Synergistic CO2-H2O sorption kinetics of ionic exchange resin for moisture swing direct air capture

[Geoengineering News]

https://www.sciencedirect.com/science/article/abs/pii/S0263876226001899

Authors: Sheng Chen, Renyu Xie, Yuxuan Zhang, Ying Ji, Tao Wang, Long Jiang 

31 March 2026

https://doi.org/10.1016/j.cherd.2026.03.037

Highlights

•Synergistic CO2-H2O sorption behaviors are investigated under diverse conditions.

•H2O-CO2 kinetics are controlled by interdependent equilibrium restriction.

•Water-quantified correction for kinetics description is proposed.

•MMO-n and LDF-n models exhibit superior fitting performance for MSA process.

Abstract

Moisture swing adsorption (MSA) is considered as a promising negative emission technology for CO2 direct air capture (DAC), but its kinetics description remains challenging due to the synergistic and interdependent sorption behaviors of CO₂ and H₂O. This study initially proposes H₂O-informed MSA kinetics characterization for D290 ionic exchange resin. By investigating the apparent sorption characteristics based on customized experimental platform, the research finding gives insights into the dynamic interdependence for binary-sorption. Under different adsorption states, two components induce phased changes in kinetics through equilibrium restriction mechanism, which underscores the significance of synergistic modeling. The diverse operating conditions including temperature, humidity, concentration, and flow rate are confirmed as dominant factors regulating mass transfer rates. Subsequently, the applicability of twelve kinetics models for fitting CO₂-H₂O synergistic adsorption and desorption processes of D290 ionic exchange resin is systematically evaluated. Results show that the MMO-n, LDF-n, Toth, and MMO models exhibit excellent versatility across adsorption and desorption processes. It establishes a connection between H2O-CO2 synergistic sorption and dynamic modeling, filling the gap in MSA kinetics modeling and providing a methodological basis for scale-up applications and technological analysis.

Source: ScienceDirect