Reactive Absorption of CO2 in Single and Blended Amine Systems

Abstract

Global warming scenario is pretty grim and is a well-known worldwide concern, most likely caused by increasing concentrations of CO2 and other greenhouse gases in the earth?s atmosphere due to human activities. CO2 absorption in amine-based absorbents is an established and proven technology. Unfortunately, this process is still very energy intensive and has high capital costs. The main theme of this work is to characterize new generation solvents; kinetics of CO2 absorption in single and blended amine system is a part of this mission.Kinetics of CO2 in aqueous MAPA system with concentration of 1/2/3/4/5 M and aqueous blended system of MAPA+DEEA with variant concentrations were measured at a temperature range of 298.15-338.15 K. The kinetic experiments for both systems were performed in string of disc contactor. Results for rate constants were interpreted in terms of single step termolecular mechanism proposed by ?Crooks et al., 1989? for the reaction of CO2 with amine because of its less number of parameters.In addition to this work, the physical properties like density from 293.15-353.15 K and viscosity with in span of 293.15-333.15 K were also measured to determine the physio chemical parameters. The solubility of N2O in aqueous MAPA system and aqueous blended systems were performed to estimate the solubility of CO2 in MAPA and blended (MAPA+DEEA) solutions at temperature range of 298.15-338.15K.Densities of systems were measured in Anton Paar DMA 4500M density meter while viscosities were estimated in Physica MCR 100 rheometer and solubility experiments were done in stirred jacketed glass vessel.Simple model based on temperature and concentration was applied on excel sheet in order to calculate the density, solubility and viscosity. The absorption flux of CO2 in MAPA and blended systems, Henry?s constants, over all mass transfer coefficients and second order rate constants were determined for each case and compared these with the citied data available in order to judge the behavior and performance of current systems.