Spray and combustion characteristics of acetone-butanol-ethanol (ABE)-diesel blend with high ABE ratio

The acetone-butanol-ethanol (ABE)/diesel blend with high ABE ratio as alternative fuel was studied and the experiments were conducted in a pre-combustion type constant volume chamber. ABE solution with typical volumetric ratios of 30%, acetone, 60%, butanol, and 10%, ethanol was blended with diesel at 80%, volume and was tested. The ambient temperature was set to be 1100 K and 900 K, which represent normal temperature combustion mode and low temperature combustion mode, respectively, and the ambient oxygen concentrations were set to be 21%, 16%, and 11%, respectively, which represent different EGR conditions for diesel engine. In-cylinder pressure was recorded by using a pressure transducer and the time-resolved Mie-scattering image and natural flame luminosity were captured by using a high-speed camera coupled with a copper vapor laser as a light source. The results show that, due to the high percentage of ABE in the blend, the liquid penetration and intensity of natural flame luminosity are reduced significantly, which indicates a high potential to reduce soot level when it is used as an alternative fuel for internal combustion engine. Furthermore, a soot-free combustion is achieved by combing the low temperature combustion with blended fuel with a high percentage of ABE. Hence, in terms of soot emission, high ABE ratio blends are a very promising alternative fuel which can be directly used in diesel engines.