Characterization of Piperazine/2-Aminomethylpropanol for Carbon Dioxide Capture

In this work, two blends of piperazine (PZ) and 2-amino-2-methyl-1-propanol (AMP) (5 m PZ/2.3 m AMP and 2 m PZ/4 m AMP) were characterized for use in CO2 capture by amine scrubbing. Experimental results on solid solubility, CO2 solubility, mass transfer rate, viscosity, volatility and thermal degradation are given. The 2/4 blend has the advantages of low viscosity (6 cP at 40 °C when the loading is 0.45) and no precipitation over a wide loading range. The heat of CO2 absorption is 72 kJ/mol (PCO2 = 1.5 kPa, 40 °C), about 10 kJ/mol higher than 8 m PZ. The 2/4 blend maintains the performance of 8 m PZ in terms of high CO2 absorption rate and CO2 capacity. The 5/2.3 blend has a better solid solubility window (0 °C) than 8 m PZ, but does not perform as well with other criteria.