This sure looks good to me. So simple - a well-insulated container, a clean afterburner, a small water tank for quenching, a light-duty loader for materials handling, and an engine for hauling the container. No feedstock processing other than cutting to length. The standard practice here in Oregon for fuel load reduction treatments is open piling and burning. The cost difference between that practice and this process would be in the capital equipment and cost to haul it to the site, yarding or forwarding the logs to the landing and loading them into the kiln. The cut to length is essentially the same.
The biggest cost difference is this: it takes a lot more time to process the material into biochar than to run around and light several hundred piles that all burn at once.
But the benefits are: eliminates smoke pollution (including climate killing black carbon), the biochar product (sells for $200 - $300 a cu yd), and the carbon sequestration benefit. In Australia, the climate benefits are starting to be worth money. This should work.
Oh, and one more benefit that rarely gets mentioned. This will CREATE JOBS! Green jobs are real and very much needed. We are not meant to just sit around on our butts all day surfing the Internet and watching TV while the world burns. We are meant to do something about it.