Zhang, et al (2024) Comparative study on the adsorption performance of CO₂ and Hg in flue gas using corn straw and pine 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 modified by KOH. Separation and Purification Technology. https://doi.org/10.1016/j.seppur.2024.130757

This study explores the potential of biochar, derived from corn straw and pine, as an eco-friendly and efficient material for capturing CO2 and mercury (Hg) from coal-fired flue gas. The researchers investigated how KOH activation affects the adsorption performance of biochar, focusing on factors like specific surface area, pore structure, and functional properties.

Key findings include:

• CO2 Capture: Pine biochar activated at 800°C achieved a CO2 adsorption capacity of 3.79 mmol/g at 25°C, while corn straw biochar performed best at 700°C. The process is driven mainly by physical adsorption within micropores (<10 Å).

• Mercury Removal: Both biochar types showed improved Hg removal under CO2 capture conditions, though efficiencies remained below 80%.

• Sustainability: Biochar’s carbon-neutral production and reliance on agricultural and forestry waste make it an economical alternative to conventional adsorbents 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.

The study highlights the importance of optimizing biochar’s pore structure and surface chemistry to enhance adsorption efficiency. While KOH activation boosts CO2 capture and offers moderate improvements in Hg removal, further research is needed to increase Hg capture capacity through the development of high-affinity surface sites.

This dual-use application of biochar could help mitigate greenhouse gas emissions and mercury pollution simultaneously, offering a sustainable solution for coal-fired power plants.