Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (8): 1426-1431.doi: 10.3866/PKU.WHXB201405231

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

pVT Properties of Alkanes Using Crossover VTSRK Equation of State

SHEN Ai-Jing, DUAN Yuan-Yuan, YANG Zhen   

  1. Beijing Key Laboratory for CO2 Utilization and Reduction Technology, Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, P. R. China
  • Received:2014-03-24 Revised:2014-05-22 Published:2014-07-18
  • Contact: DUAN Yuan-Yuan E-mail:yyduan@mail.tsinghua.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51236004).

Abstract:

Accurate predictions of the pVT properties of alkanes are very important since they are associated with many fundamental aspects in energy, power engineering, and chemical engineering fields. Predicting the properties of alkanes in the critical region, however, remains challenging. In this work, a crossover volume translation Soave-Redlich-Kwong (SRK) equation of state (EoS) was developed for C1 to C20 alkanes, in which volume translation and crossover methods were combined to improve the description of saturated liquid densities and thermodynamic properties in the critical region. The parameters of the crossover equation are set as constants or expressed as functions of critical parameters and the acentric factor. Comparisons showed that the average deviations of the crossover volume translation SRK equation results for C1 to C20 alkanes were 1.01% for vapor pressure, 1.83% for saturated vapor density, and 0.93% for saturated liquid density, and these deviations are much lower than those obtained with the SRK equation of state. In addition, prediction results for properties in the single phase region and the critical region from the crossover equation were in better agreement with experimental data than those from the SRK equation. The crossover volume translation SRK equation was also extended to the pVT properties of cycloalkanes (cyclopropane, cyclopentane, and cyclohexane), benzene and toluene. The prediction results were also satisfactory, demonstrating the superior predictive ability of the crossover equation of state.

Key words: Alkane, pVT property, Critical region, Crossover, Volume translation, SRK equation of state

MSC2000: 

  • O642