Biochar production, activation, and applications: A comprehensive technical review

Our planet has been facing critical challenges since the late 20th century, including climate change, resource shortages, environmental degradation and pollution, demanding urgent and sustainable solutions. Biochar, a carbon-rich material produced via biomass pyrolysis, has gained attention for its great potentials in environmental remediation, pollutant removals, carbon neutrality, soil amendment, building materials, and etc. The performance of biochar in these applications is closely linked to its physicochemical properties, which are influenced by the feedstock and the preparation/activation methods. This paper reviews a wide range of biochar produced from various feedstocks, and the associated performance in different applications. Advanced characterisations are discussed to unveil the fundamental mechanisms and provide insights for further improvement and optimization. The techno-economic analysis evaluates the feasibility, challenges, and opportunities for scaling up and adopting biochar in potential applications. By focusing on biochar's multifunctionality and sustainability, this paper provides a reference for future research on developing biochar as a green technology with environmental and economic benefits.