Work

Ozone-initiated low-temperature oxidation of 1,3-dioxane

Year: 2026

Type: article

Abstract: This study explores the influence of ozone addition on the low-temperature oxidation of 1,3-dioxane, a recently proposed cyclic oxymethylene ether biofuel. Experiments were conducted in a jet-stirred reactor operated slightly above atmospheric pressure over 375–850 K. A new detailed kinetic model was developed, incorporating theoretically calculated rate constants for hydrogen abstraction reactions by atomic oxygen (O), the primary decomposition product of O₃. Experimental results reveal that introducing 1000 ppm of O₃ significantly accelerates fuel reactivity, initiating 1,3-dioxane consumption near 450 K, whereas oxidation without O₃ begins around 550 K. Between 600–700 K, the pronounced negative temperature coefficient (NTC) behavior observed under O₃-free conditions is notably diminished when O₃ is present. Simulations using the new kinetic model successfully reproduce these experimental trends, including fuel conversion and formation of major products. Kinetic analyses demonstrate that O₃-derived O atoms enhance early-stage chain initiation and alter dominant reaction pathways, providing mechanistic insight into O 3 -assisted low-temperature oxidation chemistry of oxygenated fuels. Novelty and significance statement This study is the first to experimentally and computationally investigate the ozone-initiated low-temperature oxidation of 1,3-dioxane. It introduces a new detailed kinetic mechanism that incorporates ab initio–derived rate constants for hydrogen abstraction by O atoms, the primary reactive species generated from ozone decomposition. The study uniquely demonstrates how ozone addition accelerates dioxygenated cyclic ether consumption, lowers the onset temperature of oxidation by ∼100 K, and suppresses negative temperature coefficient (NTC) behavior, providing unprecedented mechanistic insights into O₃-assisted oxidation of oxygenated biofuels.

Source: Proceedings of the Combustion Institute

DOI: 10.1016/j.proci.2026.106385