The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane, butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa were calculated by using Heilig-Franck equation of state. This equation of state contains a repulsion term and an attraction term for intermolecular interaction. With pairwise combination rules for these potentials, three adjustable parameters are needed. The results showed that the critical curves of the former six binary systems belonged to typeⅠ, and CH4+H2O system belonged to type Ⅲ. The calculated data were compared with the experimental data, which yielded good results for the pressure-temperature, pressure-composition and temperature-composition behaviors of the seven systems. Moreover, the values of the adjustable parameters were obtained from the calculation of the critical curves. They can also be used for other relevant calculation.
The fusion temperature as a function of pressure for carbon tetrachloride,chloroform,bromoform and silicon tetrachloride at pressures up to 3500MPa has been determined.The experimental data were fitted by the equation T fus=T 0 (1 + △p/a 1) a 2 exp(a3△ p) and the changes of the molar enthalpy and molar internal energy on fusion were calculated using the parameters of the fitted equation.Comparisons with the data from the literature show that the experimental data,parameters of fitted equations,changes of the molar enthalpy and molar internal energy are reliable.
