Kinetics of atmospheric reactions of 4-chloro-1-butene

Abstract

Chloroalkenes are among the important anthropogenic organic compounds emitted in the atmosphere as a result of their wide use in synthetic processes in industry. Despite their well-known adverse effects on human health and air quality, the chemistry of these chloroalkenes remains poorly explored. In this work, reactions of 4-chloro-1-butene (CBE), a representative example of chloroalkenes, with O₃, OH, NO₃, and Cl are investigated in a 100-L Teflon reaction chamber equipped with gas chromatography-flame ionization detector (GC-FID). The absolute rate method was used for the reaction with O₃ while the relative rate method was used for reactions with OH, NO₃, and Cl. The following rate constants were obtained at room temperature (298 ± 2) K and atmospheric pressure: (3.96 ± 0.43) × 10⁻¹⁸, (2.63 ± 0.96) × 10⁻¹¹, (4.48 ± 1.23) × 10⁻¹⁵, and (2.35 ± 0.90) × 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹, for reactions with O₃, OH, NO₃, and Cl, respectively. Atmospheric lifetimes of CBE calculated from rate constants of the different reactions obtained in this work showed that reaction with OH is the main loss process for CBE, while in coastal areas and in the marine boundary layer, the CBE loss by Cl reaction becomes important. Estimation of the value of the photochemical ozone creation potential (POCP) indicated that CBE has a large ozone formation potential. The present work underlines the need for further studies on the atmospheric chemistry of chlorinated VOCs.