화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.45, No.7, 4685-4692, 2020
Experimental investigations of AB(5)-type alloys for hydrogen separation from biological gas streams
AB5-type intermetallic compounds are suitable materials for hydrogen separation due to their ability selectively absorb hydrogen from different gas streams, including biologically produced ones. Recent studies show that metal hydride-based purification systems can effectively extract hydrogen from biogas with high CO2 concentration. Alloys LaN15-xMx. (M = Fe, Al, Mn, Sn) are prepared and activated during several cycles of H-2 sorption/desorption and their PCT properties are measured in Sievert's type apparatus. Two compositions LaNi4.4Fe03Al0.3 and LaNi4.6Mn0.2Al0.2 are chosen for further investigations because they meet the requirements for biohydrogen separation system. After PCT measurements of 50-g samples, metal hydride powders are investigated by means of Quantochrome Nova 1200 and scanning electron microscopy to determine porosity, average particle size, specific surface area and permeability of metal hydride bed. Powder bed permeabilities are defined as 9.08 x 10(-13) m(2) for LaNi4.4Fe0.3Al0.3 and 6.86 x 10(-13) m(2) for LaNi4.6Mn0.2Al0.2 by Kozeny-Carman equation. AB(5) type LaNi4.4Fe0.3Al0.3 and LaNi4.6Mn0.2-Al-0.2 alloys show good characteristics: low equilibrium pressures 0.025-0.03 MPa and acceptable reversible hydrogen capacity 1.1 %wt. for stationary hydrogen separation system. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.