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Zhang Y, Wang H, Yang K, Zeng Q, Le L, Ran H, Liu D. Acid treatment for enhancing Hg 0 removal efficiency of chlorine-loaded biochar: mechanism and kinetic analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:4897-4909. [PMID: 38110679 DOI: 10.1007/s11356-023-31522-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023]
Abstract
Adsorbents modified solely with chlorine have limited effectiveness in removing mercury at high temperatures. This study aims to investigate the influence of various acid (HNO3, H2SO4, and H2O2) loadings on the removal efficiency of mercury from NH4Cl-modified adsorbents. The objective is to develop rice straw carbon adsorbents that are both more efficient and cost-effective. The experiments were conducted on a fixed bed experimental platform, with SEM and BET to observe the physical property changes of the modified char samples. XPS analysis was employed to analyze the effects of oxygen, chlorine, and sulfur functional groups. Additionally, a kinetic model was used to investigate the interaction mechanism between the adsorbent and mercury. The findings demonstrate that co-modification surpasses the use of NH4Cl alone, with the combination of NH4Cl and HNO3 yielding the best results. Co-modification enhances the development of a more refined and compact pore structure on the char surface, promoting the physical adsorption of mercury. Moreover, an increased presence of chlorine and oxygen functional groups is observed on the char surface, particularly in the NH4Cl and HNO3 co-modified samples, further enhancing the chemical adsorption capacity of the char. The results from the kinetic analysis support this conclusion. Furthermore, the adsorption process of Hg0 relies on both external mass transfer and chemical adsorption, with the chemical adsorption process playing a more significant role as the controlling factor.
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Affiliation(s)
- Yiwen Zhang
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Hui Wang
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Kang Yang
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Qingshan Zeng
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Lingyan Le
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Hengyuan Ran
- Huaneng Pengzhou Thermal Power Co., Ltd., Chengdu, 611939, China
| | - Dong Liu
- MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
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Masod MB, El-Fiqi A, Ebiad MA. Encapsulation of activated carbon into calcium alginate microspheres toward granular-activated carbon adsorbents for elemental mercury capture from natural gas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-28176-7. [PMID: 37318735 DOI: 10.1007/s11356-023-28176-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023]
Abstract
Activated carbon (AC) is an effective adsorbent for removing environmental pollutants. However, the traditional powder form of AC shows difficulty in handling during application which widely limits its utilization on the industrial scale. Herein, to avoid such limitation, traditional AC powder was encapsulated into calcium alginate (CA) microspheres. Calcium alginate/activated carbon (CAA) composite microspheres were prepared via cross-linking of sodium alginate/activated carbon composite solutions in a calcium chloride solution. Furthermore, in order to boost adsorption affinity of CAA composite microspheres toward elemental mercury (Hg°), ammonium iodide (NH4I)-treated calcium alginate/activated carbon (NCA) composite microspheres were obtained by a simple impregnation method using NH4I treatment. The morphological, structural, and textural properties of the microspheres were characterized and their Hg° adsorptive capacity was tested at different temperatures. Interestingly, the maximum adsorption capacity of NCA adsorbent composite microspheres was determined as 36,056.5 μg/g at a flow rate of 250 mL/min, temperature of 25 °C, and 500 μg/Nm3 of Hg° initial concentration. The Gibbs free energy (ΔG°) for NCA adsorbent composite microspheres varied from - 8.59 to - 10.54 kJ/mol indicating a spontaneous adsorption process with an exothermic nature. The experimental Hg° breakthrough curve correlated well with Yoon‒Nelson and Thomas models. The breakthrough time (tb) and equilibrium time (te) were found to be 7.5 days and 23 days, respectively. Collectively, the findings of this work indicate a good feasibility of using NCA composite microspheres as potential adsorbents for removing Hg° from natural gas.
