The analysis of hydrogen iodine (HI) decomposition based on the flow sheet developed by General Atomics (GA) was performed. The accuracy of the thermodynamic model used was validated first by comparing the bubble pressure of the HI-H(2)O mixture of the current analysis with the theoretical analysis of GA. The thermodynamic analysis was also extended to higher temperatures. The whole HI decomposition section was flow sheeted and simulated with Aspen Plus. The process operating conditions were determined for GA results reproducibility of 1 kmol/h of hydrogen production. The influence of the reactive distillation column pressure of the HI decomposition on the operating conditions was studied. The results showed a correlation between the boil-up rate and the pressure of the reactive distillation column. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.