Engine testing of RME additives

Reducing the emission of pollutants emitted from motor vehicles, and now also in greenhouse gas emissions, is a result of European Union policy. Vehicle design changes are just one way of reducing emissions of harmful substances and greenhouse gases. The second way is to change the type of fuel, by which the vehicle's engine is powered, that is the substitution of conventional fossil fuels derived from crude oil, such as gasoline or diesel fuel by so-called renewable fuels, for which the CO2 emissions are measured not only in the engine exhaust system, but also by analysis "from the source to the wheel" WTW (Well-to-wheel) - is much smaller. As part of this task the Directive 2009/28/EC introduced for all Member States to the use of renewable energy, biofuels, alternative fuels to a certain extent share of the energy and conventional fuel by 2020. This paper presents the results of measurements of emissions on the dynamometer with a diesel engine powered by six kinds of mixtures of diesel oil and rapeseed oil methyl ester (RME) – with esters containing 0 (clean diesel), 20, 40, 60, 80 and 100 (pure rapeseed oil methyl esters)% in the fuel. We analysed the reasons for the impact of changes in fuel composition on selected limited exhaust components. We found, that the addition of esters of rapeseed oil to the diesel fuel can be a reason of reducing the emissions of CO, CO2, and THC in the exhaust gases of tested engine and increased emissions of NOx and PM.