Biochar stove test

After some time of low activity, I decided to get back into action and make again biochar along the Path. So I picked up one of my last wood-gas stoves (designed to stand on a fan, to propel secondary air for the combustion of the fumes) and turn it into the brilliant passive design called Elsa, developed by Carlo Ferrato and Blucomb. You can download a PDF at this link.

 

The outside vessel turned into the combustion chamber... from a piece of garbage metal sheet I made the cone cap and there you go! It's almost done.
The inner aluminum can it's good for the recycling now...

The next day we are at a nice festival and I have the chance to show some wood-gas burns, talk about biochar, what it's good for and how the stove works. Most people know about rocket stoves and the developments of Aprovecho but just a few had and idea of what I was doing.

All the part before assembling.

Cool thing: besides the twigs I collected around the campsite and some used chopstick that I kept for this purpose, we were given some nice walnuts... so perfect timing to turn some shells into biochar! 

Elsa stove replica from scratch materials. 

During the process... hard to catch the flame though!

Still life with biochar... and some half-burn pieces.

Real black gold!

Indeed there was a lot of interest around the stove and many many people stopped by asking me questions, checking it out.
It's the very least you can expect in the land of binchotan, widely available in many forms. I must say that the prototype didn't work perfectly well due to some imprecise cutting and especially due to the fact that I didn't have a net to put on the bottom of the combustion chamber, allowing full flow of primary air from underneath.
Wet fuel doesn't help too... so it ended up in a bit of ashes and quite a lot of thick smoke at some point but c'est la vie but at the end the result was more than satisfactory, considering the very minimal effort and zero expenses I had to make the stove. The 3 cans of biomass yielded 1 can of biochar, so totally in line with the average efficiency and apart for few pieces that were not completely turned into charcoal, all the rest was just perfect! It all went back into the woods, in a sort of small compost toilet pit I made for me and my daughter...
Now I am going to get it straighten up for the next festival and display opportunity, eventually trying to turn it into an open source workshop of radical ecology!