Group-contribution modeling of gas solubility in polar and associating solvents

M. GONZALEZ PRIETO; F. SANCHEZ; S. PEREDA; E. A.BRIGNOLE

Puerto Iguazu

Conferencia; XIII International Conference on Properties and Phase Equilibria for Products and Process Design; 2013

Universidad Nacional del Sur / Universidad Federal de Rio de Janeiro

The group-contribution equation of state GC-EoS was originally proposed by Skjold-Jorgensen in 1984 to calculate gas solubility in solvent mixtures. The original version included 9 gases (H2, N2, O2, CO, CO2, CH4, C2H4, C2H6 and H2S) and 14 different functional groups to describe solvents and solvent mixtures. Non-idealities were quantified in this original version by two terms: a free-volume contribution, represented by the Carnahan-Starling equation for hard-spheres, and an attractive term based on a group-contribution version of the NRTL model, with a density-dependent mixing rule. In previous work we have shown that the predicted capability of this model can be significantly improved by the addition of a third term, to account for association and solvation effects. The new group-contribution with association equation of state GCA-EoS has been successfully applied to represent vapor-liquid and liquid-liquid equilibria using a single set of model parameters. In recent years this model has been upgraded to include a new associating model for water and new associating groups like amines, phenols, ethers and carboxylic acids. In this work the GCA-EoS equation model parameters has been revised to represent gas solubility in solvent mixtures, including associating species. The objective is to have predicted capability to represent the phase behavior of biomass-derived compounds and processes.