Current designs pair with electrolyzer sizes from pilot scale to 250MW. Removal of moisture and other contaminants like oxygen allows the hydrogen product to meet ISO 14687, SAE J2719, and other hydrogen quality standards. Dual tower, heat-reactivated design allows for continuous operation and purification. The closed-circuit design utilizes a captive volume at line pressure so no loss of process gas is required for reactivation of the adsorbent