The Challenge of Water Competition in Physical Adsorption of CO2 by Porous Solids for Carbon Capture Applications – A Short Perspective

With ever‐increasing efforts to design sorbent materials to capture carbon dioxide from flue gas and air, this perspective article is provided based on nearly a decade of collaboration across science, engineering, and industry partners. A key point learned is that a holistic view of the carbon capture problem is critical. While researchers can be inclined to value their own fields and associated metrics, often, key parameters are those that enable synergy between materials and processes. While the role of water in the chemisorption of CO2 is well‐studied, in this perspective, it is hoped to highlight the often‐overlooked but critical role of water in assessing the potential of a physical adsorbent for CO2 capture. This is a challenge that requires interdisciplinarity. As such, this document is written for a general audience rather than experts in any specific discipline. Water is intrinsic to post‐combustion flue streams. Its impact on chemisorptive carbon capture is well established. For physisorptive carbon capture, water is largely regarded as a nearly insurmountable hurdle for competitive carbon dioxide sorption. This perspective discusses, from chemical and engineering vantages, not just the opportunities to physisorb CO2 in wet gas but even suppress the sorption of water.