Selection of Blended Solvents for CO₂ Absorption from Coal-Fired Flue Gas. Part 1: Monoethanolamine (MEA)-Based Solvents

Solvent selection is the potential breakthrough for the chemical absorption method to capture CO2 from coal-fired flue gas. A total of 16 kinds of selected monoethanolamine (MEA)-based solvents were assessed by absorption at 40 °C up to 12 kPa CO2 partial pressure and desorption at 100 °C down to 1.0 kPa CO2 partial pressure. Results showed that the 20% MEA + 10% diethylenetriamine (DETA) system maintains the highest average absorption rates and reaches the highest loading of 0.556 kg of CO2/kg of solute during all of the tested systems. The absorption capacity of the 20% MEA + 10% DETA system is increased to 53%, and the corresponding average removal efficiency is enhanced more than 31% compared to 30% MEA solution. Furthermore, there is only a slight difference between the regeneration performance of the 20% MEA + 10% DETA system and that of the 30% MEA solution.