MEA Consumption – ALIGN-CCUS: Comparative Long-Term Testing to Answer the Open Questions

Solvent degradation does not solely mean loss of solvent and increasing CO2 capture cost, but has also an effect on emissions, corrosion and foaming. Even for the well-known 30wt% monoethanolamine (MEA) solvent system, published specific solvent losses from capture facilities differ by one order of magnitude (~0.3 to 3.6 kg/t CO2). Based on the results from an ongoing 12,000 hours testing campaign with 30wt% aqueous MEA at the post combustion capture pilot plant at the lignite-fired power plant at Niederaussem, it is validated, how the time-dependent contents of degradation products and trace components that might act as catalysts for degradation are developing during long-term operation and which countermeasures against degradation could be applied. A solvent degradation network model has been established to estimate the rate of solvent degradation as a function of the flue gas composition, capture plant design and operating conditions and to compare the results from Niederaussem with the data received from the other pilot plants and testing facilities which are part of the ALIGN-CCUS project (Technology Centre Mongstad (NOR), pilot rig at Tiller, Trondheim (NOR), PACT facilities at Sheffield (UK)). For the analysis of the degradation process two advanced online-solvent monitoring tools will be used. Regarding the determination of the solvent loss due to emissions, dedicated test campaigns on the dynamic behavior of the capture plant have been carried out aiming at emission control strategies for certain flexible operational scenarios. For a better understanding of the aerosol formation mechanism and the behavior of aerosol nuclei within the absorber column measurements of the particle size distribution, the particle number concentration and the aerosol composition have been performed.