Development of an Ethanol Combustion Mechanism Based on a Hierarchical Optimization Approach

A detailed reaction mechanism for ethanol combustion was developed for describing ignition, flame propagation, and species concentration profiles with high accuracy. Starting from a modified version of the ethanol combustion mechanism of Saxena and Williams (Proc. Combust. Inst. 2007, 31, 1149-1156) and adopting the H-2/CO base chemistry from the joint optimized hydrogen and syngas combustion mechanism of Varga et al. (Int. J. Chem. Kinet. 2016, 48, 407-422), an optimization of 54 Arrhenius parameters of 16 important elementary C-1/C-2 reactions was performed using several thousand direct and indirect measurement data points as well as the results of theoretical determinations of reaction rate coefficients. The final optimized mechanism was compared to 16 reaction mechanisms that have been used for the simulation of ethanol combustion with respect to the accuracy in reproducing the available experimental data, including measurements of ignition delay times in shock tubes (444 data points in 39 data sets) and rapid compression machines (20/3), laminar burning velocity measurements (1011/124), and species profiles measured using flow reactors (1750/23), jet-stirred reactors (398/6) and shock tubes (8871/14). In addition to providing best fitted values for 54 Arrhenius parameters, the covariance matrix of the optimized parameters was calculated, which provides a description of the temperature-dependent ranges of uncertainty for each of the optimized rate coefficients. (C) 2016 Wiley Periodicals, Inc.