We had the pleasure of hosting Dr. Jeff Licht from UMass Boston this week. On Wednesday, he brought up a station wagon full of cardboard to burn in our retort. He has been running experiments on a much smaller scale and was interested in seeing how his results compared with a larger burn. After clearing the previous day's snow off of the retort, we weighed and loaded all of the cardboard. Then we added three "coupons" (small metal-screen-wrapped samples)--one with cardboard, one with red oak, and one with chipboard. Finally, we topped off the load with a small layer of our mixed hardwood that we normally run, in order to diversify the load and smooth out the burn. We did the burn on Wednesday during a little snowstorm, and Jeff came back today for the unload.
Preliminary indications seemed better than he anticipated. Initial weighing showed more than twice as much biochar from the cardboard as he expected. Visually, the char looked to be of high quality too. We won't know for sure until after the lab analysis. Additionally, it looked like we were able to recover more heat than Jeff expected. Let's hope the analysis proves out these promising initial observations.
If it turns out that cardboard can be turned into a reasonable amount of high quality biochar, it would be a boon to people that don't have access to other feedstocks. Cardboard is available virtually everywhere as castoffs. Recycling it into biochar seems much more productive than merely recycling it, let alone just throwing into the trash. We've used cardboard as mulch before, but I think biochar would be an even better use.
We learned a lot from Jeff, but what I liked the most was his attitude toward proving out everything via rigorous experimentation. He said that much of what is espoused about biochar hasn't really been proven, just a lot of anecdotal information and theorizing. That's too bad, because as good as biochar is for crops and the environment, there's no need to embellish it. Reminds me of a saying in business, "under-sell and over-deliver", rather than the other way around.
We enjoyed working with Jeff and being of assistance in his research. Everything I mentioned in the previous post about the "Biochar Community" has been reconfirmed. Steve