Hope College Engineering Department
Research Experiences for Undergraduates
Summer 2007
Project Summary

 

Project Title:

A Quadratic Limit of a Cubic Equation of State
Student Name: Joshua Lanser
Student's Home Institution: Hope College
Research Advisor: Dr. Michael Misovich
Source of Support: This material is based upon work supported by Hope College.

An alternative method to estimate reduced liquid density at low temperatures was studied for possible application in improving the accuracy of vapor pressure prediction. The cubic Soave-Redlich-Kwong (SRK) equation of state was studied at the low temperature limit in which it reduces to a quadratic equation. The goals of this research were to find which two of the three cubic equation roots were found by solving the quadratic equation, then to characterize the difference between the exact cubic roots and the quadratic estimates as a function of temperature and the acentric factor. The two roots that were found by this method were the liquid density and an unphysical result which could be neglected. The error was less than two percent for Tr less than 0.789 for all acentric factors of interest. Future research will study how these new expressions for liquid densities could be incorporated into an existing method
used for vapor pressure prediction.

Publications and Presentations:
Kowalsky, C.A., Lanser, J.L., Walsh, E.J., Wadelton, K., and Misovich, M.J., "Applying a Low Temperature Limit of a Cubic Equation of State to Model Pure Component Phase Equilibrium", AlChE Ann.Mtg. CD-ROM Proc. (2008)

Kowalsky, C.A., Lanser, J.L., Walsh, E.J., Wadelton, K., and Misovich, M.J., "Applying a Low Temperature Limit of a Cubic Equation of State to Model Pure Component Phase Equilibrium", Thirteenth Annual Michigan Space Grant Consortium Conference, Univeristy of Michigan, Ann Arbor, MI (2008)

Lanser, J.L., and Misovich, M.J., "A Quadratic Limit of a Cubic Equation of State", Twelfth Annual Michigan Space Grant Consortium Conference, University of Michigan, Ann Arbor, MI (2007)

M.N. Estochen, A.R. Runge, J.L. Lanser, A.L. Miller, M.J. Misovich, "Explicit Computation Methods for Fluid Phase Equilibrium". Michigan Space Grant Consortium Annual Conference, Ann Arbor, Michigan, Oct. 2007.