Dynamic Data Reconciliation and Validation of a Dynamic Model for Solvent-Based CO₂ Capture Using Pilot-Plant Data

Abstract

This paper is focused on the development and validation of a dynamic model for a monoethanolamine-based CO2 capture unit. Starting with a rigorous steady-state process model, the dynamic model is developed in Aspen Plus Dynamics using a modified Murphree efficiency approach and is validated using dynamic data collected from the National Carbon Capture Center in Wilsonville, Alabama. The dynamic test runs were designed with due consideration of process excitation and process nonlinearities constrained by the available time to conduct the test runs and implement the experimental designs in the plant control system. The experimental data include solvent composition and loading. Because the experimental data were found to violate mass and energy balances, filtering algorithms coupled with dynamic data reconciliation techniques were used. Without adjusting any model parameters, the dynamic model satisfactorily predicted the dynamic response of CO2 capture due to step changes in the solvent flow rate, flue gas flow rate, and steam flow rates. Transient studies show that the process gain and time constants can considerably change depending on the direction of the disturbance or manipulated variables, indicating process nonlinearities. Because of a storage tank between the absorber and stripper, the time constant of the full plant can be considerably longer than the time constants of the absorber or stripper individually. Furthermore, impact of the control system on the process efficiency while following an optimal CO2 capture schedule was also studied.

Process Modeling and Techno-Economic Analysis of a CO2 Capture Process Using Fixed Bed Reactors with a Microencapsulated Solvent

“…Carbon capture and storage is one of the key strategies in combating climate change because power production using fossil fuel is projected to continue as a major power source in the foreseeable future . Monoethanolamine (MEA) is still a widely studied solvent for the postcombustion CO 2 -capture technology. − However, several advanced technologies are being developed for CO 2 capture because the state-of-the-art MEA-based carbon-capture technology has several drawbacks such as corrosion and energy penalty. − …”

Control of Solvent-Based Post-Combustion Carbon Capture Process with Optimal Operation Conditions

“…Both the absorber and stripper employed the Sulzer BX structured packing. [12,25,28,29]. Recently, the authors of this paper [30] developed a rate-based dynamic model for the MEA (monoethanolamine) solvent PCC process on the Aspen Custom Modeler ® (ACM) software platform [31].…”

“…The CO 2 capture process, as shown in Figure 1, was simulated using the unit and flowsheet models built on ACM by the authors of this paper. The modeling details and model validation are presented in [29]. The rate-based column model developed for absorber and stripper took into account the heat and mass transfer across the vapor-liquid interface, as well as the enhancement of CO 2 absorption by the liquid phase chemical reactions.…”

“…Bui et al [2] provided an extensive literature review of the simulation scenarios and characteristics of various dynamic models. Some dynamic models have undergone validation against dynamic pilot plant data [12,25,28,29]. Recently, the authors of this paper [30] developed a rate-based dynamic model for the MEA (monoethanolamine) solvent PCC process on the Aspen Custom Modeler ® (ACM) software platform [31].…”

Modeling and Bayesian Uncertainty Quantification of a Membrane-Assisted Chilled Ammonia Process for CO2 Capture

“…In post-combustion CO 2 capture, the flue gas is absorbed by the aqueous chemical solvent in an absorber near ambient conditions and is one of the leading technologies to reduce emissions from fossil-fired power plants. , The solvent is then regenerated using steam to create a product stream of high-purity CO 2 . While monoethanolamine (MEA) is the most matured, commercial solvent used for carbon capture, and has fast dynamic performance, , it has high energy penalty. , Aqueous ammonia is an alternative solvent with advantages including lower energy requirements for regeneration, high CO 2 loading, and absence of oxidative degradation as opposed to solvents such as MEA. , However, one key disadvantage of aqueous ammonia is the high volatility which results in ammonia slip from the absorber. Two typical methods, pursued separately and concurrently, are operating the absorber at low temperatures to reduce vapor pressure and inclusion of a water wash section to recover the solvent after the absorber.…”