Accurate Modeling of Evaporation and Enthalpy of Vapor Phase in CO2 Absorption by Amine Based Solution

Abstract

The effect of enthalpy of liquid and vapor phases for the CO2 absorption process in mono-ethanolamine (MEA) solution is one of the important factors involved in CO2 absorption processes. This phenomenon is more prominent at the bottom of the column for countercurrent operations resulting in corrosion, erosion, and loss in amine, mostly at high enthalpy of liquid. The absorption column temperature increases during the CO2 absorption process, due to exothermic absorption of CO2 in amine solution. This rise in temperature increases water evaporation. These water vapors condense back to the liquid phase when they come in direct contact with cold amine solution coming from the top of the column. The Kent-Eisenberg vapor-liquid equilibrium model used is accurate with less than 3% error. A loss of MEA and water in the vapor phase is studied in this research. It is revealed that only 0.001 mole% MEA and 3 mole% water leave the absorption column with flue gases at 298 K. This loss in amine solution is quite low and acceptable for industrial processes.