A proposed biochar steam activation system concept which should be scalable. To be built using the Navigator Stove TLUD mainframe. It will produce biochar while activating biochar -  the biochar produced can then be activated too and produce more biochar in the process. The activated biochar, at the end of it's use cascade, can be added to smaller growing systems to grow plants (unless, say large amounts are available, such as the replacement of activated biochar in a large modular Atmospheric Water Harvesting panel system in areas of high air pollution).

For larger growing systems, more biochar will be needed. Waste biomass can be collected after harvest, dried then used as feedstock in larger kilns, such as the 'Flame Cap 'Algorithm' Panel Kiln', for processing much larger volumes of biomass producing more general purpose biochars which can be added directly back to the field to produce crops eg. sorghum (varieties can grow in semi-arid and arid climates, saline and sodic soils, with saline irrigation - to produce biochar, bread and beer) and more biomass waste.

In both scenarios, circularity/perpetual motion for permanent Carbon sequestration can be achieved...

Why bother with biochar activation?

Higher biochar surface area with more Oxygen binding sites for water (H2O) and other molecules if needed (biochar air and biochar water chemistry).

Suitable biomass
- bamboo
- forestry/agroforestry/orchard waste

- agricultural waste residue, such as straw eg. rice, hemp, sorghum, wheat etc.
- nut shells (ideal)

- more...

Applications

• activated biochar for
• • air filtration
  • water filtration
  • atmospheric water harvesting (AWH) in various form factors, possibly without a hydrogel

Tech specs (base to top):

- 5mm old cast iron BBQ plate as base
- 50L 304 stockpot base for quench water collection, heat shield and wind shield
- Approximately 300mm galvanised chimney flue (if using new flue it will need one burn before getting close to it to avoid toxic fumes)
- Primary and secondary air slots on flue (grinded - to do)
- 25mm x 2mm x 500mm galvanised square tube pieces (2)
- 20L stainless steel bucket
- 304 fabricated fine mesh basket
- unmilled biochar (with air gaps between the pieces for steam) in the basket - ready to activate
- no electronics or moving parts (unpowered solid state)
- no additional chemicals eg.acids

- stockpot and bucket can be repurposed in between burns

USE AT OWN RISK. THIS DESIGN HAS NOT BEEN PROTOTYPED. THIS WILL GET DAMN HOT!!

I will try and design a safer system during prototyping in the next burning season in 2025.

Operation
- standard Navigator TLUD operation, wearing welders gloves from now on...
    - fill up the reactor with biomass to an inch below the secondary air slots
    - add some tinder on top eg. bamboo leaf
    - add some firelighter gel
    - using a long piece of bamboo lit at one end, light the gel with the lit end
    - add the 50cm galvanised square tube pieces to the top
    - place a 20L stainless steel bucket with water and biochar mesh basket inside on top of the square tube pieces
- during the burn
  - top up the water in the bucket before it gets dry (and warps), maybe use a large steel watering can 
- when the flame dies and possibly starts to smoke
    - remove the bucket and basket with the end of a steel landscape rake (which can also be used for landscaping, biochar milling and bushfire preparation), locking the bucket handle onto the end and upward facing tynes, at a safe distance from the flue
    - quench with water from above (mind the hot steam), using a hose at a safe distance, until no more steam
- allow the flue to cool down eg.30mins

-remove the 2 top galv square tube pieces
- lift the tube with 2 x C clamps (still wearing welders gloves) and put it next to the stockpot

- Voila - the biochar will be ready in the stockpot (possibly with a little water spillage)

- stir the biochar into the water to make sure there are no more hot pieces

- siphon off the smoke water into another bucket or large vessel - this can be used for seedling irrigation

- retrieve the biochar OR

- inoculate the biochar directly in the stockpot eg. add liquid sea kelp, microbes, molasses and fungus etc.

    - stir in and allow to soak for 48 hours before combining with composted manure, such as poultry, or even compost, at a ratio of 50:50 for a soil-free growing medium:

    - eg. wicking pots to grow herbs

    - eg2. (wicking) recycled PET/PETE fabric pots to grow dwarf fruit trees

For larger growing systems, Permafert can be made when local soil is available, with a ratio of inoculated biochar: composted manure/compost: soil at 40:40:20

    - eg3. wicking beds, swales, Zai pits or swale/Zai pit hybrid, to grow vegetables, trees, legumes, grains etc.

DONE

NOTES
- the bucket and basket could be overreach since the high temperatures (?Degs C - feedstock and moisture content dependent) of the reactor/flue will increase the surface area of the biochar and water quench will provide some steam activation, with Oxygenation of the surface of the biochar

- microclimates with afternoon shade are key for growing many plants, especially as the climate heats up in most places

- ideally, in the future recycled hemp bioplastics will be used for regular pots and fabric pots

 - cost of the ABS (in Ozzie dollars)
    - $80 for 50L stockpot
    - nothing for the repurposed flue (or $125 or less for a new one)
    - $21 for Galv square tube
    - $45 (or less) for a 20L stainless bucket
    - $27 for the 304 fine mesh panels used in the basket
    - Total: $298 (or less)

- multiple ABS units could be used for larger volumes of biochar

-alternatively, an oil drum using the flue as a chimney (or corrugated iron) could be used with a different TLUD configuration

https://www.warmheartworldwide.org/setting-up-a-backyard-biochar-system.html