A cold Sunday morning, quite still, drizzle holding off. Perfect conditions for making a batch of biochar, where temperatures in the burner reach between 400 and 600 (or more) degrees Celcius. Depending on what sort of device you use, you can even boil a cuppa whilst you char!
Anthony gave participants a run down on the origin (Terra Preta, around 400BC) and values of biochar, it’s uses in agriculture and other areas, and importantly how to use or activate it once you’ve made it. We produced around 3 or 4 kilograms of biochar from about 20kg of starting material. But you can scale up to farm level, and also make use of the other byproducts of the process – ‘biogas’ (for energy, heat) and ‘bioliquid’ (also called wood vinegar).
The process involves burning material which is high in carbon, fibre and cellulose under conditions of low oxygen and high temperature (and no smoke). After you’ve produced the biochar, you then need to ‘condition’ or ‘activate’ it before applying it to the soil. Anthony has built his own TLUD (Top Load Up Draft) furnace from 44 gallon drums, but you can also buy smaller TLUDs specifically made for use in developing countries (where continued exposure to smoke from cooking fires is a major health issue).
Watch the slideshow or the picture gallery for more info on the method. Anthony has used the ‘bible of biochar’ – The Biochar Revolution – to guide his learning and also presented an interesting paper outlining fifty-five uses of biochar … and counting?