ABSTRACT
The decreasing availability of fuel wood, coupled with the ever rising prices of kerosene and cooking gas in Nigeria draws attention to consider alternative sources of energy for domestic and cottage level industrial use in the country. This research work was conducted to design and construct a low cost briquette machine for rural communities in Nigeria. It involved the modification of the existing CINVA RAM press and evaluation of the products produced. Selected agricultural residues (i.e. rice straw and rice husk), saw dust residue of softwood and a combination of 50% rice husk + 50% saw dust by weight with 30% optimum cassava starch by weight as binder were used to produce briquettes. Performance characteristics were evaluated for the briquettes produced based on average fuel efficiency, burning rate and specific fuel consumption. Calorific value of 16,577KJ/Kg was obtained for rice straw briquette, 14,396KJ/Kg for rice husk briquette, 15,547KJ/Kg for sawdust briquette, 17,529KJ/Kg for 50% rice husk + 50% saw dust briquette and 12,378KJ/Kg for firewood (Parkia biglobosa). The average fuel efficiency, burning rate and specific fuel consumption values of 10.68%, 1.10Kg/hr, 0.3g/g, 22.42%, 0.83Kg/hr, 0.13g/g, 15.40%, 1.03Kg/hr, 0.26g/g, 18.52%, 0.93Kg/hr, 0.16g/g and 12.29%, 1.62Kg/hr, 0.36g/g were obtained for rice straw briquette, rice husk briquette, saw dust briquette, 50% rice husk + 50% saw dust briquette and firewood respectively. Statistical analysis using the least square differences in comparison to each of the fuel samples average performances showed that rice husk briquette had the most outstanding thermal performance.