Hosseinpour et al. (2025):Techno-economic study of a direct air capture system based on the carbonation of Ca(OH)2 plates integrated into cooling towers

Mohammad Hosseinpour, Bijan Hejazi, Yolanda A. Criado IN: Journal of Cleaner Production, https://doi.org/10.1016/j.jclepro.2024.144545

One of the main challenges in DAC processes is the high energy and economic costs associated with airflow systems in large-scale air contactors. Recently, there has been a growing interest in using hydrated lime to capture low concentrations of CO₂ (∼450 ppm) from the atmosphere, particularly at higher air relative humidity. Cooling towers, commonly used in various industrial units to cool process water, provide an ideal environment for hydrated lime-based DAC systems as they expose large flows of ambient air to water. This study assessed the feasibility of integrating vertically oriented parallel flat plates of Ca(OH)₂ into the upper section of an industrial mechanical draft cooling tower to simultaneously perform the dual tasks of water cooling and CO₂ capture from the passing air.

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