abstract
A new model for tracer diffusion coefficients of real systems containing at least one polar component (solvent and/or solute) is proposed in this work. It is applicable for dense gas, liquid, and supercritical phases. It is based on the Rice and Gray approach applied to the Stockmayer potential. The new expression embodies three friction coefficients to take into account a repulsive hard sphere core, a soft Lennard-Jones contribution, and a specifically polar interaction term. The model is explicit on temperature and density, and requires only two parameters. The validation was accomplished with the largest database ever compiled - 211 binary systems and 3463 data points - giving rise to an average absolute relative deviation (AARD) of 3.65%. In the particular case of systems with polar solvents - the main objective of this essay - very accurate results were also obtained: AARD=4.27% for 141 systems and 1994 experimental points. The predictive capability of the new model was also evaluated, exhibiting good and reliable behavior. A spreadsheet for D-12 calculation is provided. (C) 2011 Elsevier Ltd. All rights reserved.
keywords
SUPERCRITICAL CARBON-DIOXIDE; TAYLOR DISPERSION TECHNIQUE; LENNARD-JONES FLUID; LIMITING INTERDIFFUSION COEFFICIENTS; SLIGHTLY SOLUBLE GASES; RHO-T DATA; INFINITE-DILUTION; TEMPERATURE-RANGE; ORGANIC-COMPOUNDS; HARD-SPHERE
subject category
Engineering
authors
Magalhaes, AL; Da Silva, FA; Silva, CM
our authors
Ana Luísa Carvalho Magalhães
Post-doc Fellowship
Carlos Manuel Silva
Associate Professor
Francisco Avelino Silva Freitas
Assistant ProfessorProjects
acknowledgements
Ana L. Magalhaes wishes to thank Ph.D. grant provided by Fundacao para a Ciencia e Tecnologia (Portugal) (SFRH/BD/46776/2008). The research leading to these results has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement no CP-IP 228589-2 AFORE, and project PTDC/EQU-EQU/100476/2008 of FCT. The research leading to these results has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement no CP-IP 228589-2 AFORE, and project PTDC/EQU-EQU/100476/2008 of FCT.