How “Biochar” Captures Carbon
Created By RISC | 1 year ago
Last modified date : 1 year ago
Charcoal is familiar as a fuel for cooking, grilling, and preparing foods. But there’s another form of charcoal that can help minimize carbon dioxide emissions.
"Biochar" is carbon from biomass. Agricultural waste such as branches, bark, rice straw, and maize cobs goes through a pyrolysis process, which involves burning it at high temperatures from 500 to 1000 °C in an oxygen-free environment. Biomass has a strong porous structure that stores carbon from photosynthesis for growth. When it decays, carbon dioxide is released into the environment again. Turning biomass into biochar prevent carbon dioxide from being released.
Biochar can hold up to 2 tons of CO₂/ton CO₂, making it helpful in the construction business. Cement takes a lot of energy and emits a lot of carbon dioxide. Concrete is the most often used building material. Incorporating biochar, with negative carbon dioxide emissions, as an ingredient in concrete to replace cement or rocks and sand results in concrete with lower or negative carbon dioxide emissions. Using lots of biochar improves some features such as mechanical strength, electromagnetic wave prevention, and sound insulation.
Biochar is also used as a carbon dioxide absorbent material because to its porous structure and large surface area. Carbon dioxide can be absorbed and stored in this porous structure. Enhancing the surface with chemicals such as hydroxide or amine boosts its ability for surface adsorption.
Through research and development, worthless biomass resources may help save our planet.
Story by: Supunnapang Raksawong, Materials Researcher in Sustainable Building Material, RISC
References:
Zhang, Y., He, M., Wang, L. et al. Biochar as construction materials for achieving carbon neutrality. Biochar 4, 59 (2022).
Biochar as a building material: Sequestering carbon and strengthening concrete,
https://www.nrel.gov/docs/fy22osti/82445.pdf
Shifang Guo, Yuqing Li, Yaru Wang, Linna Wang, Yifei Sun, Lina Liu, Recent advances in biochar-based adsorbents for CO2 capture. Carbon Capture Science & Technology, 4 (2022).