Improving traditional charcoal production system for sustainable charcoal income and environmental benefits in highlands of Ethiopia

Charcoal production from Acacia decurrens has shown considerable advantages for enhancing livelihoods and boosting government revenue in Ethiopia. However, the current reliance on unsustainable traditional Earth mound kilns diminishes these benefits, causing reduced charcoal income and notable environmental damage. Therefore, there is a pressing need to improve the traditional charcoal production system. The objectives of this study were evaluating different improved charcoal production approaches on charcoal conversion efficiency, financial profitability, and gas emission reduction potential compared to traditional charcoal making in the Fagta lokoma district, Ethiopia. Charcoal was produced from Acacia decurrens small-scale plantation, using improved kilns (Green mad retort, MRV portable steel, Casamance) and traditional Earth mound kilns, with three replications of production. Statistical analysis revealed a significant increase in charcoal conversion efficiency (at P ≤ 0.001), with the MRV steel kiln exhibiting the highest efficiency (41.57%), followed by the Green mad retort (36.14%) and Casamance (34.07%). Conversely, the traditional Earth mound kilns displayed the lowest conversion efficiency (24%). The findings demonstrated that improved charcoal-making kilns enhanced wood-to-charcoal conversion efficiency by 41–72% compared to traditional kilns. Moreover, the study reveals a significant increase in average charcoal income per hectare (at P ≤ 0.001), with higher earnings (284,824.4 ETB) at MRV steel kiln, and lower-income (71,580 ETB) at traditional Earth mound kilns. Improved charcoal-making kilns significantly (P ≤ 0.001) reduced harmful gas emissions compared to the traditional Earth mound method. Reduction percentages were substantial for various gases: CO(2) (46–57.9%), CO (29.4–56.6%), NO (61.7–86.1%), NO(x) (56.6–86.2%), SO(2) (41–62.8%), and CH(4) (35.7–57%). In coclusion, the improved kiln technology has substantially enhanced the efficiency of charcoal conversion, resulting in beneficial effects through emissions reduction. To champion sustainability and cultivate positive socio-economic outcomes, it is imperative to extensively adopt these eco-friendly kilns in areas where charcoal production is prominent.