In a recent study published in Carbon Research, Gang Li and colleagues explored the production of fly ash-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 from corn stalks using hydrothermal and 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 methods. The research focused on how different production temperatures and the addition of fly ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More affect the biochar’s microstructure and its potential for carbon sequestration.  

The authors found that pyrolysis, a process involving high temperatures (300-700°C) in an oxygen-deprived environment, resulted in biochar with superior carbon sequestration potential compared to hydrothermal methods. The addition of fly ash enhanced carbon retention, with one pyrolyzed sample (P500-1:2) showing a 6.81% improvement. Furthermore, this sample exhibited only 9.93% carbon loss following oxidation, indicating increased stability.  

The study revealed that high temperatures during pyrolysis promote the formation of aromatic carbon structures and a protective layer, preventing oxidation and improving the biochar’s thermal and chemical stability. The interaction between fly ash components (like SiO2​ and Al2​O3​) and carbon at high temperatures plays a crucial role in this process.  

Overall, this research suggests that incorporating fly ash into biochar, particularly through pyrolysis, can significantly enhance its properties for carbon sequestration.  

SOURCE: Li, G., Ye, R., Wu, S., Liu, X., Huang, M., Guo, J., Gao, Y., Chen, W., & Ma, Y. (2025). Fly ash-doped biochar fabricated by pyrolysis and hydrothermal strategies: characteristics and potentialities of carbon sequestration. Carbon Research, 4(23), 1-17.