Analysis of the dynamic performance of a MEA-based carbon capture unit for coal-fired power plants
A.M. van de Haar · 2013
One of the possibilities to reduce our carbon footprint is carbon capture and storage (CCS) technology, whereby CO₂ is captured and kept for long-term storage in empty gas or oil fields. In this study the constraints and flexibility during transient operation of a post-combustion capture unit are assessed using an equilibrium-based dynamic model of the capture unit. The dynamic models are developed in Modelica, an open-source, object-oriented and equation-based language for the modeling of physical systems. Where possible, existing model libraries are used or modified in order to obtain a complete model of the capture unit. The plant utilizes monoethanolamine (MEA) as the absorption fluid. The dynamic model is validated with open-loop step response tests performed at the TNO pilot plant. Based on the performed validation, it can be concluded that the transient responses in terms of trend and time constant of the capture rate, absorber temperatures and solvent CO₂ loading are in good agreement with the experiments. In order to assess the operational flexibility of a capture unit, three test cases were defined and simulated with the validated capture unit model.