Despite the rapid development of carbon dioxide (CO 2 ) adsorbents, their industrial adoption remains hindered by the limited translation of laboratory data into process-level performance indicators. Although adsorption isotherms provide essential inputs for process-performance prediction, conventional isotherm-based assessments often overlook humidity-induced effects, for which water (H 2 O) co-adsorption and dehydration penalties remain difficult to quantify. To bridge these gaps, this study establishes a 0-D equilibrium screening framework that integrates equilibrium adsorption–desorption data and thermodynamic parameters to estimate process-level performance, using specific CO 2 emission (SCE) as the primary metric across three key carbon capture scenarios: post-combustion capture (PCC), direct air capture (DAC), and natural gas purification (NGP). For PCC and DAC, both of which are subject to pronounced competitive H 2 O adsorption, our analyses show that pre-dehydration contributes only 3–8% of the total carbon footprint in PCC, suggesting that adsorbent screening and development should prioritize dry-gas capture efficiency. In contrast, for DAC, the carbon footprint of pre-dehydration is 16–120 times greater than that of the dry CO 2 removal process. Consequently, moisture robustness must be regarded as a non-negotiable criterion for the development of DAC adsorbents. For the NGP scenario, results show that CH 4 recovery is strictly dictated by vacuum requirements, with the SCE escalating sharply once CO 2 working capacity drops below 50%. Accordingly, maintaining a high CO 2 working capacity and a high CO 2 -to-CH 4 working capacity ratio (WCR) is essential for achieving high CH 4 purity with low SCE. Overall, this work highlights the need for scenario-specific adsorbent design and offers guidance for the rational development of adsorbents for practical CO 2 capture.
Jao et al. (Fri,) studied this question.