Polyethyleneimine-functionalized HKUST-1/MDEA nanofluid to enhance the absorption of CO 2 in gas sweetening process

A new method based on addition of polyethyleneimine (PEI) functionalized HKUST-1 into an aqueous methyldiethanolamine (MDEA) solution for absorption of carbon dioxide is developed. HKUST-1 was synthesized via solvothermal method and functionalized with polyethyleneimine after activating by heating at 120 °C for 12 h. Addition of 0.2 wt% of PEI-HKUST-1 to aqueous solution of 40 wt% MDEA at different temperatures (303.15, 313.15, 323.15, 333.15 K) and carbon dioxide pressures up to 2200 kPa, increased the CO2 absorption capacity up to 16%. Absorption capacity was increased with increasing partial pressure of carbon dioxide and decreased with increasing temperature for both solutions.