biochar retort / rocket mass heaters

I've read about various adaptations for the rocket mass heater (such as its use as a water heater); but I haven't seen a discussion of combining a rocket mass heater with a biochar retort.  As the temperature with the barrel is certainly sufficient to pyrolzye wood, I was wondering whether an enclosed chamber of wood, either on top of the barrel or surrounding the barrel could be used as biochar retort. Naturally the enclosed wood chamber would require a vent/tubing outlet for the syngas/hydrocarbons/CO/H2O generated - which might theoretically either be fed back into the burn chamber or be used separately to heat water. I don't know if the heat of the pyrolyzing wood would impact the efficiency of the rocket mass heater, and wondering if anyone has had experience with this or tested designs to accomplish it.

It seems as if this might be a way of increasing the thermal output while producing biochar. Or this idea is stupid... and should be considered as my candidate for stupid the post of the month award.


If it's been discussed, and I lack the basic search skills that should be required to use the internet, my apologizes..... I am genetically stupid

Larry

It's been mentioned quite a number of times in this forum, but there is only one real discussion I know of, in the "similar threads" below: https://permies.com/t/17045/Rocket-stove-gasifier-biochar
(That's curious, after I posted this comment, the thread no longer appeared in similar threads... is it there after this edit?)
(I used my gardener powers and put several more relevant threads in the "similar threads" section.)

Even that did not go into more technical detail or real-world examples than you just described.

Thanks Glenn, I didn't find it when I searched.

I have been trying to figure out an easy way to do this.  I attached my very crude picture (not to scale) that shows my idea.  The part below the red line is what I have existing.  Just a j-tube with an insulated chimney.  I haven't figured out yet where I want to put the vent holes in the smaller top inner barrel.

Check out Jame Hookway's retort:

That's excellent.  It looks like exactly what I'm looking for, and even easier than my thoughts on how to do it.  From the video, it appears that he is just running a pipe from the wood-filled barrel back to the burn tube.  I think I could adapt what I have now to that pretty easily.  I love the idea of having no loss of wood, and that the burn stops by itself when the charcoal is complete.  My biochar experiments kind of fell to the wayside with the other things I am working on.  This may bring them back to the forefront in time for this year's gardening season.  Thanks for posting it.