A high efficiency and high capacity mercury adsorbent based on elemental selenium loaded SiO2 and its application in coal-fired flue gas

Xiao, Rihong; Zhang, Yili; Wei, Shuzhou; Chuai, Xing; Cui, Xiangzheng; Xiong, Zhuo; Zhang, Junying; Zhao, Yongchun

doi:10.1016/j.cej.2022.139946

Cited by 19 publications

(4 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the reported adsorption capacities of the sorbents were evaluated under ideal conditions (pure N 2 ), without considering the effects of SO 2 and H 2 O. Even so, the Hg 0 adsorption capacity of Se-2Cl/A p under SO 2 - and H 2 O-containing conditions is still higher than the reported capacities of most oxide-, sulfur- and selenium-based sorbents (e.g., MnO 2 /CS, LaMnO 3 , MoS 3 /TiO 2 , nano-CuS, 0.8Nano-Se/ZIF, Se/SiO 2 , etc. ).…”

Section: Resultsmentioning

confidence: 98%

Sulfur Dioxide Promoted Mercury Fast Deposition over a Selenite-Chloride-Induced Surface from Wet Flue Gas

Hong

Cai

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

Gaseous elemental mercury (Hg 0 ) extraction from industrial flue gases is undergoing intense research due to its unique properties. Selective adsorption that renders Hg 0 to HgO or HgS over metal oxide-or sulfide-based sorbents is a promising method, yet the sorbents are easily poisoned by sulfur dioxide (SO 2 ) and H 2 O vapor. The Se-Cl intermediate derived from SeO 2 and HCl driven by SO 2 has been demonstrated to stabilize Hg 0 . Thus, a surface-induced method was put forward when using γ-Al 2 O 3 supported selenite-chloride (xSeO 3 2− -yCl − , named xSe-yCl) for mercury deposition. Results confirmed that under 3000 ppm SO 2 and 4% H 2 O, Se-2Cl exhibited the highest induced adsorption performance at 160 °C and higher humidity can accelerate the induction process. Driven by SO 2 under the wet interface, the in situ generated active Se 0 has high affinity toward Hg 0 , and the introduction of Cl − enabled the fast-trapping and stabilization of Hg 0 due to its intercalation in the HgSe product. Additionally, the long-time scale-up experiment showed a gradient color change of the Se-2Cl-induced surface, which maintained almost 100% Hg 0 removal efficiency over 180 h with a normalized adsorption capacity of 157.26 mg/g. This surface-induced method has the potential for practical application and offers a guideline for reversing the negative effect of SO 2 on gaseous pollutant removal. KEYWORDS: high concentrations of SO 2 and H 2 O, fast-trapping of Hg 0 , selenite-chloride surface, induced adsorption, stability

show abstract

Section: Resultsmentioning

confidence: 98%

Sulfur Dioxide Promoted Mercury Fast Deposition over a Selenite-Chloride-Induced Surface from Wet Flue Gas

Hong

Cai

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…However, When the adsorption temperature was increased from 150 °C to 210 °C, the removal efficiency decreased sharply from 97.7% to 86.8%, as shown in Figure 2b, which was calculated according to Equation ( 2). This phenomenon illustrates that the energy provided by the temperature from 150 °C to 210 °C is not enough to make the chemical bond rupture but enough to break through the van der Waals force [16], resulting in the desorption amount greater than the adsorption amount, which is macroscopically manifested as a decrease in the amount of adsorption.…”

Section: Effect Of Temperature On Mercury Removal Performancementioning

confidence: 99%

Application Study on the Activated Coke for Mercury Adsorption in the Nonferrous Smelting Industry

Zheng,

Li,

Jiang

et al. 2024

Sustainability

View full text Add to dashboard Cite

The massive release of mercury undermines environmental sustainability, and with the official entry into force of the Minamata Convention, it is urgent to strengthen the control of mercury pollution. The effectiveness of activated coke (AC) in removing elemental mercury (Hg0) from high temperatures and sulfur nonferrous smelting flue gas before acid production was studied. Experimental results indicated that the optimal temperature for Hg0 adsorption by AC was 150 °C. And the adsorption of Hg0 by AC was predominantly attributed to physical adsorption. Flue gas components (SO2 and O2) impact studies indicated that O2 did not significantly affect Hg0 adsorption compared to pure N2. Conversely, SO2 suppressed the adsorption capacity, while the simultaneous presence of SO2 and O2 exhibited a synergistic effect in facilitating the removal of Hg0. The characterization results of X-ray photoelectron spectroscopy (XPS) indicated that the SO2 molecule favored to anchor at the Oα site, leading to the formation of SO3. This subsequently oxidized the mercury to HgSO4 instead of HgO. The study demonstrates that cheap and easily accessible AC applications in the adsorption of mercury technology may help improve the sustainability of the circular economy and positively impact various environmental aspects.

