Experimental evaluation of effect of oxidative degradation of aqueous monoethanolamine on heat of CO2 absorption, vapor liquid equilibrium and CO2 absorption rate

Takao Nakagaki, Ippei Tanaka, Yukio Furukawa, Hiroshi Sato, Yasuro Yamanaka

Research output: Contribution to journalConference article


Oxidative degradation produces carboxylic acids which are one of the undesirable degradation products and may have a negative impact on the CO2 separation energy of post combustion capture system. 30wt% MEA solutions mixed with carboxylic acids were regarded as a simulated solution for degraded MEA and effect of the additives on heat of CO2 absorption, equilibrium CO2 loading and CO2 absorption rate were experimentally evaluated by using a differential reaction calorimetry (DRC) apparatus, a pressurized vessel to obtain vapor liquid equilibrium (VLE) data and a gas-liquid contactor, respectively. At the range of CO2 loading from 0.0 to 0.3 mol-CO2/mol-amine, the heat of CO2 absorption of the simulated solution increased by around 10% compared to the normal MEA solution. Moreover, the changing-point of the heat of CO2 absorption of the simulated solution moved to a leanerCO2 loading compared to the normal solution. Result of a 13C-NMR analysis also indicated the change in reaction mechanism. At the absorber condition, the equilibrium CO2 loading of the simulated solution decreased by 20% in comparison with the normal solution, where it decreased by 10% at the stripper condition and therefore the cyclic CO2 loading also decreased. Both CO2 absorption rates decreased linearly but in different gradients with increasing CO2 loading. Higher pH in the simulated solution kept higher CO2 absorption rate, which is consistent with the result of pH measurement.

Original languageEnglish
Pages (from-to)2384-2393
Number of pages10
JournalEnergy Procedia
Publication statusPublished - 2014 Jan 1
Event12th International Conference on Greenhouse Gas Control Technologies, GHGT 2014 - Austin, United States
Duration: 2014 Oct 52014 Oct 9



  • Absorption rate
  • Carboxylic acids
  • DRC
  • HEA
  • Heat of CO absorption
  • HEF
  • VLE

ASJC Scopus subject areas

  • Energy(all)

Cite this