I am working with a group of innovators in Oregon called the Umpqua Biochar Education Team. They have come up with some super simple, very productive biochar kilns. The first one is called the "Ring of Fire" - it is a Flame Cap Kiln made with old roofing steel. As you can see, it can handle some large slash type of material. UBET member Don Morrison provided these pictures of his operation using forest slash material. It's probably the cheapest, most efficient small-scale biochar production tech I have seen yet. To make it work, you need to be able to seal the bottom of the kiln, and you need plenty of water for quenching. We are not using these kilns in a forest setting, mainly because it is too hard to seal the bottoms on rough ground. Here are the pictures:
More pictures here:
https://picasaweb.google.com/113563255252052826854/DonMorrison?authuser=0&feat=directlink
