Extension of GCM-GMA equation to long chain primary, secondary and tertiary alcohols, primary and secondary amines, and ketones using group contribution method

In the previous work [21], the GMA (Goharshadi–Morsali–Abbaspour) equation was extended to the long-chain n-alkanes based on the group contribution method (GCM). This extended equation was called GCM-GMA equation. In this work, the GCM-GMA equation has been extended to predict the density and other thermodynamic properties of primary, secondary and tertiary alcohols, primary and secondary amines, and ketones and their binary and ternary mixtures. Each of these organic compounds has been assumed as a hypothetical mixture of methyl, methylene, and a functional group. Then, the GCM-GMA equation has been modified for such a hypothetical mixture. Propane, n-butane, n-hexane, and also 1-pentanol, 2-pentanol, 2-methyl-2-propanol (t-BuOH), 1-pentylamine, 2-aminobutane, and 2-pentanone have been used as basic compounds to obtain the contribution of different segments in the GCM-GMA equation parameters. The calculated parameters along with the GCM-GMA equation have been used to calculate the density and other thermodynamic properties such as isobaric expansion coefficient, αP, isothermal compressibility, κT, and internal pressure, Pi, of different compounds at any temperature, pressure, and mole fraction. The results show good agreement between the values obtained by the GCM-GMA equation and the experimental and literature data. To show the ability of this equation in prediction of density, the calculated densities have been compared with some other equations. The results show that the GCM-GMA equation gives better results than other methods in accord with experimental data.

► GCM-GMA EoS has been extended to organic compounds using group contribution method. ► Each compound has been considered as hypothetical mixture of its constituent groups. ► The contributions of functional groups have been obtained using proper compounds. ► Using this EoS, density of organic compounds and their mixtures can be calculated. ► A comparison between this EoS and some other EoSs has been made.