A viable membrane reactor option for sustainable hydrogen production from ammonia

Young Suk Jo, Junyoung Cha, Chan Hyun Lee, Hyangsoo Jeong, Chang Won Yoon, SukWoo Nam, Jonghee Han

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Conventional hydrogen production from ammonia is both energy and process intensive, requiring high temperature and independent purification units. Here, we present a compact process of energy conversion from NH3 to electricity using a novel membrane reactor, comprised of a dense metallic Pd/Ta composite membrane and Ru/La-Al2O3 pellet catalysts, and a fuel cell unit. The fabricated Pd/Ta composite membrane, having ca. 5 times higher H2 permeability than conventional Pd-Ag membranes, can both lower NH3 dehydrogenation temperature and completely remove an additional hydrogen purification unit. Compared to a packed-bed reactor without membrane, ammonia conversion improves by 75 and 45%, respectively at 425 and 400 °C, and >99.5% of conversion is achieved at 450 °C under pressurized ammonia feed of 6.5 bar. Main barriers of practical application of Pd/Group V metals as a composite hydrogen permeable membrane, embrittlement and durability issues, are overcome owing to pertinent operating temperatures (400–450 °C) of ammonia dehydrogenation coupled with membrane separation. Finally, as-separated hydrogen with <1 ppm of NH3 is provided directly to a polymer electrolyte membrane fuel cell, showing no performance degradation for an extended time of operation. The combined results suggest a feasible and less energy/process intensive option for producing hydrogen or electricity from ammonia.

Original languageEnglish
Pages (from-to)518-526
Number of pages9
JournalJournal of Power Sources
Volume400
DOIs
Publication statusPublished - 2018 Oct 1

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Keywords

  • Ammonia dehydrogenation
  • Fuel cell
  • Hydrogen production
  • Membrane reactor
  • Sustainable energy conversion

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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