The International Biochar Initiative (IBI) describes Biochar as: “a solid material obtained from the carbonisation of biomass.” IBI goes on to state: “Biochar may be added to soils with the intention to improve soil functions and to reduce emissions from biomass that would otherwise naturally degrade to greenhouse gases. Biochar also has appreciable carbon sequestration value. These properties are measurable and verifiable in a characterisation scheme, or in a carbon emission offset protocol.”
Carbonisation also called pyrolysis occurs when biomass is heated to temperatures of between 4000C and 6000C driving off volatile organic compounds and leaving a media rich in fixed carbon with enhanced microbial stability and with a structure resembling the cellular skeleton of the biomass with micro and macro pores that enhance the surface area of the material.
Why make charcoal from wastes?
- Charcoal increases crop yields by as much as 100%
- Wastes are a low cost, sometimes negative cost, feedstock
- Converts troublesome wastes to useful products and energy
- For supplementary firing of furnaces/boilers
- For generation of electricity
- Charcoal is a substitute for coal that can earn carbon credits
- Recovery of investment possible in under 12 months
- Biochar revenues 65-100% of return
- Heat/Energy/Fuel replacement revenue/savings up to 35% of return
- Waste disposal service fees / carbon credits up to 25% of return
- Soil fertility improvement
Remarkable water holding capacity
Restore pH of acid soils
Improved microbial activity
Strong synergies with composting. Much better at retaining C in soil.
- Reduced loss of nutrients to run-off & percolation Recycle of nutrients to the land they came from
- makes less methane than aerobic composting
- 1 tonne of biochar = approx 1.7 tonnes of CO2
- Retained in soil is 100’s of years in comparison to compost
- Can sequester carbon & help in soil fertility.