Phase I: Prototype
Step 3: Make a 5″-8″ perforation on the drum lid to let the smoke out for possible collection and conversion to energy.
Step 4: Make your chimney with the metal sheet, making small incisions among the sides of the edges with the nail and hammer, then begin rolling the sheet into the desired size ( depending on the size of the lid perforation). To hold the chimney in place, have several rocks ready.
Step 7: Ignite fire; once the flames have charred the entire top portion, then you may put the lid on, followed by the chimney.
Step 8: Let it burn, the time it takes depends on how dry the plant material is. A possible indicator to look for is a change in smoke color from white to black. Or you can also track the movement of the flames by splashing water onto the outside of the barrel. This will allow you to see where the flames are.
Step 9: Once the fire has ceased, and the flames have reached the bottom of the drum, remove the chimney and rocks to suffocate any small flames that might still be active. This will prevent the plant material from burning completely and generating ash. Let the drum cool down. You can accelerate this process by adding water to the surrounding barrel and to the biochar itself.