I've experimented with a small TLUD
biochar stove made out of food cans. It worked really well, produced charcoal and cleanly flared off the
wood gas for cooking; it really was impressive.
The problem, though, was that it only produced a little bit of biochar at a time, burned out in about half an hour (TLUDs are batch stoves) and over time the cans will burn out. I'd like to scale up to a bigger size, 20 gallons or so. But I don't have he ability to work metal, and any metal will wear out over time.
Could I cast 'ferro-refractory' cement with refractory cement and metal lath or
chicken wire and rebar? Or would this just implode?
Here is a link for those who do not know what TLUDs are.
https://en.wikipedia.org/wiki/Top-lit_updraft_gasifier