It's a Top-Fed Open Draft (TFOD) biochar kiln which I originally called a 'Flat Modular Biochar Kiln' (see 'Resources' page) but like the naming convention offered by Dr TLUD as 'expandable
panel', since length expansion is a key attribute of the design and the panels aren't perfectly flat. Ergo sum, I'm calling it a 'TFOD expandable panel biochar kiln' (sub-genre).
Supports Bamboo (or thin limb wood but is probably better burnt in 300mm lengths in a Kon-Tiki 'Essential') up to 1.8m in length for biochar production or could be extended/expanded for
longer bamboo (or limb wood) with additional pairs of 'V panels'.
Approximately 280L volume
Modular panels
Lightweight panels
Flatpacked panels for easy storage and transport for many vehicles eg. Utes, Station wagons etc. and trailers
Durable panels: Redcor 2mm CW300A weathering steel panels (minimum yield strength of 300 MPa with 3 x 20mm edge folds for reinforcement)
Self-locking 'V panels' (with side and top folds) supported by ends (2) and 10 star pickets (or reinforcing bar) to hold it all together.
Only needs a guillotine and press brake for fabrication - no welding or laser cutting.
No digging a long trench needed (though may be appropriate if no access to steel and fabrication).
Can be quickly assembled on site (soft ground) where it's needed and disassembled and transported to the next site.
Multiple units could be operated simultaneously.
Could be soil, manure, or soil and manure quenched
Could be water quenched after kiln is disassembled/pulled apart after a burn to increase the lifespan of the steel.
Discussion
Bamboo is a Si-accumulator plant which after pyrolysis produces stable phytoliths (Si occluded C in the plant cell walls and cell lumens) and if burnt with a low moisture content (MC) eg.
less than 15%, will create high temperatures during pyrolysis which will vary between kilns.
According to the study 'Assessing biochar's permanence: An inertinite benchmark' (2023) by Hamed Sanei et al generally >550 degrees Celsius will produce biochar suitable for Inertinite
with 'random reflectance' (Ro) greater than 2% (known as the 'Intertinite Benchmark' or IBRo2%). For the bamboo tested, at 500 degrees C, 85% exceeded IBRo2% and for 700 and 900 degrees C, 100%
exceeded IBRo2%. In the 100% IBRo2% scenario, all of the bamboo biochar could permanently remove 'inert' Carbon at a half life of 100+ million years. See my 'Join the Dots' blog for more
information.
The feedstock needs to be locked on to the kiln - for every feedstock and kiln combination, a lab test of biochar tested against the IBRo2% could be undertaken if you're serious about
permanent/inert Carbon Removal. Alternatively, a great research paper or someone's PhD could test more bamboo species in a few different kilns eg. Bamboo trench kiln, the Bamboo Biochar Kiln
proposed here and a Kon-Tiki 'Essential' kiln against the IBRo2%. I would also love to tease out the relationship between phytoliths and Ro of biochar - I bet it's linear but needs to be proven.
A lot of work has already been done in phytoliths, mostly by archeologists and researchers in agriculture such as Dr Jeff Parr. Very little research has been done testing biochar for Ro - or I
can't find it if does exist.
For eg., SiO2 (phytolith) content of bamboo ranges from 65.85 -82.86% (according to different studies that I haven't read). Is there a direct linear relationship between SiO2 content and Ro
of biochar independent of temperature? Bamboos could be used as a test case feedstock, pyrolysing each bamboo species with a given different average SiO2 content in the same pyrolysis conditions
and build a graph - predicting as SiO2 increases, Ro will increase too in a linear fashion, Silicate structures are reflective! If this relationship exists, then could SiO2 content of a feedstock
(not limited to bamboo) be used to predict IBRo2% qualification of biochar (before pyrolysis) at a given theoretical average pyrolysis temperature, moisture content (MC) and kiln type? Machine
Learning could be employed here. Ergo sum, a web app could be coded with variables punched in to predict how many kg of biochar meeting or exceeding the IBRo2% would be produced for: a given
feedstock (with SiO2 content->predicted Ro), moisture content, kiln type, average burn temperature, kiln volume (batch), number of batches (for a batch kiln) or kg of feedstock/hour (for a
continuous kiln) etc.
A 'Charista', with internet access to use the web app, could then work out the optimal combination to maximize the amount of Biochar Inertinite produced given limitations on what plants can
be locally grown (and growing the 'best' ones) and what kiln is affordable and accessible for local construction. The amount of money earned from a Carbon Removal Marketplace (CRM) (various)
could ideally also be calculated in the web app.
There is also 'The Biochar App' in beta testing in Kenya for the X-Prize. Ideally, it would support different kiln types in the future, could also send some money your way if you're producing
bamboo biochar at scale, with a bamboo trench kiln (https://www.warmheartworldwide.org/biochar-training-resources.html), possibly with this kiln, a Kon-Tiki kiln (currently supported) or even a
TLUD oil drum kiln.
Panels will easily fit on a 1165x1165 Oz standard pallet
Permachar
