New insights into synergistic effects and active species toward Hg0 emission control by Fe(VI) absorbent

Han, Yongqin; Fan, Maohong; Russell, Armistead G.

doi:10.1016/j.fuel.2014.09.072

Cited by 5 publications

(3 citation statements)

References 37 publications

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“…In flue gas, the oxidation of Hg 0 to Hg 2+ could be obtained using oxidants such as a mixture of urea and KMnO4 solution [12], NaClO2 solution [13][14][15], H2O2 solution [16,17], K2FeO4 [18], and Fenton reagent [19,20]. However, the corrosive nature of the oxidants limits the deployment of such technology, even though the direct oxidation of Hg 0 using oxidants has higher removal efficiency.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

Shen

Zhu

Zhang

et al. 2018

Fuel

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Fe and Co co-doped Mn-Ce/TiO2 (MCT) catalysts were investigated for the simultaneous removal of nitric oxide (NO) and elemental mercury (Hg 0 ) at reaction temperature lower than 200 °C. The catalysts were characterized by Brunauer-Emmett-Teller (BET), temperature program reduction (TPR), scanning electron microscope (SEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) analysis.The experimental results showed that the co-doped 2Fe4Co-MCT catalyst exhibited better performance for the simultaneous removal of NO and Hg 0 compared to Fe or Co doped catalysts. This could be due to higher BET surface area and better redox property of 2Fe4Co-MCT catalyst. In addition, we propose that chemisorbed O2 played a dominant role in selective catalytic reduction (SCR) of NO while lattice O2 played a key role in Hg 0 oxidation. The results also indicate that the introduction of Fe species enhanced the activity of SCR, whereas the introduction of Co species enhanced the oxidation of Hg 0 . The synergistic effect of Fe and Co species in the 2Fe4Co-MCT catalyst are also suggested to be an important mechanism for simultaneously removing NO and Hg 0 .

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Section: Introductionmentioning

confidence: 99%

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

Shen

Zhu

Zhang

et al. 2018

Fuel

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“…As the major anthropogenic emission source of mercury, coal-fired power plants face certain pressures and challenges for the efficient removal of mercury from flue gas . Consequently, various mercury removal methods have been extensively studied, including adsorbent injection technology, − catalytic oxidation technology, − liquid phase oxidation technology, − etc. Among the various mercury removal technologies, the synergistic removal of mercury by existing air pollution control devices is the most cost-effective method.…”

Section: Introductionmentioning

confidence: 99%

New Insight into the Characteristics and Mechanism of Hg⁰ Removal by NaClO₂ in Limestone Slurry

et al. 2021

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In this study, the Hg0 removal characteristics of NaClO2 in limestone slurry were investigated in a bubbling reactor. The effects of slurry conditions (pH, temperature, and Cl– concentration) and flue gas components (NO, SO2, HCl, etc.) on Hg0 removal activity and efficient Hg0 removal duration were explored. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the solid products prepared under different conditions. It was found that NaClO2 exhibited superior Hg0 removal activity when both SO2 and NO were present in the flue gas, while the Hg0 removal efficiency reduced significantly in the absence of SO2 and/or NO. The Hg0 removal activity of NaClO2 decreased significantly with the increase of pH value. The slurry temperature had no obvious effect on Hg0 removal activity, while higher temperature could enhance the Hg0 re-emission at a later stage. However, the presence of Cl– in limestone slurry could notably inhibit the Hg0 re-emission. The characterization results showed that the presence of SO2 and NO promoted the formation of HgCl2, Hg(NO3)2, and HgSO4, thus significantly enhancing the Hg0 removal activity of NaClO2 in limestone slurry.

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“…The complex process of K 2 S 2 O 8 activation was a hindrance to its industrial application . K 2 FeO 4 , H 2 O 2 , and Fenton-like all had the capability of oxidizing Hg 0 to Hg 2+ , but their instability and harsh reaction conditions indicated that these oxidants were not appropriate for industrial promotion. − When NaClO was used in the simultaneous removal of SO 2 , NO, and Hg 0 , it presented a high ability to oxidize Hg 0 to Hg 2+ . Zhao et al studied the oxidation of NaClO 2 and found that Hg 0 removal efficiency could reach up to 65% under optimal conditions .…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Removal of SO₂ and Hg⁰ by Composite Oxidant NaClO/NaClO₂ in a Packed Tower

Huang

Fan

et al. 2020

ACS Omega

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Based on the implementation of the global Minamata Convention, developing an efficient and economical technology for mercury reduction in coal-fired flue gas becomes a hotspot in the field of air pollution control. The composite oxidant NaClO/NaClO 2 combined with limestone was used in the simultaneous removal of SO 2 and Hg 0 in this study, and the three-factor and four-level orthogonal experiments were performed in a packed tower. The influential sequence of various factors on SO 2 and Hg 0 removals was investigated through range analysis of the orthogonal experiments. Results showed that factors affecting desulfurization was C > A > B (liquid–gas ratio > oxidant concentration ratio > initial pH of absorption liquid), while factors affecting Hg 0 removal was A > C > B (oxidant concentration ratio > liquid–gas ratio > initial pH of absorption liquid). Optimum conditions of simultaneous desulfurization and demercuration by NaClO/NaClO 2 were A4B1C4; that is, the oxidant concentration ratio was 10/4 (mmol/L:mmol/L), the initial pH was 5, and the liquid–gas ratio was 18 (L/m 3 ). The simultaneous removal efficiencies of SO 2 and Hg 0 reached 99.5 and 85.4% under these optimum conditions, respectively. Analysis of the characteristics of the solid products showed that the main products of the wet oxidation were CaSO 4 and CaSO 3 . Analysis of the existing form of oxidized mercury showed that 23% of mercury was in the gypsum, while 77% was in the supernatant. Results of this research would provide a practical reference for promoting the simultaneous removal of SO 2 and Hg 0 by NaClO/NaClO 2 with limestone in industrial application.

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New insights into synergistic effects and active species toward Hg0 emission control by Fe(VI) absorbent

Cited by 5 publications

References 37 publications

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

New Insight into the Characteristics and Mechanism of Hg⁰ Removal by NaClO₂ in Limestone Slurry

Simultaneous Removal of SO₂ and Hg⁰ by Composite Oxidant NaClO/NaClO₂ in a Packed Tower

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New insights into synergistic effects and active species toward Hg0 emission control by Fe(VI) absorbent

Cited by 5 publications

References 37 publications

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

Simultaneous removal of NO and Hg0 using Fe and Co co-doped Mn-Ce/TiO2 catalysts

New Insight into the Characteristics and Mechanism of Hg0 Removal by NaClO2 in Limestone Slurry

Simultaneous Removal of SO2 and Hg0 by Composite Oxidant NaClO/NaClO2 in a Packed Tower

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Product

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New Insight into the Characteristics and Mechanism of Hg⁰ Removal by NaClO₂ in Limestone Slurry

Simultaneous Removal of SO₂ and Hg⁰ by Composite Oxidant NaClO/NaClO₂ in a Packed Tower