| Type of Document |
Master's Thesis |
| Author |
Oldland, Richard Justin
|
| Author's Email Address |
roldland@vt.edu |
| URN |
etd-12022004-141526 |
| Title |
Predicting Phase Equilibria Using COSMO-Based Thermodynamic Models and the VT-2004 Sigma-Profile |
| Degree |
Master of Science |
| Department |
Chemical Engineering |
| Advisory Committee |
| Advisor Name |
Title |
| Liu, Y. A. |
Committee Chair |
| Davis, Richey M. |
Committee Member |
| Marand, Eva |
Committee Member |
|
| Keywords |
- COSMO-RS
- VT-2004
- computational thermodynamics
- COSMO-SAC
- COSMO
- solvation thermodynamics
- sigma profile
|
| Date of Defense |
2004-11-16 |
| Availability |
unrestricted |
Abstract
Solvation-thermodynamics models based on computational quantum mechanics, such as the conductor-like screening model (COSMO), provide a good alternative to traditional group-contribution methods for predicting thermodynamic phase behavior. Two COSMO-based thermodynamic models are COSMO-RS (real solvents) and COSMO-SAC (segment activity coefficient). The main molecule-specific input for these models is the sigma profile, or the probability distribution of a molecular surface segment having a specific charge density. Generating the sigma profiles represents the most time-consuming and computationally expensive aspect of using COSMO-based methods. A growing number of scientists and engineers are interested in the COSMO-based thermodynamic models, but are intimidated by the complexity of generating the sigma profiles. This thesis presents the first free, open-literature database of 1,513 self-consistent sigma profiles, together with two validation examples. The offer of these profiles will enable interested scientists and engineers to use the quantum-mechanics-based, COSMO methods without having to do quantum mechanics. This thesis summarizes the application experiences reported up to October 2004 to guide the use of the COSMO-based methods. Finally, this thesis also provides a FORTRAN program and a procedure to generate additional sigma profiles consistent with those presented here, as well as a FORTRAN program to generate binary phase-equilibrium predictions using the COSMO-SAC model.
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| Files |
| Filename |
Size |
Approximate Download Time
(Hours:Minutes:Seconds)
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| 28.8 Modem |
56K Modem |
ISDN (64 Kb) |
ISDN (128 Kb) |
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Oldland_MS_Thesis(12-07-04).pdf |
1.61 Mb |
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