Eco-Performance Optimization of a CI Engine Fueled with Waste Chicken Fat Biodiesel and 2-EHN Additive Using RSM and Correlation Heatmap Analysis

Department of Mechanical Engineering, Aarupadai Veedu Institute of Technology, Vinayaka Mission’s Research Foundation,Deemed to be University, Tamil Nadu, India

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Published online: 16 April 2026

Abstract

The current study investigates the effect of Engine Load (EL), compression ratio (CR) and cetane attractive EHN additive on the performance and emission properties of a single-cylinder diesel engine operating on a blend of BD20 biodiesel and diesel. An interactive analysis between these parameters on brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), exhaust gas temperature (EGT) and significant emissions such as CO, HC, NOx and smoke opacity was conducted using a Central Compositional Design (CCD) Response Surface Methodology (RSM). Experimental data bring that higher load and compression ratios are knowingly optimistic in combustion efficiency with BTE expanding to 30 per cent in optimal conditions, and BSFC decreasing to 0.25 kg/kWh full load. EGT values rose with load and compression which indicated the enhancing of combustion and the reduction of CO and HC emissions was significantly lower because of the increased oxidation. Under full-load conditions, higher combustion temperatures is the cause for an increase in Nox and smoke emissions. As part of the typical efficiency-emission trade-off; the addition of EHN helped regulate and maintain smoke and Nox levels within acceptable limits. Statistical testing provided the performance of an excellent model with an R2 of over 0.99 and emissions at over 0.97, although experimental and imitating data proved error margins less than 2 percent. The research shows that suitable modification of engine load (EL), compression ratio (CR)and the addition of EHN additive can improve engine efficiency, combustion characteristicsand reduce exhaust emissions, thereby providing valuable insights into the sustainable utilization ofbiodiesel-diesel blends in CI engines.