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Affiliation(s)
- Mohamed Bakry Masod
- Egyptian Petroleum Research Institute (EPRI), Nasr City, 11727, Cairo, Egypt
| | - Ahmed El-Fiqi
- Glass Research Department, National Research Centre, Giza, 12622, Cairo, Egypt.
| | - Mohamed A Ebiad
- Egyptian Petroleum Research Institute (EPRI), Nasr City, 11727, Cairo, Egypt
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Ji W, Xiao X, Li F, Fan X, Meng Y, Fan M. Theoretical insight into mercury species adsorption on graphene-based Pt single-atom catalysts. RSC Adv 2022; 12:5797-5806. [PMID: 35424583 PMCID: PMC8981981 DOI: 10.1039/d1ra08891b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/24/2022] [Indexed: 01/23/2023] Open
Abstract
Mercury emission from coal-fired flue gases is environmentally crucial. Revealing the interaction between mercury (Hg) and functional materials is significant to controlling emission. We conducted an investigation into the adsorption mechanism of mercury species onto graphene-based Platinum (Pt) single-atom catalysts (SACs). Single-atom Pt is the active center for Hg species chemisorption, with an adsorption energy range of 0.555–3.792 eV. In addition, Hg species adsorbed preferentially at lower temperatures. Pt/3N-GN exhibits a higher adsorption ability than Pt/SV-GN. The strong interaction of Hg0 with Pt SACs contributed to atomic-orbital hybridization between them. Further analysis revealed that s, p orbitals of Hg contribute significantly to orbital hybridization with Pt SACs. Moreover, the charge decomposition analysis confirmed that s, p orbitals of Hg hybridized with d, s orbitals of Pt SACs. The net charge transfer from Hg0 to Pt/SV-GN and Pt/3N-GN are 0.059 and 0.097 e−, respectively. The higher the charge transfers, the more intense the electron and orbital interaction between Hg and the surface. Consequently, Pt/3N-GN is a highly effective catalyst for Hg adsorption. Adsorption mechanism: all mercury species can chemically adsorb on Pt/SV-GN and Pt/3N-GN. The charge decomposition analysis confirmed that s, p orbitals of Hg hybridized with d, s orbitals of Pt SACs. Pt/3N-GN is more superior for mercury removal.![]()
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Affiliation(s)
- Wenchao Ji
- College of Resource and Environment, Anhui Science and Technology University, Fengyang 233100, China
| | - Xiuhua Xiao
- College of Resource and Environment, Anhui Science and Technology University, Fengyang 233100, China
| | - Feiyue Li
- College of Resource and Environment, Anhui Science and Technology University, Fengyang 233100, China
| | - Xingjun Fan
- College of Resource and Environment, Anhui Science and Technology University, Fengyang 233100, China
| | - Yuanyuan Meng
- College of Chemistry & Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
| | - Maohong Fan
- Departments of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY, 82071, USA
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Guan Y, Liu Y, Lv Q, Wu J. Bismuth-based photocatalyst for photocatalytic oxidation of flue gas mercury removal: A review. JOURNAL OF HAZARDOUS MATERIALS 2021; 418:126280. [PMID: 34102357 DOI: 10.1016/j.jhazmat.2021.126280] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/06/2021] [Accepted: 05/29/2021] [Indexed: 06/12/2023]
Abstract
Photocatalytic oxidation method is a promising technology for solving flue gas mercury (Hg) pollution from industrial plants. Semiconductor photocatalysts have been widely applied in energy conversion and environmental remediation. However, key issues such as low light absorption capacity, wide energy band gap, and poor physicochemical stability severely limit the application of photocatalysts in practical industrial plants. In recent years, bismuth-based (Bi-based) photocatalysts, including bismuth oxide halide BiOX (X = Cl, Br or I), bismuth salt oxymetal BiVO4, and BiOIO3 etc., have increasingly aroused scientists' attention due to their peculiar crystalline geometric structures, tunable electronic structure and high photocatalytic performance. In present review, we firstly review the photocatalytic reaction mechanism and main photocatalytic oxidation mechanism of mercury. Secondly, the synthetic methods of Bi-based photocatalysts are summarized. Then, according to the mechanism of mercury removal, the experimental modifying approaches including heterojunction making, external atoms doping, defect creating, and crystal face regulating to promote the photocatalytic oxidation of mercury removal are summarized, as well as the determination of the band gap and electronic density of states (DOS) of Bi-based photocatalysts to elucidate the photocatalytic oxidation mechanism via density functional theory (DFT) calculation. Furthermore, constructing electronic transmission channels is an efficient way to improve the photocatalytic activity. Finally, challenges and perspectives of Bi-based photocatalyst for photocatalytic oxidation of mercury removal are presented. In addition, the excellent performance photocatalysts and efficient pollution removal equipment for mercury removal in industrial plants are still required in-depth study.
