Dynamic simulation of MEA absorption process for CO2 capture from power plants

Carbon dioxide (CO2) emissions reduction from combustion fossil fuel power plants is a key aspect in the stabilization of global climate change. Post-combustion CO2 capture from fossil fuel power plants using amine-based solvents, typically monoethanolamine (MEA), is one of the most promising technologies for the abatement of CO2 gas. In this work, a dynamic MEA absorption process model has been developed to predict the dynamic behaviour of the CO2 capture process. The resulting dynamic model was used to study the transient response of the MEA absorption process to changes in the flue gas flow rate and the reboiler heat duty. The changes in flue gas flow rate and reboiler heat duty are key process variables that affect the lean loading, liquid to gas ratio and percentage of CO2 removal. To represent the actual operation of a power plant, the dynamic response of the MEA absorption process to a sinusoidal change in the flue gas flow rate was also considered in the present analysis. The results show that the changes between the reboiler heat duty and CO2 removal follows a ratio of approximately 1:1.4. Also, the lean loading stream entering the absorber unit is key to maintain the feasible operation of the system. Moreover, the energy performance of the process (Joules per mole of CO2 captured) is directly affected by the operation of the reboiler. The outcomes from this study provide insights regarding the dynamic behaviour of this process and can be used as the basis to develop other aspects related to the dynamic operation of this plant, e.g., to develop control strategies for this system.

► A dynamic model for the complete MEA absorption process is presented.
► The process response to changes in the flue gas and reboiler's heat duty are described.
► Sinusoids in the flue gas flowrate are used to analyse the operability of the process.