Determination of Chlorobenzene Solubilities in Subcritical Water in a Fused Silica Capillary Reactor from 173 to 267 °C

Solubility and Decomposition of Organic Compounds in Subcritical Water

In this article, studies on organic solubility and stability in subcritical water reported during the past 25 years have been reviewed. Data on the solubility and decomposition of organic compounds in subcritical water, a green solvent, are needed in environmental remediation, chemistry, chemical engineering, medicine, polymer, food, agriculture, and many other fields. For solubility studies, the experimental systems used to measure solubility, mathematical equations derived and applied for the modeling of the experimentally determined solubility data, and the correlation between the predicated and experimental data have been summarized and discussed. This paper also reviewed organic decomposition under subcritical water conditions. In general, the solubility of organics is significantly enhanced with increasing water temperature. Likewise, the percentage of organic decomposition also increases with higher temperature.

Visual observations and Raman spectroscopic studies of supercritical water oxidation of chlorobenzene in an anticorrosive fused-silica capillary reactor

Supercritical water oxidation of chlorobenzene (CB) was studied using an anticorrosive fused-silica capillary reactor (FSCR) combined with a polarization microscope recorder system for visual observations and a Raman spectroscopic system for qualitative and quantitative analyses of the gaseous products. The effects of operating parameters, including the stoichiometric amount of oxidizer, temperature, and reaction time, on oxidation behavior were investigated. Our results show that a 100% conversion yield of CB and 100% CO(2) yield were achieved with a 150% stoichiometric amount of H(2)O(2) at 450 °C within 8 and 10 min, respectively. The conversion yield and the CO(2) yield both depend strongly on temperature, and the CO(2) yield is always less than the CB conversion yield under the same experimental conditions, suggesting that some carbon exists in intermediate products of incomplete oxidation, as confirmed by gas chromatography-mass spectrometry. Global kinetics analysis based on the complete conversion of CB to CO(2) showed that the reaction was first order. CB phase-changes in sub- and supercritical H(2)O-H(2)O(2) system in the FSCR were observed and recorded; CB eventually dissolved completely to form a homogeneous liquid solution above 326.1 °C. This method has great potential for use in the theoretical study of fluids and chemical reactions under elevated pressure-temperature conditions.