Performance and emission evaluations in a power generator fuelled with Brazilian diesel and additions of waste frying oil biodiesel

Performance and emission evaluations in a diesel power generator fuelled with Brazilian commercial diesel (petroleum diesel with 5% biodiesel), pure waste frying oil-based biodiesel (B100), and additions in order to obtain 20%, 30%, 50%, 75% biodiesel blends were performed. Biodiesel was produced by two-step alkaline catalyzed transesterification. The pure biodiesel was characterized considering methyl ester content, density and flash point. Blends were analyzed to quantify biodiesel added in petroleum diesel. Electrical performance of the engine-generator group (two-cylinder, 13 kVA) was determined using a resistive load bank, monitoring total power and individual phase power. During the tests, the engine was instrumented using a gas analyzer in the exhaust system. A precision gravimetric balance was used to determine fuel consumption. Best power performances was achieved by B5 and B30, whereas B20 showed the higher thermal efficiency and the lowest fuel consumption as well. Increasing concentrations of CO2 and NOx and decreasing concentrations of CO, NO2, SO2 and CxHy in the flue gases were observed as the amount of methyl ester added to fossil diesel was raised from B5 to B100.