show abstract

“…1 Mercury in coal-fired flue gas can exist in three forms: elemental mercury (Hg 0 ), oxidized mercury (Hg 2+ ), and particulate mercury (Hg P ). 2,3 Hg 2+ and Hg P can be removed by power plant pollution control devices, 4,5 while Hg 0 is considered the key component to be removed as a result of its volatility and low solubility in water. 6,7 Activated carbon injection technology is currently widely used for mercury removal.…”

Section: Introductionmentioning

confidence: 99%

“…Oxy-fuel combustion technology is the most promising CO 2 reduction technology, but it leads to the emission of a large amount of mercury in the flue gas after combustion, which poses a serious threat to CO 2 capture systems . Mercury in coal-fired flue gas can exist in three forms: elemental mercury (Hg 0 ), oxidized mercury (Hg 2+ ), and particulate mercury (Hg P ). , Hg 2+ and Hg P can be removed by power plant pollution control devices, , while Hg 0 is considered the key component to be removed as a result of its volatility and low solubility in water. , …”

Section: Introductionmentioning

confidence: 99%

Investigation of Mercury Removal Behavior by Modified Biomass Coke in Oxy-fuel Combustion Flue Gas

An,

Le,

Zhong

et al. 2024

Energy Fuels

View full text Add to dashboard Cite

The presence of circulating flue gas in oxy-fuel combustion leads to mercury pollution. Acid−chlorine-modified biomass coke was used to prepare mercury adsorbents. The influence of individual flue gas components (HCl, NO, SO 2 , and H 2 O) and complex flue gas on the behavior of modified straw coke for mercury removal under an oxy-fuel combustion atmosphere was studied. The mechanism of the flue gas reaction with mercury was investigated using temperature-programmed desorption (TPD) characterization. The density functional theory (DFT) was employed to study the mechanism of mercury removal by the adsorbent. The results showed that H 2 O has a dual effect on mercury removal: the low concentrations of H 2 O promote mercury removal, while moderate to high concentrations of H 2 O inhibit it. HCl and NO exhibited promotional effects on mercury removal. SO 2 competed with Hg 0 for active adsorption sites or adsorbed on the surface of the adsorbent, consuming active oxygen species and chlorinated functional groups to inhibit the adsorption and oxidation of Hg 0 . Under the atmosphere of complex flue gas, H 2 O and SO 2 inhibited the generation of highly oxidizing intermediate products from HCl and NO. Additionally, the coexistence of H 2 O and SO 2 generated H 2 SO 4 , further blocking the surface pore structure and hindering the diffusion of Hg 0 on the adsorbent surface. The result of the electron localization function (ELF) indicated that the introduction of O and Cl atoms can form stable covalent compounds (C�O and C−Cl) through bonding with the carbonaceous surface, serving as favorable chemical adsorption sites. The high reactivity of Cl induces Hg 0 adsorption, and the presence of O atoms not only acts as a chemical adsorption site but also activates the reactivity of Cl atoms, promoting the efficiency of mercury removal. This study provided a theoretical basis for the application of mercury adsorbents in oxy-fuel combustion fuel gas.

show abstract

A high efficiency and high capacity mercury adsorbent based on elemental selenium loaded SiO2 and its application in coal-fired flue gas

Cited by 19 publications

References 48 publications

Sulfur Dioxide Promoted Mercury Fast Deposition over a Selenite-Chloride-Induced Surface from Wet Flue Gas

Sulfur Dioxide Promoted Mercury Fast Deposition over a Selenite-Chloride-Induced Surface from Wet Flue Gas

Application Study on the Activated Coke for Mercury Adsorption in the Nonferrous Smelting Industry

Investigation of Mercury Removal Behavior by Modified Biomass Coke in Oxy-fuel Combustion Flue Gas

Contact Info

Product

Resources

About