CO₂ Adsorption Capture in Wet Gas Source: CO₂/H₂O Co-Adsorption Mechanism and Application

The presence of water vapor in gas streams is a significant technical issue for restricting the large-scale development of carbon capture. The polarity of H2O often leads to the decrease or even failure of CO2 capture rate of adsorbents. In addition, it also causes parasitic losses such as temperature and pressure drop to the system, and even causes equipment corrosion and adsorbent poisoning , thus greatly increasing the extra energy consumption and cost. In order to solve the above bottleneck, understanding the mechanism of H2O/CO2 co-adsorption and developing the highly efficient CO2 adsorbent with reasonable cost, low regeneration energy consumption and insensitivity to H2O are the important basis for the realization of effective CO2 adsorption capture under wet gas streams. At present, due to the dispersion in multiple fields and different emphasis points, there is a lack of summary on the mechanism analysis of the influence of H2O on CO2 adsorption, and it is difficult to form a relatively unified view. In this paper, the co-adsorption process of CO2 and H2O are reviewed in detail from the macro and micro levels. Firstly, according to the fundamental research of co-adsorption mechanism, the progress in the fields of competitive adsorption, moisture swing adsorption and " breathing effect" are reviewed and briefly evaluated. Secondly, based on the application research of co-adsorption, the status and progress of adsorbent development and technology improvement of wet gas CO2 adsorption are described. Furthermore , the CO2 adsorption capture level under different wet gas sources is also briefly evaluated. Finally, the shortcomings of the current research are summarized and the future directions are prospected. This paper attempts to summarize, analyze and compare the CO2/H2O co-adsorption processes in various fields, which may provide effective guidance for CO2 adsorption capture in wet gas source.