Biochar is a black, fluffy, lightweight, carbon-rich solid material produced by heating biomass (Such as agricultural waste, wood, or organic materials) to high temperatures (typically between 350°C and 700°C) under oxygen-deficient conditions using pyrolysis technology. It usually exists in granular form and is mainly composed of elements such as carbon, hydrogen, oxygen, and nitrogen, with a carbon content typically exceeding 70%. It has extremely low solubility and possesses highly carboxylated and aromatic structural characteristics. Biochar can be produced from a wide range of raw materials, including agricultural waste such as chicken manure, pig manure, wood chips, and straw, as well as industrial organic waste and municipal sludge.
Biochar is almost pure carbon and can remain in the soil for hundreds to thousands of years after being buried, effectively sequestering carbon and helping to mitigate global warming. It also has value in improving agriculture; its high carbon content and porous structure allow biochar to significantly improve soil structure (adding biochar to sandy soil can increase its water retention capacity by 92%; adding biochar to clay can increase the rate of water flow by up to three times) and fertility, fix atmospheric carbon to mitigate climate change, and adsorb and degrade harmful substances in the environment (absorbing N2O with an intensity 300 times greater than CO₂). Therefore, it has important applications in agriculture, environmental remediation, and climate change mitigation.
In 2022, the global biochar market size was approximately US$231 million, and it is expected to grow to approximately US$2.196 billion by 2030, with a compound annual growth rate exceeding 10%. Currently, the biochar market is mainly concentrated in North America and Europe, while the Asia-Pacific region, particularly China and India, shows significant growth potential. The quality of biochar produced from different raw materials varies considerably, and biochar produced through pyrolysis at different temperatures also yields different effects. However, by strictly controlling the pyrolysis technology, it is possible to create biochar with engineered properties and high reliability. This type of carbon will be suitable for more complex applications, such as replacing graphite and activated carbon electrode materials in high-demand energy storage devices (including lithium-ion batteries and supercapacitors).
