Solubility of CO2 in CO2-philic oligomers; COSMOtherm predictions and experimental results

We report the solubility of carbon dioxide in four physical solvents and compare our data to predicted phase behavior using the conductor-like screening model for real solvents (COSMO-RS) formalism. The solubility data are presented in pressure-composition (Px) diagrams as well as Henry's law coefficients on a wt% basis at 298.15 K. The oligomers presented in this study are poly ethylene glycol di-methyl ether (PEGDME), perfluoro polyether (PFPE), poly di-methyl siloxane (PDMS), and poly propylene glycol di-methyl ether (PPGDME), which is a new solvent designed for this application by our group. These oligomers had 2–5 repeat units. We assess these four oligomers for capturing CO2 from high-pressure streams. The COSMO-RS formalism is able to qualitatively and to some extent quantitatively describe solubilities of CO2 in each of the oligomers.