The temperature swing adsorption (TSA) process is the most commonly used method for air prepurification units (APU). Compared to the conventional two-bed process, the three-bed TSA-APU can achieve energy savings by recovering and reusing the used purge gas. The purification performance of the three-bed process has recently been demonstrated to be satisfactory by numerical simulation. This study aimed to further characterize the effects of water impurity in the recovered gas on the bed purification performance. Experimental and modeling works were both made on the TSA processes with the conventional regeneration and the regeneration by a used purge heating. Experimental results show that the purification performance of the bed regenerated by a used purge gas heating is still excellent, although it is slightly inferior to that of the bed by conventional regeneration. Comparisons between experimental and modeling results show that the mathematical model can be efficiently employed to predict the dynamic behaviors of adsorbent bed over a wide concentration range.