Measurement of SO2 solubility in ionic liquids

Measurements of the solubility of sulfur dioxide (SO2) in the ionic liquids 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][Tf2N]) and 1-n-hexyl-3-methylpyridinium bis(trifluoromethylsulfonyl) imide ([hmpy][Tf2N]) at temperatures from 25 to 60 degrees C and pressures up to 4 bar indicate that large amounts (up to 85 mol %) of SO2 dissolve in ionic liquids by simple physical absorption.