Numerical analysis of steam methane reforming over a novel multi‐concentric rings Ni/Al2O3 catalyst pattern

• Published in: International journal of energy research Vol. 45; no. 13; pp. 18722 - 18734
• Main Authors: Cherif, Ali, Nebbali, Rachid, Lee, Chul‐Jin
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Inc 25.10.2021; Hindawi Limited
• Subjects: Aluminum oxide; Catalysts; catalytic reaction; CFD; Comparative analysis; Comparative studies; Configurations; Conversion; Cylinders; Hydrogen production; Methane; Numerical analysis; Packed beds; porous media; Process intensification; Reactors; Reforming; Steam; steam methane reforming; Two dimensional analysis; Weight
• DOI: 10.1002/er.6973
• ISSN: 0363-907X

Summary Herein, a 2D numerical analysis is conducted to study the steam methane reforming reaction (SMR), which is the dominant method for hydrogen production, over a packed bed reactor embedded with a Ni/Al2O3 catalyst. Aiming to achieve higher methane conversion and low catalyst weight, a comparative study on an SMR reactor consisting of a 1‐m long, 0.04‐m diameter cylinder, is examined under three distinct operative configurations to explore new routes for process intensification. In the first configuration, the SMR reactor is filled with the catalyst in accordance with the conventional approach. In case 2, a novel design is proposed where the reactor is partially filled with annular catalyst bed patterns while in the last case, the length of the reactor is extended by 35.4% to obtain the same catalyst weight as in case 1 while adopting the annular catalyst patterns concept. The advantages of implementing the catalyst patterns concept over the conventional reactor are illustrated and justified. The results indicate that the partially filled reactor improves the methane conversion by 10.6% by reducing the catalyst weight by 26.16% compared to the conventional reactor. This latter leads to a lower overall cost of the reactor. Extending the reactor increases the methane conversion by around 23% compared to the conventional reactor; however, this affects the reactor compactness. Thermal cold spot, which usually appears at the inlet of the steam methane reforming (SMR) reactors, induces inefficiency of the process. We propose a novel configuration (Multi‐Concentric Rings) to avoid the abrupt decrease of temperature at the inlet and to render the wall‐adjacent pattern highly efficient because of the low released heat towards the center from the wall. Significant increase of methane conversion up to 23% with a decrease of the catalyst weight up to (~26%) can be attained.