Low-Temperature Regenerable Water-Loaded Zeolite 13X for Ammonia Capture, Reusability, and Leak Detection in Confined Space

Ammonia is a carbon-free energy carrier and a natural refrigerant with a high energy density. However, its high toxicity raises significant safety concerns in confined environments. To address this issue, this study developed a hybrid ammonia capture material, water-loaded zeolite 13X (WLZ), which combines the structural stability of zeolites with a strong chemical affinity for water. WLZ was synthesized using an ethanol-water impregnation method. A series of experiments were conducted under simulated leak conditions in pure ammonia and air. WLZ-75, containing 75% water loading, demonstrated high ammonia capture efficiency (over 90% removal at 1000 ppm), stable low-temperature regeneration below 90 °C over repeated cycles, and more than 95% retention after 10 capture/regeneration cycles. Chamber-scale tests confirmed not only its high removal performance but also exothermic behavior, potentially enabling thermal-based leak detection. These results demonstrate that WLZ is a highly regenerable and thermally responsive material suitable for ammonia safety management in refrigeration, fuel systems, and sealed environments.