Effect of acids produced by the dissolution of sulfur and nitrogen oxides in the performance of MEA solvent in CO2 capture: Experimental results and modeling

•The CO2 absorption in MEA solutions containing SO4−2 and NO3¯ was experimentally measured.•New experimental data were obtained using the pressure decay method.•The modified Kent- Eisenberg model was applied to model the investigated systems.•Successful model predictions are presented. Solvent-based CO2 capture is very important for the mitigation of greenhouse gases. The presence of SO2 and NO2 is observed in several types of CO2-containing industrial flue gases and even small concentrations can cause significant changes in the performance of the solvent. Their effects on the CO2 solubility have received very little attention. To simulate the effect of dissolution and accumulation of SO2 and NO2 acid gases on the CO2 loading of aqueous ethanolamine (MEA) solutions, H2SO4 and HNO3 were added, as sources of NO3− and SO4−2 anions, respectively. The CO2 solubility in 30 % wt. aqueous MEA solutions containing 2.9 % wt. H2SO4 with and without 1.8 % wt. HNO3 was experimentally measured using a pressure decay method at 313, 333 and 353 K and approximately 5–500 kPa. In both cases, it is revealed that the addition of H2SO4 and HNO3 substantially decreases the CO2 solubility. In addition, the modified Kent-Eisenberg model was used to predict the CO2 solubility in all systems and at all the studied conditions. The model predictions are in satisfactory agreement with the experimental data presenting Average Absolute Deviations between 4.8 and 6.8 % in all cases. [Display omitted]