A Bench-Scale Demonstration of Direct Air Capture Using an Enhanced Electrochemical System

The bench-scale demonstration of the UKy-IDEA process for direct air capture (DAC) technology combines solvent-aided CO 2 capture with electrochemical regeneration (ER) through a pH swing process, enabling efficient CO 2 capture and simultaneous solvent regeneration, producing high-purity hydrogen as a valuable co-product. The system shows stable performance with over 90% CO 2 capture efficiency and approximately 80% CO 2 recovery, handling ambient air at 280 L/min. During testing, the unit captured 1 kg of CO 2 over 100 h, with a concentrated CO 2 output purity of around 70%. Operating efficiently at low voltage (<3 V), the system supports flexible and remote operation without AC/DC converters when using intermittent renewable energy. Techno-economic analysis (TEA) and Life Cycle Assessment (LCA) highlight its minimized required footprint and cost-effectiveness. Marketable hydrogen offsets capture costs, and compatibility with renewable DC power enhances appeal. Hydrogen production displacing CO 2 produced via electrolysis achieves 0.94 kg CO 2 abated per kg CO 2 captured. The project would be economic, with USD 26 per ton of CO 2 from the federal 45Q tax credit for carbon utilization, and USD 5 to USD 12 per kg for H 2 .