Abstract
Experiments are reported for hydrogen transport in palladium-coated membranes of niobium, tantalum, and vanadium. Two geometries are studied, coated discs 2 mm thick, and coated tubes of 0.25 mm wall thickness. The hydrogen is extracted at 100% purity. Fluxes are much higher than with current palladium alloy and polymeric membranes at these pressures, and are somewhat higher than with palladium-coated porous ceramics. Palladium-coated niobium discs show effective permeabilities about 0.32 μmol/m-sec-Pa 1 2 at 425°C and 2 atm pressure (including gas-phase resistance). The coated tubes have about 1 2 this permeability, and thus mass transport resistances about 1450 m 2-sec-Pa 1 2 /mol. Coated tantalum discs have effective permeabilities about 0.1 μmol/m-sec-Pa 1 2 , but are less susceptible to hydrogen embrittlement. Since these coated-metals are stronger and more durable than palladium, ceramics of polymers, considerable design flexibility is possible. Based on these measurements, the flux for advanced membranes would be 2000 scf/hr-m 2 for a driving force of 3 atm, suggesting attractive economics for petrochemical plant use.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
