Abstract
The introduction of emulsion fuels has attenuated the problem of emissions from diesel engines without any engine modification. Emulsion fuel provides improved combustion characteristics with comparable or slightly reduced engine performance. This study presents a critical review of the research conducted on emulsion fuel technology concentrating on emulsion formulation techniques, emulsion stability, and its implications on engine performance and engine emissions. It is observed from the literature that the mixing process affects the particle size of the emulsion, which in turn influences emulsion stability. The presence of a polar solvent induces secondary atomization, which stimulates the micro-explosion phenomenon, increasing combustion efficiency. However, the decrease in combustion temperature with the addition of polar solvent limits its concentration. In addition, the accumulation of polar solvent reduces emissions, but it can have an adverse effect on the combustion phenomenon. The exergy analysis of emulsion fuel use in engines reveals opportunities for enhanced exergy efficiency. Appropriate selection of fuel components tends to improve exergetic efficiency. Future research on emulsion fuel can focus on improved fuel formulation technologies, engine endurance studies, and the long-term effect of the micro explosion phenomenon.
Disclosure statement
The authors report there are no competing interests to declare.