2.1.3.4. Carbonisation
Carbonisation describes a number of pyrolysis processes that most closely resemble
traditional, basic methods of charcoal manufacture, and which produce biochar of the highest
carbon content. The auto-thermal carbonisation process is the small-scale method widely
used in rural communities around the world (FAO, 1987). The second requires fossil fuel to
provide an external heat source, and is associated with industrial, mass production of
charcoal (FAO, 1985). The process is optimised for the solid products of pyrolysis, but
condensed gases provide an industrial product known as ‘wood vinegar’, which as well as
providing the basis for food flavouring ingredients, is considered to have a fertiliser value to
plants.