Highly efficient amino-functionalized ionic liquid membrane contactor coupled system for low-concentration carbon dioxide absorption and desorption.

Carbon dioxide (CO2) capture and storage (CCS) technology is crucial for rapid decarbonization within the fossil energy system, yet capturing low-concentration CO2 poses technical challenges due to high energy demands and limited durability. To address these obstacles, we developed four amino-functionalized ionic liquids (AFILs) targeting low CO2 concentrations (7 %, 11 % and 15 % by volume in the gas mixture, respectively). This study evaluated these AFILs in combination with a polytetrafluoroethylene (PTFE) hollow fiber membrane contactor for CO2 absorption. Notably, experimental results indicated that triethylenetetramine formate ([TETA][HCOO]) exhibited superior performance, significantly enhancing CO2 absorption and achieving a 98 % decarbonization rate. The membrane desorption method not only increased the regeneration rate but crucially reduced regeneration temperature, offering profound energy-saving benefits. Consequently, this advanced system is a promising low-concentration CO2 separation technology with substantial absorption and desorption efficiency, benefiting industries generating low CO2 concentrations by reducing carbon footprints.