Mercury emission control from coal combustion systems: A modified air preheater solution

Schofield, K.

doi:10.1016/j.combustflame.2011.12.011

Cited by 28 publications

(14 citation statements)

References 42 publications

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“…11 Therefore, a variety of studies have been conducted to investigate Hg 0 conversion over SCR catalysts. 12 −19 Among these SCR catalysts, vanadium (V 2 O 5 )-based commercial SCR catalysts, which are originally developed for reducing nitrogen oxides (NO x ) to nitrogen (N 2 ) by ammonia (NH 3 ), have been demonstrated to be active for Hg 0 conversion. 20 However, Hg 0 conversion efficiency greatly depends on the hydrogen chloride (HCl) concentration of flue gas.…”

Section: ■ Introductionmentioning

confidence: 99%

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst

et al. 2015

Environ. Sci. Technol.

159

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CuO-CeO2/TiO2 (CuCeTi) catalyst synthesized by a sol-gel method was employed to investigate mercury conversion under a selective catalytic reduction (SCR) atmosphere (NO, NH3 plus O2). Neither NO nor NH3 individually exhibited an inhibitive effect on elemental mercury (Hg(0)) conversion in the presence of O2. However, Hg(0) conversion over the CuCeTi catalyst was greatly inhibited under SCR atmosphere. Systematic experiments were designed to investigate the inconsistency and explore the in-depth mechanisms. The results show that the copresence of NO and NH3 induced reduction of oxidized mercury (Hg(2+), HgO in this study), which offset the effect of catalytic Hg(0) oxidation, and hence resulted in deactivation of Hg(0) conversion. High NO and NH3 concentrations with a NO/NH3 ratio of 1.0 facilitated Hg(2+) reduction and therefore lowered Hg(0) conversion. Hg(2+) reduction over the CuCeTi catalyst was proposed to follow two possible mechanisms: (1) direct reaction, in which NO and NH3 react directly with HgO to form N2 and Hg(0); (2) indirect reaction, in which the SCR reaction consumed active surface oxygen on the CuCeTi catalyst, and reduced species on the CuCeTi catalyst surface such as Cu2O and Ce2O3 robbed oxygen from adjacent HgO. Different from the conventionally considered mechanisms, that is, competitive adsorption responsible for deactivation of Hg(0) conversion, this study reveals that oxidized mercury can transform into Hg(0) under SCR atmosphere. Such knowledge is of fundamental importance in developing efficient and economical mercury control technologies for coal-fired power plants.

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Section: ■ Introductionmentioning

confidence: 99%

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst

et al. 2015

Environ. Sci. Technol.

159

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“…Mercury, as a kind of heavy metal, is a persistent toxic substance of increasing concern worldwide [1,2]. The combustion of coal accounts for the great majority of the global anthropogenic mercury emissions [3].…”

Section: Introductionmentioning

confidence: 99%

Co3O4/g-C3N4 Hybrids for Gas-Phase Hg0 Removal at Low Temperature

Zhang

Liu

2019

Processes

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The Co3O4/g-C3N4 hybrids are constructed via the incipient wetness impregnation method by depositing Co3O4 onto the exterior of g-C3N4, and then employed for Hg0 capture within 60–240 °C. The results show that the Co3O4/g-C3N4 hybrid with a Co3O4 content of 12 wt% performs optimally with the highest Hg0 removal efficiency of ~100% at or above 120 °C. The high performances of the Co3O4/g-C3N4 hybrids are probably attributed to the tight interfacial contact between Co3O4 and g-C3N4, with its improved electron transfer, inferring that cobalt oxide and g-C3N4 display a cooperative effect towards Hg0 removal. NO and SO2 shows a significant suppressive influence on the mercury capture performance, plausibly owing to the competing adsorption and side reactions.

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“…The majority of the mercury in burned coals is released to the atmosphere, due to its volatility and nonreactive chemical nature [1]. Although the concentration of mercury (Hg) in coal matrix is much less than other abundant elements [2,3], the 7-8 billion tons of coal burned globally each year constitutes a significant anthropogenic mercury source [4]. Because of the extreme toxicity, persistence, and bioaccumulation of methyl mercury transformed from emitted mercury [5], China and United States (U.S.) already adopted national mercury standards to limit mercury emission from coal fired power plants by December 2011 [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…For example, the adsorption strength of Hg 0 on Au(111) surface was -40.6 kJ/mol, while this value increased by a factor of 1.3 when the number of surface vacancies increased from 0 to 3 [20]. Moreover, Pd(111) [22], Pd(100) [23], Cu(100) [37], and Agn (n = 2, 4,8) [24] also exhibited strong affinity for Hg 0 and various oxidized mercury (Hg 2+ ) species. For metal oxides with unsaturated metal-endings on the surfaces, Hg 0 can also be strongly adsorbed [38].…”

Section: Introductionmentioning

confidence: 99%

Theoretical prediction the removal of mercury from flue gas by MOFs

Liu

2016

Fuel

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Removal of mercury from flue gas has been considered as one of the hot topics in both the scientific and industrial world. Adsorption of elemental mercury (Hg 0) and oxidized mercury species (HgCl2, HgO, and HgS) on a novel metal organic framework (MOF) material, named Mg/DOBDC, with unsaturated metal centers was investigated using density functional theory (DFT) calculations. The results show that Hg 0 stably physi-sorbed on the unsaturated metal center (magnesium ion) of Mg/DOBDC with a binding energy (BE) of-27.5 kJ/mol. A direct interaction between Hg 0 and magnesium ion was revealed by the partial density of state (PDOS) analysis. HgCl2 multi-interacts with two neighboring magnesium ions simultaneously by its Cl endings and thus resulted in strong adsorption strength (-89.0 kJ/mol). The adsorption energies of HgO and HgS on the Mg/DOBDC were as high as-117.0 kJ/mol and-169.7 kJ/mol, respectively, indicating a strong chemisorption. Theoretical calculations in this study reveal that Mg/DOBDC has the potential to serve as an efficient material for removal of mercury from flue gas.

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Mercury emission control from coal combustion systems: A modified air preheater solution

Cited by 28 publications

References 42 publications

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst

Co3O4/g-C3N4 Hybrids for Gas-Phase Hg0 Removal at Low Temperature

Theoretical prediction the removal of mercury from flue gas by MOFs

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Mercury emission control from coal combustion systems: A modified air preheater solution

Cited by 28 publications

References 42 publications

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO2/TiO2 Catalyst

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO2/TiO2 Catalyst

Co3O4/g-C3N4 Hybrids for Gas-Phase Hg0 Removal at Low Temperature

Theoretical prediction the removal of mercury from flue gas by MOFs

Contact Info

Product

Resources

About

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst

SCR Atmosphere Induced Reduction of Oxidized Mercury over CuO–CeO₂/TiO₂ Catalyst