Performance Evaluation of Rice Bran Oil—Waste Cooking Oil Binary Blend‐Based Biodiesel With Normal Diesel in <scp>CI</scp> Engine

ABSTRACT This research investigates the performance, combustion, and emission characteristics of a novel binary biodiesel blend synthesized from rice bran oil (RBO) and waste cooking oil (WCO), addressing the critical need for sustainable, nonedible second‐generation feedstocks. The primary objective was to evaluate the synergistic effects of combining these two distinct oils through transesterification and magnetic stirring to optimize fuel properties. The study uniquely identifies a 50:50 ratio of WCO to RBO as the optimum precursor for secondary blending with mineral diesel. Experimental results reveal that while biodiesel blends exhibit a slight reduction in Brake Thermal Efficiency (BTE) and an increase in Brake Specific Fuel Consumption (BSFC), specifically a 22.2% increase for the B70 blend, they provide superior safety profiles with flash and fire points significantly exceeding those of conventional diesel. The research demonstrates a substantial environmental benefit: B30 blend (30% biodiesel, 70% diesel) achieved a 23.5% reduction in hydrocarbon (HC) emissions and a 13.6% reduction in carbon monoxide (CO) compared to standard diesel. The uniqueness of this work lies in the strategic binary coupling of a high‐viscosity by‐product (RBO) with a post‐consumer waste (WCO) to achieve a balanced fuel profile that meets international standards without requiring engine modifications.