Solid-State Conversion of Magnesium Waste to Advanced Hydrogen-Storage Nanopowder Particles

Abstract

Recycling of metallic solid-waste (SW) components has recently become one of the most attractive topics for scientific research and applications on a global scale. A considerable number of applications are proposed for utilizing metallic SW products in different applications. Utilization of SW magnesium (Mg) metal for tailoring high-hydrogen storage capacity nanoparticles has never been reported as yet. The present study demonstrates the ability to produce pure Mg ingots through a melting and casting approach from Mg-machining chips. The ingots were used as a feedstock material to produce high-quality Mg-ribbons, using a melting/casting and spinning approaches. The ribbons were then subjected to severe plastic deformation through the cold rolling technique. The as-cold roll Mg strips were then snipped into small shots before charging them into reactive ball milling. The milling process was undertaken under high-pressure of pure hydrogen gas (H2), where titanium balls were used as milling media. The final product obtained after 100 h of milling showcased excellent nanocrystalline structure and revealed high hydro/dehydrogenation kinetics at moderate temperature (275 °C). The present study shows that primer cold rolling of Mg-strips before reactive ball milling is a necessary step to prepare ultrafine magnesium hydride (MgH2) nanopowders with advanced absorption/desorption kinetics behavior. These ultrafine powders with their nanocrystalline structure are believed to play an important role in effective gas diffusion process. Moreover, the fine titanium particles came from the ball-powder-ball collisions and introduced to the Mg matrix have not only acted as micro-scaled milling media, but they played a vital catalyzation role for the process.

Effect of Cold Rolling on Magnesium-Based Metal Hydrides

“…El-Eskandarany et al recycled Mg-machining chips by first melting them and thereafter subjecting the ribbons to cold rolling and ball milling. 67) Cold rolling produced small crystallites and enhanced hydrogenation/dehydrogenation kinetics. Donandey et al also investigated different techniques (ball milling and cold rolling) on wastes of Mg-based alloy Elektron 21 (UNS-M12310).…”

Enhanced Hydrogen Storage Performance of MgH2 by the Catalysis of a Novel Intersected Y2O3/NiO Hybrid

“…Hydrogen is considered to be one of the most promising clean energy carriers, while safe, efficient and low-cost storage of hydrogen is the key bottleneck technology for largescale application of hydrogen energy to date [1][2][3]. MgH 2 has attracted much attention as a hydrogen storage material due to its advantages of good reversibility, high mass hydrogen storage density (7.6 wt%), and low cost [3][4][5][6]. MgH 2 prepared from waste Mg-alloys also show favorable possibility for hydrogen storage [5,6], offering more opportunities to lower the cost.…”

“…MgH 2 has attracted much attention as a hydrogen storage material due to its advantages of good reversibility, high mass hydrogen storage density (7.6 wt%), and low cost [3][4][5][6]. MgH 2 prepared from waste Mg-alloys also show favorable possibility for hydrogen storage [5,6], offering more opportunities to lower the cost. However, the high thermal stability of MgH 2 (∆H = 75 kJ•mol −1 H 2 ) and the reaction barrier (∆E = 161 kJ•mol −1 ) [7] lead to high dehydrogenation temperature, where the peak dehydrogenation temperature is commonly over 360 • C [8], which limit its practical application for hydrogen storage.…”

Behavior of Compacted Magnesium-Based Powders for Energy-Storage Applications

“…Moreover, considering sustainability in a circular economy, the end of life of reactors filled with MgH 2 -Fe compounds could be easily managed, as these elements are environmentally compatible and they could potentially be recovered and reused. In this framework, the suitability of recovering Mg-Al alloys and chips from magnesium processing for preparing compounds for hydrogen-storage applications has also been demonstrated [68][69][70].…”