A Shock-Tube and Chemical Kinetics Model Investigation Encompassing all Five Pentene Isomers

Kinetic treatment of the full group of C5 olefins is presented with new measurements on 1-pentene (1-C₅H₁₀), 2-pentene (2-C₅H₁₀), and 3-Methyl-1-Butene (3M1B) combined with recently published data obtained at similar conditions from our group on 2-Methyl-2-Butene (2M2B) and 2-Methyl-1-Butene (2M1B). This extensive experimental database contains carbon monoxide and water time-history profiles, along with their measured CO and H₂O induction delay times. The oxidation of the five pentene isomers was carried out at three equivalence ratios (0.5, 1.0, and 2.0) in mixtures highly diluted in 99.5% Helium-Argon. The experiments were performed for temperatures ranging from 1400 to 1900 K at near-atmospheric pressure. A unique comparison of the complete set of pentene isomers permits the understanding of the C=C double bond position and branching impacts on combustion properties, using the chemical kinetics mechanism of both linear and branched structures. The impact of the C = C double bond location – either the 1–2 or 2–3 bond site – is described using the linear molecules 1-C₅H₁₀ and 2-C₅H₁₀. Species induction delay times were measured for the five isomers for each equivalence ratio investigated. Results showed noticeable differences between isomers, with the induction delay time results for 3M1B being the shortest, closely followed by 2-C₅H₁₀, 1-C₅H₁₀, and then after a large leap in decreasing reactivity, by 2M2B and 2M1B. Numerical predictions using up to 9 models available in the literature were performed. An error score function was used to evaluate the properties of the pentene isomer models in the current literature.