Sustainable fuel potential of beeswax pyrolytic oil in a variable compression engine: Experimental investigation and correlation development

Abstract

This research intends to investigate the sustainability of biomass as a prospective resource of alternate energy to fossil fuels due to its biodegradability, non-toxicity, and renewability in nature. Bio-oil from beeswax was extracted through thermal pyrolysis at 450ºC in a semi-batch reactor and the fuel properties were found appreciable in comparison to diesel. The beeswax pyrolysis oil (BX) was blended in different proportions with diesel,and its applicability has been tested in a diesel engine. The significance of different beeswax oil-diesel mixtures and compression ratioson performance and emission characteristics in a variable compression ratio (VCR) diesel engine was studied. Tests were conducted with 16, 17, and 18 as compression ratios and using diesel, BX10, BX20, BX30, and BX40 as fuel mixtures, respectively, at full load conditions. Theenergy, exergy, and emission study revealed that the BX20 showed the highest energy efficiency of 25.65 % and the lowest brake-specific fuel consumption of 0.33 kg/kWh at maximum engine load andcompression ratio of 18among all fuel mixtures other than diesel fuel. However, BX20 showed higher exergy efficiency by 3.4 % at the same engine conditionsas those of diesel. The maximum decrease in CO emission was found for BX40 by 9.3 % compared to that of diesel and other fuel mixtures at maximum load and compression ratio. Theemissions like HC and NO_x were found to lowest values of 24 ppm and 163 ppm for BX 20 at maximum loading and compression ratio. The overall engine performance and emission results recommended BX20as a promisingoption as an alternative to fossil fuels.Additionally, the correlations, which were developed for more general usage, supported the viability of BX20 as a superior alternative fuel.