The performance and emissions of Acetone-Butanol-Ethanol (ABE)/diesel mixtures in an AVL 5402 single cylinder diesel research engine under various engine operating conditions were investigated in this study. The experiments were conducted at three different speeds (1200, 1500, and 2000 RPM) and different injection quantities (loads) (15, 20, and 25 mg/cycle).
The fuels tested in these experiments were pure diesel, ABE10, and ABE20. The acetone-butanol-ethanol (ABE) was blended in a 3:6:1 ratio. ABE10 and ABE20 consist of 10% acetone-butanol-ethanol mixture and 90% diesel by volume and 20% ABE and 80% diesel by volume respectively.
The results showed a promising future for ABE-diesel mixture as an alternative transportation fuel. There was improved thermal efficiency even with relatively small ABE blending ratios and a slight reduction in power output due to the lower energy density. There was an overall retarded combustion phasing, including longer ignition delay time, retarded CA50 timing, peak pressure timing and end of combustion timing. Accelerated heat release during CA10∼CA50 indicates a higher degree of premixed combustion. Overall soot emissions were lower and NOx emissions were higher for ABE-containing fuels at same load and timing conditions. Tuning injection timing would be helpful for the reduction of NOx to a degree that is even lower than that of diesel.
With proper tuning of injection quantity and injection timing, adopting ABE-diesel mixtures has the potential of improving efficiency and reducing emissions at the same time. Considering the low cost of ABE production compared to other kinds of bio-fuels, ABE could become a possible alternative to the current fuel additives.