Solubilities of N-phenylacetamide, 2-methyl-N-phenylacetamide and 4-methyl-N-phenylacetamide in supercritical carbon dioxide

The solubilities of N-phenylacetamide, 2-methyl-N-phenylacetamide and 4-methyl-N-phenylacetamide in supercritical carbon dioxide were measured using a semi-flow apparatus. The experimental data were taken at 308.2, 318.2 and 328.2 K, and over the pressure range from 10 to 22 MPa. A plug flow fluid–solid mass transfer model was applied under the experimental conditions, and it showed that the corresponding solid solubility data were measured in the steady state region with low mass transfer effects. The experimental solid solubility data were then correlated using the Peng–Robinson and the Soave–Redlich–Kwong equations of state with van der Waals mixing rules. These data were also correlated with the semi-empirical equation presented by Chrastil, or that presented by Mendez-Santiago and Teja. The solid solubility data calculated from all the correlation models with optimally fitted parameters yielded absolute average deviation of 6%.