INDOOR biochar producing TLUD stoves!

[martijnmacaopino]

Hi there all, this is my first post so a bit of an introduction as well,
I'm Martijn and live in the South of Portugal so there isn't a huge need for heating except a bit in winter but even without heating you wouldn't freeze to death.

I started my journey with a simple J-tube stove from bricks outside and soon after that learned about biochar and got obsessed by that and tried various stove types and designs and quickly concluded that TLUD (Top Lit Up Draft) stoves were the most practical and efficient way of producing biochar since all the biomass is turned into char and there is no need for secondary fuel to char a primairy sourse of biomass as is needed with retort systems.

Making biochar this way is great but not using any of the heat seems like a huge waste. So at first I made a simple outdoor cookstove but that just didn't satisfy me and I decided to take the TLUD concept indoors.

Inspired by rocket mass heaters I tried combining the two but woodgas just doesn't burn as hot as burning wood down to ashes so in terms of actually heating my house it was a bit of a bust. I can cook a nice pizza on top of the hotplate thought with a ceramic dome placed over it.




This first stove lacking sufficient direct radiant heat made me decide to build a second stove but this time out of metal and it does an amazing job of heating my house.




There is still plenty of room for improvement though and my next build will use the stainless steel fuel cylinder from the first stove because its bigger yet easier to handle than the smaller steel cylinder from the second stove. The next build will also have a flat door because this will make it much easier to actually close it properly and will give space to the handles of the fuel cylinder.

I'm also thinking to connect it to a thermal bench (bell principle) and hook it up to a hot water system as well.

I have been thinking long and hard about combining true rocket stoves with biochar production but have come to the conclusion that unfortunately it just isn't viable.
Nonetheless I do hope to build a proper rocket mass heater in the near future as well because I love the concept.

[drooster]

Love it, nice design.
What would it be like with a longer insulated riser without changing anything else?

[martijnmacaopino]

Thanks drooster, no idea to be honest. Currently the risers on both stoves are not insulated but I do plan to wrap the riser of the cob stove in some ceramic fiber blanket soon to hopefully get a bit more heat on the hotplate (while not making things so hot that it will destroy the riser). With the metal stove I might do that as well but to get proper acces to the riser again I need to make the hole for the hotplate a bit larger (one of those things that would be improved upon in a new build), something I planned on doing anyway and replace the hotplate with a larger one as well but I need to find me a small sewer lid first. A downside here is that the riser would actually have to be shortened.

If you want to do any cooking on stoves like this a longer riser would make things a bit unpractical.

[briancady413]

This is interesting; Thank you, Martijn, I wonder if a TLUD canister like you use could work well with a smoke-burning ceramic bell above it, to produce char and some heat. I'm thinking of heating a cabin with such a system, in western Massachusetts, USA.