Decarbonization through Direct Air Capture: Performance Assessment of Ca(OH)₂ and NaOH for CO₂ Removal

Urbanization and industrialization mainly contribute to the rise in Carbon Dioxide (CO2) concentration in the atmosphere, which has become a challengingly important issue to the stability of the global climate. This paper is an analysis of the efficiency and effectiveness of Sodium Hydroxide (NaOH) and Calcium Hydroxide (Ca(OH)2) solutions as the solvent of a Direct Air Capture (DAC) machine. In order to do this, a specially designed direct air capture device was built to mimic an air filtration device to feed the ambient air into the solvent chamber. The turbidity measurements were used to quantify the CO2 absorption, with higher turbidity corresponding to a more significant carbonate precipitation, and thus, it could be used as a proxy to capture efficiency. The potential of Calcium and Sodium hydroxide as a potential solvent to capture and store ambient carbon dioxide in efficient way is investigated in the study, thus helping to contribute to reducing atmospheric CO2 levels.