Novel hollow fiber membrane reactor for high purity H2 generation from thermal catalytic NH3 decomposition

Although storage of H-2 in various liquid chemicals makes it very attractive for practical applications, production and purification of H-2 from decomposition of these chemicals under relatively mild conditions is still challenging. In this work, we reported production of high-purity H-2 from NH3 decomposition using a combined packed bed/ membrane reactor loaded with Ru-based catalyst. Three types of membranes (modified MFI zeolite membrane, carbon molecular sieve membrane, and Pd/Ag membrane) were employed and compared for H-2 production and purification from NH3 decomposition. All these membrane reactors exhibited high NH3 conversion of 99% with H-2 recovery of >90% under pressurized NH3 feed of 7 bar. Nevertheless, H-2 purity varied because of the different separation performance of these membranes. High H-2 purity of >99.999% with <10 ppb NH3 concentration in permeate was achieved using high-quality Pd/Ag membrane reactor. These results suggest a feasible and highly energy efficient option for producing high-purity H-2 from NH3 decomposition.