Density, Speed of Sound, Compressibility, and Excess Properties of Carbon Dioxide + n-Dodecane Binary Mixtures from 10 to 70 MPa

Abstract

Density and speed of sound of carbon dioxide + n-dodecane binary mixtures were measured at pressures from 10 to 70 MPa and at two temperatures around the critical temperature of carbon dioxide (303 and 313 K). The measurements were carried out in pure n-dodecane and five different mixtures with CO2 molar percentage ranging from 20 to 85%. A vibrating U-tube densimeter was used to measure density, whereas speed of sound measurements were carried out by a pulse-echo technique using a double path length sensor working at 3 MHz. Isothermal and isentropic compressibilities were determined from both measurements. Finally, excess volume, excess isothermal compressibility as well as excess speed of sound and excess isentropic compressibility were estimated in the same p,T range and represented as a function of CO2 content.

Density of n-Heptane + n-Dodecane and Carbon Dioxide + n-Heptane + n-Dodecane Mixtures up to 70 MPa from (293.15 to 363.15) K

“…Figure shows the deviations obtained between the experimental densities of n -dodecane with those found in the literature. In comparison to the data reported by Valencia et al, Regueira et al, García-Morales et al, and Bazile et al, the deviations are mainly within the relative deviations of ±0.05%. However, higher deviations occur from the data reported by Landau and Würflinger, Khasanshin et al, and Dzida and Cempa of 0.15, 0.09, and 0.07%, respectively.…”

“…Fractional deviations Δρ = ρ exp – ρ lit of the experimental densities ρ exp of pure n -dodecane from the values of ρ lit obtained from the experimental data available in the literature as a function of pressure. (×) Landau and Würflinger, (Δ) Khasanshin et al, (+) Dzida and Cempa, (□) Valencia et al, (*) Regueira et al, (−) García-Morales et al, and (○) Bazile et al T = 293.15 (pink), T = 303.15 K (black), T = 313.15 K (red), T = 323.15 K (green), T = 333.15 K (blue), and T = 353.15 K (orange).…”

Experimental and modeling studies of density and viscosity behavior of a live fluid due to CO2injection at reservoir condition

“…Therefore, the higher the concentration of CO 2 , the more noticeable the dependence of density on pressure becomes, causing the slope of the mixture density versus pressure to become more pronounced, then causing the crossing of the isopleths. This effect has already been reported for mixtures of CO 2 + hydrocarbons [62][63][64][65], and also for mixtures of hydrocarbons with gases other than CO 2 , such as methane [66,67].…”

“…However, for hydrocarbon + CO 2 systems, the DV/V ratio could assume both positive and negative values. The literature shows that positive values are generally observed at pressure typically above 40 MPa [53,54,64,65].…”

Density, Speed of Sound, Compressibility, and Excess Properties of the Carbon Dioxide + n-Heptadecane Binary Mixture from 10 to 70 MPa

“…The work presented here on binary CO 2 + n -heptadecane mixtures is the third in a series of experimental studies concerning the thermophysical characterization of asymmetric CO 2 + n -alkane mixtures, which include density, speed of sound, isothermal and isentropic compressibilities as well as their excess properties. The previous studies of this series was concerned with the CO 2 + n -heptane and CO 2 + n -dodecane binary systems. In this article, the investigation is extended to mixtures composed of carbon dioxide and a normal alkane with a longer alkyl chain to understand the influence of the hydrocarbon chain length on the nonideality of CO 2 + n -alkane systems.…”