Chemical Engineering & Technology, Vol.32, No.5, 710-718, 2009
CO2 Absorption into Aqueous Solutions of Monoethanolamine, Methyldiethanolamine, Piperazine and their Blends
The removal of carbon dioxide from industrial gases, e.g. in thermal power stations to meet the discharge limits for CO2 in flue gases, is usually achieved with a reactive absorption technique using aqueous solutions of alkanolamines. From the absorption performance point of view, primary and secondary amines are preferred. However, in case the costs of the solvent regeneration are also taken into account, tertiary amines are much more attractive. In order to combine the specific advantages of tertiary and primary/seconclary alkanolamines, both types of solvents are mixed. In this paper, mixtures of monoethanolamine and methyldiethanolamine with piperazine as absorption activator are experimentally compared with respect to CO2 removal performances at 25 degrees C. The absorption process in a special packed column has also been simulated with the use of published data on reaction kinetics, physicochemical properties (densities, viscosities, diffusivities, Henry coefficients) of the CO2-amines systems, including experimentally determined hydrodynamic and mass transfer characteristics of the CO2 scrubber.