Kinetic model development and experimental study of high-pressure ignition of nitropropane
Year: 2026
Type: article
Abstract: Nitropropane (NP) is a promising candidate for advanced propulsion systems as a propellant or fuel additive. While some studies of its ignition have been conducted in the past, they focused on highly diluted conditions, and only one high-pressure dataset is available. This study extends the high-pressure dataset with ignition delay time (IDT) measurements conducted in a shock tube (ST) and a rapid compression machine (RCM) at pressures ranging from 20 bar to 30 bar, temperatures ranging from 730 K to 980 K, and air-like conditions. These measurements were supplemented by species concentration profiles obtained during the IDT in the RCM using a rapid sampling system coupled with gas chromatography and mass spectrometry (GC–MS) techniques. In addition, a detailed kinetic model was developed. New rate parameters for unimolecular decomposition reactions were estimated by analogy to nitroethane (NE) and alkane-like low temperature pathways were added. The model also includes interactions between alkanes and nitrogen dioxide to better reflect the experimentally observed fuel behavior. Sensitivity and rate-of-production (ROP) analyses revealed that competition among C-N bond fission, H-migration, and H-atom abstraction (HAA) dominates NP reactivity. Previously absent NO x cycling reactions and alkane-like low temperature pathways have a significant influence on the reaction network, particularly at low temperatures. The new model outperforms the literature model over a wider range of conditions. It can predict air-like dilution experiments and the most abundant species formed during ignition. Novelty and significance statement: This work presents a new experimental dataset that includes non-diluted IDT measurements and simultaneous species measurements in the RCM at previously unexplored low-temperature and high-pressure conditions. These measurements extend the range of experimental data on high temperatures and high levels of dilution available in the literature (He et al., 2022). The model while partially based on literature has been reworked and new reaction rates are used for the main decomposition reactions to better predict the fuel behavior. The newly added reaction pathways help to understand the complex competition of decomposition, NO x cycling and conventional low temperature pathways that are critical at low levels of dilution and medium-to-low temperatures. This understanding will support the modeling of other nitrogenated compounds in future studies.
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,570
OpenAlex ID: W7167789495