GAS-PHASE DEGRADATION OF 2-BUTANETHIOL INITIATED BY Cl ATOMS. KINETICS, PRODUCT YIELDS AND MECHANISM AT 298K AND ATMOSPHERIC PRESSURE

MIYER ALEJANDRO LADINO CARDONA; MARIANO TERUEL; RODRIGO GIBILISCO; PETER WIESEN

Orleans

Conferencia; 11TH INTERNATIONAL CONFERENCE ON CHEMICAL KINETICS ORLÉANS,; 2019

L?Institut de Combustion Aérothermique Réactivité et Environnement (ICARE)

Inthe atmosphere, the sulfur is central to many environmental issuesincluding acid rain and climate change. Volatile organic sulfurcompounds (VOSC) can exist at high concentrations, they are releasedinto the environment from natural emissions and anthropogenicsources. The presence of 2-butanethiol was detected in the air fromsewerage treatment tanks of chemical petroleum, geothermal areas,muddy beach water and wastewater treatment plants (Liand Shooter, 2004; 1985; Sye and Chen, 2000).It reaches the troposphere mainly through organic matterdecomposition and is removed by gas phase reactions with atmosphericradicals such as OH and Cl atoms. The aim of this work is toinvestigate the kinetics, mechanism and products yields for thereaction of 2-butanethiol with Cl atoms, at atmospheric pressure ofsynthetic air and298K. Theexperiments were performed in a 480 L chamber of a cylindricalborosilicate glass vessel with 32 fluorescent lamps coupled to a FTIRspectrometer to enables ?insitu?monitoring of the reactants in the infrared range 4000-700 cm-1.Kinetics was studied using the relative kinetic method and thequantification of reactants and products was performed by comparisonwith calibrated reference spectra. The rate coefficient obtained byaveraging the values from different experiments was kCl=(3.2±0.7) x10-10cm3molecule-1s-1,in agreement with previous work for alkyl thiols. In addition,products studies were performed at the same conditions of syntheticair at NOxfree conditions. The identified products were HCl, 2-butanone an SO2and the yields were (97±2) %, (38±3)% and (57±2)% respectively, adegradation mechanism was proposed for the pathways that leads toformation of identified products. The high yields values observed inthe reaction system indicated that the H-atom of the S-H groupabstraction channel is an important pathway for the reaction of Clatoms with 2-butanethiol.References Li,K.-C., Shooter, D., 2004. Analysis of sulfur-containing compounds inambient air using solid-phase microextraction and gas chromatographywith pulsed flame photometric detection. Int. J. Environ. Anal. Chem.84, 749?760.Sye, W., Chen, W., 2000.Determination of odorous sulfur compounds in air by Tenax GRpreconcentration and capillary gas chromatography in combination withflameless sulfur chemiluminescence detection. Toxicol. Environ. Chem.77, 207?218.p { margin-bottom: 0.1in; direction: ltr; line-height: 115%; text-align: left; }p.western { font-size: 11pt; }p.cjk { font-size: 11pt; }a:link { color: rgb(5, 99, 193); }