Determination of energy content and heavy metals in briquettes produced from some agricultural wastes
AM Bagudo, Kofa ID, MM Warrah, Senchi DS
The decreasing availability of domestic fuel like wood, charcoal and the ever-rising of kerosene and cooking gas in Nigeria, has drawn the attention to the need to consider alternative sources of energy for domestic use. This research was carried out to analyze some properties of some bio-briquettes (Rice husk, coconut shell, sheanut shell and millet stalk) prepared at moderate pressure and die temperature using a simple extruder briquetting machine. different briquette samples were produced by blending varying percentage of the biomass materials in the ratio of 100:0, 80:20, 70:30,60:40, 50:50,and 0:100. The results of the combustion characteristic revealed that the groundnut shell briquettes has a shorter ignition time (0.8mm/s) and will catch fire easily while the sheanut shell briquettes had the longest ignition time (4.3mm/s). The coconut shell briquettes had the highest after glowtime of 82sec while sheanut shell and millet stalk blend briquettes at ratio 70:30 had the lowest afterglow time of 13 sec. It took the coconut shell briquettes 16 mins to boil two litres of water just like kerosene (control) with the same quantity of water while it took the ground nut shell briquettes 24mins to boil the same quantity of water. The heavy metals analyses revealed that Pb, Ni, Se and Cd were not detected in the ashes of the fuel briquettes hile high values of Fe and Mn were obtained from rice husk and coconut shell briquettes. All values fell below the WHO/FAO and the DPR (2002) target and intervention values. An affordable and efficient source of energy to firewood which is environmentally friendly has been obtained from these agricultural wastes.