Experimental investigations of AB5-type alloys for hydrogen separation from biological gas streams. (7th February 2020)

• Record Type: Journal Article
• Authors: Kazakov, A.N.; Romanov, I.A.; Mitrokhin, S.V.; Kiseleva, E.A.
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 7(2020)
• Page Start: 4685
• Page End: 4692
• Publication Date: 2020-02-07
• Subjects: Intermetallic compound -- Metal hydride -- Hydrogen storage -- Hydrogen separation -- Biohydrogen -- Bed permeability; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.11.207
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: 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 LaNi5-x Mx (M = Fe, Al, Mn, Sn) are prepared and activated during several cycles of H2 sorption/desorption and their PCT properties are measured in Sievert's type apparatus. Two compositions LaNi4.4 Fe0.3 Al0.3 and LaNi4.6 Mn0.2 Al0.2 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 × 10 −13 m 2 for LaNi4.4 Fe0.3 Al0.3 and 6.86 × 10 −13 m 2 for LaNi4.6 Mn0.2 Al0.2 by Kozeny-Carman equation. AB5 type LaNi4.4 Fe0.3 Al0.3 and LaNi4.6 Mn0.2 Al0.2 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. Highlights: AB5 type alloys were studied as materials for biohydrogen purification. Investigated alloys have low equilibrium pressures and hydrogen capacity 1.1 %wt. Two alloys supposed to be used in tubular MH reactor for hydrogen separation. Powder bed porosity and mean particle size are defined experimentally. Powder bed permeabilities for alloys are calculated by Kozeny-Carman equation.