Simulation and Optimization Study on Aqueous MEA-Based CO2 Capture Process

Abstract

Chemical absorption with monoethanolamine (MEA) is the most common technology used in the CO2 removal unit for a power plant. However，the application is hindered by its high energy consumption for absorbent regeneration. In this study, a rate-based model of the typical MEA-based CO2 capture process was built for a power plant with Aspen Plus software. The thermodynamic model of ENRTL-RK was adopted. Temperature fields and the flow rates changes of components in absorber and stripper were obtained. And process analysis using the equilibrium stage model was performed to investigate the effects of operation parameters (CO2 loading in lean solution and stripper pressure) on the regeneration energy consumption. With heat pump technology adopted to assist lean solution regeneration, two processes were proposed and the reboiler duties decreased to 2.77 GJ/t CO2 and 2.38 GJ/t CO2, respectively, owing to the recovery of latent heat and part of sensible heat. Moreover, condenser duties were reduced obviously.