Oxidative degradation of amine absorbents in carbon capture systems – A dynamic modelling approach

Fossil fuels are used widely for energy production and are likely to continue to play a major role world wide for many years to come. Much work has been done on the technology for capturing CO2 from gaseous industrial effluent. For large-scale applications like coal or natural gas-fired power plants, using amine solvents to capture post-combustion CO2 is the most mature CO2 capture technology. This technique can be used to retrofit existing plants by treating the flue gas after combustion. This paper details a dynamic mathematical model for the absorber column constructed from first principles. The loss of MEA through oxidative degradation has been quantified here for the first time and this is currently not possible using commercial packages. Reaction rate kinetics have been employed to predict the accumulation of oxidation products which is limited by the incomplete knowledge of the dominant reactions between O2 and MEA. When research has produced more detailed information about the products formed during this oxidation, it can be inserted easily into the model. Validation has been performed using data from the CSIRO PCC pilot plant at AGL Loy Yang. A limited parametric study of the impact of operating conditions on oxidation was performed