Method and apparatus for decomposing nitrosamines formed in removing co2 from flue gases using an aqueous amine solution

A method of decomposing nitrosamines contained in a nitrosamine-laden aqueous amine solution obtained through scrubbing of carbon dioxide from flue gases with an amine-containing circulating washing fluid, which comprises the steps of:

• (a) branching off a substream of the nitrosamine-laden aqueous amine solution from the washing fluid circulation and concentrating the nitrosamine-laden aqueous amine solution by evaporating water and low boiling constituents therefrom;
• (b) retaining the concentrated nitrosamine-laden aqueous amine solution at its boiling point in which a liquid phase and a vapor phase are in contact, to establish a vapor/liquid equilibrium between the liquid phase and the vapor phase;
• (c) irradiating the vapor phase with ultraviolet light to decompose the nitrosamines entering the vapor phase to obtain a concentrated aqueous amine solution from which the nitrosamines have been removed;
• and
• (d) recycling the concentrated aqueous amine solution from which the nitrosamines have been removed back to the circulating washing fluid.