption peak occurred at around 250°C and 320°C, respectively.