Performance and energy efficiency of a solid-state hydrogen storage system: An experimental study on La0.7Ce0.1Ca0.3Ni5

Abstract

This study presents an experimental investigation conducted on an annular porous metal hydride reactor equipped with radial fins. The reactor was filled with 9 kg of La0.7Ce0.1Ca0.3Ni5, and water was considered as heat transfer fluid. The absorption characteristics were studied under different supply pressures (5–20 bar) and desorption characteristics under different inlet temperatures of heat transfer fluid (30–50 °C). An energy efficiency based on the higher heating value of hydrogen was evaluated for the developed solid-state hydrogen storage device. Further, the effect of pre-sensible heating on desorption performance and energy efficiency was analyzed. Finally, the experimental results were compared with the extensively studied LaNi5 alloy. The results showed that the alloy exhibited a constant desorption rate despite slower desorption kinetics. The energy efficiency of the developed system was found to be 76.76%. The comparison results showed that La0.7Ce0.1Ca0.3Ni5 exhibited higher storage capacity than LaNi5 after 20 cycles and approximately similar absorption and desorption rates. The desorption process without pre-sensible heating was more efficient and reduced overall desorption time by 46.5% than the desorption with pre-sensible heating. However, the desorption process without pre-sensible heating has not significantly affected the energy efficiency.