Optimization of performance and emission characteristics of a diesel engine fuelled with a novel MXene nanoparticle-biodiesel blended fuel

Abstract This study presents a comprehensive experimental investigation into the performance and emission characteristics of a single-cylinder diesel engine fuelled with a novel MXene (Ti 3 C 2 ) nanoparticle–biodiesel blended fuel. The primary objective was to explore the influence of four critical input parameters i.e. engine load (LD), compression ratio (CR), nanoparticle concentration (NC), and biodiesel blend ratio (BD) on key engine responses. The experimental matrix was developed using Taguchi’s L 16 orthogonal array, encompassing sixteen unique test conditions to efficiently explore the input space while minimizing the number of trials. Five output responses i.e. brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and emissions of carbon monoxide (CO), unburnt hydrocarbons (HC), and nitrogen oxides (NO x ) were selected for analysis. To address the multi-objective nature of performance and emission trade-offs, a hybrid optimization framework was adopted. The CRITIC (Criteria Importance Through Inter Criteria Correlation) method was utilized to assign objective weights to each output based on both their variability and interdependencies. These weights were integrated into the Weighted Aggregated Sum Product Assessment (WASPAS) method to compute a unified performance index for each experimental run, enabling simultaneous multi-response optimization. Further statistical analyses, including Signal-to-Noise (S/N) ratio and Analysis of Means (ANOM), were employed to identify the optimal combination of input parameters. Analysis of Variance (ANOVA) was conducted to quantify the significance and contribution of each factor on the overall response. The optimal configuration i.e. engine load at 100%, compression ratio at 17:1, nanoparticle concentration at 75 ppm, and a B40 biodiesel blend yielded the most favorable trade-off between performance enhancement and emission reduction. Results demonstrated that all four input parameters significantly influenced the output responses, with the MXene-enhanced biodiesel blend exhibiting superior performance compared to neat diesel. Specifically, the BTE increased notably, while BSFC and emissions of CO, HC, and NO x were substantially reduced. These findings suggest that the incorporation of MXene nanoparticles into biodiesel blends can offer a promising pathway towards cleaner combustion, improved fuel economy, and reduced environmental impact.