They say no smoke, but there is some small bit. Still, far less than other ways. I’m going to make one of these from small cans as a test case.
And I’m having a “Damn It” moment as I just tossed a dozen #10 (about a gallon) cans a few weeks ago when cleaning the garage and dumping expired emergency food… OK, I have more I can use… Another “Damn it” is that I moved about a pickup bed load of dry aged bamboo to street pickup in the last couple of weeks. Here these folks are turning it into useful charcoal, and I cut it to chunks and tossed it. OK, I have about 2 wheelbarrows more left. Enough.
About 30 years ago I had a fire engine roll on my house. Why? I was burning some yard waste in the back yard. Absolutely normal where I grew up 200 miles away. A crime here. As I was clueful, compliant, and had a hose visible at the site, I was just given a tongue waggle. Still, any backyard fire MUST have food present to be BBQ or you get abused. OK…. For the next several years, a wide variety of yard waste, old fencing, etc. was used in the big brick BBQ as a plate of cheapest hotdogs sat next to it (and the dog sat next to that…, waiting…)
So a method of making charcoal with minimal smoke has my attention! Especially if small batch works as well.
The basic method is a wood burn box with great air flow from the bottom. Fire lit at the top to slowly burn down. An air gap at the top of this burn barrel to inject lots of air, then a secondary burn chamber on top to reburn the smoke. Once all the volatiles burn off, seal the bottom barrel to extinguish the fire and let it cool. Pretty simple, really. But insightful.
I also found the creative use of simple tools instructive.