Gabrielsen, Jostein1; Michelsen, Michael Locht3; Stenby, Erling Halfdan3; Kontogeorgis, Georgios3
1 Department of Chemical and Biochemical Engineering, Technical University of Denmark2 Center for Phase Equilibria and Separation Processes, Department of Chemical and Biochemical Engineering, Technical University of Denmark3 Center for Energy Resources Engineering, Center, Technical University of Denmark
Partial pressures of carbon dioxide (CO2) over aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), and N-methyldiethanolamine (MDEA) have been correlated using a simple approach where only one chemical equilibrium reaction is taken into account and assuming ideal gas and ideal liquid properties. The approach combines the Henry's law constant and the chemical reaction equilibrium constant for the formation of carbamate for primary and secondary alkanolamines (MEA, DEA) or bicarbonate for tertiary alkanolamines(MDEA), resulting in an explicit expression for calculating the partial pressure of CO2 over an aqueous alkanolamine solution. Accurate values for the partial pressure of CO2 are obtained for a limited loading, temperature, and pressure range that is useful in modeling CO2 capture from coal-fired power plants. Heat of absorption values derived from the model agree with experimental data from the literature.
Industrial and Engineering Chemistry Research, 2005, Vol 44, Issue 9, p. 3348-3354