Energy efficient ternary 2-amino-2-methyl-1-propanol, piperazine, and triethanolamine blend for post-combustion carbon capture

Energy efficient solvent was formulated from 2-amino-2-methyl-1-propanol (AMP), piperazine (PZ), and triethanolamine (TEA). Since AMP and PZ can precipitate, ternary blend was explored at unloaded and rich CO2 loading (0.6 mol CO2/mol amine). Either too low TEA concentration, too low PZ/AMP molar ratio, or an increase total amine concentration from 5.0 to 5.5 or 6.0 M induced the precipitation at rich CO2 loading. Even though equilibrium CO2 loaded density and viscosity of the blends were higher than that of 5.0 M MEA (especially, viscosity), they are in operational ranges. A proper solvent formulation strategy was to trade-off between an increment of PZ/AMP molar ratio (favors the absorption) and an elevation of TEA concentration (positively affects the regeneration). Respecting 5.0 M MEA, 0.7/2.8/1.5 has 9 % higher capacity, 73 % greater cyclic capacity, 45 % larger mass transfer coefficient, 5 % higher CO2 removal percentage, and 26 % lower regeneration energy.