Abstract:
The present work investigates two potential amine activators, 1-(2-aminoethyl) piperazine (AEP) and N-(3-aminopropyl)-1,3-propanediamine (APDA) for its applicability in efficient CO2 capture from flue gas streams. The study reports new experimental CO2 solubility data of absorption in various compositions of aqueous AEP and APDA system over the broad temperature and pressure range of (303.2˗323.2) K and (3-300) kPa, respectively. Along with binary system, different blended system with non-carbamate forming amines such as N-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP) and 1-dimethylamino-2-propanol (1DMAP) have been also explored in the current work. The blended amine systems considered in this work are aqueous (AEP + MDEA), (AEP + AMP), (APDA + MDEA), (APDA + AMP) and (APDA + DMAP), respectively. The experimental solubility data is modeled using modified Kent-Eisenberg (KE) equilibrium model. The equilibrium constants related to amine deprotonation, and carbamate formation reactions are regressed as a function of important operating parameters such as, CO2 partial pressure, amine concentration and temperature to fit the equilibrium CO2 solubility data. The model predicted solubility results from KE model are in good agreement with the experimental data. The application of the modified KE model developed in this study can be further extended in estimating the pH and the overall speciation profile of all the molecular as well as ionic species prevailing in the solvent system. The CO2 solubility data are also analyzed in view of estimating the heat duty requirement for the absorption process.
