Dynamic modelling and analysis of an amine-based post-combustion CO2 capture absorption column

• Published in: International journal of greenhouse gas control 2013-01, Vol.12, p.247-258
• Main Authors: Mac Dowell, N., Samsatli, N.J., Shah, N.
• Format: Article
• Language: English
• Subjects: CO2 capture; Dynamic process modelling; Flexibility; SAFT-VR
• ISSN: 1750-5836; 1878-0148
• DOI: 10.1016/j.ijggc.2012.10.013

► Dynamic, non-equilibrium model. ► Post-combustion CO2 capture using MEA. ► Validated in gPROMS using pilot plant data. ► SAFT-VR used for description thermophysical properties and reactions. ► Mass transfer zone is a compromise between mass transfer of H2O and CO2. A dynamic, non-equilibrium model of a packed column for the chemisorption of CO2 from dilute gas streams using a monoethanolamine solvent has been proposed. The model uses the SAFT-VR equation of state to describe the thermophysical properties and fluid-phase behaviour of this process. The SAFT-VR equation-of-state is used to account for all of the inter-species interactions in the fluid, including the reactions. In this way, we avoid the use of enhancement factors. Further it is not necessary to include a detailed description of the reaction mechanisms or the reaction products. Steady state validation of the proposed model is performed using pilot plant data. The position and extent of the mass transfer zone is found to be a function of competing interphase fluxes of H2O and CO2. We evaluate through dynamic simulation the effect of changing the lean solvent flowrate and thermodynamic state on column behaviour. The influence of flue gas humidity on the position and shape of the mass transfer zone is also highlighted and discussed.