Exhaust emissions from a diesel power generator fuelled by waste cooking oil biodiesel

The exhaust emissions from a diesel power generator operating with waste cooking oil biodiesel blends have been studied. Fuel blends with 25%, 50% and 75% of biodiesel concentration in diesel oil were tested, varying engine load from 0 to 25kW. The original engine settings for diesel oil operation were kept the same during the experiments with the biodiesel blends. The main physical-chemical characteristics of the fuel blends used were measured to help with the analysis of the emission results. The results show that the addition of biodiesel to the fuel increases oxides of nitrogen (NO_X), carbon monoxide (CO) and hydrocarbon (HC) emissions. Carbon dioxide (CO₂) and exhaust gas opacity were also increased with the use of biodiesel. Major increase of NO_X was observed at low loads, while CO and HC were mainly increased at high loads. Using 50% of biodiesel in diesel oil, the average increase of CO₂, CO, HC and NO_X throughout the load range investigated was 8.5%, 20.1%, 23.5% and 4.8%, respectively.