Chitosan Containing Supported Ionic Liquid Phase Materials for CO₂ Absorption

Abstract

Here we present novel CO2 sorbents based on chitosan ionogels. The powder sorbents called inverse supported ionic liquid phase (SILP) materials were prepared by dissolving chitosan in various ionic liquids (ILs) followed by encapsulation of the ionogel droplets with nanoporous fumed silica. CO2 absorption was determined at 40 °C in the range of 200 to 5500 mbar. At 1 bar, absorption capacities of these materials were 0.1–0.8 mol kg–1; at 5 bar, values of 0.2–1.5 mol kg–1 were reached. A comparison of inverse SILP materials with and without chitosan dissolved in the applied IL indicated that the presence of chitosan increased the CO2 absorption efficiency of the materials. The aim of the study was also to compare the CO2 absorption in pure chitosan and chitosan dissolved in ILs. It was found that dissolution increases the absorption capacity of chitosan about 10 times.