Preparation of charcoal briquette from palm kernel shells: case study in Ghana

Abstract

In Ghana, the potential of palm kernel shells as renewable energy in charcoal production has not been exploited adequately. Using a low-cost instrument (kiln and compressor box) built from local resources, we produced charcoal briquette from palm kernel (Elaeis guineensis) shells. Further, we measured and compared its efficiency using starch as a binder to traditional charcoal and commonly used fuelwood (Acacia) in Cape Coast. Following the American Standards for Testing and Materials (ASTM), the proximate analysis was conducted for all fuels with results indicating that palm kernel shell (PKS) briquette produced had a moisture content of 1.08 %, as compared to 9.25 % in charcoal and 16.00 % in fuelwood. The volatile matter, ash content and fixed carbon recorded were 71.80 %, 0.06 %, and 27.07 % in PKS briquette, 86.00 %, 0.78 %, and 3.97 % in charcoal and 80.50 %, 2.04 %, 1.46 % in fuelwood respectively. The calorific values for charred PKS increased after binding to form the PKS briquette with the highest value among the other fuels. The calorific value for the other fuels were 17.5 MJ/kg for charcoal, 18.72 MJ/kg for charred PKS, and 18.72 MJ/kg for PKS briquette. We also conducted an ignition test, combustion test, fuel burning rate (FBR), and specific fuel consumption (SFC) on PKS briquette and charcoal to determine their suitability as cooking fuels. Charcoal readily ignited as compared to PKS briquette with respective fuel mass of 5.08 g and 25.5 g. The resultant briquette possesses desirable combustion characteristics such as no smoke emissions and ash formation. The FBR and SFC in PKS briquette recorded the highest in comparison with charcoal. The values recorded were 2.84 g/min and 20.05 g/ml respectively while that of charcoal was 0.42 g/min and 3.48 g/ml respectively. PKS briquette produced from this study showed high calorific value, low moisture content, and a fast burning rate amongst other excellent properties. These properties are potential indicators that the proper utilization and production of PKS briquette as renewable energy in Ghana would contribute to solving the existing energy crisis. Additionally, reduce climate change impacts, via the reduction in the over-dependence on fuelwood and charcoal for domestic and commercial heating.