Experimental High-Temperature, High-Pressure Density Measurement and Perturbed-Chain Statistical Associating Fluid Theory Modeling of Dimethyl Sulfoxide, Isoamyl Acetate, and Benzyl Alcohol

Experimental high-temperature, high-pressure (HTHP) density of three solvents including dimethyl sulfoxide, benzyl alcohol, and isoamyl acetate was measured at temperatures of 293.15-473.15 K and pressures up to 35-37.5 MPa. The density was measured with an Anton Paar density meter (DMA HP) at 20 K and 2.S MPa intervals. The calibration fluids were water and benzene. The combined expanded uncertainty of density taking into account the device specification and the impurities of the materials was 1 kg"m-3 (0.95 level of confidence). The experimental density data were correlated with the Tait and new modified Tait equations. The thermal expansion coefficient (ay) and isothermal compressibility (KT) were calculated with the new modified Tait equations. Moreover, the perturbed -chain statistical associating fluid theory (PC-SAFT) equation of state was used to model the density data at HTHP. In most cases, the PC-SAFT parameters are obtained from saturated vapor pressure and liquid phase density; however, these parameters were calculated from the density at HTHP in the present study. Regarding these parameters, thermodynamic properties such as the thermal expansion coefficient (cry), isothermal compressibility (KT), isobaric heat capacity (Cp), and speed of sound (u) were calculated. Acceptable agreement between the results with experimental data demonstrated the accuracy of modeling with the obtained parameters.