Marco Banks wrote:I've watched a dozen or more Youtube videos on people's various retorts that they use to create biochar. They work --- most of the wood remains, while the nasty gasses are burned off and charred pieces of wood is left.
My logic leads me to believe that just burning the wood in a conventional fire pit, and then shoveling out the coals and the logs break down would lead to a purer lump of charcoal. Without a retort, the wood would burn hotter and that would lead to a more porous chunk of charcoal, yes? The hotter temperatures (upwards of 2000 or 2100 degrees F) would more quickly cause the wood to gas off any nasty chemicals. While there would probably be more net loss of biomass, the charcoal that remains would be qualitatively better.
I've never built a retort: I just use my fire pit and then I use a shovel to scoop out the coals as the logs disintegrate. It allows me to burn BIG hunks of wood (like tree-trunk rounds). I scoop out the coals and dump them into a water-filled bucket.
tony elder wrote:
I like everything I have learned about bio-char. Right now, I'm having trouble finding 35 gallon barrels for the retort chamber. But I'm not giving up.
Craig Butler wrote:
Thanks for the reminder, Tony. You got me thinking again about the ratio one is looking for between the charcoal and the microbacterial inoculant (and no doubt there's a technical term for that I should learn). Still very early in my research on this, but I was thinking of green manure as that source. However, questions remain as to how much charcoal should one use for one ton of manure, along with how much time does the mix need before it is stable to put in the growing soil? Would aged manure in fact be better, as green would require its own time frame to decompose? I have been thinking of having two operations going on: biochar production, and compost production. Do others combine these processes--using charcoal as a compost pile ingredient--and is that efficient?
Craig Butler wrote:
Quick question to all,
Is there no other advantage to using dry wood in the pit (or retort) other than the fact that it takes longer to expel moisture? Creating biochar in the work stream of clearing land, as I see in this Edible Acres video Edible Acres biochar, seems a good idea.