DMC-PID cascade control for MEA-based post-combustion CO2 capture process

• Published in: Chemical engineering research & design Vol. 182; pp. 701 - 713
• Main Authors: Zhang, Wenzhao, Ma, Chenbin, Li, Haifeng, Xuan, Liangyu, An, Aimin
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier Ltd 01.06.2022; Elsevier Science Ltd
• Subjects: Algorithms; Aspen plus dynamics; Carbon dioxide; Carbon sequestration; Cascade control; Coal-fired power plants; Combustion; DMC-PID; Dynamic models; Dynamic tests; Emissions control; Energy costs; Flue gas; Gas flow; Greenhouse gases; Optimal control; Optimization; PCC system; Proportional integral derivative; Solvents; Steady state models; Thermal power plants; Transfer functions; PCC system; DMC-PID; Optimal control; Aspen plus dynamics
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2022.04.030

The capture and recovery of carbon dioxide (CO2), the main source of greenhouse gases, are the principal means to reduce CO2 emissions. The optimization and control of the CO2 capture process plays a vital role in reducing energy costs, with the post-combustion CO2 capture (PCC) device using amine-based solvents considered to be the most feasible strategy to reduce CO2 emissions from coal-fired thermal power plants. In this paper, a DMC-PID cascade strategy is proposed to manipulate the PCC process order to obtain better performance. PID algorithm is used to adjust the flue gas flow to stabilize the flue gas entering absorber, and DMC algorithm is adopted to manipulate and constrain the lean solvent flow optimally order to increase CO2 capture rate. First, the corresponding steady-state model is established in Aspen Plus to get the best operating point parameters. Next, a dynamic model is built in Aspen Plus Dynamics to analyze the dynamic changes between the main variables of the system through dynamic testing, and the transfer function of the system is obtained through experimental data. Finally, three control strategies of DMC-PID, PID-PID and DMC are used to compare the control effect of CO2 capture rate. The results show that the proposed DMC-PID cascade control strategy has better performance, which improves the stability and flexibility of the PCC system, and provides a more feasible and effective operation for the CO2 capture. [Display omitted] •DMC-PID cascade strategy is firstly proposed to control PCC Process.•Establish PCC steady-state model in Aspen Plus and conduct dynamic testing.•Use of DMC-PID to obviously improves the stability, flexibility and CO2 capture rate.