Performance and emission characteristics of diesel engine fuelled with ethanol-diesel-biodiesel blend.

The article presents comparative bench testing results of a four stroke, four cylinder, direct injection, unmodified, naturally aspirated diesel engine operating on baseline (DF) arctic class 2 diesel fuel (80 vol %), rapeseed methyl ester (5 vol %) and anhydrous (200 proof) ethanol (15 vol %) blend (B5E15). The purpose of the research is to investigate the effect of simultaneous ethanol and RME addition into diesel fuel on brake mean effective pressure ( bmep ) of the engine, its brake specific fuel consumption ( bsfc ), the brake thermal efficiency (�e) and emission composition changes, including NO, NO 2, NO x, CO, CO 2, HC and smoke opacity of the exhausts. The bsfc of a fully loaded engine operating on ethanol-diesel-biodiesel blend B5E15 under bmep = 0.75, 0.76 and 0.68 MPa is higher by 10.30 %, 10.71 % and 9.65 % because of both net heating value of biofuel lower by 6.18 % comparing with diesel fuel and brake thermal efficiency lower by 5.56 %, 2.86 % and 2.86 % relative to that of neat diesel fuel at corresponding 1400, 1800 and 2200 min -1 speeds. The maximum NO x emissions emanating from blend B5E15 are lower by 13.4 %, 18.0 % and 12.5 % and smoke opacity is diminished by 13.2 %, 1.5 % and 2.7 % throughout a whole speed range relative to their values measured from neat diesel fuel. As a reasonable payoff for NO x related advantages, CO amounts from oxygenated blend BE15 are lower by 6.0 % for low 1400 min -1 speed and they are bigger by 20.1 % and 28.2 % for a higher 1800 and 2200 min -1 speeds and emissions of HC are higher by 35.1 %, 25.5 % and 34.9 % relative to that measured from neat diesel fuel at corresponding 1400, 1800 and 2200 min -1 speeds. In the case of operating on blend B5E15 residual oxygen O 2 content in the exhaust manifold is lower by 5.0 %, 7.4 % and 4.3 % and carbon dioxide CO 2 emissions are higher by 2.8 %, 3.4 % and 2.4 % relative to that obtained from diesel fuel at speeds of 1400, 1800 and 2200 min -1 .