Production, properties, and utilization of degummed/esterified mixed crude palm oil-diesel blends in an automotive engine without preheating

The production, properties, and utilization of degummed/esterified mixed crude palm oil (DgMCPO/EMCPO)-diesel blends in an indirect injection (IDI)-turbocharged automotive engine without preheating were studied. The results revealed that DgMCPO and EMCPO could be produced easily with costs comparable to diesel. Although they had a poor liquid phase and high viscosity, through blending with diesel at maximum portions of 20 vol% (DgMCPO20) and 30 vol% (EMCPO30), clear liquid blends were produced. These blends had better kinematic viscosities (5.25 and 5.85 mm2/s at 40 °C), substantial oxygen contents (6.38 and 7.57 wt%), good cetane numbers (56.8, DgMCPO20 only), and slightly lower heating values than diesel (−3.5% and −3.7%). At 2400 rpm under loads in the range of 5-32.5 kW, the blends were able to operate the tested engine in the same manner as diesel. Their oxygen content promoted easier combustion and resulted in lower emissions of black smoke (−36% and −61%) and carbon monoxide (−25% and −16%) than diesel. Their low heating values caused higher brake specific fuel consumptions (+4.2% and +4.7%) and lower brake thermal efficiencies (−0.5% and −1.0%) than diesel. Their oxygen content and their high mass flow rates resulted in higher emissions of nitrogen oxides (+8.6% and +10.9%) than diesel; (all paired values, DgMCPO20 and EMCPO30 respectively). Therefore, the blends are recommended as effective diesel substitutes for use in automotive engines.