An Evaluation of the Extraction Yield, Properties and Performance of Some Biodiesel in a Diesel Engine with Emission Patten

Biodiesel has emerged as a fuel source with the potential to reduce harmful emission, enhance energy sustainability and, more importantly for sub-Saharan Africa, reduce energy dependency and income inequality. Biodiesel derived from Jatropha, Moringa and restaurant waste oil in addition to meeting the aforementioned goals, has the potential to utilize the continents vast margin land, enhance food beneficiation and take some pressure off waste management occasioned by rapid urbanization. Jatropha and Moringa oil were extracted from sample seeds using normal hexane, petroleum ether and distilled gasoline (with soxhlet and soaking method). A series of physio-chemical properties were determined. Subsequent to which biodiesel were produced from the oil samples using potassium methoxide. The resulting fuel components were tested to meet ASME standard. 20% biodiesel/diesel blends were prepared and ran on a four stroke, single cylinder internal combustion diesel engine for each of the fuel. Normal diesel was also tested for comparative analysis. Result obtained for the extraction using soxhlet method yielded 37.1%, 24.3% and 40.2% wt/wt. for n-hexane, pet-ether and distilled gasoline respectively. For Jatopha, the yield was 51.8%, 25.3% and 34.1% wt/wt in the same order. Engine performance for the various blend for corresponding specific fuel consumption gave a slightly reduce specific brake power when compared with diesel but, the emission data speaks in favour of the biodiesel blends. For Carbon-Monoxide emission, a high of 0.82% was recorded at 4350 rpm with n-diesel while the highest for any of the blends was 0.02%. Oxygen in exhaust gas for n-diesel was within the range of 13-16% but, for the blends, it was 16-18% (recorded atmospheric oxygen was 20.9%). The NOX data was temperature dependant with the oil sump temperature giving a better direct correlation than the exhaust gas temperature. A high of 417ppm at sump temperature of 95.3°C for n-diesel and a low of 211ppm at sump temperature of 87°C for Jatropher. Clearly, mid-size seed oil extraction using readily available gasoline is feasible. Also, biodiesel blends broadly produced acceptable performance at a reduced harmful emission level when compared to conventional diesel.