SO2 absorption/desorption performance of renewable phenol-based deep eutectic solvents

Six renewable DESs prepared from choline chloride (CC) and phenols (guaiacol, GC; cardanol, CL) with molar ratios of phenols to CC of 3:1, 4:1 and 5:1 were investigated to absorb SO2 at 293.15-323.15K and 0-1.0 bar. Results showed that DESs demonstrated satisfactory SO2 absorption performance, and GC-CC (3:1) exhibited the maximum absorption capacity of 0.528g SO2 per g DES. The SO2 enriched DESs could be easily regenerated and recycled five times. Moreover, the DESs exhibited high selectivity of SO2/CO2. Present DESs seem to be promising absorbents for SO2 due to good performance.