Understanding ethanolamine (MEA) and ammonia emissions from amine based post combustion carbon capture: Lessons learned from field tests

The study discusses the origin and driving factors of the ammonia (NH3) and ethanolamine (MEA) emissions from post combustion carbon capture (PCCC) pilot installations. The objective of this research is not presenting PCCC emission values as such but presenting the current understanding of the different emission processes based on pilot plant FTIR measurements. NH3 is being continuously produced as a result of the oxidative degradation of MEA. The study shows that its emission level is closely correlated to the solvent metal ion concentration. A good solvent chemistry in which metal ion concentrations are kept low is required to minimise NH3 emissions. The fluctuating behaviour of the MEA emissions is found to be related to mist (aerosol) formation phenomena. Whether and to what extent mist is formed depends to a large extent on the flue gas composition upstream the CO2 capture plant and on the carbon capture pilot plant's design and operating conditions. Preliminary tests suggest that a single water wash is efficient for the removal of gaseous MEA emissions but may not be suitable for the removal of the submicron mist emissions.

► The study presents pioneering on-line emission data from amine based CC pilots.
► NH3 emissions is closely linked to solvent chemistry control.
► MEA emissions is found to be related to mist (aerosol) formation phenomena.
► Single water wash is efficient for the removal of gaseous MEA emissions.
► Single water wash may not be suitable for the removal of submicron mist emissions.