Detailed kinetic modeling and sensitivity analysis of hydrogen iodide decomposition in sulfur–iodine cycle for hydrogen production

A new detailed kinetic modeling was developed for homogeneous decomposition of hydrogen iodide (HI) in the sulfur–iodine cycle. Results show the HI decomposition reaction is sensitive to temperature, and the response time of reaction reduces from 1 s to 10 ms as temperature increases from 500500 to 800∘C. The decomposition is also improved as pressure increased. Kinetic calculations are also compared with the experimental data, and all trends of the experiment can be reproduced by the model. Sensitivity analysis shows that the reactions of HI with HI, H and I play a major role in the hydrogen production process and the hydrogen consumption occurs primarily by reaction of H with I2I2 and reaction of I with H2H2 to form HI. As temperature increases, different reactions play a dominant role in HI decomposition process. Based on the detailed kinetic modeling and sensitivity analysis results, the HI decomposition reaction path diagram was constructed in this paper.