Overview and Definition
Definition
Biochar is a solid, porous, carbon-rich material produced by pyrolysis of biomass under oxygen-free or oxygen-limited conditions.
IUPAC (2024) defines it as a solid multi-functional porous carbonaceous product of agricultural biomass pyrolysis in the temperature range 350–1000 °C, with molar H/C_org < 0.7 and O/C_org < 0.4 to ensure abundant fused aromatic structures and distinguish it from inadequately carbonized materials (IUPAC biochar terminology; DOI: 10.1515/pac-2021-0106).
IPCC (2019) inventory appendix defines biochar for GHG accounting as solid material from heating biomass >350 °C under controlled/limited oxidant (pyrolysis or gasification), applicable to mineral soils in cropland/grassland (IPCC 2019 Refinement, Vol. 4, Appendix 4 · estimates soil C stock change from biochar).
Not the same as
| Material | Distinction |
|---|---|
| Charcoal | Traditionally fuel / metallurgy |
| Activated carbon | Char given an extra activation step to build pores for sorption; see Biochar vs Activated Carbon |
| Hydrochar | Hydrothermal carbonization; typically higher H/C, less aromatic |
| Biocoal / torrefied biomass | Mainly energy fuel |
Primary links
Related notes
- Production — how it is made
- Properties — H/C_org, O/C_org, aromaticity
- Permanence — why fused aromatics matter for CDR
- Terra Preta and Pyrogenic Carbon — historical inspiration
- Science Hub