Solubility, absorption heat and mass transfer studies of CO₂ absorption into aqueous solution of 1-dimethylamino-2-propanol

In this work, the CO₂ absorption performance of aqueous 1-dimethylamino-2-propanol (1DMA2P) was comprehensively investigated in terms of CO₂ equilibrium solubility, CO₂ absorption rate, CO₂ absorption heat, and mass transfer efficiency. The CO₂ equilibrium solubility in 2 M 1DMA2P was measured over the temperature range of 298-333 K and CO₂ partial pressure range of 8-101 kPa. The results showed that the CO₂ equilibrium solubility of 1DAM2P was higher than those of conventional amines, MEA and MDEA. The CO₂ absorption heat of 1DMA2P based on the Gibbs-Helmholtz equation was found to be -30.5 kJ/mol, which suggests that 1DMA2P needs a lower regeneration energy as compared with MEA and MDEA. Ion speciation (including 1DMA2P, 1DMA2PH⁺, HCO₃^-, CO₃^2-) plots obtained from the pH method were also generated at the temperatures of 298 K and 313 K. In addition, the overall mass transfer coefficient (K_Ga_v) of 1DMA2P in a packed column was also experimentally obtained and compared with those of MEA and MDEA. The ranking was: MEA > 1DMA2P > MDEA.