Emerhi, E. A.
The study was undertaken to assess the calorific value of briquettes produced from mixed sawdust of three tropical hardwood species (Afzelia africana, Terminalia superba, Melicia elcelsa) bonded with different binding agents (starch, cow dung and wood ash). Sawdust from each of the species was mixed with the binder in ratio of 70:30 for cow dung and wood ash and 70:15 of starch. The sawdust where mixed in a ratio 50:50 for each briquette combination produced. Combustion related properties namely percentage volatile matter, percentage ash content, percentage fixed carbon and calorific value of the briquettes where determined. All processing variables assessed in this study were not significantly different except for percentage fixed carbon at five percent level of probability. The result shows that briquette produced from sample of Afzelia africana and Terminalia superba combination bonded with starch had the highest calorific value of 33116kcal/kg while briquette produced from sample of Afzelia Africana and Terminalia superba bonded with ash had the least calorific value of 23991kcal/kg. Since the aim of briquetting is to produce briquette that will serve as good source of fuel and support combustion, the best briquette was produced when sawdust was mixed with starch. Also the use of mixed wood residue from the selected species and other hardwood species for briquette production should be encouraged as this will provide an alternative to firewood for household cheap energy source.
