Experimental And Theoretical Study On The Surface Tensions Of Carbonated Aqueous Solution Of Alkanol Amines

The surface tensions of carbonated monoethanolamine(MEA) aqueous solutions and carbonated N-methyldiethanolamine(MDEA)-piperazine(PZ) aqueous solutions were measured by using an automatic surface tension-meter (BZY-1), with the temperature ranging from293.15to323.15K. The mass fractions of MEA and (MDEA+PZ) respectively ranged from10%to30%and10%to45%. Theoretical models applicable for the surface tensions of aforementioned2systems were proposed and the calculated results agree well with the experiments. The average relative deviations are respectively0.76%and0.61%. The influences of temperature, amine concentration and CO2loading (α, mol CO2/mol amines)were demonstrated on the basis of experiments and calculations.The results showed that the surface tension of carbonated MEA aqueous solutions decreases with increasing temperature and mass fraction of MEA, monotonically increases with the increase of α, and the relationship between the surface tension and α can be well described by using quadratic function. For carbonated MDEA-PZ aqueous solutions, the increase of mass fraction of amines and the temperature tends to decrease the surface tensions, yet the increase of a tends to increase the surface tensions. The residual mole numbers of MDEA and PZ decrease with increasing a-, but they do not tend to be zero even in the case of high α,hence the surface tensions of the carbonated solutions are lower than those of pure water. The results provide basic data and predictive models for the design and simulation of the absorption process using amine aqueous solutions.