Total and partial pressure measurements for the sulphur–iodine thermochemical cycle

Raman scattering studies of the condensed phase of the HIx feed of the sulfur-iodine thermochemical cycle

“…Our work on the HI x system complements studies of the vapor phase of the HI x system using UV-Visible and FT-IR absorption spectroscopies [20] The compositions of mixtures in terms of the reagents used were determined to o0.01 wt% by weighing ampoules following each separate addition. The uncertainties in HI and I 2 concentrations are greater than 0.01 wt% as a consequence of the uncertainty in the wt% of HI present in the HI 57 and HI 67 stock solutions; there is a slow appearance of I 2 in these solutions due to unspecified oxidation processes.…”

Vapor−Liquid Equilibria for the HI + H2O System and the HI + H2O + I2 System

“…7 It has been confirmed that the azeotropic concentration shifts to the left, or more dilute side, as the pressure elevates. However, the results of Doizi et al 8 show the opposite behavior. Even with the same composition of hydriodic acid (x 1 ) 0.157), the solution was under azeotrope at 386 K (0.016 MPa) and over azeotrope at 353 K (0.059 MPa).…”

“…Recently Doizi et al 8 reported data using a static cell which featured optical windows for the measurement of vapor composition. They published experimental VLE data of hydriodic acid and polyhydriodic acid.…”

HIx system thermodynamic model for hydrogen production by the Sulfur–Iodine cycle

“…In fact, more and accurate detailed composition data are needed to consider system features like the dissociation of HI in the vapor phase but also the probable poly-iodide formation in the liquid phase that could be described by a solvation of HI by I 2 . The CEA has recently launched a program to measure the relevant partial pressures [51], which are necessary to effectively estimate the hydrogen production potential under the reactive distillation process expected conditions (up to 300°C and 50 bars).…”