H2 production via ammonia decomposition in a catalytic membrane reactor

• Published in: Fuel processing technology Vol. 216; p. 106772
• Main Authors: Cechetto, Valentina, Di Felice, Luca, Medrano, Jose A., Makhloufi, Camel, Zuniga, Jon, Gallucci, Fausto
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2021; Elsevier Science Ltd
• Subjects: Ammonia; Ammonia decomposition; catalysts; Conversion; Decomposition; Decomposition reactions; Flow velocity; hydrogen; Hydrogen production; Hydrogen separation; Hydrogen storage; Membrane reactor; Membrane reactors; Membranes; Packed beds; Purity; Separation; temperature; Thermodynamic equilibrium; thermodynamics; Hydrogen separation; Membrane reactor; Hydrogen storage; Ammonia decomposition
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2021.106772

The membrane reactor is proposed in this work as a system with high potential to efficiently recover the hydrogen (H2) stored in ammonia (NH3), which has been recently proposed as an alternative for H2 storage. With this technology, NH3 decomposition and high-purity H2 separation are simultaneously performed within the same unit, and high H2 separation efficiency is achieved at lower temperature compared to conventional systems, leading to energetic and economic benefits. NH3 decomposition was experimentally performed in a Pd-based membrane reactor over a Ru-based catalyst and the performance of the conventional packed bed reactor were used as benchmark for a comparison. The results demonstrate that the introduction of a membrane in a conventional reactor enhances its performance and allows to achieve conversion higher than the thermodynamic equilibrium conversion for sufficiently high temperatures. For temperatures from and above 425 °C, full NH3 conversion was achieved and more than 86% of H2 fed to the system as ammonia was recovered with a purity of 99.998%. The application of vacuum at the membrane permeate side leads to higher H2 recovery and NH3 conversions beyond thermodynamic restrictions. On the other hand, the reactor feed flow rate and operating pressure have not shown major impacts on NH3 conversion. •The Pd-based membrane reactor was investigated for pure H2 recovery from NH3.•The membrane reactor performance exceeds the one of standard H2 recovery systems.•H2 purification units can be avoided by using membrane reactors for H2 production.•High H2 separation efficiency is achieved at lower temperature than other systems.