Solubility of HFCs in pentaerythritol tetraalkyl esters

The solubilities of difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (H FC125), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1,1-trifluoroethane (HFC143a ), and 1,1-difluoroethane (HFC152a) in pentaerythritol tetranonanoate, pent aerythritol tetra-2-ethylbutanoate, and pentaerythritol tetra-2-ethylhexano ate have been measured at temperatures between 303 and 363 K and pressures between 0.07 and 2.1 MPa. Henry's constant and the activity coefficient for HFCs at infinite dilution were derived for measurements below 0.34 MPa. Th e measurements were made by an isochoric method with an uncertainty of <2% for Henry's constant and <3% at high pressure. Within the investigated temp erature range, solubilities for HFCs in pentaerythritol tetraalkyl esters d ecrease in the following order: HFC152a > HFC134a > HFC32 > HFC125 > HFC143 a. The experimental data have been correlated with a Flory-Huggins model wi th an extended temperature dependence, which is able to describe the data w ith a deviation from measured data of <2.7%.