Stability of a Benzyl Amine Based CO₂ Capture Adsorbent in View of Regeneration Strategies

In this work, the chemical and thermal stability of a primary amine-functionalized ion-exchange resin (Lewatit VP OC 1065) is studied in view of the potential options of regenerating this sorbent in a CO₂ removal application. The adsorbent was treated continuously in the presence of air, different O₂/CO₂/N₂ mixtures, concentrated CO₂, and steam, and then the remaining CO₂ adsorption capacity was measured. Elemental analysis, BET/BJH analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis were applied to characterize adsorbent properties. This material was found to be thermally and hydrothermally stable at high temperatures. However, significant oxidative degradation occurred already at moderate temperatures (above 70 °C). Temperatures above 120 °C lead to degradation in concentrated dry CO₂. Adding moisture to the concentrated CO₂ stream improves the CO₂-induced stability. Adsorbent regeneration with nitrogen stripping is studied with various parameters, focusing on minimizing the moles of purge gas required per mole of CO₂ desorbed.