Quantification of temperature-dependent CO2 adsorption kinetics in Lewatit VP OC 1065, Purolite A110, and TIFSIX-3-Ni for direct air capture

Abstract

One of the critical factors affecting the performance of an adsorption-based direct air capture (DAC) process is the CO2 adsorption kinetics. Yet, this data is not currently available in the literature for many DAC adsorbents, particularly at the relevant conditions for DAC (i.e. ~ 0.04%vol or 400 ppm). In this study, we report temperature-dependent linear driving force constants (kLDF(T)) measured at 400 ppm CO2 between 20 °C and 70 °C for three promising DAC adsorbents: Lewatit VP OC 1065, Purolite A110, and TIFSIX-3-Ni. TIFSIX-3-Ni exhibits the fastest adsorption kinetics across the whole temperature range, while Purolite A110 has faster adsorption kinetics compared to Lewatit VP OC 1065 at temperatures greater than 40 °C. Overall, the kLDF(T) values determined in this work can be used for initial process scale modelling to assess the process performance of these adsorbents for DAC, while additional experiments would have to be conducted to determine kLDF constants outside this temperature range and at different CO2 concentrations.