Evaluation of new density based model to correlate the solubilities of ricinoleic acid, methyl ricinoleate and methyl 10-undecenoate in supercritical carbon dioxide

- Solubilities of three castor oil derived fatty compounds were obtained.
- Solubility trend: methyl 10-undecenoate > methyl ricinoleate > ricinoleic acid.
- A new three parameter model was derived using the solution theory.
- Regular solution theory of activity coefficient was used for SCF phase non-ideality.

The solubilities of ricinoleic acid, methyl ricinoleate, and methyl 10-undecenoate were determined in supercritical carbon dioxide (SCCO2). The solubility measurements were performed in the range of temperatures of 313-333 K, and pressures of 10-18 MPa. The solubilities followed a trend of methyl 10-undecenoate > methyl ricinoleate > ricinoleic acid for the investigated compounds. A new model was derived using the solution theory and regular solution theory for the activity coefficient for correlating the solubility data. The solubility data were fitted using the new model and the average absolute relative deviation (AARD) for each compound was obtained. It was found to be 1.66%, 5.30%, and 6.43% for ricinoleic acid, methyl ricinoleate, and methyl 10-undecenoate, respectively. These AARD values are comparable to other three parameter solution theory model reported in literature indicating the utility of the developed model.

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