Membranes for Direct Air Capture Driven by Moisture Gradients

Summary Direct Air capture is a high-energy consuming and expensive carbon-negative process but may be indispensable to reach the carbon emission reduction goals. Membranes are usually not effective in direct air capture, as they are driven by a pressure gradient which is very low in the case of direct air capture (40 Pa). A new process which exploits a moisture-swing chemistry may overcome this issue and make the membrane-based moisture-driven direct air capture of CO2 feasible at ambient pressure, just providing a humidity difference. This could be coupled to renewable energy or waste heat to further reduce energy use.