Vapor liquid equilibrium of two ternary systems potassium formate (HCOOK) + propylene glycol (C3H8O2) + water (H2O) and potassium formate (HCOOK) + glycerol (C3H8O3) + water (H2O) were studied at temperature ranges from 313.15 to 453.15 K and mass fraction of absorbent species from 0.4 to 0.8 with varying mass ratio of potassium formate/propylene glycol and potassium formate/glycerol (mass ratios = 4, 3 and 2). Experimental data are correlated with the nonrandom two-liquid model. The solubility, density, and viscosity of these mixtures were also measured.