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

Abstract

Two equilibrium stills have been designed for measuring vapor−liquid equilibria of hydriodic acid and polyhydriodic acid. The acids are so corrosive that the devices must be made of corrosion resistant materials. For the HI + H2O binary system, a still has been made of tantalum and Hastelloy and operated under pressure. For the HI + H2O + I2 ternary system, another still has been made of glass and operated at atmospheric pressure. With these devices, VLE data of hydriodic acid have been acquired. The experimental conditions for the binary system were as follows: the pressure range was from (0.11 to 0.58) MPa; the HI mole fraction range in the liquid was from 0 to 0.157; and the temperature range was from (375 to 456) K. For the ternary system, the pressure was atmospheric pressure; the HI concentration in the liquid was close to the azeotrope; the HI to I2 mole ratio in the liquid range was from 1/0 to 1/4; and the temperature range was from (396 to 408) K.

Modeling and validation of the iodine‐sulfur hydrogen production process

“…Thus, the basic value we selected is optimal. As Hodotsuka et al's experimental data and Guo et al's calculated results indicate, the relative volatility of HI in the HI x mixture is quite large when the composition is within the overazeotropic region. Therefore, it is possible and not difficult to obtain a distillate with HI mole fraction equaling 0.23, 0.3, or even higher at the top of the HI distillation column at atmospheric pressure, when the feed is concentrated to over azeotropic.…”

A Literature Survey to Identify Potentially Volatile Iodine-Bearing Species Present in Off-Gas Streams

“…Most of these species have been identified in the atmospheric (Baker et al 2001;Filistovic and Nedveckaite 1998;Hodotsuka et al 2008;Moore and Groszko 1999;Moore and Tokarczyk 1992;Sturges and Barrie 1988;Yoshida and Muramatsu 1995;Zhang and Hou 2013) or reactor accident literature (Browning 1963;Browning et al 1963;Browning et al 1965;Browning et al 1964;Choi et al 2001;Paquette 1989;Parsley 1971;Routamo 1996;Wren et al 1986). Despite the differences between reprocessing off-gas streams and the atmosphere such as temperature and overall composition, the concentrations of iodine species in the atmosphere are similar to or slightly less than those expected in a reprocessing facility (Campos et al 1996) and the iodine-bearing species are similar to those expected in a reprocessing facility (Baker et al 2001;Campos et al 1996;Filistovic and Nedveckaite 1998;Hodotsuka et al 2008;Moore and Groszko 1999;Moore and Tokarczyk 1992;Sturges and Barrie 1988;Yoshida and Muramatsu 1995;Zhang and Hou 2013).…”

Thermochemical water-splitting cycle using iodine and sulfur

“…28 Especially, knowledge of the vapor-liquid equilibrium of the HI-I 2 -H 2 O system is insufficient in spite of its importance, and measurements to enhance the database are in progress at Commissariat a l' energie atomique (CEA), 29 Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA) 30 and Japan Atomic Energy Agency (JAEA). 31 Fig. 4 shows the T-x-y curves at elevated pressures reported by JAEA.…”

“…Recently, Sandia -(bubbling point curves) and / (dew point curves) were drawn by eye. 31 Fig. 5 Scheme of continuous hydrogen production test apparatus.…”

“…A broken line with A keys indicates the azeotrope calculated by Berndh€ auser from Ref. 15b.-(bubbling point curves) and / (dew point curves) were drawn by eye 31. Fig.5Scheme of continuous hydrogen production test apparatus 33.…”