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.