Efficient Mercury Removal Using Cu/Co-Doped Biochar

A study synthesized Cu/Co co-doped biochar through one-step pyrolysis to efficiently remove elemental mercury from coal combustion flue gas. The biochar showed enhanced pore structure, high mercury removal efficiency, and resistance to sulfur and water, offering a cost-effective alternative to traditional sorbents.

October 4, 2024

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Liu, et al (2024) Salts-activated synthesis of Cu/Co co-doped biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More for efficient removal of elemental mercury from coal combustion flue gas. *Chemical Engineering Journal.* https://doi.org/10.1016/j.cej.2024.156174

A recent study published in the Chemical Engineering Journal explores an innovative approach to removing elemental mercury (Hg0) from coal combustion flue gas, a major source of mercury pollution. The research focuses on the synthesis of copper and cobalt (Cu/Co) co-doped biochar through a single-step pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More process. This method offers a cost-effective and efficient alternative to traditional mercury sorbents like activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More.

By loading wood with Cu and Co salts before pyrolysis, the researchers were able to significantly enhance the pore structure and surface area of the biochar, making it more effective for mercury capture. The co-doping of cobalt improved the dispersion of copper oxides on the biochar, leading to increased mercury removal efficiency. The optimal biochar, produced at a Cu/Co molar ratio of 1:1 and pyrolysis temperature of 650°C, achieved over 88% mercury removal across a wide temperature range (100°C–180°C).

Additionally, the co-doped biochar demonstrated excellent resistance to both sulfur and water, key challenges in mercury capture. The study further identified chemisorbed oxygen, CuO, and Co3O4 as active components in the catalytic oxidation and adsorption of mercury. This innovative approach simplifies biochar production and holds promise for reducing mercury emissions in coal-fired power plants, providing a more sustainable solution to this environmental issue.