Carbon dioxide (CO2) capture performance of aqueous tri-solvent blends containing 2-amino-2-methyl-1-propanol (AMP) and methyldiethanolamine (MDEA) promoted by diethylenetriamine (DETA)

Abstract

In this present research, promising aqueous amine tri-solvent blends for carbon dioxide (CO2) capture in post-combustion processes were investigated for their cyclic loadings, cyclic capacities, initial absorption rates, desorption rates, potentials of reducing regeneration energy, and relative costs of the aqueous amine solutions. The absorption experiments were conducted at 101.3 kPa and 313 K using 15.1%v/v CO2, while the desorption experiments were carried out at 101.3 kPa and 363 K. Amines selected in the tri-solvent blends included 1-2 kmol/m3 methyldiethanolamine (MDEA), 1-2 kmol/m3 2-amino-2-methyl-1-propanol (AMP), and 1.5 kmol/m3 diethylenetriamine (DETA), while the total amine solutions concentration were kept constant at 4.5 kmol/m3. The experimental results indicated that all the AMP - MDEA - DETA tri-solvent blends were all superior to 5 kmol/m3 MEA in equilibrium CO2 loadings, absorption capacities, initial desorption rates, cyclic loadings, cyclic capacities, amine - CO2 ratio and regeneration energies. For the initial absorption rates at the first 60 min, only tri - solvent blends with AMP/MDEA molar ratio of 1 and 2 was higher than that of 5 kmol/m3 MEA. The predicted corrosion potential of the AMP - MDEA - DETA blends is lower than 5 kmol/m3 MEA. It was also discovered that the relative costs of the aqueous solutions of the tri - solvent blends considering their estimated circulation rates were lower than that of 5 kmol/m3 MEA. Findings from this research revealed the potentials of the tri - solvent blends in reducing absorber and regenerator sizes and possible reductions in the regeneration energy. 2016 Elsevier Ltd. All rights reserved.