Kinetics and modeling of hydrogen iodide decomposition for a bench-scale sulfur–iodine cycle

In this work, the decomposition of hydrogen iodide (HI) over platinum catalyst in a frame work of the development of a bench-scale Sulfur–Iodine (S–I) cycle is studied. The catalyst Pt/γ-alumina 1.0wt% is prepared by impregnation–calcination method. The experiments of HI decomposition over the as-prepared catalyst are conducted at the temperature range of 350–550°C and at the atmospheric pressure. The experimental data are then used to estimate new kinetic parameters for HI decomposition on the basis of Langmuir–Hinshelwood type where the surface reaction is considered as the rate-limiting step. The kinetics with the estimated parameters shows a reasonable agreement with the experimental data. It also reflects the fact that, HI conversion is significantly decreased with a small amount of iodine present in the feeding solution.