A Semi-Detailed Chemical Kinetic Mechanism of Acetone-Butanol-Ethanol (ABE) and Diesel Blends for Combustion Simulations

With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. To seek for an optimized volumetric ratio for ABE-diesel blends, the previous work in our team has experimentally investigated and analyzed the combustion features of ABE-diesel blends with different volumetric ratio (A: B: E: 6:3:1; 3:6:1; 0:10:0, vol. %) in a constant volume chamber. It was found that an increased amount of acetone would lead to a significant advancement of combustion phasing whereas butanol would compensate the advancing effect. Both spray dynamic and chemistry reaction dynamic are of great importance in explaining the unique combustion characteristic of ABE-diesel blend. In this study, a semi-detailed chemical mechanism is constructed and used to model ABE-diesel spray combustion in a constant volume chamber. This mechanism comprises Acetone, Butanol, Ethanol and n-heptane as surrogate fuel species. Validations are conducted for the present mechanism with results from literatures. KIVA-3V program coupled with the validated mechanism is used to simulate the spray dynamics and combustion characteristics inside the constant volume chamber. Simulation results and previous experimental data are presented and discussed in detail. Reasonable agreements both in shock tube simulation and constant volume chamber simulation of ignition delay, cylinder pressures and heat release rates were achieved between experimental and calculated results. In summary, the presented semi-detailed chemical mechanism is demonstrated to be computational acceptable in timescales while maintaining the kinetic behavior of newly studied ABE-diesel blends.