Martijn Jager

It was Dutch soil scientist Wim Sombroek who rediscovered Terra Preta, not Johannes Lehman

Below is a webinar I did for the Mycelium Network in which I take you on nearly a decade long journey of biochar making and stove development.
I go over what works and more importantly what doesn't work so you don't have to waste your valuable time with inefficient biochar production methods.

My wood vinegar production is not covered in this video as I'm still refining my methodology.



If you find this useful then please leave a like and or comment on youtube to help me grow my channel.

Chars,
Martijn

Yes this works but like Douglas already mentioned is quite laborious and somewhat risky.
If you do go ahead with this make sure to screen your sand beforehand so you can also screen it out of your biochar afterwards.

And make sure everything has cooled down or it will reignite!

William Bronson wrote:Stacking charcal making with space heating is one of my man obsessions.
Distilling tars/oils/resins/vinegar  from wood is very doable at the homestead scale.
I'd be  concerned that some of the condensates wll be toxic.

Here's a video of a technique that produces high quality charcoal and condensate:
https://youtu.be/fTOHBrFuh68?si=1ZEUuKoUja4tPCPI

This method heats the charcoal feedstock directly with the combustion gasses of the wood fire

Like most of the methods we see, the wood fire that provides the heat for the pyrolysis is relatively dirty and inefficient.

Firing retort/still with a tlud,rocket stove or even a properly managed modern conventional woodstove could be an improvement.
I've favored using a tlud, despite the fuel prep needed ,because they can burn for a long time without tending,  and they are dead simple to make.
A recent thread made me realize that a charcoal making retort heated by a charcoal fire would do the same, with less labor, and the same equipment.

That is exactly what I am doing to make my wood vinegar, I fire my retort with a 20 liter TLUD gasifier using stove pellets for maximum energy density and fire duration.

Check out MadeofAustralia, they make pottery in what is essentially a retort (they call them saggars), a box made from what I suspect is insulated firebrick.

The ceramics is places in the box and then the gaps are filled with vermiculite and biomass, the biomass is there to leave it's mark on the ceramics and after the burn it has turned to biochar. Their kiln is fired with gas and the retort takes multiple days to cool down.

Plans are now available for €13.99 from my website
Http://www.carbonconsciouscreations.com

Very interesting thread and I'll read it more thoroughly later.

What I can say is that ceramics tend to need a slow heating and cooling down cycle.

My retort tends to heat up super fast.

As for temperatures, inside my flame cap kilns I'm reaching close to 1000°C
The temperature inside my TLUD is around 750-850°C and my retort was reaching about 850-900°C

With pottery it's not only about the temperature reached but also the time it stays at that temperature.

Use a TLUD gasifier but instead of quenching allow things tk burn down to ashes, I've seen what I suspect to be potassium salts (greenish and pink) when I did this using carob pods as feedstock.

Justin Vink wrote:Very interesting. What is the length of time on the burn?

Burn time varies between 2h20m and 2h45m dependjng on atmospheric conditions

Fuel consistency is a key factor in success with TLUDs. My personal favourite is stove pellets due to their high energy density.

I use my TLUD stoves, which all have forced air, to cook on and as the heat source for my retorts.