Quantification of HO2 and other products of dimethyl ether oxidation (H2O2, H2O, and CH2O) in a jet-stirred reactor at elevated temperatures by low-pressure sampling and continuous-wave cavity ring-down spectroscopy

• Published in: Fuel (Guildford) Vol. 158; pp. 248 - 252
• Main Authors: Le Tan, Ngoc Linh, Djehiche, Mokhtar, Jain, Chaitanya D., Dagaut, Philippe, Dayma, Guillaume
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2015; Elsevier
• Subjects: Chemical Sciences; Dimethyl ether; Engineering Sciences; Hydrogen peroxide; Hydroperoxyl radical; Jet-stirred reactor; or physical chemistry; Oxidation; Reactive fluid environment; Theoretical and; Jet-stirred reactor; Oxidation; Hydroperoxyl radical; Dimethyl ether; Hydrogen peroxide; Hydrogen peroxide H2O2; ho2; Cavity ringdown spectroscopy
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2015.05.042

Measuring the formation of HO2 and H2O2 from the oxidation of fuels is challenging but extremely important for determining their tendency to follow chain-termination pathways from R+O2 compared to chain-branching leading to the production of OH radicals. Furthermore, such data are vital for improving existing detailed chemical kinetics models. Dimethyl ether (DME), a clean renewable fuel, is the simplest ether exhibiting cool flame oxidation chemistry, a key-process for auto-ignition in internal combustion engines. Although the oxidation of DME has been studied in the past, little information is available for the production of HO2 and H2O2. The oxidation of dimethyl ether was performed in a jet-stirred reactor at atmospheric pressure, over a range of temperatures (∼540–850K) and equivalence ratios (φ=0.5–2) and, for the first time, the concentrations of HO2 and H2O2 were measured using a newly developed experimental setup involving low-pressure sampling and near-infrared cw-cavity ring down spectroscopy. Concentrations of H2O and CH2O were also measured. These new experimental results extend the available kinetic database for the oxidation of dimethyl ether which is needed to assess the validity of combustion kinetics models, as shown here.