2.4. Adsorption measurements
The adsorption isotherms of SO2 by IL/MILs were
determined on the BSD-PM analyzer. Before each adsorption experiment,
around 100 mg of samples were weighed and degassed at 353 K and vacuum
(<10-5 Pa) for 12 h. Furthermore, the
adsorption isotherms of CO2 and N2 at
298 K by IL/MILs were determined on BSD-PS (M) analyzer and ASAP 2020
plus HD88 physisorption analyzer (Micromeritics, USA), respectively.
2.5 Breakthrough
experiment
The breakthrough experiment for the removal of 2000 ppm
SO2 was performed at 298 K and 1 bar (Figure S1). In the
dynamic separation experiment, the stainless-steel column with an inner
diameter of 11 millimeters and a loading length of 59 mm was filled with
1.0582 grams of IL/MIL. The activation of samples was carried out with a
carrier gas (He ≥ 99.999%, 30 mL·min-1) purged for 2
h at 373 K. Then, the mixed gas consisting of 2000 ppm
SO2, 15% CO2 and 84.8%
N2 was pumped at the rate of 40
mL·min-1 for the adsorption of SO2.
The mass spectrometer (MS) continuously monitored the recovered gas
passed through the adsorption bed.
3.
Results and discussion