Investigation of briquettes properties made from hand operated machine

Population and economic activities increase in the society result in high demand for primary energy especially for cooking which is a major use of energy in developing countries. In these countries the biomass energy in terms of wood and charcoal fuel is the only source of energy for cooking and heating that can accessed by most people. The high demand of fuel lead to the utilization of agro and forest wastes as source of fuel through briquetting processes which increase energy to volume ratio. In this study saw dust briquette made by Mkombozi group in Lushoto were analyzed. The method used to analyze properties of briquettes involves the Bomb Calorimeter test, Water Boiling Test (WBT), Friability test and Moisture Content (MC) test. The briquettes tested are categorized into two groups which are high MC and low MC briquettes with average MC of 29% (wb) and 12% (wb), respectively. The Bomb Calorimeter test result showed that calorific value of dry briquette material is 15 MJ/kg. Friability test showed that the briquette with High MC has Impact to Resistance Index (IRI) range from 55 to 71 while the IRI of the briquettes with low MC is between 80 and 160. Combustion analysis showed that both briquettes emit more CO than CO2. The CO emitted was between 150 to 300 ppm while CO2 were less than 100 ppm. The study concludes that MC affects the mechanical resistance which can result into breakages during transportation and handling. Also the shape and size of briquettes from Lushoto are not suitable for cooking in the household stove (charcoal stove).