A generalized isothermal equation of state for dense liquids

Abstract

1corresponding states correlation for the isothermal compressibility of pure liquids. Further, we suggested that the integrated form of this correlation could be useful in determining the volumes of isothermally compressed liquids. Such calculations are reported here for several representative liquids and compared with the predictions of the Yen and Woods correlation (1966), which is now widely used in computerized process design.The generalized correlation for the isothermal compressibility is based on a statistical mechanical solution theory. It contains only one adjustable parameter, a characteristic volume, for each liquid. For many substances, this parameter can be approximated by the critical volume. This feature makes the method potentially very attractive for handling substances for which no compression data are available.The correlation iswhere is the reduced density and v" is the characteristic volume parameter tabulated previously for many substances (Brelvi and O'Connell, 1972). Equation ( 1) describes experimental compressibility data for most liquids in the range 1.6 6 7" 3.7. For nonpolar fluids u", as fitted from experimental data, is close to the critical volume. For polar fluids, however, o" is less than the critical volume.From the definition of the isothermal compressibility K, we have Equation (6) relates the isothermal change in density corresponding to a pressure change and holds over the same reduced density range as Equation (1). Table 1 shows numerically integrated values of the right-hand side of Equation ( 6 )

Modeling high-pressure densities at wide temperature range with volume scaling: Cyclohexane+n-hexadecane mixtures

“…Nasrifar et al [15] presented a corresponding states model for compressed liquid densities and compared their model with the models of Yen and Woods [16]; Chueh and Prausnitz [17]; Brelvi and O'Connell [18]; Thomson et al [19]; Lee and Liu [20]; and Aalto et al [21]. The authors [15] found their model superior to the other models, in the case of hydrocarbons, refrigerants and some light gases.…”

“…(17)) a function of pressure and temperature, with these functions obtained in the procedure described in Section 2, and given in Eqs. (18) and (19). The model has six adjustable pure component…”

Evaluation and extrapolation of the solubility of H2 and CO in n-alkanes and n-alcohols using molecular simulation

“…In the NRTL-RK property option, w i is calculated from the Redlich-Kwong [18] equation, and g i is obtained from the NRTL [19] activity-coefficient correlation. The infinite-dilution partialmolar volume needed for the solute in the Poynting factor has been estimated using the Brelvi-O'Connell [20] correlation. The Henry's constant in Aspen Plus is represented by the following empirical temperature-dependent equation:…”

Correlation and prediction of synthesis gas solubility in n‐paraffin systems

“…The formalism, as later generalized temperature, these integrals for pure liquids are relatively insensitive to the nature of the intermolecular forces, yielding a two parameter-corresponding states model for the bulk modulus for a large range of fluids. This leads to an isothermal equation of state [15,161 where all departures of density with pressure from the saturated liquid can be found using a characteristic temperature and volume for each substance. These values are close, or are the critical values for the noble gases; however, they are different for complex compounds.…”