Farm-scale CO2 sequestration using biochar
The Rainforest Information Centre (RIC) was created out of the successful struggle to save the sub-tropical rainforests of New South Wales, Australia in the early 1980s. Since then RIC have been involved in campaigns and projects which protect rainforests and the indigenous people who depend on them.
Amazonian Terra Preta shows that we can sequester CO2 for millennia by turning waste biomass into charcoal and burying it. This biochar simultaneously enhances soil fertility. Large scale, high tech methods of producing biochar costs thousands of dollars and requires biomass to be transported long distances which results in an expensive product.
The problem of doing this on a low tech, farm scale does not appear to be insurmountable: it requires a retort kiln where all the methane and carbon monoxide are burned to create the heat needed to complete the charring process. To do this requires a feedback mechanism ensuring sufficient oxygen for complete combustion. The project is to build a kiln able to char 3 cubic metres of agricultural waste, sawdust etc at a cost of less than $5000. Once constructed research and tests can be carried out and if successful plans can be produced so anybody can construct one.