Hey there everybody
For folks who are unfamiliar with us, we’re a small scale plant nursery that follows permaculture and regenerative agriculture principles. We’ve used tons of wood chips over the years and we’re getting ready to receive more over today and tomorrow. What would you like to know?
Have you tried your hand at biochar? I know composting the chips for mulch is high value in a farm operation, but a few tons of biochar can work like a permanent upgrade - improving the soil permanently with one addition - though ongoing permaculture operation continues. I am about to make a biochar cooker out of two steel barrels - inner fuel chamber and outer draft shell. It would probably be more effective with wood scraps than chips though - some air passages through the fuel.
To test it out for myself, I made a miniature version documented at https://github.com/jcadej/TLUD-biochar-reactor (uses a gallon paint can for the fuel chamber. You could test it small and see how it does with wood chips. When I make my bigger version, I will add it to the github project. My rough idea is to cut one barrel down the side and squeeze it smaller and bolt it so it fits inside the other.
We have! We set aside chips to offset our fuel wood usage, and place them in stainless steel serving trays that fit in our wood stove. That’s something we picked up from Sean Dembrosky. I’ve experimented with them in a pit cone style as well but once the coals are raging it’s a good deal of management effort to keep feeding it to prevent it turning to ash. It’s difficult to come across barrels around us apparently, and I’d prefer not to buy them in while I have other options. That said, we do have feelers out for them so fingers crossed I can do some trials like that as well.
I agree that the lack of air space may cause a problem for the pyrolysis in a retort system.