Critical Evaluation of Thermochemical Properties of C1–C4 Species: Updated Group-Contributions to Estimate Thermochemical Properties

A review of literature on enthalpies of formation and molar entropies for alkanes, alkenes, alcohols, hydroperoxides, and their associated radicals has been compiled and critically evaluated. By comparing literature values, the overall uncertainty in thermochemical properties of small hydrocarbons and oxygenated hydrocarbons can be highlighted. In general, there is good agreement between heat of formation values in the literature for stable species; however, there is greater uncertainty in the values for radical species and for molar entropy values. Updated values for a group-additivity method for the estimation of thermochemical properties based on the evaluated literature data are proposed. The new values can be used to estimate thermochemical data for larger, combustion-relevant species for which no calculations or measurements currently exist, with increased confidence.