The purpose of this project was to design a charcoal production oven to be incorporated with a biogas digester to provide a sustainable, continuous source of charcoal for the communities of East Africa. The ultimate objective of the project is to develop a system that will replace the current method of charcoal production, which is one of the causes for the deforestation of the Impenetrable forest. This project is sponsored by Ecolife, a nonprofit organization focused on sustainability, devoted to the protection of valuable biological resources though improvement of the quality of life of communities around the world.
The initial design, the vertical rocket oven, consisted of a reactor created using a burner, steel drum, false bottom, chimney, and fuel source. The reactor was constructed by inserting the burner, which produced a flame from the fuel source, below the steel drum. The false bottom was placed inside the steel drum above the burner to provide full combustion of the fuel before contacting the feedstock. The feedstock in the drum would rise in temperature as the moisture would escape thorough the chimney as dense smoke, due to the hot-cold air gradient. The process would be starved of oxygen after the density of smoke was significantly reduced, in order to initiate the pyrolysis process. Once the drum has been cooled, the feedstock within the drum can be removed and used as charcoal.
A five gallon prototype of the rocket oven design was constructed to observe the chemical and physical characteristics of the charcoal production process first hand. This design was then scaled up to a fifteen gallon prototype with thermocouples installed in order to take temperature data from inside the reactor. From variables such as temperature readings, burn time, and charcoal quality analysis, a process to develop quality charcoal through visual cues was developed. It was determined that an average operation requires about six to eight hours including feedstock collection and cooling time, and would uses five ounces of propane, which converted into biogas (produced by cow dung) is roughly sixteen ounces. For reconstruction and application in the field, an fabrication manual for the rocket oven was developed, and an operation manual to produce quality charcoal was prepared.
In order to further control the air flow of the system, a brick channel design was assembled out of a thirty-five and fifty-five gallon drum. The brick channel prototype is constructed by laying brick foundation below the steel drum consisting of an inlet for the burner, and exhaust holes that circulate air within the reactor before being pulled out through the chimney. Though this prototype is still in a development phase, the easy fabrication and operation suggest that further investigation is believed to produce promising results.