Performance, emissions, combustion and injection characteristics of a diesel engine fuelled with canola oil–hazelnut soapstock biodiesel mixture

•The detailed analyses of engine test with the mixing biodiesel were performed.•The short ignition delay is mainly due to the short injection delay of the biodiesel fuels.•The NOx and smoke emissions have trade-off characteristics.•The high blend ratios may not be suitable to operate the engine without modification.

This study investigates performance, emissions, combustion and injection characteristics of a diesel engine fuelled with blends of diesel fuel No. 2 and a mixture of canola oil–hazelnut soapstock biodiesels. The hazelnut soapstock biodiesel was mixed with the canola oil biodiesel to improve some properties of the canola oil biodiesel and to reduce the cost of the fuel. The experiments were performed on a single-cylinder direct injection diesel engine running with No. 2 diesel (D100) and No. 2 diesel/biodiesel blends containing 5% (B5) and 10% (B10) biodiesel fuels. The experimental results showed that the injection and ignition delays and the maximum heat release rates decreased with the biodiesel addition while the injection and combustion durations increased. In addition, it was determined that the oxygen content of B5 enhanced the combustion resulting in increased NOx emission and decreased THC, CO and smoke emissions. However, B10 fuel deteriorated the combustion due to higher density, viscosity and surface tension. Therefore THC, CO and smoke emissions increased while NOx emission decreased. CO2 emissions for both blends were very similar to those of No. 2 diesel.