Integration of thermal augmentation methods in hydride beds for metal hydride based hydrogen storage systems: Review and recommendation

This manuscript thoroughly analyzes and comprehensively reviews the reactor configurations and thermal augmentation systems adopted in metal hydride-based hydrogen absorption/desorption studies and their issues and challenges in reactor design and its operation. The advantages and issues related to each method are studied and compared. This review article aims to critically evaluate the relative system performance on thermal dynamics and hydrogen transfer aspects. The evolution of different types of alloy beds, issues related to the alloy filling and the thermal augmentation systems coupled with metal hydride beds are studied carefully. The various conventional and nonconventional heat exchanger-metal hydride assemblies are here given special attention. Enhancement of heat transfer within and from/to the hydride bed by adding high-performance thermal augmentation systems without a significant reduction in alloy to storage reactor weight ratio was identified as an essential factor in reactor design. In conjunction, it is observed that the hydrogen storage technique incorporated should be compact, reliable, and inexpensive to replace existing hydrogen storage systems. Hence, studies on the gravimetric hydrogen storage capacity of hydrides, reaction kinetics, and heat transfer management in storage systems must be kept integral to reach the objective. This article might help analyze the performance characteristics of the hydride reactor and the selection of various thermal augmentation techniques to design a comparatively effective metal hydride system for precise applications.