Efficient recovery of low-concentration hydrogen from industrial by?product tail gas is of great significance for energy utilization and low-carbon transition. This study employs a flow-through reactor packed with ReNi_4.35Co_0.4Mn_0.05Al_0.2 alloy, using a 25%H₂+75%N₂ gas mixture as the simulated feed, to systematically investigate the effects of the temperature of the circulating medium, inlet flow rate, and pressure on hydrogen separation and purification performance, with hydrogen utilization efficiency at a cumulative flow of 500 L as the core evaluation index. The results indicate that under the same circulating medium temperature and inlet gas pressure, hydrogen utilization efficiency decreases with increasing flow rate, with a more significant drop in the low to medium flow rate range; the influence of temperature shows a unimodal distribution, with 5 ℃ being optimal (balancing thermodynamics and kinetics); and increasing pressure enhances utilization efficiency, with the pressure-induced improvement more pronounced at low flow rates. The optimal process conditions are as follows: circulating medium temperature of 5 ℃, inlet gas pressure of 5 MPa, and inlet gas flow rate of 5 L/min. Under these conditions, the hydrogen utilization efficiency can reach 97.1%. The research content can provide theoretical and parameter basis for the recovery of low?concentration industrial by-product hydrogen via the metal hydride method.