Liquid Phase Enthalpy Values for the Methane-Ethane System.

Abstract

In PREVIOUS investigations (8,10,11) saturated liquid phase enthalpies have been calculated for five binary hydrocarbon systems over the pressure range 100 to 600 p.s.i.a. These enthalpy data were calculated from P-V-T-x data and the differential heat of condensation. The basic relationships, which are thermodynamically rigorous, employed are given by Dodge (7) and are / dP \ AHc(1)

A Correlating Equation for Dewpoint Temperature-Pressure-Composition Data of the Methane-Ethane System between 100 and 600 Psia

“…This is likely a factor causing difficulty in obtaining a good correlation. The average of absolute difference between the calculated values and the values of Houser and Weber (1961) for nine pressure levels of 90 points is 4.37%, which is higher than 1.6% reported for those from the bubblepoint temperature correlation (Corn, et al, 1974). Again, large errors appear in the range of y, = 0.95 to 1.0.…”

“…A more sensitive test is to compare slopes determined from correlation with those in the literature (Houser and Weber, 1961). The slopes are calculated by using eq 8 and pressures from eq 1.…”

“…Such a relationship thus would provide coherence and can facilitate the retrieval of variables in an optimization type of design calculations. It also could aid the computation of partial derivatives (e.g., Houser and Weber, 1961) in estimating thermodynamic properties. Due to their complexities, correlations of dewpoint temperatures in terms of a single equation have not been found in the literature.…”

Chebychev Polynomial Correlation Equations of Composition and Bubble/Dew Point Temperature of Binary Mixtures Containing Ethane with Propane, Butane, and Pentane.

“…16,No. for mixtures, Corn et al (1974) demonstrated the feasibility of obtaining two correlating equations for mixtures of methane and ethane, one for bubble point and the other for dew point as functions of composition, over the range of 100 to 600 psia. Such equations are useful in the design of partial and total condensers as well as for thermodynamic calculations of partial derivatives along the bubble point or dew point surfaces (e.g., Houser and Weber, 1961). This approach of direct correlation of bubble/dew point data thus provides a simple and convenient alternative to the use of equations of state.…”

Liquid Phase Enthalpy Values for the Ethane-n-Pentane System.

“…In previous investigations of this type (9,10,15,16) the Benedict-Webb-Rubin equation (3,4) P = RTd + (BoRT-A0 -C0/T2)d2 + (bRT-a)d3 + a a d6 + cd3/T2[(l + d2) exp. (-7 d2)] (8) was used to predict the volumetric behavior of the pure components and their mixtures.…”