Excellent Mercury Removal in High Sulfur Atmosphere Using a Novel CuS-BDC-2D Derived by Metal-Organic Frame.

To effectively remove high concentrations of mercury in a high sulfur atmosphere of nonferrous smelting flue gas, a novel two-dimensional CuS-MOF (CuS-BDC-2D) material is synthesized by anchoring S to Cu sites in the Cu-BDC MOF. The highly dispersed CuS active sites and MOF framework structural properties in CuS-BDC-2D enable efficiently collaborate in capturing mercury. CuS-BDC-2D exhibits a layered floral structure with high specific surface area and thermal stability, with poor crystallinity. Compared to CuS and the three-dimensional CuS-MOF (CuS-BDC-3D) structure, CuS-BDC-2D demonstrates significantly higher mercury capture capacity due to the high exposure of active sites and defects sites in the two-dimensional material. Moreover, CuS-BDC-2D exhibits excellent resistance to sulfur, maintaining its high efficiency in removing Hg0 even at high levels of sulfur dioxide (SO2), such as 5000-20,000 ppm. The superior performance of CuS-BDC-2D makes it suitable for controlling mercury emissions in actual nonferrous smelting flue gas. This discovery also paves the way for the development of new mercury adsorbents, which can guide future advancements in this field.

Efficient removal of Hg0 in flue gas using a novel Sn-based porphyrin polymer.

A Sn-based porphyrin polymer (TAPP(Sn)-FAC) synthesized in a mild condition was introduced for the Hg0 removal in flue gas. The properties characterization of materials revealed the two-dimensional sheet structure, an amorphous structure and high stability of TAPP(Sn)-FAC, and Sn was successfully incorporated into TAPP-FAC in the form of SnN. The removal performance of Hg0 under different conditions was investigated using a lab-scale fixed-bed reactor. TAPP(Sn)-FAC presented an excellent Hg0 removal efficiency from 100 °C to 250 °C, which can reach 8 mg/g of Hg0 capture capacity at 100 °C for 300 min. Besides, TAPP(Sn)-FAC had a strong sulfur and water resistance, and the presence of NO and O2 had a facilitating effect for Hg0 removal. Moreover, the existence of Sn can enhance the Hg0 adsorption and oxidation capacity of TAPP(Sn)-FAC by promoting the electron transfer process. Furthermore, TAPP(Sn)-FAC presented an excellent chemical stability, which was a promising material in the Hg0 removal in flue gas.

Efficient mercury removal in chlorine-free flue gas by doping Cl into Cu2O nanocrystals.

The low content of hydrogen chloride (HCl) in flue gas is difficult to meet the request of Hg0 removal. Here, a small amount of Cl was doped into the crystal lattice of Cu2O nanocrystals (Cl-Cu2O), presenting excellent Hg0 removal efficiency in chlorine-free coal combustion flue gas. SEM, XRD, BET, and XPS characterizations revealed well crystal morphology and structure of Cl-Cu2O catalyst. Besides, Cl-Cu2O had smaller sizes and higher BET surface area compared with Cu2O. Hg0 removal behaviors were studied using a lab-scale fixed-bed reactor. After doping Cl, Hg0 removal efficiency was improved obviously and could reach nearly 100% above 150 â„ƒ, indicating chlorine incorporated into the catalyst lattice had a better role for Hg0 removal. Besides, gas composition effect on Hg0 removal was analyzed. Cl-Cu2O had high sulfur resistance capacity, and Hg0 removal efficiency can still reach above 90% even at 2000 ppm SO2. O2 played a critical role in the Hg0 removal reaction. Furthermore, a plausible mechanism for Hg0 removal was analyzed. Doping Cl into the lattice of Cu2O nanocrystals was beneficial for the activation of molecular oxygen, and generated reactive oxygen species can further activate Cl to participate in the Hg0 removal reaction.