| 초록 |
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. 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 significantly under pressurized ammonia feed of 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 of ammonia dehydrogenation coupled with membrane separation. The combined results suggest a feasible and less energy/process intensive option for producing hydrogen or electricity from ammonia. |
