The Effect of Blending Ratio on Biodiesel Properties, Emissions and Engine Performance

Abstract

This work presents the effects of biodiesel blending on its properties, emissions, and performance. The rubber seed oil (RSO) and waste cooking oil (WCO)-based biodiesel were prepared using a transesterification method in the presence of a heterogeneous catalyst. Several formulations were derived from two types of biodiesels (RSO and WCO) and tested according to the ASTM D6751 specification for acid value, free fatty acid (FFA), kinematic viscosity, pour point, cloud point, density, and calorific value. For the WCO-based biodiesel, the best blend was WCO B5, with properties closely matching those of petrodiesel. Significantly, the formulations with higher WCO content (e.g., B10 and above) suffered from serious drops (above 8%) in calorific value. In contrast, the RSO diesel blend showed less than 5% drops in calorific value for formulations up to a 20% biodiesel blend (B20). In addition, an indiscernible difference was obtained between the WCO B5, RSO B5, and petrodiesel in terms of engine power, torque, and CO2 emissions, although the RSO B5 did produce less NOx (158 ppm) than both the WCO B5 (390 ppm) and the petrodiesel (220 ppm). The results showed that blending of WCO and RSO with petrodiesel up to 10%, i.e., B10, is practically applicable for diesel cars with power reduction less than 10%.