Experimental studies on a novel La0.7Ce0.3Fe0.75Ni4.25 loaded in annular finned reactor for hydrogen storage, fuel cell and space heating applications

Metal hydride based thermally driven systems have attracted significant attention for storing and transporting hydrogen due to their higher energy density. However, their utility can extend to other diverse applications, such as space heating and fuel cell integration, due to their inherent MH formation or decomposition processes. In this perspective, the objective of the present study is to analyse the hydrogen storage or release behavior and thermal characteristics of a newly developed La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 using an annular finned MH reactor under various operating conditions. The absorption outcomes revealed that La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 stored a maximum hydrogen storage capacity of 1.35 wt.% in 1237 s while releasing heat with an average heat output rate of 104.4 W/kgMH MH at a supply inlet pressure of 25 bar. Also, the achieved peak temperature gain of 14.6 K under similar conditions indicates its utilization in space heating applications, especially in cold countries. The outcomes of desorption at constant pressure indicate that La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 demonstrated 96 % reversibility by releasing 1.31 wt.% of hydrogen in 4509 s with an average heat input rate of 36.4 W/kgMH MH when operating at a HTF temperature of 303 K. Further, the MH reactor was capable of supplying hydrogen at a discharge rate of 13 lpm for 123.5 min at 323 K HTF temperature, ensuring its possible integration with a 1-kW PEM fuel cell. Further, the La 0.7 Ce 0.3- Fe 0.75 Ni 4.25 achieved gravimetric and volumetric storage densities of 0.76 % and 24.6 kg/m3 3 of H2. 2 . Moreover, La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 showed excellent reversibility and exhibited superior desorption characteristics compared to La 0.7 Ce 0.1 Ca 0.3 Ni 5 .