Method and plant for amine emission control

A method for eliminating or substantially reducing emission of amines and alkaline degradation products thereof to the atmosphere from a plant for CO2 capture from a flue gas, the method comprising:

• introducing the flue gas into an absorber;
• allowing the flue gas to flow countercurrent to an absorbent comprising an aqueous solution of one or more amine(s) in an absorption zone for capturing the CO2 to form a CO2 lean exhaust gas and a CO2 rich absorbent;
• collecting the CO2 rich absorbent;
• regenerating the CO2 rich absorbent in a regeneration column to give a CO2 rich gas and a regenerated absorbent;
• withdrawing the CO2 rich gas for further treatment;
• recycling the regenerated absorbent to the absorption zone;
• washing the CO2 lean exhaust gas with an aqueous solution comprising an acid selected from the group consisting of sulphuric acid, phosphoric acid, nitric acid, acetic acid, formic acid, and citric acid, to remove or substantially reduce an amount of amine(s) and alkaline degradation products thereof in the CO2 lean exhaust gas;
• wherein a part of an acid washing solution is bled off and introduced into an amine reclaimer where amine salts in solution is boiled in the presence of alkali to liberate amine cations as free amine vapor which is reused as amine absorbent for CO2 capture;
• and
• wherein steam and gaseous amine from the reclaimer is routed to a fractionating column for separation of gaseous ammonia from water and amine distillate.

A method for eliminating or substantially reducing emission of amines and alkaline degradation products thereof to the atmosphere from a plant for CO2 capture from a flue gas, the method comprising:

• introducing the flue gas into an absorber;
• allowing the flue gas to flow countercurrent to an absorbent comprising an aqueous solution of one or more amine(s) in an absorption zone for capturing the CO2 to form a CO2 lean exhaust gas and a CO2 rich absorbent;
• collecting the CO2 rich absorbent;
• regenerating the CO2 rich absorbent in a regeneration column to give a CO2 rich gas and a regenerated absorbent;
• withdrawing the CO2 rich gas for further treatment;
• recycling the regenerated absorbent to the absorption zone;
• washing the CO2 lean exhaust gas with an aqueous solution comprising an acid selected from the group consisting of sulphuric acid, phosphoric acid, nitric acid, acetic acid, formic acid, and citric acid, to remove or substantially reduce an amount of amine(s) and alkaline degradation products thereof in the CO2 lean exhaust gas;
• wherein a part of an acid washing solution is bled off and introduced into an amine reclaimer where amine salts in solution is boiled in the presence of alkali to liberate amine cations as free amine vapor which is reused as amine absorbent for CO2 capture;
• and
• wherein bleed of washing solution is introduced into a pre-reactor, wherein the washing solution is reacted with an alkali and stripped by vacuum or introduction of a stripping gas selectively to remove ammonia from the washing solution before the washing solution is introduced into the amine reclaimer.