Study on enhanced absorption of carbon dioxide by porous liquid in mine water

In order to realize the resource utilization of mine water, amino functionalized ionic liquid diethylenetriamine imidazole ([DETA][Im]) and modified ZIF-8 were synthesized to prepare porous liquid [DETA][Im]-(mPEG)ZIF8, which was used to form a solution with mine water to enhance the CO2 absorption capacity of mine water. The metal-organic framework (MOF) materials and porous liquids were characterized by Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) spectroscopy and Brunner-Emmet-Teller (BET) measurements. The saturated CO2 absorption capacity of the porous liquid reached up to 4.5 mol/kg, and the addition of just 20 % of the porous liquid could increase the CO2 absorption capacity of mine water by 53 times. The reaction between [DETA][Im] in porous liquid and CO2 followed the "zwitterion" mechanism. After forming a porous mixed solution by adding [DETA][Im]-(mPEG)ZIF-8 in mine water, the final absorption product was bicarbonate.