Performance combustion and emission characteristics of novel biofuel peppermint oil in diesel engine

In this experimental work, the performance, combustion and emission characteristics of a novel peppermint oil blends are evaluated at different load conditions in a direct injection diesel engine without any engine modifications. The peppermint blend proportions are named as P10, P20, P30 and P40 based on the ratio of the peppermint oil in the diesel fuel. Suitability of the selected novel peppermint oil blends is determined based on its physical and chemical properties. The number of experimental trials is conducted at different load conditions; from the results, it is found that Brake thermal efficiency of P20 (31.89%) is comparatively better than conventional diesel fuel at full-load condition. Considering the emission aspects at full-load condition, reduction in smoke emission values was observed for all peppermint blends compared to diesel fuel. The smoke emission values are 51.0, 49.1, 43.6, 41.9 and 52.8 HSU for P10, P20, P30, P40 and diesel, respectively. However, the oxides of nitrogen emission are higher than those of diesel fuel at full-load condition. Through combustion analysis, it was observed that all the peppermint blends exhibit higher ignition delay compared to conventional diesel fuel. From this study, it is evident that the selected novel peppermint oil has meritorious advantages over conventional diesel fuel in terms of performance and emission.