Measurement and correlation of binary diffusion coefficients of lithium acetylacetonate in supercritical carbon dioxide and in liquid ethanol

摘要

The infinite dilution binary diffusion coefficients D-12 of lithium acetylacetonate were measured in supercritical carbon dioxide by the chromatographic impulse response (CIR) method at 308.15-333.15K and pressures up to 36.00 MPa. The D-12 values were also measured in liquid ethanol at 298.15-333.15K, and at 0.10, 10.00 and 30.00 MPa by the Taylor dispersion method. The effects of temperature, pressure and density of fluid on D-12 values were studied. The D-12 data increased from 1.140 x 10(-9) m(2) s(-1) in liquid ethanol at 298.15K and 30.00 MPa to 2.218 x 10(-8) m(2) s(-1) in supercritical carbon dioxide at 333.15 K and 14.00 MPa. It was observed that the D-12 data in supercritical carbon dioxide at 15.00, 20.00 and 30.00 MPa can be well correlated as a function of temperature using an Arrhenius type equation, which provided the diffusion activation energies of 17.5, 13.4 and 11.0 kJ mol(-1); that in liquid ethanol at 0.10,10.00,30.00 MPa gave the diffusion activation energies of 14.0, 14.2 and 13.8 kJ mol(-1), respectively. It was found that the proposed correlation based on hydrodynamic approach can well represent all the measured D-12 data of lithium acetylacetonate in supercritical carbon dioxide and in liquid ethanol with the average absolute relative deviation (AARD) of 1.7% for 88 data points. (C) 2015 Elsevier B.V. All rights reserved.