Environmental Technology & Innovation 20 (2020) 101162 Contents lists available at ScienceDirect Environmental Technology & Innovation journal homepage: www.elsevier.com/locate/eti Modeling and simulation of non-isothermal packed-bed membrane reactor for decomposition of hydrogen iodide Purujit Tandon, Manish Jain * Department of Applied Chemistry, Delhi Technological University, New Delhi 110042, India article info Article history: Received 24 May 2020 Received in revised form 23 August 2020 Accepted 11 September 2020 Available online 19 September 2020 Keywords: Membrane reactors Mathematical modeling Thermochemical water-splitting HI decomposition Thermochemical iodine–sulfur (IS) process abstract HI decomposition using a membrane reactor is one of the important steps in hydrogen production by the thermal splitting of water using the Sulfur–Iodine cycle. Though, this reaction is endothermic. The mathematical model available to study the performance of such a reactor is an isothermal model. In this study, a non-isothermal mathematical model is developed by microscopic material and energy balance across the length of the membrane reactor. Experimental results from the literature are used for validation of the developed model. Comparing the simulations from the developed model and already reported isothermal model showed significant differences, which endorses the importance of the developed model. Later, the effects of different operating and design parameters were analyzed. Higher feed temperature (950–1000 K), lower feed pressure (100,000–150,000 Pa), lower feed flow rate (<200 ml/min), lower permeate pressure (<2500 Pa) and low to moderate N 2 /HI ratio (0.3–0.4) were found to be the optimum operating conditions. Similarly, the conversion also increased with increasing reactor length, membrane area, and membrane permeance but eventually became constant. Reactor length around 0.4 m, membrane area around 0.008 m 2 and membrane permeance around 2 × 10 -7 mol m 2 Pa -1 s -1 were estimated to be the optimum design conditions for the maximum HI decomposition. © 2020 Elsevier B.V. All rights reserved. 1. Introduction Fossil fuels are a scarce commodity and are a major source of air pollution. The energy demand is expected to increase due to an ever-growing population. Thus, it has become essential to reduce the load on fossil fuels by shifting to clean fuel. Hydrogen is an excellent energy carrier, which only produces water on combustion, and can be stored, unlike other carriers. Since hydrogen is a carrier and not a source of energy, it can only be as clean as its method of production. Currently, most of the hydrogen is produced by reforming of fossil fuels, which in turn releases CO and CO 2 , thus defeating the purpose of using hydrogen as a clean fuel. Moreover, large scale electrolysis and direct thermal splitting of water are challenging due to high energy requirements (Barreto et al., 2003; Marbán and Valdés-Solís, 2007; Penner, 2006). An upcoming source of hydrogen is the thermochemical splitting of water, having relatively lower energy consumption which can be provided from solar power or nuclear waste heat sources (Rao and Dey, 2017). It is a series of reactions such that the net reaction is that of water decomposition. Besides hydrogen and oxygen, all the other reaction products are recycled back to the process resulting in water being the only feed stream (Nguyen et al., 2014). Various such thermal * Corresponding author. E-mail address: manishjain@dtu.ac.in (M. Jain). https://doi.org/10.1016/j.eti.2020.101162 2352-1864/© 2020 Elsevier B.V. All rights reserved.