High-efficiency adsorption of elemental mercury from flue gas by K-intercalated 1T&2H MoS2. (1st March 2022)

• Record Type: Journal Article
• Authors: Wei, Jie; He, Ping; Wu, Jiang; Chen, Naichao; Xu, Tianhong; Shi, Enqi; Pan, Changyu; Jia, Haodong; Wang, Aofei
• Is Part Of: Fuel. Volume 311(2022)
• Publication Date: 2022-03-01
• Subjects: 1T-MoS2 -- K intercalation -- Phase transition -- Mercury removal -- High efficiency; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.122615
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: This study explored a simple method successfully transformed 2H-MoS2 into 1T-MoS2 . Compared with 2H-MoS2, the Hg 0 removal efficiency of MK-3 was increased by about 40%. After K intercalation, the layer spacing of MoS2 is enlarged, which broadens the adsorption space of Hg 0 . 1T-MoS2 significantly improves the surface activity of the adsorbent. Abstract: Alkali metal K is widely present in the earth's crust (the seventh abundant element), which can improve the activity and stability of the adsorbent. This study explored a simple calcination method, using the intercalation of K ions, successfully partially transformed commercial molybdenum disulfide (2H-MoS2 ) into 1T-MoS2, and used it for the adsorption of Hg 0 in the flue gas. The experimental results showed that when the K ratio was 2:1(MK-3), the removal rate of Hg 0 can reach 90.5 in a wide temperature range. Compared with 2H-MoS2, the mercury removal efficiency of MK-3 was increased by about 40%. After long-term and cycles experiments, the mercury removal efficiency of the MK-3 remained largely unchanged. In the simulated flue gas experiment, HCl could promote the mercury removal efficiency of sample MK-3, SO2 had no obvious effect on the mercury removal efficiency of sample MK-3, while SO2 and low concentration NO have no obvious effect on the mercury removal efficiency of the sample. It was found that during the intercalation of K ions, the interlayer spacing of MK-3 increased, and holes and cracks appeared on the base surface, which made it possible for Hg 0 to enter the MoS2 interlayer and adsorb, thereby expanded the adsorption space of Hg 0 . DFT simulations showed that 1T-MoS2 significantly improves the surface activity of the adsorbent, thereby enhancing the stability of the sample to adsorb Hg 0 . Therefore, K intercalated in MoS2 can provide a promising method to capture Hg 0 in coal-fired flue gas.