Formation of solid sulfur by decomposition of carbon disulfide in the oxygen-lean cold plasma environment

In general, the conventional thermal processes for treating toxic carbon disulfide (CS2) gas were by the oxidation of sulfur on CS2 to form SO2. However, this study demonstrated that by using a radio-frequency cold plasma reactor in the oxygen-lean condition (O2/CS2 = R = 0.6) at the applied power of 90 W, the decomposition fraction of CS2 could reach 88.2%, and there was 76.9% of input sulfur mass from CS2 converted into solid sulfur with the purity of 99.2%. No solid sulfur was observed for the no-oxygen (R = 0) or oxygen-rich conditions (R = 3.0). Hence, the results of this study provided an approach for sulfur recovery to reduce the emissions of both CS2 and SO2. In addition, the reaction mechanisms for the decomposition of CS2 and for the formation of gaseous SO2, CO, CO2, and OCS in the CS2/O2/Ar plasma were also built up and discussed.