Measurements and modeling of high-temperature, high-pressure density for binary mixtures of propane with n-decane and propane with n-eicosane

Abstract

a b s t r a c tBinary mixture density data are reported for propane (C 3 ) with n-decane (C 10 ) and with n-eicosane (C 20 ) at T = (320 to 525) K and pressures to 265 MPa. The (C 3 + C 10 ) mixture density data are in good agreement with available literature data to 70 MPa, which is the maximum reported literature pressure. There are no available binary mixture density data to compare to the (C 3 + C 20 ) mixture density data reported in the present study. The mixture density data are correlated with the Tait equation to facilitate interpolation of the data at different experimental conditions. Equations of state that are suitable for reservoir simulations are used to model the reported data. These models include the Peng-Robinson equation of state (PREoS), a volume-translated PREoS fit to high temperature, high pressure (HTHP) pure component density data, the PC-SAFT EoS, and modifications of the PC-SAFT EoS developed for better representation of HTHP data. The models give superior density predictions for (C 3 + C 10 ) mixtures compared to (C 3 + C 20 ) mixtures.

High-Temperature, High-Pressure Volumetric Properties of Propane, Squalane, and Their Mixtures: Measurement and PC-SAFT Modeling

“…The trends of the excess volume with pressure and temperature are also similar to those observed for previously reported propane binary mixture with octane 8 and with decane and eicosane. 7 In the present study, the most negative value of the excess volume for the propane−squalane mixture is obtained at a propane mole fraction of 0.6550, where the highest degree of packing for the mixture exists. However, the trends depicted in Figure 5 exhibit some hysteresis…”

“…The smooth linear trends were similarly observed for the molar volume for previously published propane−decane and propane−eicosane mixtures. 7 Excess volumes of mixing for the propane−squalane mixture are calculated using eq 3 where V Ex is the excess molar volume, ρ m is the mass density of the mixture, and x i , M i , and ρ i are the mole fraction, molecular weight, and mass density of component i, respectively. The excess volumes are mostly negative for the propane−squalane binary system similar to the behavior exhibited for systems of compounds in the same chemical family.…”

“…Furthermore, the experimental studies on asymmetric binary mixtures of propane with long-chain alkanes at HTHP conditions are scarce in the literature. This gap in the literature has recently been addressed to an extent with publications on HTHP mixtures of propane with octane, decane, and eicosane. − For the propane–squalane system, Nanu et al reported the vapor–liquid equilibrium properties for the mixtures at temperatures to 473 K for 14 different mixture compositions. Aalto et al reported the volumetric properties of the mixture but only in the vicinity of the critical point of propane and at a single mixture composition, which is in excess of 0.996 mole fraction of propane.…”

Phase Behavior and Densities of Propylene + Hexane Binary Mixtures to 585 K and 70 MPa

“…Figure shows the schematic diagram of the view cell used for VLE and density experiments. Found elsewhere − are more details on this apparatus. In the present case, the view cell uses a metal bellow rather than an O-ring-sealed piston to generate pressure.…”

“…A thin Kapton film is used to seal the window against the base of the window holder that is inserted in the front of the cell where the holder makes a metal-to-metal seal. Hence, elastomeric O-rings previously used by our group − to seal the piston and sapphire window are eliminated with these design changes, which improves the reliability of the apparatus when operating at high temperatures. The system pressure, generated by introducing water into the bellows, is measured with a Heise pressure gauge (Heise Corporation, Model CM57303, 0–68.9 MPa, standard uncertainty of 0.07 MPa).…”