Four ionic liqs. were used as entrainers in sepn. of Me2CHOH and H2O (an azeotropic mixt.) by extn. distn. under atm. pressure or 300 mbar. Effect of structure, amt. and recycle of the ionic liqs. on the process course was studied. Some H2O-contg. spent solvents from industry were also successively dehydrated, optionally in presence of moL sieves. AddnL, corrosion test was carried out to confirm good corrosion resistance of steel in the ionic liq.-contg. mediums at 30-120 degrees C.