Carbonyls Emission Comparison of a Turbocharged Diesel Engine Fuelled with Diesel, Biodiesel, and Biodiesel-Diesel Blend

In order to characterize the carbonyls emissions from a turbocharged, direct injection, and intercooled compression ignition engine, an experimental study was conducted using diesel, biodiesel, and 20% biodiesel-diesel blend as test fuels. Fourteen carbonyls were identified and quantified from the engine exhaust at four different engine conditions. Experimental results show that formaldehyde and total carbonyls from the test fuels exhibit maximum BSE at low load, which decreases with the increase in load. Carbonyls such as formaldehyde, acetaldehyde, acrolein + acetone, propionaldehyde, crotonaldehyde, and methyl ethyl ketone show higher, but aromatic aldehydes (benzaldehyde and tolualdehyde) reflect lower BSE from B20 and B100 as compared to diesel fuel. Total carbonyls emissions from B20 and B100 are 8% and 32% higher respectively than those from diesel fuel. Formaldehyde is the most abundant carbonyl of the test fuels with 56.5%, 53.9%, and 52.7% contribution to total carbonyls in case of diesel, B20, and B100 respectively. Specific reactivity of carbonyls from the test fuels follow the order as B20 < D < B100.