Hybrid behaviors of CO2 absorption into blended DEEA-based solution for the improvement of capture performance

BACKGROUND

At present, the chemical absorption method of CO₂ capture is considered to be an effective means to reduce carbon emissions. The development of blended amine systems with excellent CO₂ capture performance is the focus of research.

RESULT

The hybrid behaviors of N,N-diethylethanolamine (DEEA) with addition of monoethanolamine (MEA), 2-(methylamino)ethanol(MAE) and 2-((2-aminoethyl)amino)-ethanol(AEEA) as absorbents were investigated and developed to reduce the energy consumption for solvent regeneration in the CO₂ capture process. The equilibrium solubility of CO₂ for blended DEEA/MEA, DEEA/MAE and DEEA/AEEA with a series of molar ratios (0.0:2.0, 0.5:1.5, 1.0:1.0, 1.5:0.5 and 2.0:0.0) was examined. The experimental results showed that the values of CO₂ equilibrium solubility of amine blends exhibited a compromise behavior between each individual amine solution. Additionally, the effects of molar ratios on the relative CO₂ absorption rate, regeneration rate and CO₂ cyclic capacity for the tested amine blends were studied using an improved rapid absorbent screening method.

CONCLUSION

The experimental data showed that the blended DEEA/MAE solution exhibits much higher CO₂ cyclic capacity than that of DEEA/AEEA under the nitrogen atomic conservation. However, the mixing DEEA and AEEA could obviously reduce the CO₂ equilibrium solubility and CO₂ cyclic capacity compared with that of individual AEEA solution, indicating the DEEA had an inhibiting effect on AEEA. Furthermore, the mass transfer performances of DEEA, DEEA/MAE and DEEA/AEEA were tested in order to validate the accuracy of the improved rapid absorbent screening method. © 2024 Society of Chemical Industry (SCI).