Characterization and Correlations of CO2 Absorption Performance into Aqueous Amine Blended Solution of Monoethanolamine (MEA) and N,N-Dimethylethanolamine (DMEA) in a Packed Column

To get a more accurate mass transfer coefficient model of CO 2 into aqueous monoethanolamine (MEA)/ N, N -dimethylethanolamine (DMEA) solution in a packed column, the Henry’s law constant, equilibrium CO 2 solubility, volumetric overall mass transfer coefficient ( K G a v ), overall gas-phase mass transfer coefficient ( K G ), and effective gas–liquid interfacial area ( a v ) were comprehensively studied. The Henry’s law constant was obtained using a jacketed stirred glass reactor, and the equilibrium CO 2 solubility was investigated using a bubbling absorption reactor. Additionally, the mass transfer performance was measured and evaluated experimentally in a packed column with DX-Type structured packing in terms of K G a v, K G, and a v . These experiments were conducted under the MEA/DMEA concentration of 6 kmol·m –3 with ratio of 5:1. The dynamic changes of solubility, species concentration, and absorption heat of solution were analyzed under different CO 2 loadings. The experimental results showed that the relationship of successive absorption without synergistic effect from the perspective of equilibrium state for the MEA/DMEA solution and the blended MEA/DMEA solution can reduce the CO 2 absorption heat compared to that of MEA solution. Furthermore, a predicted model of K G a v, which should be suitable for different solution systems with DX-Type structured packings in a packed column, was also proposed and developed based on the K G model and a v model in this work.