Plantwide Design and Control of Sulfur-Iodine Thermochemical Cycle Plant for Hydrogen Production


  • Noraini Mohd School of Energy and Chemical Engineering, Xiamen University Malaysia
  • Jobrun Nandong Department of Chemical and Energy Engineering, Curtin University Malaysia


Hydrogen Fuel, Sulfur Iodine Thermochemical Cycle, Plantwide Control, Renewable Energy


Through several credible studies, some researchers have identified the Sulfur-Iodine Thermochemical Cycle (SITC) process as the most promising one among over 350 different types of thermochemical cycles for large-scale hydrogen production. Detailed complete design and control study of the SITC plant at an industrial scale so far remains scarce. This paper presents the plantwide design and control study based on a pre-defined SITC flowsheet. In the flowsheet, a multi-bayonet reactor configuration is adopted in the sulfuric acid decomposition section to improve the plant's thermal efficiency. A fundamental model of the complete SITC plant enables process scale-up, optimization, and plantwide simulation. The Self-Optimizing Control Structure (SOCS) approach is adopted to construct a complete control (PWC) strategy for the SITC plant. The plantwide SOCS strategy enables robust and flexible operation of the SITC plant, which allows the production rate to vary over a wide range, from 24 tons/day to 57.6 tons/day of hydrogen without leading to unstable operation. At the maximum production capacity, the plant thermal efficiency reaches 68.6% and gross profit of USD 35 million per annum. The extensive simulation study shows that it is vital to control the Bunsen reactor well within a narrow range of conditions. Poor control of the Bunsen reactor can lead to severe challenges to achieving smooth plant operation overall. Detailed analyses and simulations show that the industrial-scale SITC plant is viable in terms of economic and controllability.


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How to Cite

N. Mohd and J. . Nandong, “Plantwide Design and Control of Sulfur-Iodine Thermochemical Cycle Plant for Hydrogen Production”, AJPC, vol. 1, no. 1, pp. 1–24, Sep. 2022.