Nonlinearity Analysis and Multi-Model Modeling of an MEA-Based Post-Combustion CO2 Capture Process for Advanced Control Design

Abstract

Abstract:The monoethanolamine (MEA)-based post-combustion CO 2 capture plant must operate flexibly under the variation of the power plant load and the desired CO 2 capture rate. However, in the presence of process nonlinearity, conventional linear control strategy cannot achieve the best performance under a wide operation range. Considering this problem, this paper systematically studies the multi-model modeling of the MEA-based CO 2 capture process for the purpose of (1) implementing well-developed linear control techniques to the design of an advanced controller and (2) achieving a wide-range flexible operation of the CO 2 capture process. The local linear models of the CO 2 capture process are firstly established at given operating points using the method of subspace identification. Then the nonlinearity distribution at different loads of an upstream power plant and different CO 2 capture rates is investigated via the gap metric. Finally, based on the nonlinearity investigation results, the suitable linear models are selected and combined together to form the multi-model system. The proposed model is validated using the measurement data, which is generated from a post-combustion CO 2 capture model developed in the go-carbon capture and storage (gCCS) simulation platform. As the proposed multi-linear model has a simple mathematical expression and high prediction accuracy, it can be directly employed as the control model of a practical advanced control strategy to achieve a wide operating range control of the CO 2 capture process.

COSMO-RS Analysis of CO2 Solubility in N-Methyldiethanolamine, Sulfolane, and 1-Butyl-3-methyl-imidazolium Acetate Activated by 2-Methylpiperazine for Postcombustion Carbon Capture

“…Assessing the possibilities of COSMO-RS for the important parameters of prediction and analysis, the current study is proposed for CO 2 capture through absorption. The nonlinearity exhibited in the absorption of CO 2 in previously studied solvents , suggests that using a quantum calculation method may yield an accurate estimation of various involved thermodynamic properties. The selection of proposed blends is based on an extensive literature survey.…”

Solvent-based post-combustion CO2 capture for power plants: A critical review and perspective on dynamic modelling, system identification, process control and flexible operation

“…The fuzzy modelling technique was also used in Liang et al [93], where local state-space models were identified from data and then linked together according to the CO2 capture level. The developed fuzzy model was used to capture the dynamics among CO2 capture level, re-boiler temperature, lean solvent and re-boiler steam flow rates.…”

Off-Design Operation of Conventional and Phase-Change CO2 Capture Solvents and Mixtures: A Systematic Assessment Approach

“…Optimizing control architectures by comparing PID (proportional-integral-derivative) and MPC were also studied by Arce et al [35]. Liang et al [36] propose a multi-linear model for MEA-based CO 2 capture. The proposed approach first identifies local linear models at typical operating points.…”