Dynamic modelling and control strategies for flexible operation of amine-based post-combustion CO2 capture systems

The abatement of anthropogenic CO2 gas and extensive demand for electrical energy has motivated cleaner power production from fossil fuels. This paper presents a mechanistic model of amine-based post-combustion CO2 capture (PCC) process. Validation of the proposed model is performed using pilot plant data available from literature. Process control analysis is then performed using this model whereby three control schemes are proposed; a standard PID feedback control scheme, a cascade-PID scheme and thirdly a model-based strategy in the form of model predictive control (MPC). Stepwise set point tracking and disturbance rejection scenarios are employed to evaluate the performance of the proposed controllers for flexible operation, i.e., under variable plant load condition surrogate to electricity and carbon market prices patterns. Three elements of constraints include operational, economic and environmental are considered in selecting the best control strategy. The closed-loop simulation results showed that the MPC strategy handles very well the servo and regulator problems without violating the above mentioned constraints.