Spray and combustion characteristics of acetone-butanol-ethanol and diesel in a constant volume chamber and a diesel engine

Acetone;Butanol;Ethanol;Diesel;Alternative;Fuel;Acetone-butanol-ethanol (ABE);Baelene

Lee, Timothy H. ; Hansen ; Alan C.

关键词: Acetone;    Butanol;    Ethanol;    Diesel;    Alternative;    Fuel;    Acetone-butanol-ethanol (ABE);    Baelene;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/88164/LEE-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Recent research has shown that butanol, instead of ethanol, has the potential of introducing a more suitable blend in diesel engines. This is because butanol has properties similar to current transportation fuels in comparison to ethanol. However, the main downside is the high cost of the butanol production process. Acetone-butanol-ethanol (ABE) is an intermediate product of the fermentation process of butanol production. By eliminating the separation and purification processes, using ABE directly in diesel blends has the potential of greatly decreasing the overall cost for fuel production. This could lead to a vast commercial use of ABE-diesel blends on the market. Research has been done in the past five years concerning spray and combustion processes of both neat ABE and ABE-diesel mixtures. Additionally, different compositions of ABE mixtures had been characterized with a similar experimental approach. This thesis reviews the production of ABE and characterization of its spray and combustion processes. The results obtained during the recent four years will also be presented. The main focus of this paper is to review the efforts made in fundamental spray research under quasi-steady flow field environments provided by a high-pressure, high-temperature constant volume chamber. In-cylinder pressure traces were calculated to derive apparent heat release rates, high-speed Mie-scattering images were acquired to characterize liquid spray penetration, and natural flame luminosity was also captured to depict spatial and temporal soot distribution. It is observed that the acetone content has a major influence in the combustion behavior of the ABE mixture. An increased content of acetone will lead to a significantly advanced combustion phasing. Butanol, as another important species in the ABE mixture, is able to compensate the advancing effect caused by acetone and ethanol. More importantly, butanol can increase the overall energy density of the mixture, which makes the property of the mixture closer to that of current transportation fuels. In addition, the underlying challenges faced in this area of research are described.Additionally, 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 is mixed with 80% diesel by volume, respectively.The results showed a promising future for ABE-diesel mixtures 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 the same load and timing conditions.Tuning the 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 the 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.