Vapor-liquid equilibria of nitrogen-hydrocarbon systems at elevated pressures

Abstract

The phase equilibria behavior of nitrogen + hydrocarbon binary, ternary, and quaternary systems was studied. Measurements were made over the temperature range from 305.4 K (90 °F) to 373.2 K (212 °F) at pressures up to 35.85 MPa (5200 psia). The binary systems studied Included nitrogen + n -heptane, nitrogen + n -octane, nitrogen + n -nonane, nitrogen + n -decane, nitrogen + n-dodecane, nitrogen + benzene, and nitrogen + toluene. The methane + n -butane + n -decane, nitrogen + n -butane + n-decane, and nitrogen + methane + n -butane + n -decane systems are also reported. Comparisons with binary data from the literature show good agreement and consistency of a new experimental vapor-liquid equilibrium (VLE) measurement design.

A Parametric Study of the Choice of Binary Interaction Parameter and Equation of State for High Pressure Vapor-Liquid Equilibrium of Nitrogen – n-Dodecane Binary System

“…Even though all k ij values predict the trends quite well, it is observed that both temperature dependent and average k ij values (Gao, Robinson Jr., & Gasem, 1999) predict the liquid-phase nitrogen mole fraction more accurately against the experimental data (Gao, Robinson Jr., & Gasem, 1999), when compared to that predicted using the k ij value reported in Curtis & Farrell (1992). A comparison between theoretical model predictions of the mole fraction of ndodecane in the liquid-phase against the experimental data of Llave & Chung (1988) is shown in Figure 2. As the ambient pressure increases, the liquid-phase mole fraction of n-dodecane decreases due to additional quantities of dissolved ambient gas in the liquid-phase.…”

“…The percentage deviations between the experimental data and the theoretical predictions using different k ij values are shown in Table 2, which consolidates all the above results. The predictions using different EOS such as RK-EOS, SRK-EOS and PR-EOS are compared with the experimental data reported in Gao, Robinson Jr., & Gasem (1999) and Llave & Chung (1988) Gao et al (1999) for a nitrogen-n-dodecane binary system in thermodynamic equilibrium at different temperatures (a) 327.6 K (b) 344.3 K and (c) 366.5 K.…”

“…There are also a few data reported for systems containing hydrocarbons heavier than n-decane (Azarnoosh & McKetta, 1963;D'Avila, Kaul & Prausnitz, 1976;Lin, Kim & Chao, 1981;Llave & Chung, 1988;de Leeuw, de Loos, Kooijman, & de Swaan Arons, 1992;Tong, Gao, Robinson Jr. & Gasem, 1999;Gao, Robinson Jr., & Gasem, 1999). The vapor-liquid phase behavior of a binary mixture is predicted using a real-gas equation of state (EOS), along with proper mixing rules.…”

“…A limited number of experimental data is available for nitrogen−n-dodecane for a moderate range of pressures and temperatures (Llave & Chung, 1988;Gao, Robinson Jr., & Gasem, 1999). However, a theoretical model to predict the same, after due validation with experimental values, especially for a wide range of ambient pressures and temperatures, is scarce.…”

“…: Percentage deviations between the theoretical predictions using PR-EOS and the experimental data of Llave and Chung(1988), Gao et al (1999) Gao et al (1999) and the experimental data of Llave and Chung(1988), Gao et al (1999), when different equations of state are employed.…”