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Affiliation(s)
- Yu Guan
- State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China; College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Yinhe Liu
- State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Qiang Lv
- State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jiang Wu
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
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Wu J, Wang H, Shen H, Shen C, Zhu Y, Wu J, Ran H. Experimental and Kinetic Analysis of H 2O on Hg 0 Removal by Sorbent Traps in Oxy-combustion Atmosphere. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c01636] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Jingmao Wu
- School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Hui Wang
- School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Haotian Shen
- Nanjing Institute of Future Energy System, Institute of Engineering Thermodynamics Chinese Academy of Sciences, Nanjing 210000, China
| | - Chang Shen
- Tsien Hsue-shen College, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yiming Zhu
- School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jianfei Wu
- School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Hengyuan Ran
- School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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Shan Y, Liu Y, Li Y, Yang W. A review on application of cerium-based oxides in gaseous pollutant purification. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.117181] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Duan X, Yuan CG, Jing T, Yuan X, Xie J. Elimination of elemental mercury in flue gas by Arachis hypogaea Linn. shell generated activated carbon. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:20055-20065. [PMID: 32236807 DOI: 10.1007/s11356-020-08370-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
It is very necessary to produce bio-activated carbon for special use with easy procedure and low cost. One kind of huge surface area microporous bio-material was successfully prepared from agricultural residues (peanut shell, Arachis hypogaea Linn.) and beneficially applied to control elemental mercury (Hg0) in simulated coal-fired flue gas in this study. The possible effects of experimental factors including activator, reaction temperature, and flue components were investigated. The physicochemical properties of the prepared adsorbents were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), and X-ray photoelectron spectroscopy (XPS). The results indicated that the peanut shell activated carbon presented excellent Hg0 removal efficiency near 90% at 150 °C. The characterization analysis indicated that the removal characteristics were governed by both physical adsorption and chemical adsorption. The chemisorbed mercury on the activated carbon was mainly distinguished into mercuric chloride (HgCl2) and mercuric oxide (HgO). The presence of C-Cl and O* promoted Hg0 into HgCl2 and HgO. Zinc chloride could not only improve the micropore quantity of activated carbon but also have remarkably positive effects on the elemental mercury removal. This study provided a practical and easy preparation method of bio-activated carbon for Hg0 removal with low cost. Graphical Abstract.
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Affiliation(s)
- Xuelei Duan
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071000, China
| | - Chun-Gang Yuan
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071000, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, China.
| | - Tiantian Jing
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071000, China
| | - Xiaodong Yuan
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071000, China
| | - Jiaojiao Xie
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071000, China
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Elemental Mercury Adsorption by Cupric Chloride-Modified Mesoporous Carbon Aerogel. COLLOIDS AND INTERFACES 2018. [DOI: 10.3390/colloids2040066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mesoporous carbon aerogels (MCA) synthesized via aqueous polymerization of resorcinol and formaldehyde were modified by copper chloride and applied for adsorption removal of elemental mercury (Hg0) at a low temperature. The sorbents were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), nitrogen adsorption/desorption isotherms, and X-ray photoelectron spectroscopy (XPS) techniques. The results show that CuCl2-modified MCA exhibited good ability for Hg0 adsorption in the 40–160 °C temperature range, with Hg0 removal efficiency all above 95.0%. The Hg0 removal efficiency first increased and then decreased with the elevation of reaction temperature. It performed optimally at 80 °C with the highest Hg0 removal efficiency of 98.7%. XPS results indicate that covalent chlorines (C-Cl groups) play an important role in elemental mercury adsorption process. Hg0 is firstly captured in the form of oxidized mercury (Hg2+) and then reacts with C-Cl groups to form HgCl2.
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