Biochar furnace, 2nd attempt !

Here is my testimony about my second attempt of a biochar furnace
After TLUD and tilted barrel (which works great but time consuming), i planned for a more autonomous furnace
Classic design as TLUD : a closed barrel in a furnace
I get an old gasoil tank, make opening, and barrel support.
Barrel has six 8mm holes in line for gas exhaust

Here are some video of the ROARing machine
The soudn was impressive, gas exhaust burning was frightning !
Got a 400° C on the cheminee top, 450°C on the tank sides, 600°C+ on the barrel



[youtube]https://youtube.com/shorts/Tn_yfUVeYWo[/youtube]



Pros : antonomous, you fired it up, it goes alone!
Cheminee was great sized ! (external metal  sheet from a water heater)

Cons : six 8mm holes were not enough, barrel went surpressed and deformed and leaks on the cover
Tank 2mm tick metal was to weak, got a deformed tank after 2 burns
Temperature wa sway too high to feed the fire (but not a problem, gas exhaust was maintening heating !)

What would i try next steps ?
either brick/motar construction with thicker barrel
or find a strong furnace with suffisant opening

Very cool. Thank you for sharing! I've been thinking about building something similar based on 55 gallon drums, and looks like this design works really well. If anything, it sounds like your setup produced TOO much heat.

I'd like to make something where you can swap out the 55 gallon drum for a fresh one....thinking like a morning burn and an afternoon burn to get two 55 gallon drums worth of material processed in one day. 600 degrees Celsius makes it a bit too hot for a mid-burn swap out, though!

Some setups says that it's a 45min burn
So lot of heat should be the way to go, right ?

Following  my calculations, for a 200m² garden, I need 0.5 cubic meter of biochar
From my observations, one 55 gal full of wood (not organised) reduced by 4
Then, what crushing to 0-5 mm, also reduced by 4

so I need 40 batch to achieve my goal !
so I need an efficient way to do it

I based mine on this version:

https://www.youtube.com/watch?v=YIbGkmt1VdE&t=43s

It works really well for me.   No damage to the metal many years in.

It's a TLUD with chimney.

John S
PDX OR