Hydrothermal Decomposition Rate of Thiodiglycol in Supercritical Water

Hydrothermal Decomposition Rate of Thiodiglycol in Supercritical Water

Supercritical water (SCW) has been used as a reaction medium, primarily for the oxidation ofhazardous chemical wastes. It is essential to btain the hydrothermal reaction kinetics and provide data for theintermediate products if the supercritical water oxidation proces is to be developed. In this paper, thehydrothermal decomposition rate of thiodiglycol [(HOC2H4)2S, TDG], as the model compound of HD mustard,was investigated in an isothermal continuous tubular reactor under SCW conditions. The reaction temperaturesranged from 386 to 528oC and the residence times varied from 13 to 87 s at a fixed pressure of 25 MPa. Theconversion of TDG was monitored by analyzing the total organic carbon (TOC) content of the liquid efluentsamples. By using a first-order global power-law reaction rate xpression, the hydrothermal decompositionrate of TDG, based on the TOC disappearance rate, in SCW was regressed from experimental data to a 95 %confidence interval. The resulting activation energy was 71.32±5.20 kJ/mol and the pre-exponential factor ofthe reaction was 5.57(±0.002)×103 s-1.

Supercritical water (SCW) has been used as a reaction medium, primarily for the oxidation ofhazardous chemical wastes. It is essential to btain the hydrothermal reaction kinetics and provide data for theintermediate products if the supercritical water oxidation proces is to be developed. In this paper, thehydrothermal decomposition rate of thiodiglycol [(HOC2H4)2S, TDG], as the model compound of HD mustard,was investigated in an isothermal continuous tubular reactor under SCW conditions. The reaction temperaturesranged from 386 to 528oC and the residence times varied from 13 to 87 s at a fixed pressure of 25 MPa. Theconversion of TDG was monitored by analyzing the total organic carbon (TOC) content of the liquid efluentsamples. By using a first-order global power-law reaction rate xpression, the hydrothermal decompositionrate of TDG, based on the TOC disappearance rate, in SCW was regressed from experimental data to a 95 %confidence interval. The resulting activation energy was 71.32±5.20 kJ/mol and the pre-exponential factor ofthe reaction was 5.57(±0.002)×103 s-1.