PARAMETRIC INVESTIGATION ON THE PURIFICATION CHARACTERISTICS OF La<inf>0.9</inf>Ce<inf>0.1</inf>Ni<inf>5</inf> UNDER VARIOUS ABSORPTION/DESORPTION CONDITIONS

Abstract

Metal hydride-hydrogen system can provide efficient solution for hydrogen separation from the impure gas mixtures. The present study reports the effect of various absorption/desorption conditions on the hydrogen separation and alloy poisoning characteristics of La0.9Ce0.1Ni5. The experiments is being conducted by varying absorption pressure in the range of 5-20 bar, absorption temperature between 20-30 °C and desorption temperature between 60-90 °C. According to the experimental outcomes, absorption kinetics improves with increase in the absorption pressure and decrease in the absorption temperature. For 20 bar and 20 °C, 12.8232 g of hydrogen get absorbed for 10% impure gas mixture. The desorption temperature played a significant effect on the bed poisoning characteristics of the reactor bed. Desorption kinetics improves with increase in the bed temperature, and is significant for 80-90 °C. For lower range of desorption temperature (60-70 °C), the bed poisoning was significant. Even for 10% impurity, the reaction kinetics of alloy decreases significantly after 4-5 purification cycle. However, for higher desorption temperature (90 °C), the alloy regenerated itself and the bed poisoning is delayed. The system is capable of delivering 99.9995% pure hydrogen for an impurity range from 5-15% for gaseous impurities like CO2, CH4, N2, Ar etc.