Control of the CO2 Capture Using the Absorption and Stripping System for Improved Performance

• Published in: Chemical engineering transactions 2021-11, Vol.88
• Main Authors: Flavia Ilea, Vasile-Mircea Cristea, Ana-Maria Cormos
• Format: Article
• Language: English
• ISSN: 2283-9216
• DOI: 10.3303/CET2188043

The paper presents a new control system configuration for the post combustion CO2 carbon capture process using amines. The control system structure consists in six control loops and has in its core the cascade control strategy. The proposed cascade control system has the desired carbon capture rate as the master controller target, and the molar ratio between the lean MEA and the influent CO2 flowrates as the slave controller manipulated setpoint. They have associated the reboiler temperature control in the stripper and the concentration of MEA, temperature and level control in the buffer tank. The buffer tank, accompanied by its control loops, was specifically introduced in the carbon capture plant in order to reduce the interaction between the absorption and stripping units. The decentralized control system was tested for assessing its performance to cope with the typical influent CO2 flowrate disturbance, considered to act in a periodic scenario. Good disturbance rejection and effective restoration of the nominal operation state were achieved, while the energy performance index value was kept at reduced values. They demonstrate valuable operation flexibility of the controlled CO2 carbon capture plant.