On the phase behavior of sorbitol/water/H2/CO2 mixtures at high pressures and temperatures by in situ infrared spectroscopy

Abstract

The thermodynamic behavior of multi-component system, which includes sorbitol dissolved in water under CO 2 and H 2 pressure, is investigated by in situ infrared spectroscopy. Our study focuses on the gas phase of binary, ternary, and quaternary systems at temperatures ranging from 40 °C to 220 °C and at CO 2 pressures between 30 and 120 bar, while maintaining a constant pressure of H 2 at 30 or 60 bar. The influence of addition of sorbitol in the liquid aqueous phase and of H 2 in the CO 2 -rich gas phase on the mutual solubility of CO 2 and water is evaluated. In our experimental conditions (T < 220 °C and P< 120 bar), it is found that in such multi-component system, a water-rich liquid phase always coexists with a CO 2 -rich gas phase. Presence of sorbitol in the water-rich phase and H 2 in the CO 2 -rich phase has a limited impact on the mutual solubility of water and CO 2 . Furthermore, sorbitol is not soluble in the CO 2 -rich phase and instead remains in the water-rich liquid phase over the thermodynamic range investigated.