Biochar

Summary

Biochar is elemental carbon residue derived from biomass by pyrolysis or torrefaction.

History

(making of charcoal as a better form of cooking fuel than wood - hotter, impervious to rot, light weight, uniform combusion, etc.)
(Amazonian terra preta - indigenous people created fertile soil with charcoal and ceramic debris(?) where infertile rainforest soils otherwise prevailed. This soil has proven to be a durable sequestration and fertile)

Forms and Variations

(primitive: batch charcoal-making - stack biomass, usually wood, and ignite it in an earthen pit. Once the fire is hot, cover it with soil to block further oxygenation and the residual heat drives the decomposition of the wood to charcoal.)
(more sophisticated: burn biomass in an engineered furnace with features that allow oxygen to be blocked by the operator after a degree of combustion has occurred)
(more sophisticated: heat biomass in the absence of oxygen using an external heat source. The decomposition gases are captured and either are burned to supplement the external heat source or collected as products for some other process or use.)

Notable Projects

Further Learning