Estimation of Ideal Gas Heat Capacities of Hydrocarbons from Group Contribution Techniques. New and Accurate Approach

Abstract

An additive group technique for calculation of ideal gas heat capacities is proposed. Testing with hydrocarbons at several temperatures reveals that this technique is more accurate than any now appearing in the literature.

Hydrogenation of aromatics compounds: Calculation of thermodynamic properties using molecular index connectivity

“…Benson's method and Constantiou and Gani's method use this approach. Other methods, like Yoneda's method and Thinh's method, are also reported in the literature, but they are less used and more limited, and applied only for hydrocarbons. Among the methods listed above, Benson's method is widely used and presents relative success for estimation of thermodynamics properties.…”

An exponential expression for gas heat capacity, enthalpy, and entropy

“…Furthermore, there is no coherent relationship between the 4 constants and molecular properties. Thinh et al [21] expanded the exponential model to a 7-parameter group additive correlation:…”

“…Group additive correlations are often the most accurate [10,22] but also the most complex to handle [21,[23][24][25]. Thinh et al further developed additive models to calculate enthalpy, entropy and Gibbs free energy [26,27].…”

Accurate prediction of the standard net heat of combustion from molecular structure

“…Joback's method is easier to use and has wide applicability (Reid et al, 1987;Joback, 1984). The property calculations may be simple algebraic additions of the group contribution values or a very complex set of equations, such as Thinh et al's equations for calculating the heat capacity (Reid et al, 1987;Thinh et al, 1971;Thinh and Trong, 1976). In general, the complex methods are more accurate, but the simple methods provide reliable estimates and are easier to use (Reid et al, 1987).…”