PYROLYSIS OF AGRO WASTE FOR PRODUCTION OF CHARCOAL BRIQUETTES

Abstract

Wood charcoal has been the primary fuel for cooking in Ethiopia because it is cheap and easily available. However, using wood charcoal has consequences on health and pollution due to smoking. This study aims at providing a biomass as an alternative to wood charcoal using agricultural wastes (cob and sawdust) converted into charcoal briquettes to provide much needed source of cheap fuel that is cleaner in burning. In this project method for carbonizing of charcoal briquette from agricultural waste (cob and saw dust) with locally available material and investigation side product essential charcoal briquette is carried out. The briquette was carbonized from cob and sawdust by employing the combustion steps. During carbonization process the smoke changes its color from dark grey smoke to white yellow a more translucent hue, this color changing is a critical point which implies the ending of combustion of gas and the beginning of combustion of the char. By visual observation we then controlled the combustion of the solid char from turning in to ash. The char is then milled, bind with different agents (starch and rice water) and molded then dried at 105oc for 6hr in an oven. The fuel briquette quality evaluated in a participatory manner in terms of yield, ash content, moisture content, time taken to ignite, time needed to cook and time taken to burn completely to ash. sawdust briquette was received the highest yielding (9%). In terms of smoke realize during burning and cob with binding agent starch and saw dust with binding agent starch briquette has higher quality and has no smoke but sawdust with binding agent rice water briquette does. Therefore, we conclude that using sawdust as a raw material and starch as binding agent is preferable. Investigation on the technical and economic feasibility of the work for briquette production was performed. Results from the feasibility study indicated that the proposed work was feasible with return on investment (ROI) 14% and the payback period of the project is estimated to be 3.2 years.