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

 

Project Title:

Extending Equation of State Phase Equilibrium Calculations to Mixtures
Student Name: Meg Estochen
Student's Home Institution: Hope College
Research Advisor: Dr. Michael Misovich
Source of Support: This material is based upon work supported by the Michigan Space Grant Consortium and Hope College.

Equations of state relate temperature, pressure and molar volume of a system. The purpose of this research was to extend previous research done in vapor liquid equilibrium for pure substances to mixtures. The ability to model physical properties of mixtures from limited information is essential to practicing chemical engineers, since substances are rarely pure industrially. An existing program which used the Soave-Redlich-Kwong (SRK) cubic equation of state and pure substance fugacity expression to calculate vapor pressures was modified to calculate the bubble point pressure of a binary mixture. Standard mixing rules were added to the SRK equation, and the pure substance fugacity expression was replaced by individual component fugacity expressions for the mixture. The new program modified the single variable regula falsi algorithm of the existing program to work with two independent variables, pressure and vapor mole fraction, and two dependent variables, differences between liquid and vapor fugacities for both components. Development of the method is ongoing.

Publications and Presentations:
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.

Runge, A.R., Estochen, M.N., and Misovich, M.J., "Universal Vapor Pressure Estimation", Twelth Annual Michigan Space Grant Consortium Conference, University of Michigan, Michigan (2007).