Spray evaporation characteristics of isopropanol-butanol-ethanol (IBE)/diesel blends in a constant volume chamber

As an intermediate fermentation product of butanol, isopropanol-butanol-ethanol (IBE) can be used as an alternative fuel for diesel directly to reduce the separation and purification costs during the butanol fermentation process. However, how the properties of IBE affect the spray evaporation characteristics of diesel is rarely studied. In this regard, IBE was blended into diesel at various volumetric ratios and then tested in a constant volume chamber using Mie scattering method. The experimental results show that after blending IBE into diesel, the spray evaporation characteristics improve noticeably. The more IBE blended into diesel, the shorter liquid spray penetration and smaller spray area are. However, the reduction of the liquid spray penetration and spray area are not linear, they exhibit a huge drop when the IBE to diesel ratio increases from 60% to 80% in volume. With more IBE blended into diesel, the time for the spray to reach the stable stage decreases. Results also show that the ambient temperature has great effects on both the spray evaporation of pure diesel and IBE/diesel blends. As the ambient temperature rises, their spray jets become smaller, and the corresponding liquid spray penetration become shorter. That means elevate the ambient temperature can further improve the spray evaporation of IBE/diesel blends.