Jo, Young Suk Cha, Junyoung Lee, Chan Hyun Jeong, Hyangsoo Yoon, Chang Won Nam, Suk Woo Han, Jonghee 2024-01-19T21:33:21Z 2024-01-19T21:33:21Z 2021-09-04 2018-10-01 0378-7753 https://pubs.kist.re.kr/handle/201004/120813 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 H-2 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 degrees C, and > 99.5% of conversion is achieved at 450 degrees 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 degrees 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. English ELSEVIER SCIENCE BV PALLADIUM MEMBRANES THERMAL-DEGRADATION DECOMPOSITION GENERATION SEPARATION ENERGY SIMULATION NITROGEN SYSTEM STEAM A viable membrane reactor option for sustainable hydrogen production from ammonia Article 10.1016/j.jpowsour.2018.08.010 1 JOURNAL OF POWER SOURCES, v.400, pp.518 - 526 JOURNAL OF POWER SOURCES 400 518 526 scie scopus 000447555400055 2-s2.0-85052143514 Chemistry, Physical Electrochemistry Energy & Fuels Materials Science, Multidisciplinary Chemistry Electrochemistry Energy & Fuels Materials Science Article PALLADIUM MEMBRANES THERMAL-DEGRADATION DECOMPOSITION GENERATION SEPARATION ENERGY SIMULATION NITROGEN SYSTEM STEAM Hydrogen production Ammonia dehydrogenation Fuel cell Membrane reactor Sustainable energy conversion