There's a bit of a buzz in the biochar community over these type of cone kilns (TFOD) and 'Moxham' kilns. Backyard biochar has led the way on this... http://backyardbiochar.net/
Although not stated, I think this video has been put together by Hans-Peter Schmidt at the Ithaka Institute in Switzerland during a recent visit by Paul Taylor.
This type of simple, low cost, versatile and relatively clean biochar production may be the way forward for many home biochar production scenarios. It looks particularly suitable for unprocessed woody biomass. It may even offer a better solution than 200L TLUD's for my suggested haze reduction project.
I will be visiting the Ithaka Institute later this month and hope to progress biochar plantation trials later in the year. The plantation companies will want to see some economic validation for biochar before there is any investment in biochar production or large scale support for developing plantation biomass to biochar projects.