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

Measurements and correlation of solid–liquid equilibria of the HI + I2 + H2O system

“…Initial charging of the HIx mixtures ensured that excess solid phase always existed in the system. The whole system was sealed and heated using an electrical heating mantle (8) and agitated with an external magnetic stirrer (9,10). A glasscapped thermocouple (4) was used for measuring and controlling the system temperature.…”

Two-dimensional simulation of hydrogen iodide decomposition reaction using fluent code for hydrogen production using nuclear technology

“…Berndh€ auser et al [18] compared the calculated homogeneous gas-phase reaction results with those of direct HI decomposition from HIeH 2 OeI 2 solutions, and found that the rate of direct HI decomposition was several orders of magnitude higher than that of the gas-phase reaction. Furthermore, Lanchi et al [19], Murphy and O'Connell [20], and Hadj-Kali et al [21], reviewed the phase equilibrium properties of the HIeI 2 eH 2 O (HI x ) system and proposed new thermodynamic models for describing the thermodynamic properties of this system. Many researchers have attempted to develop appropriate models for the HI decomposition reaction in the SI process [22,23].…”

Bunsen section thermodynamic model for hydrogen production by the sulfur–iodine cycle

“…Acid generation refers to the Bunsen section. We have recently proposed a new approach to model the HI x section [4]: the Peng Robinson equation of state (EoS) approach is supplemented with the MHV2 complex mixing rule that incorporates an Excess Gibbs energy model (G Ex ) to handle the strong non ideal behavior of the HI x system. UNIQUAC G Ex model is combined with solvation of hydrogen iodide HI by water H 2 O according to Engel's solvation model.…”

“…In the HI x section, the resulting EoS/G Ex model is able to describe with accuracy, by using a single set of parameters, all literature vapor -liquid, liquid -liquid, vapor -liquid -liquid and solid -liquid equilibrium data for the HI x ternary system and the three binary subsystems. Compared to other models for the HI x system based on an electrolyte model [5][6][7], the homogeneous EoS/G Ex approach of Hadj-Kali et al [4] has two major interests: first, it is theoretically compatible with calculations above HI critical temperature, that is likely to occur if a reactive distillation process is chosen for the HI x section [8][9][10]. Second, using Engel's solvation model for the solvation of HI by H 2 O, like Neumann's model [11,12], it is based on a symmetric convention in which the same reference state is supposed for all species, enabling to readily explore equilibrium properties for any composition.…”

“…Second, using Engel's solvation model for the solvation of HI by H 2 O, like Neumann's model [11,12], it is based on a symmetric convention in which the same reference state is supposed for all species, enabling to readily explore equilibrium properties for any composition. Because of a lack of experimental data under the HI x system conditions, HI dissociation reaction, producing H 2 and I 2 was not considered [4]. Polyiodide formation in aqueous solution [13][14][15] was not explicitly considered for the HI x section but is likely to occur in the Bunsen section, because the milder temperature favors polyiodide formation.…”