Control of a post-combustion CO2 capture plant during process start-up and load variations

Abstract

Dynamic and flexible operation of a carbon capture plant is important as thermal power plants must be operated very flexibly to accommodate large shares of intermittent energy sources such as wind and solar energy. To facilitate such operation, dynamic models for simulation, optimization and control system design are crucial. In this paper, we present a dynamic mathematical model for the absorption and desorption columns in a carbon capture plant. Moreover, we implement a decentralized proportionalintegral (PI) based control scheme and we evaluate the performance of the control structure for various operational procedures, e.g. start-up, load changes, noise on the flue gas flow rate and composition. Note that the carbon capture plant is based on the solvent storage configuration. To the authors knowledge, this is the first paper addressing the issue of start-up operation and control of carbon capture. The study demonstrates that the implemented control structure keeps the carbon capture process at 90% CO 2 removal rate with a deviation up to 8% during load variations. In addition, it reveals that the control structure brings the process to the desired set point in approximately 10 min during process start-up.

Deep learning for industrial processes: Forecasting amine emissions from a carbon capture plant

“…For instance, the design and operation of current and future power plants will need to constantly adapt to the increased share of intermittent renewable energy generation. [2][3][4][5] This requires tools that fully capture the dynamic and multivariate behaviour of the plant away from its steady-state operation. The classical analysis techniques, such as response function fits, 6,7 or chemometrics approaches 8 give some insights into the typical response to the different perturbations.…”

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

“…Based on the insights gained from the PCC process dynamics (i.e. heuristics), a general control structure was applied in [25], [29], [30], [33], [39], [47], [51], [96][97][98][99][100], as illustrated in Fig. 3.…”

“…Gaspar et al [97] implemented the conventional decentralized control structure to a PCC process and evaluated its performance in cases of start-up and power plant load changes. Normally distributed pseudo-random noise was added to the flue gas flow rate and CO2 content to mimic the operation condition of real power plant.…”

“…Gaspar et al [97] compared the performance of constant L/G ratio control with the conventional PI control during the start-up of the PCC plant. In their simulation, the given L/G ratio was not attained until the flue gas flow rate was in steady state.…”

Dynamic Process Model Validation and Control of the Amine Plant at CO2 Technology Centre Mongstad

“…Among the different options and technologies for CO 2 capture in thermal power generation, post-combustion CO 2 capture with chemical absorption is considered the more mature technology that can contribute to significantly reducing the carbon intensity (kgCO 2 /kWh el ) of fossil-fueled thermal power plants. In future energy systems with a high penetration of renewable energy sources, the variability in demand and generation will introduce a change in the operating patterns of thermal power generation plants, which will have to change operating conditions [4][5][6]; there will also be a higher frequency of significant transient events including load changes, and start-up and shut-down events [7,8]. In this regard, Boot-Handford et al's carbon capture and storage update 2014 concludes that the financial case for CCS requires that it operates in a flexible manner and that load-following ability is extremely important to the long-term economics [9].…”