Low-Temperature combustion of 3-Pentanol and its blends with Hydrogen: An experimental and modeling study

• A new mechanism for the oxidation, and autoignition of 3-pentanol is proposed. • New experimental Rapid Compression Machine data, including speciation, is reported. • The model includes a set of new ab initio calculated reaction rate coefficients. • The model is validated on existing data in all temperature regimes of combustion. • This work is extended to blends with hydrogen, in the context of decarbonization. Reducing emissions in the transportation sector has highlighted the potential of oxygenates as alternative fuels, known for lowering soot emissions. Blending these alcohols with hydrogen, a carbon-free fuel, offers further potential for reducing carbon-based emissions. Because the description of the low-temperature combustion pathways of C 5 alcohols still needs to be improved, this study investigates the ignition delay times (IDTs) and mole fraction profiles of intermediates of 3-pentanol/hydrogen mixtures using a rapid compression machine over a low-to-intermediate temperature range. Experiments were also conducted for 3-pentanol/H 2 blends with mixing ratios of 100/0, 75/25, and 50/50 at pressures of 10, 15, and 20 bar, and equivalence ratios of 1.0 and 0.5. Gas chromatography, flame ionization detection, thermal conductivity detection, and mass spectrometry were employed for the quantification of the intermediates. These results therefore provide a rare detailed database for the validation of 3-pentanol kinetic models at high-pressure, low-temperature combustion conditions. Furthermore, ab initio calculations were performed to determine β-scission and isomerization reaction rates, supporting the development of a novel kinetic sub-mechanism for 3-pentanol, which shows better or equivalent agreement that previous works on the hereby-reported or existing literature data. This mechanism highlights the importance of the branching ratio of the initial H-abstraction step in the prediction of the IDTs as well as the importance of the 3-pentanone relevant pathways. It was used to evaluate the impact of hydrogen addition on 3-pentanol IDTs, revealing the importance of H 2 as a sink for hydroxyl radicals, readily converting them to H atoms then hydroperoxyl radicals.