Direct Air Carbon Capture and Recovery Utilizing Alkaline Solution Circulation

Direct air capture (DAC) represents a promising technologyformitigating climate change by extracting CO2 from the atmosphere.This study introduces a novel application for effective CO2 capture from dispersed emission sources, integrated with a liquidelectrolysis system to improve capture cycle efficiency. By focusingon distributed sources, the DAC application overcomes the constraintsof traditional stationary CO2 capture methods. It employsa thin-layer moving bed spray and air convection to capture CO2 in lean liquid, which converts into rich trap liquid whenthe carbonate concentration exceeds a certain threshold. Electrolysisis then used to recover the lean liquid. This design allows for quick,energy-efficient CO2 absorption even under low partialpressure conditions (462 ppm). The technology is designed to facilitatesignificant CO2 capture while concurrently generating high-purityhydrogen and collecting carbon dioxide. By reusing the capture liquid,an integrated capture and desorption process is realized. In a testwith 1 M KOH as a lean trap solution and a wind speed of 9 m/s, arich trap solution was obtained after 13 h, lowering the CO2 concentration at the outlet by 97 ppm compared to the input air,demonstrating the device's effectiveness.