I normally put charcoal fines in the garden as biochar. In Rwanda our charcoal is all fines from crop waste. With these fines, we make large cooking briquettes 4" round X 3" high. Now I need to make some tiny briquettes to run a gasifier in Rwanda. Today I tried using a sausage stuffer to extrude small diameter charcoal–no go. Then I tried a heavy duty meat grinder with sausage stuffer attachment. Still poor results–the charcoal has to be too wet to extrude. Only makes soft irregular sized “briquettes.” I finally went extremely low tech with a 1/2" rod and a 1/2" pipe.
I used the pipe like a cookie cutter. Pushed down into a 1" thick pile of moist charcoal with 5% binder. Place over nylon window screen (lets water squeeze out easier) on a board and bang the rod in the pipe up and down a few times. Then push out the pellet. Voila, carbonite. Labor intensive, but labor is cheaper than importing gasoline to a remote village in a landlocked country. Now to make enough for a gasifier test run.