Evaluation of the Fuel Value Indices of Selected Wood fuel Species Used in Nigeria

Abstract

This study evaluates the fuel value indices of selected wood fuel species in Nigeria, focusing on the hardwood Iroko (Milicia excelsa) and softwood Obeche (Triplochiton scleroxcylon). Proximate and ultimate analyses were conducted on 2kg samples of sawdust (Biomass) from each species to determine their moisture content, ash content, and calorific value, bulk density, the percentage quantity of composition of Carbon (C), Oxygen (O), Hydrogen (H), Nitrogen (N) and Sulphur (S) respectively. The threshold values for high fuel indices were set as follows: calorific value ≥19.5 kg/m², ash content <1.5%, moisture content <25%, bulk density ≥320 kg/m³, carbon content ≤48%, sulfur ≤0.15%, nitrogen ≤0.8%, hydrogen ≥6.0%, and oxygen ≤40%. The proximate analysis showed that the calorific values of Milicia excelsa and Triplochiton scleroxcylon were 94.9 and 10.9 kg/m², Ash content was 3.3% and 6.1%,with moisture contents of 6.0% and 6.7%, respectively. Bulk densities were 17.8 and 16.2 kg/m³. The ultimate analysis revealed their carbon content of 33.2% and 29.6%, sulfur content of 0.08% and 0.12%, nitrogen content of 0.57% and 0.65%, hydrogen content of 3.1% and 2.78%, and oxygen content of 24.1% and 22.7%, respectively. These results indicate that both hardwood and softwood species possess favorable fuel indices, suggesting they can contribute to a cleaner environment if used sustainably. The study helps enhance understanding of the suitability and efficiency of different wood fuel species in Nigeria, providing insights for better fuelwood management and utilization strategies. The research recommends using this methodology to study more wood biomass species.

Keywords; Biomass; Wood fuel; Climate change; Fuel indices