Biochar retort kiln best material to use around .
I have decided to go with a "hornito biochar kiln" type of design which is the combination of the rocket stove on the bottom (which I will probably go with Ianto Evan''s design) and the retort kiln on top, which will be used for pyrolysis. With this, should I go with a 55 gallon drum around the heat riser, or should I go with firebricks around the heat riser instead?