Simultaneous determination of ammonia emission and hydrogen capacity variation during the cyclic testing for LiNH(2)-LiH hydrogen storage system

作者：Ikeda Shingo; Kuriyama Nobuhiro; Kiyobayashi Tetsu^*

来源：International Journal of Hydrogen Energy, 2008, 33(21): 6201-6204.

DOI：10.1016/j.ijhydene.2008.08.003

• Hydrogen storage
• Amide-base material
• Ammonia emission
• Cycling properties

The hydrogen desorption and absorption cycles of the LiNH(2)-LiH system were investigated. We have devised a method to simultaneously measure the hydrogen capacity and the amount of ammonia emitted from the system as a by-product during the hydrogen desorption. The initial hydrogen capacity of ca. 5 mass% exponentially decreased to ca. 2 mass% after 200 cycles at 573 K in which one cycle comprises the hydrogen desorption in vacuo for 3 h and the hydrogen absorption under 3 MPa of pure hydrogen for 2 h. The ammonia concentration in the desorbed hydrogen gradually increased with repeated cycling and abruptly dropped by re-mixing the sample after 100 cycles. By comparing the observed decay rate in hydrogen capacity with the mean ammonia concentration of 0.24 +/- 0.05 mol%(NH(3)/H(2)), we found that about half the decay in hydrogen capacity can be explained by the loss of the constituent nitrogen due to the ammonia emission.

• 出版日期2008-11