Herewith Part 1 of the trials and tribulations of starting a Biochar project in Guatemala. Emphasis is on manufacturing Biochar from invasive alien species in the forests of Guatemala, without creating excessive air pollution. Using a retort system means that gaseous products that are normally vented unburnt are in fact now utilised to provide the heat back into the retorts, creating exothermic conditions, providing its own heat for carbonisation. Efficiencies are higher and the final conversion to Biochar (as opposed to making charcoal conventionally) should be around the 25% mark. The ‘3-Drum Retort’ system, whereby lower quality and smaller diameter feedstock is burned as fuel to provide the heat into the internal retorts is in the Beta phase and these types of testing will yield valuable lessons. There were many challenges in getting the kiln on to the farm in question. First it travelled by road on the back of a pickup truck and then by boat some 400 kilometres.
Then it had to be carried on foot to the burn site. Some innovative approaches are adopted, including the use of bamboo sticks to carry the pieces through the bush.
Other challenges we foresee would be to try to get hold of clay to seal the kiln off and this seems to be in short supply. The humidity is high and the first test burn resulted in creating torrefied wood only, so the burn will have to be extended to allow moisture to be driven off. We suggested placing wood piles close to the kiln to dry pre-dry the wood and to consider two subsequent burns: one burn to create the torrefied wood and a second to turn that into Biochar.
To be continued…
- Biochar: a slow-burn success (telegraph.co.uk)
- Biochar – lessons learnt so far (stacysdailyinvention.wordpress.com)
- Biochar, The Secrets Out (moandsogrow.org)
- Mayan biochar hugle culture trench burn (stacysdailyinvention.wordpress.com)
- Using ‘Biochar’ to cut greenhouse gas emissions (greenreview.blogspot.com)