Effects of Waste Cooking Oil Biodiesel Use on Engine Fuel Consumption and Emissions: a Study on the Impact on Oxidation Catalyst and Particulate Filter

The wide use of biodiesel has been driven by its reduction potential on greenhouse emissions from diesel engines without significant technological modifications. In this study a diesel engine for non-road applications has been fuelled with Waste Cooking Oil biodiesel blended with commercial fossil fuel at 6% and 30% v/v. In line with literature trends, experimental results indicate a significant reduction of PM emissions and only a slight increase in NOx emissions. This study has been focused on diesel emissions and in particular on the analysis of PM/NO2 ratio in presence of the Diesel Oxidation Catalyst (DOC). In fact, although the NO2/NOx ratio on raw exhaust is almost unaffected, the use of biodiesel shows a slight reduction of the NO-NO2 light-off temperature. This reduction can ensure more favorable operating conditions for the Diesel Particulate Filter (DPF), and has a positive effect on fuel consumption reduction. In order to deeply analyze these issues, a numerical model of an Aftertreatment system (AS) representing the a DOC and a DPF has been developed and validated with experimental data.