Validation of a new model with reduced virial coefficients for heat capacity of ring hydrocarbons over a 300 to 1,000 K temperature range based on molecular weight

Abstract

Extensive validation of the new model for heat capacity of Davey & Daughtry (2010), with a reduced number of viral coefficients and based on molecular weight, against independent data is presented. This new model was synthesised from the widely used virial temperature model. When assessed against three classes of a total of 51 compounds from the independent Yaws Database of 17-substituted benzenes (benzene to 1-phenylhexadecane), 17-cyclopentanes (cyclopentane to 1-cyclopentylhexadecane) and 17-cyclohexanes (cyclohexane to 1-cyclohexylhexadecane) the model showed a per cent discrepancy (%Df,g) and per cent bias (%Bf,g) overall of, respectively, +0.6% and -0.07%. Discrepancy between the new model and the established cubic virial model for practical purposes therefore is so small as to be negligible. On average the new model predicts lesser values of heat capacity for these compounds than the virial model as indicated by the negative sign on the per cent bias. The model is simple in form and is easy to use as a practical aid to quick and accurate prediction for this wide range of ring compounds. It can be readily be integrated in heat and energy calculations to obtain, for example, enthalpy. The new model therefore appears to be a generalised model form suitable for a wide range of compounds.