Experimental study on the micro-explosion characteristics of biodiesel/1-pentanol and biodiesel/ methanol blended droplets

Alcohols and biodiesel are promising alternative biofuels for their excellent physicochemical properties and renewable property. Compared with low-carbon alcohols, high-carbon 1-Pentanol has better fuel characteristics. The objective of the present study was to reveal the effects of different 1-pentanol addition ratios on the micro-explosion characteristics of blended droplets. Single droplet suspension experiment under atmospheric pressure and 700 °C was carried out, and results were compared with that of methanol. The droplet had three initial diameters (1.281, 1.451, and 1.537 mm). The droplet evaporation images were recorded at 500 fps with a resolution of 1024 × 1024 pixels by a high-speed video camera, and the corresponding droplet diameter in the evaporation process was obtained by a MATLAB program. A new dimensionless micro-explosion intensity was proposed. The results showed that when the 1-pentanol volume content was 50% (B50P50), the micro-explosion number and total micro-explosion intensity reached the maximum. With the increase of initial droplet diameter, the micro-explosion number, total micro-explosion intensity and droplet lifetime increased. Compared with biodiesel/1-pentanol blended droplets, biodiesel/methanol ones had better micro-explosion characteristics and shorter droplet lifetime. White fog formed in the evaporation process of blended droplets and pure biodiesel ones. In short, the addition of methanol and 1-pentanol caused micro-explosions, changed the evaporation behavior of biodiesel, and reduced droplet lifetime, which could be considered as an alternative fuel blended with biodiesel.