Experimental and modeling studies on the solubility of CO2, CHC1F2, CHF3, C2H2F4 and C2H4F2 in water and aqueous NaCl solutions under low pressures

Solubilities of CO2, CHC1F2 (R22), CHF3 (R23), C2H2F4 (R134a) and C2H4F2 (R152a) in water and aqueous NaCl solutions containing salt 0.0121, 0.0291 and 0.0564 (mole/mole) were measured at three temperatures (278.15, 308.15 and 338.15 K) under low pressures (P < 0.1 MPa). The experimental apparatus consists of a degassing system and a gas absorption unit. Special attention was paid to degassing the solvents in order to obtain reliable solubility data under low pressures. The amount of gas dissolved in the solutions was determined by measuring the PVT data of the gas system. From the measured data, molar concentration of solutes on a salt-free basis and the Henry coefficients were determined. The EOS-approach proposed by Zuo and Guo (1991) was used for correlating the measured data. In this work, the short-range interactions were described by SRK-EOS coupling with van der Waals on fluid mixing rules, while the long-range interactions were represented by the modified Debye-Hückel model. Satisfactory calculation results were obtained.