Evolution of four-decade atmospheric mercury release from a coal-fired power plant in North China

Li, Zhonggen; Chen, Xufeng; Liu, Wenli; Li, Taishan; Chen, Ji; Lin, Che‐Jen; Sun, Guangyi; Feng, Xinbin

doi:10.1016/j.atmosenv.2019.06.045

Cited by 16 publications

(8 citation statements)

References 40 publications

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“…The toxic effect of mercury on humans and the environment makes reduction in air, water, and soil a goal of national and international efforts. Established separation processes for mercury removal, such as adsorption by entrained flow adsorbers − or absorption by scrubbers , are mainly suitable for removal from large continuous waste gas streams. Small discontinuous waste gas streams can be efficiently treated from a technical and economic point of view by fixed-bed adsorption with impregnated − and nonimpregnated − activated carbons.…”

Section: Introductionmentioning

confidence: 99%

Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon

2021

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In this work, the influence of water on the adsorption of mercury is systematically investigated on basic and washed activated carbons. Breakthrough curves were measured and temperature-programmed desorption (TPD) experiments were performed with mercury and water. Both physisorptive and chemisorptive interactions are relevant in the adsorption of mercury. The experiments show that the presence of water in the pores promotes chemisorption of mercury on washed activated carbons while there is little influence on chemisorption on basic materials. Washing exposes or forms oxygen functional groups that are chemisorptive sites for mercury. Obviously, effective chemisorption of mercury requires both the presence of water and of oxygen functional groups. As mercury chemisorption is preceded by a physisorptive step, higher physisorptive mercury loading at lower temperature (30 °C) enhances chemisorption though the reaction rate constant is smaller than at higher temperature (100 °C). Sequential adsorption and partial desorption of water at lower temperature changes the surface chemistry without inhibiting mercury physisorption. Here, the highest chemisorption rates were found. The number of desorption peaks in the TPD experiments corresponds to the number of adsorption and desorption mechanisms with different oxygen functional groups in the presence of water. The results of the TPD experiments were simulated using a transport model extended by an approach for chemisorption. The simulation results provide reaction parameters (activation energy, frequency factor, and reaction order) of each mechanism. As in many heterogeneously catalyzed reactions, the activation energy and the frequency factor are independent of mercury loading and increase with increasing temperature.

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Section: Introductionmentioning

confidence: 99%

Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon

2021

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“…Hg can long-distance transport in air and presents toxicity, persistence and bioaccumulation in the environment. Therefore, it has attracted some attention, and the largest anthropogenic source of Hg emission has been considered as coal combustion [ 6 ]. Consequently, many efforts about the emission of Hg from CFPPs have been carried out over the past few years [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Release characteristics of elemental mercury during low calorific value coal combustion

Gao

Guo

et al. 2022

R. Soc. open sci.

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The dynamic release characteristics of Hg 0 during low calorific value coal combustion were investigated in a combining laboratory-scale furnace coupled with atomic fluorescence spectroscopy. The results show that the sulfur has an inhibitory effect on the homogeneous oxidation of Hg 0 in flue gas. The instant intensity of Hg 0 release increases with increasing temperature while the amount of Hg 0 release gradually decreases with increasing temperature. Compared with that under air, the instant intensity of Hg 0 release under O 2 /CO 2 atmosphere increases to some extent with a lower decreasing rate of Hg 0 release peak. The release ratio of elemental mercury (Hg) from Yuwu (YW) and Qinxin (QX) coal increases while that from Yonghao (YH) coal decreases under O 2 /CO 2 atmosphere. In the range of 800–1100°C, the release rate of Hg reaches more than 96% under the residence time of 50 s.

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“…However, a large amount of atmospheric pollutant emissions, such as SO x , NO x , and dust, are produced in the operation of coal-fired power plants every year. [4][5][6] These have caused many environmental problems, including acid rain and haze. [7,8] For the aim of environmental protection and sustainable development, the Chinese government has put forward many emission standards.…”

Section: Introductionmentioning

confidence: 99%

Effect of ash composition on adsorption and agglomeration characteristics in low‐low‐temperature electrostatic precipitator systems

et al. 2021

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The low‐low temperature electrostatic precipitator (LLT‐ESP) has been applied in many power plants to improve the emission performance. In this study, a number of fix‐bed experiments were conducted, which simulated the operation condition of LLT‐ESP. The effect of chemical composition on the adsorption characteristics of ash samples and the agglomeration after adsorption were studied. The results show that the agglomeration of ash particles occurs in three forms, including agglomeration among small particles, adhesion of loose pellets to large particles, and agglomeration among large particles. The capacity of ash particles to adsorb sulphuric acid is less affected by the increase of added amounts of NaCl or KCl. At the same time, the added amount of NaCl or KCl also has little effect on the agglomeration degree of ash particles. The addition of MgO, CaO, Fe2O3, Na2CO3, or K2CO3 from 0% to 13.3%, 22.4%, 23.9%, 18.4%, or 14.2%, promotes the adsorption of sulphuric acid by ash particles from 1.95 mg g−1 to 7.33, 7.71, 6.72, 5.1, or 5.44 mg g−1 (based on sulphur content), respectively, thereby promoting the agglomeration between ash particles. As the addition amount increases, the agglomeration phenomenon among particles becomes more conspicuous. The form of agglomeration changes from agglomeration among small particles to agglomeration among large particles. In addition, the addition of MgO or CaO has great influence on the adsorption and agglomeration.

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Evolution of four-decade atmospheric mercury release from a coal-fired power plant in North China

Cited by 16 publications

References 40 publications

Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon

Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon

Release characteristics of elemental mercury during low calorific value coal combustion

Effect of ash composition on adsorption and agglomeration characteristics in low‐low‐temperature electrostatic precipitator systems

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Evolution of four-decade atmospheric mercury release from a coal-fired power plant in North China

Cited by 16 publications

References 40 publications

Impact of H2O on the Adsorption of Hg0 on Activated Carbon

Impact of H2O on the Adsorption of Hg0 on Activated Carbon

Release characteristics of elemental mercury during low calorific value coal combustion

Effect of ash composition on adsorption and agglomeration characteristics in low‐low‐temperature electrostatic precipitator systems

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Product

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Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon

Impact of H₂O on the Adsorption of Hg⁰ on Activated Carbon