Multi-criteria decision-making framework for selection of surfactant-free microemulsion fuels as a sustainable diesel alternative

Abstract

In this work, multi-criteria decision-making (MCDM) framework is proposed for selection of surfactant-free microemulsion fuel. Based on performance and emission characteristics, different beneficial and non-beneficial criteria were measured for 16 fuel samples across different engine loads. AHP method was implemented to obtain criteria weights, which were incorporated into three different MCDM methods i.e., AHP-VIKOR, AHP-TOPSIS, and AHP-PROMETHEE to rank all fuels. Results obtained from the proposed framework showed that microemulsion fuels with 20-40% diesel replacement were better alternatives to diesel. The Spearman rank correlation method was used to obtain correlation coefficients across rankings from different MCDM methods. These coefficients were used to combine the rankings to select a better fuel alternate. Microemulsion fuel with 20% diesel replacement was found to perform better compared to other alternatives owing to their lower BSFC and higher BTE at all loading conditions. Diesel was ranked last indicating microemulsions to be a sustainable fuel alternative.