Experimental and correlational study of isobaric molar heat capacities of fatty acid esters: Ethyl nonanoate and ethyl dodecanoate

An experimental study on the isobaric molar heat capacities of ethyl nonanoate and ethyl dodecanoate was performed at temperatures between 303 K and 393 K and at pressures between 0.1 MPa and 25.2 MPa. An increase of isobaric molar heat capacity with temperature increase was observed, and temperature was found to have a greater effect on isobaric molar heat capacity than pressure. Then the isobaric molar heat capacity data of 18 saturated fatty acid methyl and ethyl esters in literature were selected, to get a general correlation for the isobaric molar heat capacity of saturated fatty acid alkyl esters. The average absolute relative deviation and the maximum deviation of the present correlation from experimental data are lower than 0.70% and 3.82%, respectively. At last, to test the predictive ability of the proposed correlation, the heat capacities of ethyl nonanoate and ethyl dodecanoate were calculated. The average absolute relative deviation and the maximum deviation from our experimental results are 0.88% and 2.10%, respectively.