<![CDATA[This study evaluates the adsorption performance of regenerated molecular sieves repurposed as moisture adsorbents for compressed oxygen gas. The spent adsorbents were collected from a Phase Technology Freezing Point analyzer after reaching saturation through repeated use. Two thermal regeneration methods were investigated: (1) staged heating in a furnace at 350 °C for two hours followed by a 30-minute vacuum treatment, and (2) staged heating in a gas chromatography (GC) oven at 350 °C with a dry-nitrogen purge for one hour, followed by one hour without purging and a 30-minute vacuum period. Physical characteristics after regeneration were assessed using UOP Method 422 for particle size distribution (PSD) via micromesh sieving. Moisture adsorption performance was measured according to ASTM D1142, based on dew-point determination using compressed oxygen at operating pressures of 30–50 psi and flow rates of 0.5–1.0 L/min. Results show that regenerated molecular sieves retained approximately 80–90% of the adsorption capacity of new material, with the GC-oven method offering slightly superior performance compared to furnace regeneration. These findings demonstrate that proper regeneration allows spent molecular sieves to be reused effectively, offering a technically viable and economically favorable strategy for moisture removal in oxygen-drying applications while minimizing laboratory waste.]]>
