Influence of Water on the H2SO4 Yield from the Ozonolysis of 2,3-dimethyl-butene (TME) in Presence of SO2

Alexandre Kukui (1) , Hui Chen (2) , Véronique Daële (2) , Wahid Mellouki (2)

1 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
2 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement

The influence of the water vapor content on the yield of H2SO4 from the ozonolysis of 2,3-dimethyl-butene (TME) in presence of SO2 was studied using laminar flow reactor coupled with Chemical Ionisation Mass Spectrometer (CIMS) for the H2SO4 monitoring within the range of H2O from 10 ppmv to 3×104 ppmv at different concentrations of TME, O3, SO2. The observed dependences of the H2SO4 yield on H2O concentration can be interpreted by assuming two different paths of the H2SO4 formation: 1) via the formation of SO3 in the reaction of Stabilized Criegee Intermediate (SCI) with SO2 (2a) followed by the reaction of SO3 with H2O (3) and 2) via the formation of stabilized secondary ozonide (SOZ) (2b) producing H2SO4 in the reaction with H2O (4a) in competition with the SOZ decomposition to other products (5): O3+TME => (CH3)2COO (1) (CH3)2COO + SO2 => SO3 (2a) => SOZ (2b) SO3 + H2O => H2SO4 (3) SOZ + H2O => H2SO4 (or SO3) (4a) SOZ + M => products (5) The yield of the SCI, SOZ and the rates of the SCI and SOZ decomposition relative to their reactions with SO2 and H2O, respectively, were estimated from the dependencies of the H2SO4 yield on the concentrations of the reactants.

Mots clés: 0317 Chemical kinetic and photochemical properties; ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0340 Middle atmosphere: composition and chemistry; ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry; ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0394 Instruments and techniques; ATMOSPHERIC COMPOSITION AND STRUCTURE

Domaines: Océan, Atmosphère

Alexandre Kukui, Hui Chen, Véronique Daële, Wahid Mellouki. Influence of Water on the H2SO4 Yield from the Ozonolysis of 2,3-dimethyl-butene (TME) in Presence of SO2. American Geophysical Union, Fall Meeting 2016, abstract #A33E-0267, Dec 2016, San Francisco, United States. ⟨insu-03520060⟩