Rate-Based Modelling and Validation of an Absorber and Stripper in an Amine-Based Post-Combustion CO2 Capture Process

Abstract

Carbon emissions capture and storage is regarded as an essential approach to mitigate the greenhouse effect led by carbon dioxide emissions from the fossil fuels combustion. Amine-based post-combustion CO₂ capture technologies have great potential for retrofitting existing coal-fired power plants. In this paper, a mathematical model for a packed absorber and stripper in a CO₂ capture process are developed. Typical aqueous monoethanolamine (MEA) with 30 wt.% concentration is selected as the absorbent. A rate-based method is implemented to represent the mass and heat transfer in carbon dioxide absorption and desorption processes. In addition, the heat of CO₂ is derived by Gibbs-Helmholtz equation. In this way, the effect of chemical equilibrium and thermodynamic equilibrium on absorption capacity and absorption heat can be obtained. Finally, these models are validated by literature data in different plant operating conditions. The present mathematical models can be used to analyse the mass and heat transfer behaviour and to improve the overall performance of the CO₂ process.