109 Int J Petrochem Res. ISSN: 2638-1974 Volume 2 • Issue 1 • 1000120 International Journal of Petrochemistry and Research Research Article Open Access Multi-stage membrane reactors for hydrogen production by ammonia decomposition Abashar MEE* Department of Chemical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421 , Saudi Arabia Article Info *Corresponding author: M. E. E. Abashar Department of Chemical Engineering College of Engineering King Saud University P.O. Box 800, Riyadh 11421 Saudi Arabia E-mail: mabashar@KSU.EDU.SA Received: November 15, 2017 Accepted: January 28, 2018 Published: February 3, 2018 Citation: Abashar MEE. Multi-stage membrane reactors for hydrogen production by ammonia decomposition. Int J Petrochem Res. 2018; 2(1): 109-115. doi: 10.18689/ijpr-1000120 Copyright: © 2018 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Published by Madridge Publishers Abstract A heterogeneous mathematical model is used to simulate a cascade of multi-stage fixed bed membrane reactors (MSFBMR) for the decomposition of ammonia. The numerical results show that a single fixed bed membrane reactor (FBMR) exhibits a poor performance and limited by the kinetics to give 29.49% exit ammonia conversion, whereas efficient seven multi-stage beds achieve 100% ammonia conversion. An effective hydrogen permeation zone has been identified by a critical point. It is observed that the locus of the total inter-stage heating load assumes a maximum inflection point. The results show that the multi-stage fixed bed membrane reactors configuration has many benefits and can the future generation of reactors for production of hydrogen. Keywords: Ammonia decomposition, hydrogen, membrane reactor, modeling, multi- stage reactors. Introduction In recent years the demand for ultra-clean hydrogen is increased significantly to power polymer electrolyte membrane (PEM) fuel cells. [1, 2]. Conventional steam reformers produce hydrogen with a high level of traces of impurities not suitable for the PEM. Today, hydrogen perm-selective composite membranes produce high quality of hydrogen. Moreover, they play an important role in displacement of thermodynamic equilibriums [3-6] and enhancement of the reactors performance. Further improvements are still needed for best design and operation. Decomposition of ammonia is an attractive process for pure hydrogen production. The reaction gives only hydrogen and nitrogen. The reaction has received much attention for on-site (local) hydrogen production. Several theoretical studies have been published on ammonia decomposition. However, these studies have been largely directed toward the removal of ammonia traces as a pollutant [6-8]. The chemical engineering literature contains limited theoretical and modeling studies for hydrogen production by ammonia decomposition at the level of experimental bench scale reactors [9]. In fact, more modeling and simulation studies for different reactors configurations for ammonia decomposition are needed. Surprisingly, theoretical studies of multi-stage fixed bed membrane reactors (MSFBMR) for the decomposition of ammonia are scarce. In this study, the mathematical modeling and numerical simulation approach has been implemented to investigate application potential of multi-stage membrane reactors for production of ultra-clean hydrogen. The benefits that can be gained by these reactors configurations are explored. Moreover, deeper insight understanding of the process might be gained. Furthermore, the effect of the key parameters on the performance of the MSFBMR are considered. ISSN: 2638-1974