The paper details the model of a rotating packed bed absorber. The developed model shows good predictive ability in various conditions. The authors highlight that proper accounting of liquid holdup is critical to the prediction of capture efficiency, also that a modified enhancement factor is necessary at high MEA concentrations.
The model is developed with the following simplifying assumptions:
- An ideal gas phase.
- No accumulation in gas and liquid films.
- Fluxes of compounds between gas and liquid phase allowed in both directions.
- Gas and liquid flow only in the radial direction.
- All reactions occur in the liquid phase.
The compounds being considered in the gas phase are CO2, water, MEA, and an inert gas (assumed to be nitrogen) while the compounds considered in the liquid phase are CO2, MEA, H2O, N2, and the ionic species H3O+, OH-, MEAH+, HCO3- and MEACOO-.
The model was implemented in gPROMS Model Builder. Liquid phase non-idealities were described with the electrolyte non-random-two-liquid (electrolyte NRTL) model available in Aspen Properties. Physical properties of gas and liquid phases such as densities, viscosities, surface tensions were obtained from Aspen Properties through the CAPE-OPEN Thermodynamic socket available in gPROMS.
CO-LaN welcomes the combination, through CAPE-OPEN, of a specialized thermodynamic model with an advanced modeller. It is typically the kind of combination which has been seen early on as a use case for CAPE-OPEN.