Decomposition of Ethanethiol by a Corona Radical Injection System

Abstract

The decomposition of ethanethiol by a corona radical injection system, using water vapor and O3as radical source, was investigated. It is found that only 83.6% of ethanethiol can be decomposed in dry air flow with relative humidity of 13.4%. A proper quantity of water vapor injection can improve the decomposition efficiency, but which is not always increased. The maximum decomposition efficiency of 99.1% can be obtained in wet air flow with relative humidity of 74.7%. 97.6% of ethanethiol can be decomposed when the relative humidity of gas flow is 51.6%, but it is found that only 76.3% of element sulfur is converted to SO2, based on sulfur balance. However, the conversion efficiency of sulfur to SO2increases obviously with the increasing of O3injection. The decomposition efficiency of ethanethiol and conversion efficiency of sulfur to SO2can reach 99.8% and 95.3% respectively, when O3is injected into the reactor by high voltage electrode tubes with concentration of 1 g/m3 and flow rate of 300 L/h. The decomposition products are SO2, CO2and H2O, while no organic product is found, based on which the decomposition mechanism is discussed. The weakest chemical bond C-S in ethanethiol molecule is firstly decomposed to ·SH and ·C2H5radicals. ·SH can be oxidized to elemental sulfur and SO2, and ·C2H5is oxidized to CO2and H2O.