Aqueous piperazine (PZ) blended with N-(2-aminoethyl) piperazine (AEP) is an attractive solvent for CO2 capture from coal-fired power plants. A rigorous thermodynamic model was developed in Aspen Plus® to predict properties of PZ/AEP/H2O/CO2, using the electrolyte-Nonrandom Two-Liquid (eNRTL) activity coefficient model. A sequential regression was performed to represent CO2 solubility, speciation, and amine volatility data over operationally significant loading and temperature ranges. The model predicts a CO2 cyclic capacity of 0.86 mol/kg (PZ + AEP + water) for 5 m PZ/2 m AEP, compared to 0.50 mol/kg for 7 m MEA and 0.86 mol/kg for 8 m PZ. The predicted heat of absorption is 75 to 85 kJ/mol CO2 in the operating loading range (0.288-0.380 mol CO2/mol alkalinity). Speciation for PZ/AEP/H2O at various CO2 loading and temperature was also predicted, from which behavior of CO2 in the amine system was proposed.
|Original language||English (US)|
|Number of pages||21|
|State||Published - 2014|
|Event||12th International Conference on Greenhouse Gas Control Technologies, GHGT 2014 - Austin, United States|
Duration: Oct 5 2014 → Oct 9 2014
- CO capture
ASJC Scopus subject areas