Investigation of tertiary amine-based PILs for ideal efficient SO2 capture from CO2

Four tertiary amine-based protic ionic liquids (PILs) have been carefully designed to investigate the performance of SO2 uptake. Their physical properties of densities and viscosities were determined. In the four PILs, the highest capacity for SO2 of the four PILs reached up to 5.64 mol/kg ILs (P = 1.0 bar, T = 313.2 K). The ideal selectivity of SO2/CO2 was up to 250 in the separation application of SO2 from CO2. The kinetic study demonstrated that the PILs could efficiently capture SO2 quickly under the ambient pressure. Based on the SO2 absorption capacity and selectivity, excellent recyclability, and fast absorption process, the PILs in this work are considered as a potential alternative to traditional absorbents in the flue gas desulfurization (FGD).

Automated summary

Four tertiary amine-based protic ionic liquids have been designed and tested for SO2 uptake, showing a high capacity for SO2 and a high selectivity for SO2/CO2 separation. The kinetic study demonstrated their efficient and quick absorption of SO2 under ambient pressure. Due to their excellent recyclability and fast absorption process, these PILs are considered as a potential alternative to traditional absorbents in flue gas desulfurization (FGD).