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 Al(2)O(3)-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 Al(2)O(3)-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. Al(2)O(3)-NPs were synthesized by a sol-gel method and characterized using UV-vis, FTIR spectroscopy, PSA, and XRD. The effect of Al(2)O(3)-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 Al(2)O(3)-NPs (various loading rates) on the engine performance and emission characteristics were also investigated. Addition of Gly-lac and Al(2)O(3)-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 Al(2)O(3)-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 % Al(2)O(3)-NP/3-armed Gly-lac was used as an additive compared to B20.