Dynamic modelling of the absorber of a post-combustion CO2 capture plant: Modelling and simulations

• Simple correlations for representing the thermodynamics and physics in the dynamic model are sufficient.
• Model predictions are significantly sensitive on the combination of the correlations in use.
• Validation against pilot plant data is appreciable.
• Capable of predicting the transient conditions under plant start-up and under disturbances.

Modelling work related to carbon dioxide (CO2) capture technologies is of great importance with respect to the design, control, and optimization of the capture process. Development of dynamic models as such is important since there is much information embedded with the dynamics of a plant which cannot be studied with steady state models. A model for the absorption column of a post-combustion CO2 capture plant is developed following the rate based approach to represent heat and mass transfer. The Kent–Eisenberg model is used to compute the transfer and generation rates of the species. Sensitivity of the model for different physiochemical property correlations is analyzed. The predictions of the dynamic model for the capture plant start-up scenario and operation of the absorption column under varying operating conditions in the up-stream power plant and the down-stream stripping column are presented. Predictions of the transient behaviour of the developed absorber model appear realistic and comply with standard steady state models.