Synergistic Effect of Alumina Nanoparticles and 3-Armed Glyceryl Lactate Additives on Biodiesel Cold Flow Properties, IC Engine Performance, and Emission Characteristics

Abstract

The energy demand of future generations cannot be realized by fossil fuel resources due to their exhaustible nature and the largest source of greenhouse gas emissions. Biodiesel is a potential renewable energy that can replace petro-diesel. However, it is required to improve cold flow properties, engine performance, and emission characteristics of biodiesel. In this study, a 3-armed glyceryl lactate bioadditive was used with Al₂O₃-NPs simultaneously to enhance engine performance and reduce emissions. 3-Armed Gly-lac can be used as a cold flow improver, oxygenate additive, and dispersant for Al₂O₃-NPs. It was synthesized from glycerol and lactic acid. The biodiesel used in this study was also synthesized from soybean oil and methanol through a trans-esterification reaction. Al₂O₃-NPs were synthesized by a sol–gel method and characterized using UV–vis, FTIR spectroscopy, PSA, and XRD. The effect of Al₂O₃-NP-dispersed 3-armed Gly-lac on the cloud point (CP) and pour point (PP) of biodiesel was studied. The synergetic effects of Gly-lac and Al₂O₃-NPs (various loading rates) on the engine performance and emission characteristics were also investigated. Addition of Gly-lac and Al₂O₃-NPs (3 wt %) into the biodiesel brought a maximum reduction in the CP and PP by 7 and 9.44 °C, respectively, as compared to pure biodiesel. Similarly, the addition of Gly-lac and Al₂O₃-NPs (3 wt %) into B20 brought a maximum improvement in the brake power and brake thermal efficiency by 0.843 kW and 6.837%, respectively, during full load operation. However, the brake-specific fuel consumption was reduced by 25.26%. Maximum reduction in emissions of unburned HC, NO_x, and CO by 61.20%, 24.42%, and 39.52% were obtained, respectively, when 3 wt % Al₂O₃-NP/3-armed Gly-lac was used as an additive compared to B20.