We used hydrate separation method in this paper to recover H-2 and N-2 from tail gases of ammonia plant in the presence of tetra-n-butylammonium bromide (TBAB). The formation condition of H-2/N-2/CH4/TBAB hydrates was measured by pressure search method. Then the continuous separation of H-2/N-2/CH4 via hydrates formation was conducted in the presence of TBAB, and a two-stage separation process was proposed to increase the recovery of H-2 and N-2. The influences of experimental pressure, temperature and gas flow on the separation results were investigated. The results show that the total concentration of H-2 and N-2 in the unhydrated gas (recovered gas) is 95.28 mol%, and the total recovery of H-2 and N-2 is more than 90%. This work supplies the preliminary ideas and fundamental data for the industrial application of hydrate separation method. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.