Study on the thermophysical properties of waste cooking oil biodiesel fuel blends with 1-butanol

Abstract

An Anton Paar vibrating tube densimeter HPM DMA calibrated with an uncertainty of ±0.7 kg•m−3 has been used for accurate measurements of liquid densities of Waste Cooking Oil Biodiesel (WCOB) and 1-butanol as pure fluids and binary liquid mixtures. The densities measurements were performed at temperatures (298.15 K to 393.15 K) and pressures (0.1 MPa to 140 MPa) and showing an absolute deviation of less than 0.007 g/cm−3 compared to the literature data. Using these new experimental data (908 points), excess molar volumes VE, isobaric thermal expansivity, αp, and isothermal compressibility, кT, have been calculated. The Tait and PC-SAFT equations correlate successfully the densities with a small absolute average deviation (AAD), the PC-SAFT model performs very well in all concentration range with a global absolute average deviation (AAD) of 0.325% and for Tait equation a global absolute average deviation of 0.086% for each concentration. PC-SAFT equation correlates satisfactorily the density and shows that it can explain the same interactions between fluid molecules contrary to the Tait equation. Excess volumes values were calculated from the experimental data and show a positive parabolic shape in all composition range almost symmetrical in the fraction molar 0.5. Furthermore, VE values were fitted to the Redlich-Kister equation and showed satisfactory correlation with very small standard deviation values with a global of 4.23·10−5 cm3·mol−1.