Ideal-Gas Thermochemical Properties for Alkanolamine and Related Species Involved in Carbon-Capture Applications

We calculated ideal-gas thermochemical properties (molar enthalpy, entropy, Gibbs energy, and heat capacity, Cp) for 30 primary and 12 secondary alkanolamines and their neutral, protonated, and carbamate forms, and for 7 tertiary alkanolamines and their protonated forms. The data, provided in a spreadsheet format in the Supporting Information document, are useful for the construction of both macroscopic and molecular-based thermodynamic models of CO2-capture processes involving the indicated species. The calculations were implemented using a combination of Spartan18 and Gaussian16 electronic structure software using two typical high-order methods, G4 and G3B3, and for comparison, we also calculated results from the commonly used and less computationally expensive B3LYP/aug-cc-pVTZ method. Our calculation methodology is validated by comparing results for a set of molecules for which literature data are available. The thermochemical data for each species over the temperature range 200–1500 K is given as a function of temperature in the form of NASA seven-term polynomial expressions, permitting the properties to be calculated over this temperature range. The accuracy of the G3B3 and G4 results is estimated to be 6 kJ·mol–1 for the species formation enthalpies, and the B3LYP/aug-cc-pVTZ results are generally of inferior quality.