Experimental investigation and thermodynamic modeling of wax disappearance temperature for n-undecane+n-hexadecane+n-octadecane and n-tetradecane+n-hexadecane+n-octadecane ternary systems

S. Aftab, J. Javanmardi*, K. Nasrifar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


In this investigation, the wax disappearance temperatures (WDT) of two ternary n-alkane systems including n-undecane + n-hexadecane + n-octadecane and n-tetradecane + n-hexadecane + n-octadecane are measured using a homemade visual-based apparatus working under atmospheric pressure (0.9. bar). The two aforementioned ternary systems are modeled thermodynamically without using any adjustable parameter to predict the wax disappearance temperature. Two methods are used for modeling. In one method, perturbed-chain statistical associating fluid theory (PC-SAFT) is used to describe the liquid phase while the solid phase is described by a solid solution model. In the other method, the nonidealities of the liquid and solid phases are both captured using activity coefficient models. Ideal solution, regular solution theory and predictive Wilson are used separately for description of the liquid phase while ideal solution, regular solution theory, predictive Wilson, predictive UNIQUAC and UNIFAC activity coefficient models are used to describe the nonideality of the solid phase. The obtained results show that the use of regular solution theory for the liquid phase and predictive Wilson for the solid phase leads to closer results to the experimental data compared with other combinations of models for both examined systems.

Original languageEnglish
Pages (from-to)70-77
Number of pages8
JournalFluid Phase Equilibria
Publication statusPublished - 2015


  • Activity coefficient model
  • N-Alkanes
  • SAFT
  • Ternary mixtures
  • Thermodynamic modeling
  • Wax disappearance temperature

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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