Conclusion
A natural draft, carbonization reactor with no need for electricity or mechanical power input was successfully developed and operated. Charcoal yields of 33 – 38% were obtained. It can produce good quality charcoal from locally available biomass materials, similar to those produced from traditional charcoal kilns, but the process takes no more than 4 hours, compared to 72 – 84 hours for traditional charcoal kilns. The system proved to perform very well and it may be adopted in place of traditional kilns.