To screen amine solvents for application in CO2 capture from coal-fired
power plants, the equilibrium CO2 partial pressure and liquid film mass
transfer coefficient were characterized for CO2-loaded and highly
concentrated aqueous amines at 40 - 100 °C over a range of CO2 loading.
Promising solvents with large CO2 capacity, fast mass transfer rate and
moderately high heat of absorption were identified. A rigorous
thermodynamic model was developed for a selected amine solvent in the
framework of the Electrolyte Nonrandom Two-Liquid model using the
vapor-liquid-equilibrium and liquid speciation data. The lab-scale mass
transfer rate data was represented with a rate-based model created in
Aspen Plus(R), in which the reaction rate was described with
activity-based termolecular mechanism. The rate-based model can be used
for design and simulation of large-scale CO2 capture process.