Measurement and Correlation of Excess Molar Enthalpies of CO2 + CH3OH System in the Vicinity of Critical Point of Carbon Dioxide

Abstract

The excess molar enthalpies of the carbon dioxide + methanol system were measured in the vicinity of the critical point of carbon dioxide using a flow-type isothermal microcalorimeter at temperatures 303.15 K and 308.15 K and pressures from 6.5 to 8.0 MPa. A strong dependence of HE on pressure at this area was observed. The correlation of the excess molar enthalpies was made using a composition-dependent equation composed of two polynomial expressions. It worked successfully for the HE−x curves including the region where there is a complicated change.