Control strategies for flexible operation of power plant with CO₂ capture plant

Abstract

About 20% power output penalties will be incurred for implementing CO 2 capture from power plant. This loss can be partially compensated by flexible operation of capture plant. However, daily large variations of liquid and gas flows may cause operation problems to packed columns. Control schemes were proposed to improve the flexibility of power output without causing substantial hydraulic disturbances in capture plant is presented. Simulations were implemented using ASPEN Plus. In varying lean solvent flow strategy, the flow rate of recycling solvent was manipulated to control the CO 2 capture rate. The liquid flow of the absorber and gas flow of the stripper will vary substantially. In an alternative strategy, the lean solvent loading will be varied. Variation of gas throughput in the stripper is avoided by recycling part of CO 2 vapor to stripper. This strategy provided more stable hydraulics condition in both columns and is recommended for flexible operation.

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

“…In recent years, monoethanolamine (MEA)-based post-combustion CO 2 capture technology has been extensively studied to capture the CO 2 from the coal-fired power plants [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The MEA-based CO 2 capture technique has several distinguishing features, such as a high CO 2 capture level, easy integration to power plants without much reformation of the existing plants, and relatively low construction cost, which makes it the most promising technique for commercial use [1,17].…”

Process control strategies for flexible operation of post-combustion CO 2 capture plants

“…The dynamic modelling and controllability analysis of the integrated power and capture plant is therefore highly important in this context. Most studies in the literature consider individually the capture plant, or even discrete parts of the capture plant such as the absorber and stripper for control, while in this study the integrated coal 35 and gas power plants with post-combustion are considered [6], [7], [8], [9], [10], [11].…”

“…The operation of the plant without controller showed a settling time of 30 min compared to the ratio controller where the settling time was decreased in 1 min. Lin et al [7], presented two different control strategies to control the CO 2 capture 55 rate. The manipulated variables were the lean solvent flowrate and the reboiler heat duty.…”

“…Although the gas flow in the regeneration column is changed, the flow conditions can be maintained, if needed, by recirculating part of the CO 2 produced stream, as proposed by Lin et al [7], [35]. Some studies suggest that the best control strategy for a post-combustion carbon capture plant depends on the operating 295 region [18].…”

Improving Flexibility and Energy Efficiency of Post-Combustion CO2 Capture Plants Using Economic Model Predictive Control

“…They considered a disturbance in the steam availability to the reboiler and used the liquid to gas flow ratio as the manipulated variable. Lin et al [5] presented two different PI control strategies to maintain a desired absorption efficiency. They used the lean solvent flow rate and the reboiler heat input as the manipulated variables.…”