Dynamic modeling of CO2 absorption from coal-fired power plants into an aqueous monoethanolamine solution

Among carbon capture and storage (CCS), the post-combustion capture of carbon dioxide (CO2) by means of chemical absorption is actually the most developed process. Steady state process simulation turned out as a powerful tool for the design of such CO2 scrubbers. Besides steady state modeling, transient process simulations deliver valuable information on the dynamic behavior of the system. Dynamic interactions of the power plant with the CO2 separation plant can be described by such models. Within this work a dynamic process simulation model of the absorption unit of a CO2 separation plant was developed. For describing the chemical absorption of CO2 into an aqueous monoethanolamine solution a rate based approach was used. All models were developed within the Aspen Custom Modeler® simulation environment. Thermo physical properties as well as transport properties were taken from the electrolyte non-random-two-liquid model provided by the Aspen Properties® database. Within this work two simulation cases are presented. In a first simulation the inlet temperature of the flue gas and the lean solvent into the absorber column was changed. The results were validated by using experimental data from the CO2SEPPL test rig located at the Dürnrohr power station. In a second simulation the flue gas flow to the separation plant was increased. Due to the unavailability of experimental data a validation of the results from the second simulation could not be achieved.

► A transient process simulation model for CO2 capture from coal-fired power plants is presented.
► A rate-based approach coupled with an enhancement factor formulism is used for modeling.
► A 7M aqueous monoethanolamine solution is assumed as the CO2 scrubbing agent.
► The simulation results showed good accordance to data measured at the CO2SEPPL test facility.