Thermochemical model for evaluating CO2 regeneration energy for amine absorbents

Abstract

We present a thermochemical model for evaluating CO2 regeneration energies for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), 2-amino-2-methyl-1-propanol (AMP), and 2-(isopropylamino)ethanol (IPAE). The regeneration heat consists of the reaction heat, the sensible heat, and the vaporization heat. We calculated the reaction heat using a thermochemical model. We calculated the concentrations of all chemical species present in the CO2 absorption state at 40 °C and the CO2 release state at 120 °C. We calculated the reaction heat by summing enthalpies of associated reactions and reacted molar quantities derived from the concentration changes between the absorption and release states. For sterically hindered amines AMP and IPAE, the contribution of the protonation reaction to the reaction heat is large, whereas the contributions of protonation and carbamate hydrolysis are large for MEA and DEA. In the regeneration heat, the sensible heat is much larger than the reaction and vaporization heats.